Post-treatment method for methanol / water mixture in the production of alkali metal methoxides in a reaction tower.

Abstract

The invention relates to a process for the work-up of a methanol / water mixture used in the preparation of an alkali metal methoxide in a reaction column, in which the mixture is separated by distillation in a rectification column. The vapor obtained at the top of the rectification column is compressed in at least two stages, the energy of the compressed vapors being advantageously transferred to the bottom and side streams of the rectification column, respectively. This allows the energy of the compressed vapors to be utilized in a particularly energy-efficient manner in the process according to the invention. The process for the work-up of a methanol / water mixture is used in the preparation of an alkali metal methoxide in a reaction column, in which methanol and an alkali liquid are reacted with each other in countercurrent. The alkali metal methoxide dissolved in methanol is then removed at the bottom end, and a methanol / water mixture is removed at the top end and worked up with the work-up process according to the invention. The energy of the compressed vapors can be used further for the operation of this reaction column or for the operation of a reaction column in which an alcohol exchange process of an alkali metal alkoxide is carried out.

Description

[Technical Field]

[0001] The present invention relates to a post-treatment method for a methanol / water mixture used in the production of alkali metal methoxides in a reaction column. Here, the mixture is separated by distillation in a rectification column. The vapor obtained at the top of the rectification column is compressed in at least two stages, and the energy of the compressed vapor is advantageously transferred to the bottom flow and side flow of the rectification column. This makes it possible to utilize the energy of the compressed vapor particularly energy-efficiently in the method according to the present invention. The post-treatment method for the methanol / water mixture is used in the production of alkali metal methoxides in a reaction column, where methanol and an alkali liquid are reacted with each other in a countercurrent. Here, the alkali metal methoxide dissolved in methanol is taken out at the bottom, and the methanol / water mixture is taken out at the top and post-treated by the post-treatment method according to the present invention. The energy of the compressed vapor can further be used to operate this reaction column or to operate a reaction column in which an alcohol exchange method for alkali metal alkoxides is carried out.

[0002] 1. Background of the Invention Alcohol / water mixtures are produced, for example, when producing alkali metal alkoxides from an aqueous alkaline solution optionally mixed with an alcohol and an alcohol. In these methods, methanol and ethanol are particularly used as the alcohol.

[0003] Alkali metal alkoxides are used as strong bases in the synthesis of many chemicals, for example, in the manufacture of active ingredients for pharmaceuticals or agrochemicals. Furthermore, alkali metal alkoxides are used as catalysts in transesterification and amidation reactions.

[0004] Alkali metal alkoxides (MORs) are produced by reactive distillation in a countercurrent distillation column from alkali metal hydroxides (MOHs) and alcohols (ROHs), during which the following reaction occurs. <1> The reaction water generated is removed along with the distillate. [ka]

[0005] Such a process principle is described, for example, in U.S. Patent No. 2,877,274, in which an aqueous alkali metal hydroxide solution is reacted with gaseous methanol in a countercurrent in a reaction rectification column. This method is also described in International Publication No. 01 / 42178 in essentially unchanged form.

[0006] British Patent Application Publication No. 377,631 and U.S. Patent No. 1,910,331 describe a similar method, but further using an entraining agent such as benzene, where the entraining agent separates water from the water-soluble alcohol. In both patent specifications, the condensate is phase-separated to separate the reaction water. Another similar method is the reaction of an alkali metal alkoxide with another alcohol in a reaction column ("alcohol exchange") as described in German Patent Application Publication No. 2726491.

[0007] Accordingly, German Patent No. 968903 describes a method for the continuous production of alkali metal alkoxides in a reaction column, in which a water-alcohol mixture taken out at the top is condensed and then subjected to phase separation. Here, the aqueous phase is discarded, and the alcohol phase is returned to the top of the column along with fresh alcohol. A similar method is described in European Patent Application Publication No. 0299577, in which the separation of water in the condensate is carried out using a membrane. Industrially important alkali metal alkoxides are sodium and potassium alkoxides, with methoxides and ethoxides being particularly important. Their synthesis is often described in the prior art, for example, in European Patent Application Publication No. 1997794.

[0008] In the synthesis of alkali metal alkoxides by reaction distillation described in the prior art, vapors containing the alcohol and water used are typically obtained. For economic reasons, it is reasonable to reuse the alcohol in the vapors as a reactant in reaction distillation. Therefore, the vapors are usually fed into a distillation column, where the alcohol is separated (for example, as described in British Patent Application Publication No. 737453 and U.S. Patent No. 4,566,947). The alcohol thus recovered is then fed as a reactant, for example, into reaction distillation.

[0009] Alternatively or additionally, a portion of the alcohol vapor can be used to heat the rectification column (as described in International Publication No. 2010 / 097318). However, this requires compressing the vapor until it reaches the temperature level necessary to heat the rectification column. Multistage compression of the vapor is particularly thermodynamically advantageous. In this case, the vapor is cooled between compression stages. Intercooling also helps to prevent the maximum allowable temperature of the compressor from being exceeded. The drawback of this cooling method, as performed conventionally, is that the energy extracted during the process is dissipated without being used.

[0010] Therefore, there is a need for improvements in the post-treatment methods for alcohol / water mixtures, particularly those applicable in connection with the production of alkali metal alkoxides. This method is characterized by particularly efficient utilization of the energy contained in the compressed steam for the operation of the rectification column. It is desirable that this method enables energy-efficient utilization of the heat generated during the compression and cooling of the steam.

[0011] 2. Outline of the Invention The present invention is based on formula M A OR[wherein R is methyl, M A The present invention relates to a method for producing at least one alkali metal alkoxide of a metal selected from sodium and potassium, preferably sodium.

[0012] In the method for producing at least one alkali metal alkoxide according to the present invention, a mixture G containing water and methanol ROH is obtained, and this mixture G is used in a post-treatment method for mixture G containing water and alcohol ROH (where R is methyl), and is post-treated by the post-treatment method for mixture G. The post-treatment method for mixture G is carried out in a rectification column and is therefore a distillation method.

[0013] In a further preferred embodiment, the present invention relates to a method for alcohol exchange of alkali metal alkoxides. In this method, alkali metal alkoxide M c Replace the alcohol in OR' with another alcohol R''OH, and at that time, M c OR' is reacted with R''OH in a reaction tower to form M c OR'' is generated, and in this method, the energy of a specific vapor flow produced by the post-treatment method of mixture G according to the present invention is used for operation. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows an embodiment of a method not according to the present invention. [Figure 2] This figure shows an embodiment of a method not according to the present invention. [Figure 3] This figure shows one embodiment of the method according to the present invention. [Figure 4] This figure shows one embodiment of the method according to the present invention. [Figure 5] This figure shows one embodiment of the method according to the present invention. [Figure 6] This figure shows one embodiment of the method according to the present invention. [Figure 7] This figure shows one embodiment of the method according to the present invention. [Figure 8] This figure shows one embodiment of the method according to the present invention. [Figure 9] This figure shows one embodiment of the method according to the present invention. [Figure 10] This figure shows the energy savings in the method according to Example 3 of the present invention.

[0015] 3. Drawings 3.1 Figure 1 Figure 1 shows an embodiment of a process for producing an alkali metal methoxide according to the prior art (International Publication No. WO 2010 / 097318, Figure 1) in which the separation of a methanol-water mixture by distillation is carried out in the same manner as in the present invention.

[0016] Here, an aqueous NaOH solution S AE2 <102> reacts with methanol S A <100> in reaction column RR AE1 <103> to produce the corresponding sodium alkoxide. At the top of reaction column RR A <100>, an aqueous NaOH solution is added as reaction stream S AE2 <102>. Also, a methanol solution of NaOH can be added as reaction stream S AE2 <102>. To produce the corresponding potassium methoxide, an aqueous KOH solution or a methanol solution of KOH is added as reaction stream S AE2 <102>. Above the bottom of reaction column RR A <100>, methanol is added in vapor form as reaction stream S AE1 <103>.

[0017] At the bottom of reaction column RR A <100>, a mixture S AP* <104> of the corresponding methoxide in methanol is withdrawn. The concentration of the sodium methoxide solution S AP* <104> is adjusted to a desired value by bottom evaporator V A <105> at the bottom of column RR SA <100> and any evaporator V SA’ <106>.

[0018] At the top of reaction column RR A <100>, a vapor stream S AB <107> is withdrawn. In cooler K RRA <108>, a part of the vapor stream S AB <107> is condensed and returned in liquid form to reaction column RRA <100> It is supplied to the top of the cooler K. RRA <108> The setting for recirculation is optional.

[0019] The resulting steam S AB <107> This is a mixture G used in rectification columns and water / methanol columns RD, all or part of which are used as a mixture G. A <300> It is supplied to the rectification column RD. A <300> internal structure <310> It contains. In this column, mixture G is separated by distillation, and methanol is vaporized at the top of this column by distillation S. OA <302> It will be recovered as such.

[0020] Rectification tower RD A <300> It is also possible to set up reflux. In this case, steam S OA <302> Part of the cooler K RD <407> It is then condensed in the rectification column RD A <300> It will be returned to S. OA <302> The remainder of, or all vapor flow S in embodiments where reflux is not set. OA <302> However, the compressor VD AB2 <303> It is pre-compressed. A portion of this pre-compressed steam is used in the reaction tower RR. A <100> It is recycled, and there the reaction logistics S AE1 <103> It is used as S. OA <302> The remaining part is the compressor VD1 <401> It is supplied to a steam flow S, where it is further compressed. OA1 <403> And from there, any intermediate cooling device WT X <402> Energy can be extracted from it.

[0021] Steam flow S OA1 <403> The compressor VD x <405> Compressed by the following, the steam S obtained next OA2 <404> For heating, the rectification column RD A <300> Evaporator V at the bottom SRD<406> It is supplied to, and then fresh methanol as needed. <408> This is added to it, and then refluxed back into the rectification column RD A <300> It is supplied to the rectification column RD. A <300> If recirculation is set, then flow S OA2 <404> RD A <300> Before returning it, please follow the instructions. OA2 <404> The return of K RD <407> Mix with the condensate produced and together with RD A <300> It can be supplied to: rectification column RD A <300> At the bottom, the water flow S UA <304> This is obtained, and this is at least partially (flow S UA1 <320> ) Again, the rectification tower RD A <300> It can be returned to Evaporator V. SRD <406> and / or V SRD’ <410> It can be passed through.

[0022] 3.2 Figure 2 Figure 2 shows a further embodiment of a method not according to the present invention, which corresponds to the embodiment shown in Figure 2 of International Publication No. 2010 / 097318.

[0023] This embodiment adds the following additional or different features to the embodiment shown in Figure 1: bottom evaporator V SRD’ <406> and V SRD’ <410> In addition, rectification column RD A <300> Intermediate evaporator V ZRD <409> It has a side flow S ZA <305> is a rectification column RD A <300> Extracted from V ZRD <409> It is then passed through the rectification column RD again. A <300> It is supplied to the steam flow S. OA <302> Part of the compressor VD AB2 <303> It is pre-compressed, and a portion of it is used in the reaction tower RR. AAfter being branched into <100>, it is compressed by the compressor VD1 <401> into a vapor stream S OA1 becoming <403>, and this vapor stream S OA1 <403> is supplied to the intermediate evaporator V ZRD <409> for heating. S OA1 The evaporator V by <403> SRD <406> or the evaporator V SRD’ <410> is not heated. V ZRD The vapor stream S used for heating <409> OA <302> is then mixed with the condensate generated at K RD <407> and fresh methanol <408>, and returned as reflux to the rectification column RD A <300>. S OA The reflux of <302> can also be separately returned to the rectification column RD A <300> in the same way.

[0024] 3.3 Figure 3 Figure 3 shows an embodiment of the method according to the present invention. This corresponds to the embodiments shown in FIGS. 1 and 2. The rectification column RD A <300> has an intermediate evaporator V ZRD <409>, a bottom evaporator V SRD <406>, and optionally a bottom evaporator V SRD’ <410>.

[0025] The embodiment according to the present invention has the following differences from the above-described embodiments: 1. In the compressor VD1 <401>, after a part of the vapor stream S OA <302> is compressed, the vapor stream S OA1 <403> is divided into two parts S OA11 <4031> and S OA12 <4032>.

[0026] 2. S OA11 <4031> is supplied to the intermediate evaporator V ZA <409> for heating the stream S ZRD <305>.

[0027] 3.S OA12 <4032> is further compressed by the compression device VD x <405> to form a flow S OA2 <404>, and S OA2 <404> is the flow S UA1 <320> is supplied to the bottom evaporator V SRD <406> for heating.

[0028] 4.S OA11 <4031> and S OA2 <404> enter each evaporator V ZRD <409> or V SRD <406>. After leaving these, they are combined, and the combined flow is mixed with the reflux (i.e., the condensate generated by K RD <407>) and fresh methanol <408>, and then returned to the rectification column RD A <300>. It is also possible to return these flows separately to the rectification column RD A <300>.

[0029] Due to these differences, the energy of the vapor S OA1 <403> can be utilized more efficiently for heating the rectification column RD A <300> compared to the embodiments according to FIGS. 1 and 2.

[0030] 3.4 Figure 4 FIG. 4 shows an embodiment of the method according to the present invention. This corresponds to the embodiment shown in FIG. 3, except that in the second reaction tower RR B <200>, the aqueous KOH solution S BE2 <202> reacts with the methanol S A <100> used in the reaction to produce the corresponding potassium methoxide, which is different. BE1 <203>.

[0031] At the top of the reaction tower RR B <200>, the reaction stream S BE2 <202> is added as an aqueous KOH solution. Also, a methanol solution of KOH is added to the reaction stream S BE2<202> It can also be added as such. Reaction tower RR B <200> Above the bottom, methanol reacts with logistics S BE1 <203> It is added in vapor form.

[0032] Reaction tower RR B <200> At the bottom, a mixture of the corresponding methoxide in methanol S BP* <204> It is extracted. Potassium methoxide solution S BP* <204> The concentration of the tower RR B <200> Bottom evaporator V at the bottom SB <205> and any evaporator V SB’ <206> The desired value is then adjusted. Reaction tower RR B <200> At the top, the steam flow S BB <207> It is removed. Cooler K RRB <208> So, the steam flow S BB <207> A portion of it condenses and refluxes as a liquid into the reaction tower RR. B <200> It is supplied to the top of the cooler K. RRB <208> The setting for recirculation is optional.

[0033] The resulting steam S BB <207> is the cooler K RRA <108> Uncondensed vapor S AB <107> Mixed with a portion of the rectification column RD A <300> It is supplied to.

[0034] Another difference from the embodiment shown in Figure 3 is that steam S OA <302> The pre-condensed portion is partially in the reaction tower RR A <100> and RR B <200> It is recycled, and there the reaction logistics S AE1 <103> or S BE1 <203> It is to be used as such.

[0035] 3.5 Figure 5 Figure 5 shows one embodiment of the method according to the present invention. This corresponds to the embodiment shown in Figure 4, however, S OA2 <404> Part of Tower RR A <100> Evaporator V at the bottom SA’ <106> and Tower RR B <200> Evaporator V at the bottom SB’ <206> The difference lies in the fact that it is also used for heating.

[0036] 3.6 Figure 6 Figure 6 shows one embodiment of the method according to the present invention. This corresponds to the embodiment shown in Figure 5, except that the reaction tower RR A <100> and RR B <200> Each of these is an intermediate evaporator V ZA <110> or V ZB <210> The difference lies in the presence of side flow S. ZAA <111> is a reaction tower RR A <100> Extracted from V ZA <110> It is then passed through to the reactor tower RR again. A <100> It is supplied to the side flow S. ZBA <211> is a reaction tower RR B <200> Extracted from V ZB <210> It is then passed through to the reactor tower RR again. B <200> It is supplied to. Unlike Figure 5, S OA2 <404> Part of it is Tower RR A <100> Evaporator V at the bottom SA’ <106> It is used solely for heating. In contrast, S OA11 <4031> Part of it is evaporator V ZB <210> It is used to heat [something].

[0037] 3.7 Figure 7 Figure 7 shows one embodiment of the method according to the present invention. This corresponds to the embodiment shown in Figure 5, except that the reaction tower RR A <100> Intermediate evaporator V ZA <110> The difference lies in the presence of side flow S. ZAA <111> is a reaction tower RRA <100> Extracted from V ZA <110> It is then passed through to the reactor tower RR again. A <100> It is supplied to. Unlike Figure 5, S OA2 <404> Part of it is Tower RR B <200> Evaporator V at the bottom SB’ <206> Used solely for heating. Intermediate evaporator V ZA <110> is a pump <501> Heat transfer medium W transported by <502> In particular, it is heated by water, and this heat transfer medium W <502> In particular, water is used in the intermediate cooling device WT X <402> S OA12 <4032> It absorbs heat from the intermediate evaporator V ZA <110> It releases heat.

[0038] 3.8 Figure 8 Figure 8 shows one embodiment of the method according to the present invention. This corresponds to the embodiment shown in Figure 5, except that the reaction tower RR A <100> and RR B <200> However, each is an intermediate evaporator V ZA <110> or V ZB <210> The difference lies in the presence of side flow S. ZAA <111> is a reaction tower RR A <100> Extracted from V ZA <110> It is then passed through to the reactor tower RR again. A <100> It is supplied to the side flow S. ZBA <211> is a reaction tower RR B <200> Extracted from V ZB <210> It is then passed through to the reactor tower RR again. B <200> It is supplied to.

[0039] Furthermore, Figure 8 shows a further preferred embodiment of the method according to the present invention. This is a reaction rectification column RR for alcohol exchange from sodium methoxide to sodium ethoxide. C <600> This shows that this reaction rectification column RR C <600> At least partially, flow S OA12<4032> It is powered by energy from the tower RR. C <600> The bottom evaporator V SC <605> and V SC’ <606> It holds.

[0040] Here, sodium methoxide solution S CE1 <602> Reaction tower RR C <600> Ethanol S CE2 <603> It is reacted in a countercurrent to produce sodium ethoxide, which is then isolated as an ethanol solution.

[0041] Reaction tower RR C <600> At the bottom, a bottom product flow S containing sodium ethoxide is present. CP <604> It is removed. Reaction tower RR C <600> At the top, the steam flow S CB <607> This is removed. Here, the cooler K RRC <608> So, the steam flow S CB <607> At least a portion of it condenses, and at least a portion of it remains liquid as reflux in the reaction tower RR. C <600> It is supplied to the top of the steam flow S. CB <607> It is in gaseous form and cools down K RRC <608> Extracted upstream (shown by dashed line), and / or flow <609> As a liquid, cooler K RRC <608> It is extracted downstream. Side flow S ZC <610> Preferably, the reaction tower RR C <600> It is removed from, and at that time, intermediate evaporator V ZC <611> Energy is transferred to this, and then S ZC <610> RR C <600> It can be returned to [the specified address].

[0042] Preferably, reaction tower RR A <100> and RR B <200> The bottom flow S obtained AP* <104> or S BP* <204> At least a portion of it is sodium methoxide solution SCE1 <602> It is used as a bottom evaporator V. SC’ <606> is a pump <501> Heat transfer medium W1 transported by <502> In particular, it is heated by water, and this heat transfer medium W1 <502> In particular, water is used in the intermediate cooling device WT X <402> S OA12 <4032> It absorbs heat from the bottom evaporator V SC’ <606> It releases heat. Similarly, S OA2 <404> S OA11 <4031> S OA11 and S OA12 S before separation into OA1 <403> From another flow selected from, bottom evaporator V SC’ <606> or other bottom evaporators V SC <605> Energy can also be transferred to the flow S. OA1 <403> S OA11 <4031> S OA12 <4032> S OA2 <404> From at least one of the following, ethanol flow S CE1 <603> Sodium methoxide solution S CE1 <602> or side flow S ZC <610> It can also transfer energy to [this point].

[0043] 3.9 Figure 9 Figure 9 shows one embodiment of the method according to the present invention. This corresponds to the embodiment shown in Figure 8, except that the bottom evaporator V SC’ <606> S OA2 <404> The difference is that some parts are directly heated.

[0044] 3.10 Figure 10 Figure 10 shows the energy savings in the method according to Example 3 of the present invention compared with the methods according to Examples 1 and 2, which do not conform to the present invention. The x-axis shows each example, and the y-axis shows the power supplied (power of heating steam and compressor) in kW. The shaded portion of the bar graph shows the required heating power by low-pressure steam, and the open portion of the bar graph shows the total power of the compressor.

[0045] 4. Detailed Description of the Invention The present invention is based on formula M A OR[wherein R is methyl, M A The present invention relates to a method for producing at least one alkali metal alkoxide of a metal selected from sodium and potassium, preferably sodium.

[0046] The present invention comprises steps (a) to (f) and includes a post-treatment method for a mixture G containing water and the alcohol ROH [wherein R is methyl]. Thus, ROH is methanol.

[0047] 4.1 Post-treatment method for mixture G The post-treatment method for mixture G according to the present invention is the method for formula M according to the present invention. A The method for producing at least one alkali metal alkoxide of OR comprises steps (a) to (f). Mixture G is in particular gaseous form, also called “vapor” in this case. Mixture G is the top flow of a reaction tower in which an alcohol ROH is reacted with an alkali metal hydroxide NaOH or KOH to produce the corresponding alkali metal alkoxide NaOR or KOR.

[0048] According to the present invention, the mixture G used in step (a) is the vapor flow S AB At least a portion of it is used, and if step (α2) is performed, the steam flow S BB At least a portion of it will be used.

[0049] Steam flow S AB This is obtained in step (α1) (described in Section 4.2.1).

[0050] If any step (α2) is performed, the steam flow S in this step BB This can be obtained (as described in Section 4.2.2).

[0051] Steam flow S BB This is obtained only if any step (α2) is performed.BB S BB If at least a portion of it is used as mixture G, S BB At least a portion of S AB In a mixed state with S AB Separately, it is used as mixture G.

[0052] In step (β) of this method, the vapor flow S AB At least a portion of it, and if step (α2) is performed, S BB At least a portion of S AB In a mixed state with S AB Separately, it is used as mixture G in step (a) of a post-treatment method for mixture G containing water and alcohol ROH.

[0053] According to the present invention, a mixture G containing water and alcohol ROH is post-treated by a post-treatment method for mixture G.

[0054] 4.1.1 Step (a) of the method according to the present invention In step (a) of the method according to the present invention, the mixture G is directed to the rectification column RD A Send to RD A In RD A At least one vapor stream S containing ROH is taken out at the upper end. OA And, RD A At least one flow S containing water is taken out at the lower end. UA It is separated into two parts.

[0055] "RD A At least one vapor stream S containing ROH is taken out at the upper end. OA " is RD A This means that the steam obtained at the upper end can be extracted there as one or more steam streams. If it is extracted there as multiple steam streams, then m steam streams are called "steam stream S OAI "Steam flow S OAII ", [...], "Steam flow S OAm It is expressed as ", where "m" is RD A The number of steam streams extracted at the upper end is indicated (in Roman numerals).

[0056] "RD A At least one flow S containing water is taken out at the lower end. UA " is RD A This means that the steam obtained at the lower end can be extracted there as one or more flows. If it can be extracted there as multiple flows, the n flows are "flow S UAI "Flow S UAII ", [...], "Flow S UAn It is expressed as ", where "n" is RD A The number of flows extracted at the lower end is indicated (in Roman numerals).

[0057] Here, the mixture G is supplied to the rectification column RD through one or more supply points. A It can be sent to. For example, in a method according to a preferred embodiment of the present invention, step (α2) is carried out, and in step (β), the vapor flow S BB At least a portion of S AB Separately, in the embodiment used as mixture G in step (a) of the method, mixture G is delivered through multiple supply points. Thus, in this embodiment, mixture G is delivered as two separate flows to the rectification column RD A It will be sent to [location].

[0058] Mixture G flows into two or more separate streams in the rectification column RD. A In embodiments of the present invention, the individual flow supply points are sent to the rectification column RD A It is advantageous to be at essentially the same height.

[0059] In a preferred embodiment of step (a) of the method according to the present invention, the mixture G is placed in the rectification column RD A In RD A A single vapor stream S containing ROH is extracted at the upper end. OA And, RD A A single stream S containing water is extracted at the lower end. UA It is separated into two parts.

[0060] Another term for the "upper end" of a rectification column is the "top." Another term for the "lower end" of a rectification column is the "bottom" or "foot."

[0061] at least one vapor flow S OA The pressure that it has is, "p OA It is represented as "T OA This is represented as ". This is especially true for at least one vapor flow S OA Step (a) rectification column RD A This refers to the pressure and temperature at which it is extracted.

[0062] pressure p OA In particular, the range is 0.5 bar abs. to 8 bar abs., more preferably 0.6 bar abs. to 7 bar abs., more preferably 0.7 bar abs. to 6 bar abs., even more preferably 1 bar abs. to 5 bar abs., and most preferably 1 bar abs. to 4 bar abs.

[0063] temperature T OA In particular, the temperature range is 45°C to 150°C, more preferably 48°C to 140°C, more preferably 50°C to 130°C, even more preferably 60°C to 120°C, and most preferably 60°C to 110°C.

[0064] Step (a) of this method: Distillation column RD A Any rectification column known to those skilled in the art can be used. Preferably, a rectification column RD AThis includes internal structures. Suitable internal structures include, for example, trays, irregular packing, or regular packing. As trays, bubble cap trays, sieve trays, valve trays, tunnel cap trays, or slit trays are commonly used. Irregular packing is generally random packing. As random packing, Raschig rings, pole rings, bar saddles, or Intalox® saddles are commonly used. Regular packing is sold, for example, by Sulzer under the trade name Mellapack®. In addition to the internal structures listed, other suitable internal structures are known to those skilled in the art and can be used in the same manner.

[0065] A preferred internal structure has a low specific pressure drop per theoretical separation stage. For example, ordered packing and random packing have significantly lower pressure drops per theoretical separation stage than trays. This is the case for rectification column RD. A This has the advantage of keeping the pressure loss as low as possible, which also has the advantage of keeping the mechanical performance of the compressor and the temperature of the alcohol / water mixture being evaporated low.

[0066] Rectification tower RD A If the mixture contains regular or irregular packing, these may be divided or may be a single continuous packing. However, typically at least two packings are provided, with one packing above the supply point of the mixture G and one packing below the supply point of the mixture G. Alternatively, one packing may be provided above the supply point of the mixture G, and multiple trays may be provided below the supply point of the mixture G. If irregular packing, such as random packing, is used, the random packing is usually placed on a suitable support grid (e.g., a sieve tray or mesh tray).

[0067] Step (a) of the method according to the present invention, at least one vapor flow S containing ROH OA Next is the rectification column RD A It is extracted at the upper end. This steam flow S OAThe preferred weight fraction of ROH in the mixture is ≥99% by weight, more preferably ≥99.6% by weight, and even more preferably ≥99.9% by weight, with the remainder being water in particular.

[0068] RD A At the lower end, there is at least one flow S containing water. UA This is extracted, which may preferably contain <1% by weight, more preferably ≤5000 ppm by weight, and even more preferably ≤2000 ppm by weight of alcohol.

[0069] Within the scope of the present invention, rectification column RD A At the top of the vortex, at least one vapor flow S containing ROH OA To extract means, in particular, at least one vapor flow S OA However, the rectification column RD A In this context, it means that the flow is extracted as a top flow or as a lateral extraction flow above the internal structure.

[0070] Within the scope of the present invention, rectification column RD A At the bottom, there is at least one flow S containing water. UA Extracting means, in particular, at least one flow S UA However, as bottom flow, or rectification column RD A This means it is removed from the bottom.

[0071] Rectification tower RD A It is operated with or without recirculation, preferably with recirculation.

[0072] "With reflux" refers to the rectification column RD A Steam flow S extracted at the upper end OA The ions are not completely discharged, but are partially condensed and returned to each rectification column RD. A This means that it is supplied to [the system]. When setting up such reflux, the reflux ratio is preferably 0.0001 to 1, more preferably 0.0005 to 0.9, and even more preferably 0.001 to 0.8.

[0073] Reflux is performed in the rectification column RD ACooler K at the top RD This can be configured by installing the following: Cooler K RD So, each steam flow S OA It is partially condensed and then returned to the rectification column RD A It is supplied to the following. In the present invention, the reflux ratio is generally understood, and in the spirit of the present invention, to be the ratio of the mass flow rate (kg / h) that is returned to each column in liquid (reflux) form out of the total mass flow rate (kg / h) taken out of the column, to the ratio of the mass flow rate (kg / h) that is discharged from each column in liquid or gaseous form.

[0074] 4.1.2 Step (b) of the method according to the present invention Step (b) of the method according to the present invention involves at least one side flow S ZA RD A Removed from and again RD A It will be returned.

[0075] In a preferred embodiment of step (b) of the method according to the present invention, one side flow S ZA RD A Removed from and again RD A It will be returned.

[0076] "RD A Side flow S from ZA According to the present invention, this flow is RD A Dispensing point E is located below the top and above the bottom. ZA It is extracted, and in particular, RD A Supply point Z located below the top and above the bottom. ZA (This is each side flow S ZA RD A (This is the part that will be returned to) and then RD again A This means it will be returned in addition to the original shipment.

[0077] This is especially true for rectification column RD A Each side flow S ZA Extraction point E ZA However, and preferably at the supply location Z ZA Also, RD A All vapor flow S extracted fromOA Extraction point E OA Located below, preferably RD A Steam flow S extracted from OA And that is the extraction point E OA RD A The lowest point of the item is the retrieval point E. OA This means that it is located at least one theoretical stage lower, more preferably at least five theoretical stages lower, and even more preferably at least ten theoretical stages lower.

[0078] Furthermore, this is particularly relevant to the rectification column RD A Each side flow S ZA Extraction point E ZA However, and preferably at the supply location Z ZA Also, RD A All flows S extracted from UA Extraction point E UA Located above, preferably flow S UA And that is the extraction point E UA RD A The topmost item is located at the retrieval point E. UA This means that it is located at least one theoretical stage higher, more preferably at least two theoretical stages higher, and even more preferably at least four theoretical stages higher.

[0079] Furthermore, at least one vapor flow S OA at least partially rectification column RD A If it is returned to (for example, reflux is rectification column RD) A (This applies when set to) In particular, at least one steam flow S OA Supply location Z OA (That is, at least one vapor flow S OA at least partially rectification column RD A The part that will be returned to RD A All side flows S extracted from ZA Extraction point E ZA Above, especially at the supply point Z ZA Located above, preferably RDA All side flows S extracted from ZA It is located at least one theoretical stage, more preferably at least five theoretical stages, and more preferably at least ten theoretical stages, above the highest of all the extraction and supply points.

[0080] Furthermore, at least one flow S UA However, at least partially again, the rectification column RD A If returned, in particular, at least one stream S UA Supply location Z UA (That is, at least one flow S) UA However, at least partially again, the rectification column RD A The part that will be returned to RD A All side flows S extracted from ZA Extraction point E ZA Below, especially at the supply point Z ZA Located below, preferably RD A All side flows S extracted from ZA It is located at least one theoretical stage, more preferably at least two theoretical stages, and more preferably at least four theoretical stages, below the lowest of all the extraction and supply points.

[0081] Rectification tower RD A Side flow S in ZA Extraction point E ZA and side flow S ZA Supply location Z ZA RD A They can be placed between the same trays. However, it is also possible for them to be positioned at different heights.

[0082] In one preferred embodiment of the method according to the present invention, the rectification column RD A at least one side flow S in ZA Extraction point E ZA And preferably at supply location Z ZA However, mixture G is in the rectification column RD A Supply point Z to which it is sent GBelow and RD A It is located above the bottom of the rectification column RD. More preferably, A at least one side flow S in ZA Extraction point E ZA And preferably at supply location Z ZA Also, RD A It is also located below the concentration device section.

[0083] In one particularly preferred embodiment of the method according to the present invention, the rectification column RD A at least one side flow S in ZA Extraction point E ZA And more preferably, the supply location Z ZA However, mixture G is in the rectification column RD A Supply point Z to which it is sent G Located below, and RD A All flows S extracted from UA The rectification column RD is located above the highest point among all the extraction and supply points. A It is located in the upper 4 / 5 of the range, preferably the upper 3 / 4, preferably the upper 7 / 10, more preferably the upper 2 / 3, and more preferably the upper 1 / 2. Even more preferably, the rectification column RD A at least one side flow S in ZA Extraction point E ZA And preferably at supply location Z ZA Also, RD A It is also located below the concentration device section.

[0084] In a more particularly preferred embodiment of the method according to the present invention, the rectification column RD A This includes a concentration unit and a rectification column RD A at least one side flow S in ZA Extraction point E ZA And more preferably, the supply location Z ZA Also, it is located below the concentration unit, and RD A All flows S extracted from UA The rectification column RD is located above the highest point among all the extraction and supply points. AIt is located in the upper 4 / 5 of the range, preferably the upper 3 / 4, preferably the upper 7 / 10, more preferably the upper 2 / 3, and more preferably the upper 1 / 2.

[0085] 4.1.3 Step (c) of the method according to the present invention Step (c) of the method according to the present invention involves at least one vapor flow S OA at least a portion of ("at least one vapor flow S OA "at least a part of" = "S OA At least a portion of it is compressed. As a result, S OA Compared to the compressed vapor flow S OA1 This can be obtained.

[0086] Steam flow S OA1 The pressure that it has is, "p OA1 It is represented as "T OA1 It is represented as ".

[0087] pressure p OA1 is, p OA higher. p OA1 The exact value of is p OA1 >p OA As long as the conditions are met, a person skilled in the art can set it according to the requirements of step (d). OA1 / p OA The ratio of pressures (units for each pressure are bar / abs.) is preferably in the range of 1.1 to 10, more preferably 1.2 to 8, more preferably 1.25 to 7, and most preferably 1.3 to 6.

[0088] temperature T OA1 This is especially true at temperature T OA Higher, T OA1 / T OA The ratio of each temperature (unit is °C) is preferably in the range of 1.03 to 10, more preferably 1.04 to 9, more preferably 1.05 to 8, more preferably 1.06 to 7, more preferably 1.07 to 6, and most preferably 1.08 to 5.

[0089] p OA1 and T OA1 The preferred value is preferably S OA11and S OA12 This also applies to...

[0090] Steam flow S in step (c) OA At least a portion of the compression can be carried out in any manner known to those skilled in the art. Therefore, compression can be carried out, for example, mechanically, in a single stage or multiple stages, preferably multiple stages. In the case of multi-stage compression, multiple compressors of the same design or compressors of different designs can be used. Multi-stage compression can be carried out using one or more compressors. The use of single-stage or multi-stage compression depends on the compression ratio, and therefore the steam S OA It depends on the pressure at which it is compressed.

[0091] In the method according to the present invention, the compression device is particularly the steam flow S OA to S OA1 to, or S OA12 to S OA2 Suitable compressors for compressing gases are any compressors capable of compressing gas flows, known to those skilled in the art, preferably mechanical compressors. Suitable compressors include, for example, single-stage or multi-stage turbines, piston compressors, screw compressors, centrifugal compressors, or axial-flow compressors.

[0092] In multi-stage compression, a compression device suitable for each pressure stage to be overcome is used.

[0093] 4.1.4 Step (d) of the method according to the present invention In step (d) of the method according to the present invention, S ZA RD A Before returning it, compressed steam flow S OA1 The first part S OA11 From S ZA It transfers energy to [this point].

[0094] In particular, S OA1 In step (d), first, at least two parts S OA11 and S OA12 It is divided into S. OA11 The mass flow rate (kg / h) and SOA12 The ratio of the mass flow rate (kg / h) is preferably in the range of 1:99 to 99:1, more preferably in the range of 1:50 to 50:1, even more preferably in the range of 1:20 to 30:1, and even more preferably in the range of 5:20 to 15:1.

[0095] In step (d) of the method according to the present invention, the energy is the first part S OA11 From S ZA It is moved to. As a result of step (d), S OA11 Because the energy decreases, especially in flow S OA11 It condenses, at least partially.

[0096] According to this invention, "energy transfer" specifically means "heating," that is, the transfer of energy in the form of heat.

[0097] "Compressed steam flow S OA1 The first part S OA11 From S ZA "Transfer of energy to" is S OA11 A part of it is separated, and S is derived from only this part. ZA This also includes cases where energy is transferred to S. OA11 Crude RP A If step (α2) is performed, alternatively or additionally, crude RP B This is an embodiment of the present invention that is further moved to (as described in Section 4.2).

[0098] S OA11 From S ZA Energy transfer to, preferably S OA11 S by ZA The heating is preferably carried out directly or indirectly.

[0099] "Directly" means S OA11 and S ZA However, when these two flows come into contact without mixing, energy, especially heat, is transferred to S OA11 From S ZA It means to move to.

[0100] This is S OA11 and S ZA rectification column RD A Intermediate evaporator V ZRD Pass through, S OA11 S ZA This can be done by heating.

[0101] Heat transfer devices (other terms for "heat transfer devices" = "heat exchangers"), especially the heat transfer devices WT described below. X WT Y WT Z As such, heat transfer devices well known to those skilled in the art, particularly evaporators, can be used. In step (d) of the method according to the present invention, S OA11 From S ZA Energy, more preferably heat, is transferred to the intermediate evaporator V. ZRD It will be held at [location].

[0102] "Indirectly" means, in particular, S OA11 However, preferably at least one heat transfer device WT X This means that the heat transfer medium W1 comes into contact with the heat transfer medium through S, where the heat transfer medium is S ZA Rather, that is, W1 is S ZA This is different from, and as a result, energy, preferably heat, S OA11 These two flows move from W1 to S without mixing, and then heat moves from W1 to S ZA Move to, and at that time, W1 and S ZA When they come into contact, S ZA W1 and S may or may not mix, but preferably they do not mix. ZA If the two do not mix, energy, preferably heat, is not transferred, especially with further heat transfer devices WT Y It will be held at [location].

[0103] In a further embodiment of the method according to the present invention, S OA11 From S ZA Energy is indirectly transferred to, especially S OA11 S ZAWhen it is heated, first, energy, preferably heat, S OA11 From W1 to preferably at least one heat exchanger WT X Moved by contact through, then from W1 to S ZA To a further heat transfer medium W2, which is different from the heat transfer medium, preferably at least one heat exchanger WT Y It can also be moved by contact through it. Then, in the final step, from W2 to S ZA Heat is transferred to S, and at that time, ZA W2 and S may or may not mix, but preferably they do not mix. ZA If the two do not mix, energy, preferably heat, is not transferred, especially with further heat transfer devices WT Z It will be held at [location].

[0104] Naturally, in further embodiments of the present invention, additional heat transfer media W3, W4, W5, etc., can be used accordingly.

[0105] Any heat transfer medium known to those skilled in the art can be used as the heat transfer medium W1, or additionally used heat transfer mediums W2, W3, W4, W5, which are preferably selected from the group consisting of water; aqueous alcohol solutions; aqueous salt solutions, which include ionic liquids, e.g., LiBr solutions; dialkylimidazolium salts, e.g., particularly dialkylimidazolium dialkyl phosphates; mineral oils, e.g., diesel oil; hot oils, e.g., silicone oils; bio-oils, e.g., limonene; and aromatic hydrocarbons, e.g., dibenzyltoluene. The most preferred heat transfer medium W1 is water.

[0106] Furthermore, suitable saline solutions are described, for example, in German Patent Application Publication No. 102005028451 and International Publication No. 2006 / 134015.

[0107] Following step (d), S OA11 Then, optionally with fresh alcohol, and / or in a rectification column RD A With reflux, the rectification column RD returnsA It can be supplied to S. OA11 Therefore, especially energy S ZA After the energy is transferred to S, further energy is transferred. In a preferred embodiment of the method according to the present invention, step (d) is performed by S OA11 From S ZA After energy is transferred to S, energy, preferably heat, is S OA11 From S OA It is moved to, in particular, compressed, preferably S OA Pre-compression or S OA From S OA1 S supplied to the compression in step (c), which may be a compression to OA It is moved to the part. Preferably, this is flow S OA Tower RD A This is the first compression received after leaving. OA11 A portion of the residual energy or heat still stored by the process is used in the process, and in this case, compressed S OA This makes it possible to use it for heating. OA Any liquid droplets present inside will evaporate, preventing them from entering the compression device.

[0108] S OA11 Other desirable additional reductions in energy, preferably heat, in this process will be discussed later (see Section 4.3).

[0109] Step (d) of the method according to the present invention reflects one aspect of an unexpected effect of the present invention. Here, the vapor flow S OA Compressed steam flow S OA1 The excess energy obtained during compression is not wasted but used for rectification. This is because S OA From S OA1 Compression is performed to S OA11 From S ZA This allows for adjustment to the optimal value for energy transfer to S, and then S OA11 A different part S OA12 to S OA2This process can be carried out in such a way that it can be further compressed. OA12 S OA2 The heat of condensation obtained during further compression is supplied to the bottom evaporator of the tower. The additional power required for the compressor is less than the power of the heating steam saved as a result. The energy required by the method according to the present invention is less than that of prior art methods such as those shown in Examples 1 and 2. OA2 By compressing to S, OA2 From S UA1 or S UA S OA2 The pressure and temperature can be adjusted.

[0110] 4.1.5 Step (e) of the method according to the present invention Step (e) of the present invention involves S OA11 A different compressed steam flow S OA1 Part S OA12 It is further compressed, and as a result, S OA11 Compared to the compressed vapor flow S OA2 This can be obtained.

[0111] Naturally, S OA2 After step (e) is performed, S OA12 and S OA1 It is in a compressed state compared to [the previous version].

[0112] Steam flow S OA2 The pressure that it has is, "p OA2 It is represented as "T OA2 It is represented as ".

[0113] pressure p OA2 is, p OA1 higher, p OA2 / p OA1 The ratio of pressures (units of each pressure are bar abs.) is preferably in the range of 1.1 to 10, more preferably 1.2 to 8, more preferably 1.25 to 7, and most preferably 1.3 to 6. Temperature T OA2 This is especially true at temperature T OA1 Higher, T OA2 / T OA1The ratio of each temperature (unit is °C) is preferably in the range of 1.03 to 10, more preferably 1.04 to 9, more preferably 1.05 to 8, more preferably 1.06 to 7, more preferably 1.07 to 6, and most preferably 1.08 to 5.

[0114] S in step (e) OA12 The compression of steam S can be carried out by methods known to those skilled in the art. Therefore, the compression can be carried out, for example, mechanically, in a single stage or multiple stages, preferably multiple stages. In the case of multi-stage compression, multiple compressors of the same design or compressors of different designs can be used. The use of single-stage or multi-stage compression is for steam S OA12 It depends on the pressure at which it is compressed. S in relation to step (c) OA The pre-compression described for S OA12 From S OA2 It can also be performed to compress to, but in particular in step (e), single-stage compression, i.e., compression device VD x Compression using [this method] is sufficient.

[0115] 4.1.6 Step (f) of the method according to the present invention In step (f) of the method according to the present invention, S UA1 RD A Before being returned to S OA2 at least one flow S from at least a portion of UA at least part of S UA1 Energy is transferred to this point.

[0116] Preferably, in step (f) of this method, S UA1 RD A Before being returned, the energy S OA2 at least one flow S from at least a portion of UA Part of S UA1 It will be moved to [location].

[0117] Step (f) OA2 Because the energy decreases, especially in flow S OA2 It condenses, at least partially.

[0118] Step (f) of the method according to the present invention includes the following preferred embodiment (f1), (f2), (f3): (f1) Energy is S OA2 at least one flow S from at least a portion of UA Part of S UA1 Moved to, then S UA1 is RD A It will be returned to [the specified address]; (f2) energy is S OA2 at least one flow S from at least a portion of UA Part of S UA1* Moved to, then S UA1* From, some S UA1 RD A It will be returned to [the specified address]; (f3) energy is S OA2 Flow S from at least a portion of UA Moved to the whole, then flow S UA Overall or flow S UA Part of S UA1 Only, preferably flow S UA Part of S UA1 Only RD A It will be returned.

[0119] S OA2 at least one flow S from at least a portion of UA at least part of S UA1 Energy transfer to, preferably S OA2 at least one flow S by at least a portion of UA at least part of S UA1 The heating is preferably carried out directly or indirectly.

[0120] "Directly" means S OA2 at least a portion of and at least one flow S UA at least part of S UA1 However, when these two flows come into contact without mixing, energy, especially heat, is transferred, at least partially S OA2 From at least one flow S UA at least part of S UA1It means to move to.

[0121] This is S OA2 at least a portion of and at least one flow S UA at least part of S UA1 rectification column RD A Bottom evaporator V SRD Pass through, S OA11 at least one flow S UA at least part of S UA1 This can be done by heating.

[0122] As a heat transfer device, in particular the heat transfer device WT described later X WT Y WT Z As such, heat exchangers, particularly evaporators, that are well known to those skilled in the art can be used. In step (f) of the method according to the present invention, in particular, S OA2 at least one flow S from at least a portion of UA at least part of S UA1 Energy, more preferably heat, is transferred to the bottom evaporator V. SRD It will be held at [location].

[0123] "Indirectly" means, in particular, S OA2 At least a portion of it is preferably at least one heat exchanger WT X This means contact with at least one heat transfer medium W1 through, where the heat transfer medium is at least one flow S UA at least part of S UA1 Rather, that is, W1 is different from it, and thereby energy, preferably heat, S OA2 These two flows move from at least a portion of the flow to at least one heat transfer medium W1 without mixing, and then heat moves from W1 to at least one flow S UA at least part of S UA1 It moves to the component, and at that time, W1 and the component come into contact, and at that time, at least one flow S UA at least part of S UA1 W1 may or may not mix, but preferably it does not mix.

[0124] In a further embodiment of the method according to the present invention, S OA2 at least one flow S from at least a portion of UA at least part of S UA1 Energy is indirectly transferred to, especially S OA2 At least one flow S by at least a part of UA at least part of S UA1 When it is heated, first, energy, preferably heat, S OA2 From W1 to preferably at least one heat exchanger WT X Moved by contact through W1, and then at least one flow S UA at least part of S UA1 To a further heat transfer medium W2, which is different from the heat transfer medium, preferably at least one heat exchanger WT Y It can also be moved by contact through. Then, in the final step, at least one flow S from W2 UA at least part of S UA1 Heat is transferred to and at that time, at least one flow S UA at least part of S UA1 W2 and W3 may or may not mix, but preferably they do not mix. Naturally, in further embodiments of the present invention, additional heat transfer media W3, W4, W5, etc., may be used accordingly.

[0125] Any heat transfer medium known to those skilled in the art can be used as the heat transfer medium W1, or additionally used heat transfer mediums W2, W3, W4, W5, which are preferably selected from the group consisting of water; aqueous alcohol solutions; aqueous salt solutions, which include ionic liquids, e.g., LiBr solutions; dialkylimidazolium salts, e.g., particularly dialkylimidazolium dialkyl phosphates; mineral oils, e.g., diesel oil; hot oils, e.g., silicone oils; bio-oils, e.g., limonene; and aromatic hydrocarbons, e.g., dibenzyltoluene. The most preferred heat transfer medium W1 is water.

[0126] Furthermore, suitable saline solutions are described, for example, in German Patent Application Publication No. 102005028451 and International Publication No. 2006 / 134015.

[0127] Following step (f), S OA2 At least a portion of it, then optionally with fresh alcohol, and / or in a rectification column RD A Along with the recirculation, and / or after the execution of step (d), the flow S obtained OA11 Along with, the rectification column RD again A It can be supplied to S. OA2 From at least a portion of it, in particular, energy S UA at least part of S UA1 After the energy is transferred to S, further energy is transferred. In a preferred embodiment of the method according to the present invention, step (f) is performed by S OA2 S from at least a portion of UA at least part of S UA1 After energy is transferred to S, energy, preferably heat, is S OA2 S from at least a portion of OA It is moved to, in particular, compressed, preferably S OA Pre-compression or S OA From S OA1 S supplied to the compression in step (c), which may be a compression to OA It is moved to the part. Preferably, this is flow S OA Tower RD A This is the first compression received after leaving. This results in at least a portion of S OA2 A portion of the residual energy or heat still stored by the process is used in the process, and in this case, compressed S OA It can be used for heating.

[0128] S OA2 Other desirable additional reductions in energy, preferably heat, in at least a portion of the above will be discussed later (see Section 4.3).

[0129] 4.2 Method for producing at least one alkali metal alkoxide The mixture G used in the post-treatment method for mixture G according to the present invention is a water / methanol mixture extracted from a reaction tower for alkali metal alkoxide production.

[0130] Therefore, the present invention is based on formula M A OR[wherein R is methyl, M A The present invention relates to a method for producing at least one alkali metal alkoxide of a metal selected from sodium and potassium, preferably sodium.

[0131] Therefore, ROH is methanol.

[0132] 4.2.1 Step (α1) In step (α1) of the method according to the present invention, the reaction rectification column RR A So, reaction logistics S including ROH AE1 M A Reaction logistics S including OH AE2 And it reacts with a countercurrent, M A OR, water, ROH, and M A Crude product RP containing OH A Generates.

[0133] According to the present invention, a "reaction rectification column" is defined as a rectification column in which the reaction according to step (α1) or step (α2) of the method according to the present invention proceeds in at least some part. This is sometimes abbreviated as "reaction column".

[0134] In step (α1), RR A At the lower end, ROH and M A Bottom product flow S including OR AP Take it out. RR A At the upper end, a vapor flow S containing water and ROH. AB Take it out.

[0135] M A It is selected from sodium and potassium, and preferably sodium.

[0136] Reaction Logistics SAE1 This includes ROH. In a preferred embodiment, S AE1 The weight fraction of ROH in the mixture is ≥95% by weight, and more preferably ≥99% by weight, S AE1 It also contains water in addition to the above.

[0137] In step (α1), reaction logistics S AE1 The alcohol ROH used may be commercially available alcohol in which the weight fraction of alcohol is greater than 99.8% by weight and the weight fraction of water is a maximum of 0.2% by weight.

[0138] Reaction Logistics S AE1 It is preferably added in vapor form.

[0139] Reaction Logistics S AE2 M A Contains OH. In a preferred embodiment, S AE2 M A In addition to OH, it comprises at least one further compound selected from water and ROH. More preferably, S AE2 M A In addition to OH, it contains water, in this case S AE2 M A It is an aqueous solution of OH.

[0140] Reaction Logistics S AE2 M A If OH and water are present, S AE2 M relative to the total weight of the aqueous solution that forms A The weight fraction of OH is particularly in the range of 10 to 75% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and most preferably 40 to 52% by weight.

[0141] Reaction Logistics S AE2 M A If OH and ROH are included, S AE2 M in ROH relative to the total weight of the solution forming the solution A The weight fraction of OH is particularly in the range of 10 to 75% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and most preferably 40 to 52% by weight.

[0142] Reaction Logistics S AE2 M A In certain cases, S AE2 M in ROH and water relative to the total weight of the solution forming A It is particularly preferable that the weight fraction of OH is in the range of 10 to 575% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and especially preferably 40 to 52% by weight.

[0143] Step (α1) is performed in the reaction rectification column (or "reaction column") RR A It will be implemented in [location / location].

[0144] Step (α2), described later, is performed in the reaction rectification column (or "reaction column") RR. B It will be implemented in [location / location].

[0145] Preferably, reaction tower RR A or RR B This includes internal structures. Suitable internal structures include, for example, trays, ordered packing, or irregular packing. Reaction tower RR A or RR B If trays are included, suitable trays are bubble cap trays, valve trays, tunnel cap trays, Tolman trays, cross-slit bubble cap trays, or sieve trays. Reaction tower RR A or RR B If trays are included, preferably, those trays are selected so that a maximum of 5% by weight, preferably less than 1% by weight, of the liquid drips into each tray. Design measures necessary to minimize liquid dripping are well known to those skilled in the art. In the case of valve trays, for example, a particularly tight valve design is selected. By reducing the number of valves, the vapor velocity at the tray openings can be further increased to twice the value that is normally set. When using sieve trays, it is particularly advantageous to reduce the diameter of the tray openings and maintain or even increase the number of openings.

[0146] When using regular or irregular packing materials, regular packing materials are preferred from the viewpoint of uniform distribution of liquid.

[0147] In towers with irregular packing, particularly towers with random packing and towers with regular packing, the desired liquid distribution characteristics can be achieved by reducing the liquid trickle density in the edge region of the tower cross section adjacent to the tower jacket, which corresponds to approximately 2-5% of the total cross section of the tower, by up to 100%, preferably 5-15%, compared to other cross section regions. This can be easily achieved, for example, by precisely distributing the dripping points and holes of the liquid distributor.

[0148] The method according to the present invention can be carried out continuously or discontinuously. Preferably, the method according to the present invention is carried out continuously.

[0149] "Reaction logistics including ROH" AE1 M A Reaction logistics S including OH AE2 "To react in a countercurrent" means, according to the present invention, in particular, the reaction tower RR A Reaction logistics S including ROH in step (α1) AE1 At least some of the supply locations are M A Reaction logistics S including OH AE2 This is guaranteed by being located below the supply point.

[0150] Reaction tower RR A Preferably, the reaction logistics S AE1 Supply locations and reaction logistics S AE2 The supply point includes at least two, particularly 15 to 40, theoretical plates.

[0151] Reaction tower RR A It can be operated as a pure stripping tower. In that case, the reaction logistics S including ROH AE1 is a reaction tower RR A It is supplied in vapor form in the lower region.

[0152] Step (α1) involves the reaction logistics S containing ROH.AE1 A portion of it is alkaline solution M A Reaction logistics S including OH AE2 Although it is below the supply point, the reaction tower RR A This also includes cases where it is added in vapor form at the upper end or in the upper region. A The dimensions of the lower region can be reduced. Reaction logistics S containing ROH, especially methanol. AE1 Part of the reaction tower RR A At the upper end or upper region, especially when added in vapor form, only a portion of 10-70% by weight, preferably 30-50% by weight (relative to the total amount of alcohol ROH used in step (α1)) is added to the reaction tower RR. A It is introduced at the lower end, and the remaining portion is divided into a single flow or into multiple partial flows, preferably in 1 to 10 theoretical stages, particularly preferably 1 to 3 theoretical stages, M A Reaction logistics S including OH AE2 It is added in vapor form below the supply point.

[0153] Next, the reaction tower RR A In this context, reaction logistics S including ROH AE1 and M A Reaction logistics S including OH AE2 and the above reaction <1> Respond accordingly, M A OR and H2O are produced, and since this is an equilibrium reaction, these products are reactants ROH and M. A It is mixed with OH. Therefore, in step (α1), the reaction tower RR A In this case, product M A In addition to OR and water, ROH and M A Crude product RP including OH A This can be obtained.

[0154] RR A At the lower end, ROH and M A Bottom product flow S including OR AP This is obtained and then extracted.

[0155] RR A The upper end, preferably RR AAt the top of the tower, the above-mentioned "steam flow S containing water and ROH" AB An alcoholic stream containing water is extracted, which is described as "[...]."

[0156] This is a vapor stream S containing water and ROH. AB In step (β), it is used in step (a) of the method according to the present invention, at least partially as mixture G. OA A portion of the alcohol obtained by distillation in step (a) is used in the reaction column RR A Reaction to logistics S AE1 It can be supplied as such.

[0157] In a preferred embodiment of the method according to the present invention, S OA Part of it reacts in step (α1) with logistics S AE1 Used as such, and if step (α2) is carried out, alternatively or additionally in step (α2) the reaction logistics S BE1 It is used as such.

[0158] In a more preferred embodiment of the method according to the present invention, the vapor flow S OA 5 to 95% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and even more preferably 30 to 70% by weight of the reaction logistics S AE1 Used as such, and if step (α2) is carried out, alternatively or additionally in step (α2) the reaction logistics S BE1 It is used as such.

[0159] In this preferred embodiment, the reaction logistics S AE1 or reaction logistics S BE1 Flow S used as OA It is advantageous to compress this part.

[0160] Preferably, reaction logistics S AE1 The amount of alcohol ROH contained in it is that it simultaneously produces a bottom product flow S AP Alkalialkoxide M obtained from A Selected to also act as a solvent for OR. Preferably, reaction logistics S AE1The amount of alcohol ROH inside is determined by the presence of an alkali alkoxide solution of the desired concentration at the bottom of the reaction column, which is ROH and M A Bottom product flow S including OR AP It is selected to be extracted as such.

[0161] In one preferred embodiment of the method according to the present invention, in particular, S AE2 M A When water is also present in addition to OH, the reaction logistics S in step (α1) AE1 The total weight (kg) of the alcohol ROH used as the reaction logistics S in step (α1) AE2 M used as A The ratio of the total weight of OH (weight; unit: kg) to the ratio is 4:1 to 50:1, more preferably 8:1 to 48:1, even more preferably 10:1 to 45:1, and still more preferably 20:1 to 40:1.

[0162] Reaction tower RR A It is operated with or without recirculation, preferably with recirculation.

[0163] "With reflux" means that in step (α1), the reaction tower RR A In step (α2), the reaction tower RR B A steam flow S containing water and ROH is extracted from the top of each tower. AB or S BB However, this means that it is not completely discharged. Therefore, in that case, in step (β), the vapor flow S AB or S BB Not all of it is used as mixture G; at least a portion, preferably a portion, is used in step (α1) in the reaction tower RR. A In step (α2), the reaction tower RR B The wastewater is returned to each tower as recirculation. When such recirculation is set up, the recirculation ratio is preferably 0.01 to 1, more preferably 0.02 to 0.9, even more preferably 0.03 to 0.34, particularly preferably 0.04 to 0.27, and very particularly preferably 0.05 to 0.24.

[0164] Reflux can be established by installing coolers at the top of each column. In step (α1), the reaction column RR is particularly important for this purpose. A Cooler K RRA A reactor tower RR is installed. In step (α2), a reactor tower RR is specifically installed for this purpose. B Cooler K RRB A cooler is installed. AB or S BB It is at least partially condensed, and in step (α1) the reaction tower RR A or RR B They are returned to each tower.

[0165] Reaction tower RR A In an embodiment in which reflux is set, step (α1) is performed on the reaction logistics S AE2 M used as A The OH may be mixed with at least partially refluxed flow, and the resulting mixture may be supplied to step (α1).

[0166] Step (α1) is carried out at a temperature in the range of 45°C to 150°C, preferably 47°C to 120°C, more preferably 60°C to 110°C, and at a pressure in the range of 0.5 bar abs. to 40 bar abs., preferably 0.7 bar abs. to 5 bar abs., more preferably 0.8 bar abs. to 4 bar abs., more preferably 0.9 bar abs. to 3.5 bar abs., and even more preferably 1.0 bar abs. to 3 bar abs.

[0167] In one preferred embodiment, the reaction tower RR A In particular, intermediate evaporator V ZA and bottom evaporator V SA Includes at least one evaporator selected from the following. Reaction tower RR A Particularly preferably, at least one bottom evaporator V SA Includes.

[0168] According to the present invention, the "intermediate evaporator" V Z This refers to the area above the bottom of each tower, especially the RR of the reaction tower.A or RR B It is located above the bottom (in that case, "V ZA " or "V ZB (represented as "), or rectification column RD A It is located above the bottom (in that case, "V ZRD It means an evaporator (represented as RR). A or RR B In that case, in particular, the side flow S from the tower ZAA or S ZBA Crude RP extracted as A or RP B It evaporates.

[0169] Bottom evaporator V S According to the present invention, the bottom of each tower, in particular, the reaction tower RR A Or RR B Alternatively, the RR used in a preferred embodiment, which is described in more detail below. C Heat the bottom (in that case, "V SA " or "V SA’ " or "V SB " or "V SB’ " or "V SC " or "V SC’ (represented as ") or rectification column RD A Heat the bottom (in that case, "V SRD " or "V SRD’ This refers to an evaporator (represented as RR). A or RR B In that case, in particular, the bottom product flow S AP or S BP Evaporate at least a portion of it. RR C In that case, in particular, the bottom product flow S CP Evaporate it. RD A In that case, in particular, the bottom product flow S UA , or S UA S is part of UA1 It evaporates.

[0170] Evaporators are typically located outside each reaction column or rectification column. Evaporators are heat transfer devices (WT) because energy, particularly heat, is transferred from one flow to another. The mixture to be evaporated is extracted from the column through an extraction section and fed into at least one evaporator. (Reaction column RR) A or RR B In this case, this is crude RP A or RP B During the intermediate evaporation, it is extracted and at least one intermediate evaporator V ZA or V ZB It is supplied to.

[0171] Rectification tower RD A In this case, at least one side flow S occurs during intermediate evaporation. ZA RD A Removed from ("extracted") at least one intermediate evaporator V ZRD It is supplied to.

[0172] Rectification tower RD A In this case, at least one flow S occurs during bottom evaporation. UA RD A Removed ("extracted") from, at least part, preferably part, of at least one bottom evaporator V SRD It is supplied to.

[0173] The evaporated mixture, sometimes with some liquid remaining, is returned to each tower through at least one feed section. The evaporator is an intermediate evaporator, i.e., an intermediate evaporator V ZA or V ZB or V ZRD In this case, the extraction section from which each mixture is extracted and supplied to the evaporator is a lateral extraction section, and the supply section from which the evaporated mixture is supplied back to each column is a lateral supply section. When the evaporator is a bottom evaporator, that is, when the bottom of the column is heated, i.e., a bottom evaporator V SA or V SB or V SRD If so, at least a portion of the bottom outflow, especially S AP or S BPIt is supplied to the bottom evaporator, evaporates, and is returned to each column in the bottom region. However, alternatively, for example, when using an intermediate evaporator, a suitable tray may be placed on it, or a tube may be formed at the bottom of each column, and a heat transfer medium, for example, each compressed steam flow S, may be placed inside. OA11 or S OA2 (V S or V Z RD A (If present) or it is also possible to flow the heat transfer medium W1. In this case, evaporation takes place on the tray of the tower or at the bottom of the tower. However, it is preferable to place the evaporator on the outside of each tower.

[0174] Suitable evaporators that can be used as intermediate and bottom evaporators include, for example, natural circulation evaporators, forced circulation evaporators, forced circulation evaporators with expansion chambers, kettle-type reboilers, thin-film gravity evaporators, or thin-film evaporators. In natural circulation and forced circulation evaporators, tube bundles or plate devices are typically used as the heat transfer devices for the evaporator. When using tube bundle heat transfer devices, the heat transfer medium is, for example, a rectification column RD. A V SRD Or V ZRD Compressed vapor flow S in OA11 Or S OA2 Alternatively, the heat transfer medium W1 may flow through the tube and the mixture to be evaporated may flow around the tube, or the heat transfer medium may be, for example, the rectification column RD A V SRD Or V ZRD Compressed vapor flow S in OA11 Or S OA2 Alternatively, the heat transfer medium W1 may flow around the tube, and the mixture to be evaporated may flow inside the tube. In the case of a thin-film gravity evaporator, the mixture to be evaporated is usually added as a thin film to the inside of the tube, and the tube is heated from the outside. Unlike a thin-film gravity evaporator, a thin-film evaporator is further equipped with a rotor with a wiper, which disperses the liquid to be evaporated on the inner wall of the tube to form a thin film.

[0175] However, in addition to the above, any other type of evaporator known to those skilled in the art and suitable for use in a rectification column can also be used.

[0176] For example, compressed steam flow S OA11 Alternatively, if the evaporator operated using the heat transfer medium W1 as heating steam is an intermediate evaporator, the intermediate evaporator is the rectification column RD A In the stripping section, between the supply point of mixture G and the upper part of the column bottom, or in the reaction column RR A or RR B In this case, reaction logistics S AE2 or S BE2 It is preferable that the intermediate evaporator is located in a region below the supply point. This allows the majority of the heating energy to be introduced by the intermediate evaporator. For example, more than 80% of the energy can be introduced by the intermediate evaporator. According to the present invention, it is preferable that the intermediate evaporator is positioned and / or designed so that more than 10%, particularly more than 20%, of the total energy required for distillation is introduced by it.

[0177] When using intermediate evaporators, it is particularly advantageous to arrange the intermediate evaporators such that each rectification column or reaction column has 1 to 50 theoretical stages below the intermediate evaporator and 1 to 200 theoretical stages above it. In particular, it is preferable that the rectification column or reaction column has 2 to 10 theoretical stages below the intermediate evaporator and 20 to 80 theoretical stages above it.

[0178] The mixture is transferred from the rectification column or reaction column to the intermediate evaporator V. Z The lateral extraction flow supplied to the intermediate evaporator V is then used to transport the evaporated mixture to the intermediate evaporator V. Z The side feed section, which supplies the material back to each rectification column or reaction column, can be located between the same trays in the column. However, the side extraction section and the side feed section can also be located at different heights.

[0179] Such an intermediate evaporator V ZA So, the reaction tower RR A M exists A OR, water, ROH, and M A Liquid crude material RP containing OH A Since it can be converted into a gaseous state, the efficiency of the reaction in step (α1) of the method according to the present invention is improved.

[0180] In such an intermediate evaporator V ZB in the reaction tower RR B the M B OR, water, ROH, and M B OH-containing liquid crude product RP B can be converted into a gaseous state, so the efficiency of the reaction in step (α2) of the method according to the present invention is improved.

[0181] In the reaction tower RR A one or more intermediate evaporators V ZA or V ZB are arranged in the upper region, so that the dimensions of the lower region of the reaction tower RR A can be reduced. In an embodiment having at least one, preferably a plurality of intermediate evaporators V ZA or V ZB it is also possible to supply a partial stream of ROH in liquid form to the upper region of the reaction tower RR A .

[0182] In a further preferred embodiment, energy, preferably heat, is transferred from at least a part of the stream selected from S OA1 , S OA2 , particularly S OA11 , S OA12 , S OA2 , preferably S OA11 , S OA2 to the crude product RP A , and when step (α2) is carried out, alternatively or additionally to the crude product RP B .

[0183] "Transfer of energy, preferably heat, from at least a part of S OA1 to the crude product RP A , and when step (α2) is carried out, alternatively or additionally to the crude product RP B " includes transfer from at least one stream selected from S OA11 , S OA12 , or from the stream S OA11 , S OA12 before separation into S OA1 to the crude product RP AIf step (α2) is performed, alternatively or additionally, crude RP B This also includes the transfer of energy, preferably heat, to S. OA11 S OA12 Crude RP from a portion A If step (α2) is performed, alternatively or additionally, crude RP B This also includes the transfer of energy to [the target].

[0184] In relation to this, in particular, S OA1 S OA2 A portion of the flow selected from, or S OA1 S OA2 The heat transfer medium W1, selected from the flow to which energy has previously been transferred, is at least partially connected to the intermediate evaporator V. ZA or V ZB Energy is passed through S OA1 S OA2 From the selected flow or W1, RR A or RR B The crude materials extracted at the lateral extraction section are moved to the logistics, in particular, S OA1 S OA2 The flow or W1 selected from is used in the evaporator V ZA or V ZB It is used for heating.

[0185] According to the present invention, the bottom evaporator is located in each rectification column RD A or reaction tower RR A Or RR B Or RR C It is placed at the bottom, and in that case, "V SRD " or "V SRD’ " or "V SA " or "V SA’ " or "V SB " or "V SB’ " or "V SC " or "V SC’ This is expressed as "[...]. In such a bottom evaporator, each column (especially the reaction column RR) A or RR B ) Bottom product flow present in (especially S AP or SBP ) can be removed at least partially therefrom through, for example, ROH. S AP or S BP In the case of, thereby, S AP with respect to M A The bottom product stream S with an increased weight fraction of M OR AP* or S BP with respect to M B The bottom product stream S with an increased weight fraction of M OR BP* can be obtained.

[0186] In step (α1) of the method according to the invention, at the lower end of the reaction column RR A a bottom product stream S containing ROH and M A OR is withdrawn. AP

[0187] The reaction column RR A includes at least one bottom evaporator V SA to which the bottom product stream S AP is partially passed, and it is preferred that ROH is partially removed from the bottom product stream S[[ID=�8]] AP thereby, S AP with respect to M A The bottom product stream S with an increased weight fraction of M OR AP* is obtained.

[0188] Thus, in another preferred embodiment, if step (α2) is carried out to the crude product RP OA1 from at least a part of the stream selected from S OA2 especially S OA11 S OA2 > the following is done to transfer energy, preferably heat, to the crude product RP A alternatively or additionally: B In particular, a part of the stream selected from S OA1 S OA2 or the heat transfer medium W at least partially from the stream selected from S OA1 S OA2 from which energy has been previously transferred is then at least partially to the bottom evaporator VSA or V SB Energy is passed through S OA1 S OA2 The selected flow or bottom product flow S from W1 AP or S BP Moved, in particular, S OA1 S OA2 The flow or W1 selected from is used in the evaporator V SA or V SB It is used for heating.

[0189] Here, the bottom product flow S AP* M A The weight fraction of OR is particularly important for bottom product flow S AP M A Compared to the weight fraction of OR, it is increased by at least 0.5%, preferably ≥1%, more preferably ≥2%, and even more preferably ≥5%.

[0190] Preferably, S AP or at least one bottom evaporator V SA This is used, and the bottom product flow S AP If at least partially passes through and at least partially removes ROH from there, then S AP* is, S AP M in ROH is present in a range of 1 to 50% by weight, preferably 5 to 35% by weight, more preferably 15 to 35% by weight, and most preferably 20 to 35% by weight, relative to the total weight of each. A It has a weight fraction of OR.

[0191] Here, S AP or S AP* The weight fraction of residual water inside is preferably S AP The weight of the total weight is <1% by weight, preferably <0.8% by weight, and more preferably <0.5% by weight.

[0192] Here, S AP or S AP* Reactant M inside A The weight fraction of OH is preferably S APThe weight of the total weight is <1% by weight, preferably <0.8% by weight, and more preferably <0.5% by weight.

[0193] 4.2.2 Step (α2) (Optional) Step (α2) is an optional embodiment of the method according to the present invention. This means that within the scope of preferred embodiments of the method according to the present invention, step (α2) may or may not be performed. In the optional step (α2), simultaneously with and spatially separated from step (α1), the reaction rectification column RR B So, reaction logistics S including ROH BE1 M B Reaction logistics S including OH BE2 And it reacts with a countercurrent, M B OR, water, ROH, and M B Crude product RP containing OH B Generates.

[0194] In step (α2) of the method according to the present invention, RR B At the lower end, ROH and M B Bottom product flow S including OR BP It is extracted. RR B At the upper end, a vapor flow S containing water and ROH. BB It is taken out.

[0195] M B It is selected from sodium and potassium, and preferably potassium.

[0196] Reaction Logistics S BE1 This includes ROH. In a preferred embodiment, S BE1 The weight fraction of ROH in the mixture is ≥95% by weight, and more preferably ≥99% by weight, S BE1 It also contains water in addition to the above.

[0197] In step (α2) of the method according to the present invention, the reaction logistics S BE1 The alcohol ROH used may be commercially available alcohol in which the weight fraction of alcohol is greater than 99.8% by weight and the weight fraction of water is a maximum of 0.2% by weight.

[0198] Reaction Logistics S BE1 It is preferably added in vapor form.

[0199] Reaction Logistics S BE2 M B Contains OH. In a preferred embodiment, S BE2 M B In addition to OH, it comprises at least one further compound selected from water and ROH. More preferably, S BE2 M B In addition to OH, it contains water, in this case S BE2 M B It is an aqueous solution of OH.

[0200] Reaction Logistics S BE2 M B If OH and water are present, S BE2 M relative to the total weight of the aqueous solution that forms B The weight fraction of OH is particularly in the range of 10 to 75% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and most preferably 40 to 52% by weight.

[0201] Reaction Logistics S BE2 M B If OH and ROH are included, S BE2 M in ROH relative to the total weight of the solution forming the solution B The weight fraction of OH is particularly in the range of 10 to 75% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and most preferably 40 to 52% by weight.

[0202] Reaction Logistics S BE2 M B In certain cases, S BE2 M in ROH and water relative to the total weight of the solution forming B It is particularly preferable that the weight fraction of OH is in the range of 10 to 75% by weight, preferably 15 to 54% by weight, more preferably 30 to 53% by weight, and especially preferably 40 to 52% by weight.

[0203] Step (α2) of the method according to the present invention is to use a reaction rectification column (or "reaction column") RR B It will be carried out at the reactor RR. B A preferred embodiment is described in Section 4.2.1.

[0204] "Reaction logistics including ROH" BE1 M B Reaction logistics S including OH BE2 "To react in a countercurrent" means, according to the present invention, in particular, the reaction tower RR B Reaction logistics S including ROH in step (α2) BE1 At least some of the supply locations are M B Reaction logistics S including OH BE2 This is guaranteed by being located below the supply point.

[0205] Reaction tower RR B Preferably, the reaction logistics S BE1 Supply locations and reaction logistics S BE2 The supply point includes at least two, particularly 15 to 40, theoretical plates.

[0206] Reaction tower RR B It can be operated as a pure stripping tower. In that case, the reaction logistics S including ROH BE1 is a reaction tower RR B It is supplied in vapor form in the lower region. Step (α2) of the method according to the present invention is to supply reaction logistics S containing ROH. BE1 A portion of it is alkaline M B Reaction logistics S including OH BE2 Although it is below the supply point, the reaction tower RR B This also includes cases where it is added in vapor form at the upper end or in the upper region. B The dimensions of the lower region can be reduced. Reaction logistics S containing ROH, especially methanol. BE1 Part of the reaction tower RR B At the upper end or upper region, especially when added in vapor form, only a portion of 10-70% by weight, preferably 30-50% by weight (relative to the total amount of alcohol ROH used in step (α2)) is added to the reaction tower RR.B It is introduced at the lower end, and the remaining portion is divided into a single flow or into multiple partial flows, preferably in 1 to 10 theoretical stages, particularly preferably 1 to 3 theoretical stages, M B Reaction logistics S including OH BE2 It is added in vapor form below the supply point.

[0207] Next, the reaction tower RR B In this context, reaction logistics S including ROH BE1 and M B Reaction logistics S including OH BE2 and the above reaction <1> Respond accordingly, M B OR and H2O are produced, and since this is an equilibrium reaction, these products are reactants ROH and M. B It is mixed with OH. Therefore, in step (α2) of the method according to the present invention, the reaction tower RR B In this case, product M B In addition to OR and water, ROH and M B Crude product RP including OH B This can be obtained.

[0208] RR B At the lower end, ROH and M B Bottom product flow S including OR BP This is obtained and then extracted.

[0209] RR B The upper end, preferably RR B At the top of the tower, the above-mentioned "steam flow S containing water and ROH" BB An alcoholic stream containing water is extracted, which is described as "[...]."

[0210] Step (β) of the method according to the present invention involves a vapor flow S containing water and ROH. BB At least a portion of this is used in step (a) of the method according to the present invention, in particular as mixture G. Here, this vapor flow S BB At least part of it is S AB In a mixed state with S AB In a state where it is not mixed with, that is, S ABSeparately, as mixture G, rectification column RD A It is supplied to the vapor flow S. Preferably, the vapor flow S BB and S AB and are mixed, and this mixture is then used as mixture G in step (a) of the method according to the present invention.

[0211] Preferably, reaction logistics S BE1 The amount of alcohol ROH contained in it is that it simultaneously produces a bottom product flow S BP Alkalialkoxide M obtained from B Selected to also act as a solvent for OR. Preferably, reaction logistics S BE1 The amount of alcohol ROH inside is determined by the presence of an alkali alkoxide solution of the desired concentration at the bottom of the reaction column, which is ROH and M B Bottom product flow S including OR BP It is selected to be extracted as such.

[0212] In one preferred embodiment of the method according to the present invention, in particular, S BE2 M B When water is also present in addition to OH, the reaction logistics S in step (α2) BE1 The total weight (kg) of the alcohol ROH used as the reaction logistics S in step (α2) BE2 M used as B The ratio of the total weight of OH (weight; unit: kg) to the ratio is 4:1 to 50:1, more preferably 8:1 to 48:1, even more preferably 10:1 to 45:1, and still more preferably 20:1 to 40:1.

[0213] Reaction tower RR B It is operated with or without recirculation, preferably with recirculation.

[0214] "With reflux" means that in each tower, in step (α2), the reaction tower RR B A vapor flow S containing water and ROH extracted at the upper end BB It is not completely discharged, that is, it is completely used as mixture G in step (a) of the method according to the present invention, i.e., in the rectification column RDA Instead of being supplied to the reaction tower RR, at least a portion, preferably a portion, is supplied to each tower in step (α2). B This means that it is supplied again as reflux. When such reflux is set up, the reflux ratio is preferably 0.01 to 0.99, more preferably 0.02 to 0.9, even more preferably 0.03 to 0.34, particularly preferably 0.04 to 0.27, and very particularly preferably 0.05 to 0.24.

[0215] Reaction tower RR B In an embodiment in which reflux is set, the reaction logistics S in step (α2) BE2 M used as B The OH group may be mixed with at least partially refluxed water, and the resulting mixture may be supplied to step (α2).

[0216] Any step (α2) is carried out at a temperature in the range of 45°C to 150°C, preferably 47°C to 120°C, more preferably 60°C to 110°C, and at a pressure in the range of 0.5 bar abs. to 40 bar abs., preferably 0.7 bar abs. to 5 bar abs., more preferably 0.8 bar abs. to 4 bar abs., more preferably 0.9 bar abs. to 3.5 bar abs., and even more preferably 1.0 bar abs. to 3 bar abs.

[0217] In one preferred embodiment, the reaction tower RR B In particular, intermediate evaporator V ZB and bottom evaporator V SB Includes at least one evaporator selected from the following. Reaction tower RR B Particularly preferably, at least one bottom evaporator V SB Includes.

[0218] Such an intermediate evaporator V ZB So, the reaction tower RR B M exists B OR, water, ROH, and M B Liquid crude material RP containing OH BSince it can be converted into a gaseous state, the efficiency of the reaction in step (α2) of the method according to the present invention is improved.

[0219] Reaction tower RR B One or more intermediate evaporators V in the upper region ZB By arranging the reactor tower RR, B The dimensions of the lower region can be reduced. At least one, preferably more than one intermediate evaporator V ZB In embodiments having a partial flow of ROH in liquid form in the reaction tower RR B It is also possible to supply it to the upper region.

[0220] In step (α2) of the method according to the present invention, the reaction tower RR B At the lower end, ROH and M B Bottom product flow S including OR BP It is taken out.

[0221] Reaction tower RR B at least one bottom evaporator V SB It includes, and the bottom product flow S BP It is passed through at least partially, and ROH is flowed through the bottom product stream S BP Preferably, it is removed at least partially from S BP M B Bottom product flow S with increased weight fraction of OR BP* This can be obtained.

[0222] Here, the bottom product flow S BP* M B The weight fraction of OR is particularly important for bottom product flow S BP M B Compared to the weight fraction of OR, it is increased by at least 0.5%, preferably ≥1%, more preferably ≥2%, and even more preferably ≥5%.

[0223] Preferably, S BP or at least one bottom evaporator V SB This is used, and the bottom product flow S BPIf at least partially passes through and at least partially removes ROH from there, then S BP* is, S BP M in ROH is present in a range of 1 to 50% by weight, preferably 5 to 35% by weight, more preferably 15 to 35% by weight, and most preferably 20 to 35% by weight, relative to the total weight of each. B It has a weight fraction of OR.

[0224] Here, S BP or S BP* The weight fraction of residual water inside is preferably S BP The weight of the total weight is <1% by weight, preferably <0.8% by weight, and more preferably <0.5% by weight.

[0225] Here, S BP or S BP* Reactant M inside B The weight fraction of OH is preferably S BP The weight of the total weight is <1% by weight, preferably <0.8% by weight, and more preferably <0.5% by weight.

[0226] In embodiments of this method in which step (α2) is also performed, preferably the bottom product flow S AP at least partially bottom evaporator V SA They were led through, and ROH was S AP S is at least partially removed from it, thereby AP M A Bottom product flow S with increased weight fraction of OR AP* This is obtained, and / or preferably, and a bottom product flow S BP at least partially bottom evaporator V SB They were led through, and ROH was S BP S is at least partially removed from it, thereby BP M B Bottom product flow S with increased weight fraction of OR BP* This can be obtained.

[0227] In an embodiment of the present invention in which step (α2) of the method according to the present invention is carried out, step (a2) is carried out simultaneously with and spatially separated from step (α1). Two reaction towers RR A and RR B By performing steps (α1) and (α2), spatial separation is ensured.

[0228] In one advantageous configuration of the present invention, the reaction tower RR A and RR B The tower is housed in a tower jacket, in which the tower is at least partially partitioned by at least one partition. A tower having at least one partition is denoted as a "TRD". Such partitioned towers are known to those skilled in the art, for example, in U.S. Patent No. 2,295,256, European Patent Application Publication No. 0122367, European Patent Application Publication No. 0126288, International Publication No. 2010 / 097318, and [ka] It is described in [the document]. Similarly, Chinese Patent Application Publication No. 105218315 describes a partitioned column used in methanol rectification.

[0229] In a partitioned column considered in the method according to the present invention, the partitions preferably extend to the bottom and particularly preferably extend at least 1 / 4, more preferably at least 1 / 3, even more preferably at least half, even more preferably at least 2 / 3, and still even more preferably at least 3 / 4, in the longitudinal direction of the column. The partitions divide the column into at least two reaction spaces, in which spatially separated reactions can take place. The reaction spaces created by at least one partition may be the same size or different sizes.

[0230] In each region separated by a partition wall, in this embodiment, the bottom product flow S AP and S BPThese can be removed separately, preferably by a bottom evaporator V installed in each reaction space formed by at least one reaction wall. SA or V SB Pass through, and there S AP or S BP Remove at least partially the ROH from S AP* or S BP* You can obtain this.

[0231] Therefore, in a preferred embodiment of the method according to the present invention, the rectification column RD A , Reactor RR A And if step (α2) is carried out, the reaction tower RR B At least two, more preferably exactly two, of the towers selected from are housed in the tower jacket, with each tower separated from the others by a partition wall that extends at least partially to the base of the tower.

[0232] Reaction tower RR in the method according to the present invention A (or in embodiments in which step (α2) is carried out, the reaction tower RR A and reaction tower RR B ) and rectification column RD A In combination with, rectification column RD A It is preferable that the towers be operated at a pressure selected to minimize pressure drop between them.

[0233] In the method according to the present invention, alcohol ROH is consumed, and therefore, especially in the case of continuous operation, it is necessary to replenish with fresh alcohol ROH.

[0234] At that time, fresh alcohol ROH, in particular, reactants S containing ROH AE1 For example, the reaction tower RR A In an embodiment in which step (α2) is carried out, the reaction tower RR A and RR B It is supplied directly.

[0235] In the method according to the present invention, a vapor flow S containing ROH OAPartially, in step (α1), the reaction logistics S AE1 It is used as such, and optionally in step (α2), the reaction logistics S BE1 It is even more preferable to use it as such. Alternatively or additionally, compressed steam flow S OA1 Partially, in step (α1), the reaction logistics S AE1 It is used as such, and optionally in step (α2), the reaction logistics S BE1 It can be used as a rectification column RD. In this preferred embodiment, A It is even more preferable that fresh alcohol ROH is added.

[0236] Rectification tower RD A When fresh alcohol ROH is added, the rectification column RD A It is supplied to the concentration section of the rectification column RD A It is preferable to supply it directly to the top. The optimal supply location depends on the water content of the fresh alcohol used and the vapor flow S. OA It depends on the desired residual water content inside. The water content of the alcohol used is high, and the vapor flow S OA The higher the purity requirement, the more the rectification column RD A Injecting slightly below the top, by the number of theoretical plates, is advantageous. (Rectification column RD) A It is preferable that it be at least 20 theoretical stages below the top, and particularly preferable that it be at least 1 to 5 theoretical stages below.

[0237] Rectification tower RD A When fresh alcohol ROH is added, the rectification column RD A It is added at a temperature up to the boiling point at the top of the rectification column, preferably at room temperature. In this case, fresh alcohol may be planned to be added separately, but the rectification column RD A If some of the alcohol extracted at the top is returned after condensation, it is mixed with the rectification column RD A It is also possible to supply them together. In this case, the steam flow S OA It is particularly preferable to add fresh alcohol to the condensate container from which the condensed alcohol is collected.

[0238] As described above, in one advantageous configuration of the present invention, the rectification column RD A , Reactor RR A And if step (α2) is carried out, the reaction tower RR B At least two of the towers selected from are housed in the tower jacket, in which case each tower is separated from each other by a partition wall that extends at least partially to the base of the tower. Thus, in the preferred embodiment described above in which step (α2) is carried out, they are separated from each other by two partition walls that extend to the base of the tower.

[0239] In this preferred embodiment, in particular, the crude product RP produced by step (α1) A To, or crude RP by steps (α1) and (α2) A and RP B The reaction to the reaction takes place in part of the TRD, during which reaction logistics S AE2 and optionally reaction logistics S BE2 It is added below the upper end of the partition wall, but at almost the same level, and reaction logistics S AE1 and optionally reaction logistics S BE1 It is added in vapor form at the lower end. The alcohol / water mixture produced above the supply point of the reaction logistics is fed into the rectification column RD A It is distributed above the partition throughout the entire column region, which functions as the enrichment section. The second or third lower part of the column, separated by the partition, is the rectification column RD A This is the stripping section. The energy required for distillation is supplied through the evaporator at the lower end of the second section of the column, which is separated by a partition wall. In this case, the evaporator is heated as in the conventional way, or compressed vapor flow S OA2 It is also possible to heat a portion of it. If the evaporator is heated in the conventional way, the compressed vapor flow S OA11 An additional intermediate evaporator, which is heated in part, may be provided.

[0240] S OA Part of the reaction logistics S AE1 and / or reaction logistics S BE1 In embodiments used as, S OAIn particular, the first compressor VD AB2 It is compressed ("pre-compressed"), and this allows RD A Reaction tower RR against internal pressure A and RR B The difference in internal pressure can be taken into consideration.

[0241] Alternatively or additionally, in this preferred embodiment, the rectification column RD A It is connected downstream of S OA Compressor VD performs pre-compression. AB2 Instead, rectification column RD A Compressor VD connected upstream AB1 It is also possible to use this compressor VD, and the mixture G is used in this compressor VD AB1 After being sent to RD A It will be sent to [location].

[0242] at least one vapor flow S OA The remaining part, namely the reaction logistics S AE1 and / or reaction logistics S BE1 The portion not used is returned as RD A In this preferred embodiment, unless returned to S OA1 This is the result. According to the present invention, S OA S is first detected at the compression stage. OA1 And then, S OA1 is, S OA11 and S OA12 It is divided into and which are used in step (d) according to the present invention. OA to S OA1 This compression, which compresses to a certain degree, is shown in the drawings and embodiments as being performed by a compression device VD1 (in the drawings). <401> It will be carried out as indicated.

[0243] 4.2.3 Step (β) In step (β) of the method according to the present invention, the vapor flow S AB At least a portion of it, and if step (α2) is carried out, the steam flow S BB At least a portion of S AB In a mixed state with S ABSeparately, it is used as mixture G in step (a) of the method according to the present invention. When step (α2) is carried out, the vapor flow S AB At least a portion of and the steam flow S BB Preferably, at least a portion of the mixture is mixed with the mixture and then used as mixture G in step (a) of the method according to the present invention.

[0244] "Used as mixture G in step (a) of the method according to the present invention" means, in particular, two flows S AB and S BB However, preferably in a pre-mixed state in the rectification column RD A This means it will be sent to [a specific location].

[0245] However, these are also supplied at two different locations in the rectification column RD A It can also be sent to [another address].

[0246] 4.3 Preferred embodiment: Alcohol exchange method for alkali metal alkoxides In an advantageous embodiment of the present invention, flow S OA1 S OA 2, S OA11 S OA12 The energy contained in at least one of these is used to operate other industrial processes. This is particularly advantageous in integrated production sites (chemical parks, technology parks) where there is always a demand for heat for heating. This energy can be advantageously utilized in integrated production, particularly in the use of multiple alkali metal alkoxide production plants. Such integrated production typically includes alcohol exchange methods, such as those described in German Patent Application Publication No. 2726491. U.S. Patent No. 3,418,383 describes an alcohol exchange method from methoxide to propoxide.

[0247] In one preferred embodiment of the present invention, in the method according to the present invention, M c Reaction logistics S containing OR' and optionally R'OH CE1 The reaction rectification column RR C Then, reaction logistics S containing R''OH CE2 And it reacts with a countercurrent, M cCrude RP containing OR'' and R'OH C Generate, RR C At the bottom end, M c Bottom product flow S containing OR'' CP It was removed, RR C At the upper end, a vapor flow S containing R'OH CB It was taken out, R' and R'' are two different C1-C6 hydrocarbon groups, M C This is a metal selected from sodium and potassium, preferably sodium. Energy is S OA1 S OA2 Crude RP from at least a portion of the selected flow C It will be moved.

[0248] A preferred embodiment of the present invention is a method according to the present invention, such as that described in German Patent Application Publication No. 2726491, which involves a given alkali metal alkoxide M c OR' is another alkali metal alkoxide M c This is for alcohol exchange with OR''.

[0249] R' and R'' are two distinct C1-C6 hydrocarbon groups, preferably two distinct C1-C4 hydrocarbon groups. More preferably, R' is methyl and R'' is a C2-C4 hydrocarbon group, and even more preferably, R' = methyl and R'' = ethyl.

[0250] A preferred embodiment of the present invention (hereinafter also referred to as "alcohol exchange") is performed in a reaction rectification column RR C This will be carried out. As a reaction rectification column, in relation to step (α1) in Section 4.2.1, RR A A tower like the one described is suitable.

[0251] Reaction tower RR C It is operated with or without reflux, preferably with reflux. When reflux is set, in particular steam S CBThis is partially or completely cooler K RRC The condensed steam is then sent to the reactor tower RR. C It can also be supplied to reaction logistics S AE1 or S BE1 It can also be used as RD. A It can also be used as a fresh alcoholic drink.

[0252] During alcohol exchange, RR C At the bottom end, M c Bottom product flow S containing OR'' CP It is extracted. RR C At the upper end, a vapor flow S containing R'OH CB It is taken out.

[0253] M c Reaction logistics S containing OR' and optionally R'OH CE1 Preferably, in an embodiment of alcohol exchange in which the method for producing alkali metal alkoxides according to the present invention is also carried out, preferably S AP At least a portion of these is used, and in particular, since R = methyl, in that case R' is also methyl. In that case, R'' = ethyl is particularly preferred. Thus, alcohol exchange from alkali metal methoxide to the corresponding alkali metal ethoxide is performed.

[0254] M c Reaction logistics S containing OR' and optionally R'OH CE1 In a preferred alternative embodiment of the alcohol exchange, in which a method for producing alkali metal alkoxides including step (α2) according to the present invention is also carried out, preferably S BP At least a portion of these is used, and in particular, since R = methyl, in that case R' is also methyl. In that case, R'' = ethyl is particularly preferred. Thus, alcohol exchange from alkali metal methoxide to the corresponding alkali metal ethoxide is performed.

[0255] S BP and S APIf both streams contain the same alkali metal alkoxide and the same alcohol ROH, these two streams can be used separately or mixed in S CE1 It can be used as such, that is, especially after mixing first, one reaction logistics S CE1 Tower RR C It can also supply two reaction logistics S CE1 Tower RR C It can also be supplied to.

[0256] Reaction Logistics S CE2 It contains R''OH. In a preferred embodiment, S CE2 The weight fraction of R''OH in the mixture is ≥85% by weight, more preferably ≥90% by weight, in which case S CE2 In addition, especially M c Contains OR'' or another denaturing agent. Reaction logistics S CE2 The alcohol R''OH used may be a commercially available alcohol in which the weight fraction of alcohol is greater than 99.8% by weight and the weight fraction of water is up to 0.2% by weight.

[0257] "M c Reaction logistics S containing OR' and optionally R'OH CE1 And the reaction logistics S containing R''OH CE2 "Countercurrent reaction" refers, in particular, to the reaction tower RR according to the present invention. C M in c Reaction logistics S including OR' CE1 At least some of the supply points contain reaction logistics S containing R''OH. CE2 This is guaranteed by being located above the supply point.

[0258] Reaction tower RR C It is operated with or without recirculation, preferably with recirculation.

[0259] In one preferred embodiment, the reaction tower RR C In particular, intermediate evaporator V ZC and bottom evaporator V SC Includes at least one evaporator selected from the following. Reaction tower RR CParticularly preferably, at least one bottom evaporator V SC Includes.

[0260] Reaction tower RR C In this case, at least one side flow S occurs during intermediate evaporation. ZC RR C Removed from ("extracted") at least one intermediate evaporator V ZC It is supplied to.

[0261] Reaction tower RR C In this case, at least one flow occurs during bottom evaporation, for example, S CP RR C Extracted from ("extracted"), at least in part, S CP In this case, preferably a portion is at least one bottom evaporator V SC It is supplied to.

[0262] Suitable evaporators that can be used as intermediate evaporators and bottom evaporators are described in Section 4.2.1.

[0263] During alcohol exchange, S OA1 S OA2 Crude RP from at least a portion of the selected flow C Energy, preferably heat, is transferred to S. OA1 S OA2 From at least a portion of the flow selected from, S CE1 or S CE2 RR C Before being sent, S CE1 or S CE2 Energy is transferred to S CE1 or S CE2 Therefore, they get mixed together, RR C Crude products within RP C This is done by transferring energy to it.

[0264] Therefore, energy, preferably heat, is S OA1 S OA2 From at least a portion of the flow selected from, in particular S OA11S OA12 S OA2 From at least one flow selected from, preferably S OA11 S OA2 From at least one stream selected from a portion of the crude RP C It will be moved to [location].

[0265] "S OA1 Crude RP from at least a portion of C "Transfer of energy, preferably heat, to" includes S OA11 S OA12 S OA11 and S OA12 The flow S before it separates into two parts. OA1 Crude RP from at least one stream selected from C This also includes the transfer of energy, preferably heat, to [a certain point].

[0266] Furthermore, crude RP C Intermediate evaporator V ZC or bottom evaporator V SC Send to V ZC or V SC So, energy, preferably heat, S OA1 S OA2 Crude RP from at least a portion of the selected flow C It can also be moved to [location].

[0267] Furthermore, bottom product flow S CP Partially bottom evaporator V SC It is sent to, and then partially again to RR. C You can also return it to V SC So, energy, preferably heat, S OA1 S OA2 From at least a portion of the flow selected from S CP It is moved to the returned portion, then to Tower RR C So, S CP Crude items found inside the tower RP C It will be moved to [location].

[0268] Here, S OA1 S OA2The transfer of energy from at least a portion of the selected flow to the aforementioned flow occurs directly or indirectly, i.e., without or with the heat transfer medium W1, as described in Section 4.1.4.

[0269] According to a preferred embodiment of the method of the present invention, S OA1 S OA2 , especially S OA2 S OA11 S OA12 This allows for the efficient utilization of energy from other sources. As a result, the total energy required is reduced.

[0270] 5. Examples 5.1 Example 1 (not according to the present invention), corresponding to Figure 1: 100 kg / h flow of NaOH aqueous solution (50 wt%) S AE2 <102> , reaction tower RR A <100> A 30°C vaporized methanol flow S is supplied to the top at counterflow at a rate of 1034.9 kg / h. AE1 <103> Reaction tower RR A <100> It is supplied to the bottom of the reactor tower RR. A <100> It will be operated at a top pressure of 2.15 bar abs. Tower RR A <100> At the bottom, a nearly water-free production flow rate of 219.7 kg / h is observed. AP* <104> Remove (30% by weight sodium methoxide in methanol). Reaction column RR A <100> Evaporator V SA <105> Then, low-pressure steam is used to supply approximately 24 kW of heating power. (Vaporized methanol-water flow S) AB <107> Reaction tower RR A <100> It is extracted from the top, and 80 kg / h of it is cooled in cooler K RRA <108> It is condensed and refluxed into the reaction tower RR. A <100> The remaining 915.2 kg / h flow is returned to the rectification column RD. A <300> To supply. Rectification column RD A <300> The rectification column RD is operated at a top pressure of 2.0 bar abs. A<300> At the bottom, a liquid water flow S of 72.2 kg / h UA <304> Discharge (500 ppm by weight methanol). Distillation column RD A <300> At the top, a vaporized methanol flow of 1903.6 kg / h S OA <302> (Water at 2 bar, 83°C, and 200 ppm by weight) was taken out, and 63.9 kg / h of it was cooled in condenser K RD <407> It is condensed in the first compressor VD. AB2 <303> It is supplied to the reactor, where it is compressed to 2.6 bar abs. Then, this flow is split and a 1034.9 kg / h flow is sent to the reactor RR. A <100> It is returned to [location]. The remaining 804.8 kg / h is supplied to the multi-stage compressor equipped with an intermediate cooling section. Compressor VD1 <401> So, the flow is p OA1 = 4.8 bar abs. and T OA1 = Compressed to 156℃, flow <403> Obtain the subsequent intercooling device WT. X <402> During the intermediate cooling process, the flow is cooled to 145°C, and approximately 4.4 kW of heat is dissipated through the cooling water. Compressor VD x <405> Then, the flow was further compressed to 9.0 bar and 200°C, and the flow <404> Obtain the result. Rectification column RD A <300> Bottom evaporator V SRD <406> However, in the downstream condenser, the rectification column RD A <300> Approximately 238 kW of heating power is provided for this purpose. The methanol flow that condenses at this time <404> to 191.9 kg / h of fresh methanol (with 1000 ppm by weight of water) <408> And mixed with previously condensed steam at 63.9 kg / h, in the rectification column RD A <300> Return it to the top.

[0271] The total power consumption of the compressor is approximately 55 kW.

[0272] When combined with the 24kW required for heating steam, the total power required for the compressor and heating steam is approximately 79kW.

[0273] 5.2 Example 2 (not according to the present invention), corresponding to Figure 2: The configuration of Example 2, which does not conform to the present invention, is the same as the configuration of Example 1, except for the following differences: Rectification tower RD A <300> Intermediate evaporator V ZRD <409> It has a rectification column RD. A <300> So, liquid flow S ZA <305> Remove it at 94°C and then place it in an intermediate evaporator V ZRD <409> Approximately 230 kW of heat is transferred, and in the process, this flow is partially evaporated, and then returned to the rectification column RD. A <300> To supply. Rectification column RD A <300> At the top, a vaporized methanol flow of 1887.1 kg / h S OA <302> (Water at 200 ppm by weight) was taken out, and 89.4 kg / h of it was cooled in a cooler K RD <407> The remaining flow is condensed in the first compressor VD, as in Example 1. AB2 <303> It is then compressed to 2.6 bar abs. Next, a partial flow of 1034.9 kg / h is introduced into the RR reactor. A <100> It will be returned to [location]. The remaining 762.8 kg / h will be compressed to 5.6 bar abs. and 168°C, and the flow will be [unclear]. <403> Obtain the result. Rectification column RD A <300> Intermediate evaporator V ZRD <409> However, in the downstream condenser, the rectification column RD A <300> Approximately 230 kW of heating power is provided for this purpose. The methanol flow that condenses at this time <403> to 191.9 kg / h of fresh methanol <408> And mixed with previously condensed steam at 89.4 kg / h, in the rectification column RD A <300> Return to the top of the rectification column RD. A <300> Bottom evaporator V SRD <406> Then, low-pressure steam is used to supply approximately 20 kW of heating power. Unlike Example 1, the intermediate evaporator V ZRD <409> The boiling point is the bottom evaporator V SRD <406> Because it is lower than the boiling point, evaporator V ZRD<409> To enable heating, the steam flow does not need to be compressed to 9 bar abs., but only to 5.6 bar abs. Therefore, the power of the compressor in total is only about 38 kW (instead of 55 kW), but the bottom evaporator V SRD <406> Therefore, 20 kW of heating power is required, and since this is introduced using heat from low pressure, the amount of heating steam required increases to approximately 44 kW compared to Example 1. Consequently, the total power required for the compressor and heating steam is approximately 82 kW.

[0274] 5.3 Example 3 (according to the present invention), corresponding to Figure 3: The configuration of Example 3 according to the present invention is the same as that of Examples 1 and 2, except for the following differences: Rectification tower RD A <300> At the top, a vaporized methanol flow of 1898.9 kg / h S OA <302> (Water at 200 ppm by weight) was taken out, and 33.9 kg / h of it was cooled in a cooler K RD <407> The remaining flow is condensed in the first compressor VD, as in Example 2. AB2 <303> It is then compressed to 2.6 bar abs., and then a partial flow of 1034.9 kg / h is introduced into the reaction tower RR. A <100> It will be returned to [location]. The remaining 830.1 kg / h will first be compressed to 5.6 bar abs. and 169°C, thereby flowing S OA1 <403> Obtain a part of this process S OA11 <4031> (761.7 kg / h) rectification column RD A <300> Intermediate evaporator V ZRD <409> However, it is sent to a downstream condenser, and this condenser then processes the rectification column RD A <300> Approximately 230kW of heating power will be provided for the other portion S OA12 <4032> (68.4 kg / h), followed by the intermediate cooling unit WT X <402> During the intermediate cooling process, the temperature is reduced to approximately 154°C, at which point approximately 0.5 kW of heat is dissipated through the cooling water. Next, the flow S OA12 <4032> Further compression device VD x <405> Compressed with p OA2=9.0 bar, T OA2 = Flow S at 196℃ OA2 <404> This is obtained. (RD distillation column) A <300> Bottom evaporator V SRD <406> However, in the downstream condenser, the rectification column RD A <300> Approximately 20kW of heating power will be provided for the intermediate evaporator V. ZRD <409> and bottom evaporator V SRD <406> Condensed methanol flow S OA11 <4031> and S OA2 <404> to 191.9 kg / h of fresh methanol <408> And mixed with previously condensed steam at 33.9 kg / h, in the rectification column RD A <300> Return it to the top.

[0275] The total power consumption of the compressor is approximately 42 kW (compared to 55 kW in Example 1). Bottom evaporator V SRD <406> Since low-pressure steam is not required, only about 24 kW needs to be supplied by heating steam, similar to Example 1. Therefore, the total power required for the compressor and heating steam is reduced to about 66 kW.

[0276] In contrast to Example 1, the total power of the compressor is reduced because only a smaller amount of vapor flow needs to be compressed to 9 bar abs., and the majority of the vapor flow needs to be compressed to 5.6 bar abs. as in Example 2. However, in contrast to Example 2, in steady-state operation, the bottom evaporator V SRD <406> Since low-pressure steam is not required, the amount of heating steam needed is less than in Example 2.

[0277] The total energy required can be minimized by the method described in Example 3.

[0278] Figure 10 shows the proportion of heating power required for low-pressure steam and the power of the compressor, respectively.

[0279] resultThe method according to the present invention, which compresses the steam flow in stages and as a result operates the intermediate evaporator and bottom evaporator with different compressed steams, can save a remarkable amount of energy.

Claims

1. Formula M Ａ OR [wherein R is methyl, M Ａ In a method for producing at least one alkali metal alkoxide, [where is a metal selected from sodium and potassium], (α1) Reactive distillation column RR Ａ in which a reaction stream S containing ROH ＡＥ１ is reacted countercurrently with a reaction stream S Ａ containing MOH to produce a crude product RP ＡＥ２ containing MOR, water, ROH, and MOH Ａ Ａ Ａ Ａ Ａ ​ RR Ａ At the lower end, ROH and M Ａ Bottom product flow S including OR ＡＰ Take out RR Ａ At the upper end, a vapor flow S containing water and ROH ＡＢ Take it out, (α2) and optionally, simultaneously with step (α1) and spatially separated, the reaction rectification column RR Ｂ So, reaction logistics S including ROH ＢＥ１ M Ｂ Reaction logistics S containing OH ＢＥ２ And it reacts with a countercurrent, M Ｂ OR, water, ROH, and M Ｂ OH [wherein, M Ｂ Crude RP containing a metal selected from sodium and potassium. Ｂ Generate, RR Ｂ At the lower end, ROH and M Ｂ Bottom product flow S including OR ＢＰ Take out RR Ｂ At the upper end, a vapor flow S containing water and ROH ＢＢ Take it out, (β) Steam flow S ＡＢ At least a portion of it, and if step (α2) is performed, S ＢＢ At least a portion of S ＡＢ In a mixed state with S ＡＢ Separately, in step (a) of the post-treatment method for mixture G containing water and alcohol ROH, In the post-treatment method for the mixture G, (a) Mixture G to rectification column RD Ａ Send to RD Ａ In RD Ａ At least one vapor stream S containing ROH is taken out at the upper end. ＯＡ And, RD Ａ At least one flow S containing water is taken out at the lower end. ＵＡ It is separated into two parts. (b) at least one side flow S ＺＡ RD Ａ Take it out and put it back into RD Ａ Send it back to (c) S ＯＡ By compressing at least a portion of S, ＯＡ Compared to the compressed steam flow S ＯＡ１ Having obtained, (d) S ＺＡ RD Ａ Before returning it, compressed steam flow S ＯＡ１ The first part S ＯＡ１１ From S ＺＡ Transferring energy to, (e) S ＯＡ１１ A different compressed steam flow S ＯＡ１ Part S ＯＡ１２ By further compressing, S ＯＡ１１ Compared to the compressed steam flow S ＯＡ２ Having obtained, (f) Send at least a portion of SUA back to RD A as SUA1, ＵＡ１ RD Ａ Before returning it, S ＯＡ２ S from at least a portion of ＵＡ１ A method for transferring energy to [something].

2. In step (d), the intermediate evaporator V ＺＲＤ So, S ＯＡ１１ From S ＺＡ The method according to claim 1, which transfers energy to

3. In step (f), the bottom evaporator V ＳＲＤ So, S ＯＡ２ S from at least a portion of ＵＡ１ The method according to claim 1 or 2, which transfers energy to

4. Step (d) S ＯＡ１１ From S ＺＡ After transferring energy to S ＯＡ１１ From S ＯＡ Energy is transferred to and / or by step (f) S ＯＡ２ S from at least a portion of ＵＡ１ After transferring energy to S ＯＡ２ S from at least a portion of ＯＡ The method according to claim 1 or 2, which transfers energy to

5. Rectification tower RD Ａ , reaction tower RR Ａ And if step (α2) is carried out, the reaction tower RR Ｂ The method according to claim 1 or 2, wherein at least two of the towers selected from are housed in a tower jacket, and each tower is separated from one another by a partition wall that extends at least partially to the bottom of the tower.

6. S ＯＡ A portion of the reaction logistics S is carried out in step (α1). ＡＥ１ If used as such, and step (α2) is carried out, the reaction logistics S may be used alternatively or additionally in step (α2). ＢＥ１ The method according to claim 1 or 2, used as such.

7. S ＯＡ１ S ＯＡ２ Crude RP from at least a portion of the selected flow Ａ And if step (α2) is carried out, alternatively or additionally crude RP Ｂ The method according to claim 1 or 2, which transfers energy to

8. M ｃ Reaction logistics S including OR' ＣＥ１ Reaction rectification column RR Ｃ Then, reaction logistics S containing R''OH ＣＥ２ And it reacts with a countercurrent, M ｃ Crude product RP containing OR'' and R'OH Ｃ Generate, RR Ｃ At the lower end of, M ｃ Bottom product stream S containing MOR’’ ＣＰ is withdrawn, and at the upper end of RR Ｃ Vapor stream S containing R’OH ＣＢ is withdrawn. R' and R'' are two different C's. １ ~C ６ It is a hydrocarbon group, M Ｃ It is a metal selected from sodium and potassium. S ＯＡ１ 、 S ＯＡ２ transfer energy to the crude product RP Ｃ from at least a part of the stream selected from, according to the method of claim 1 or 2.

9. The method according to claim 8, wherein R' = methyl.

10. S ＡＰ We obtain, where R = methyl and S ＡＰ At least a portion of S ＣＥ１ The method according to claim 9, used as such.

11. The method according to claim 1 or 2, which carries out the above step (α2), ＢＰ We obtain, where R = methyl and S ＢＰ At least a portion of S ＣＥ１ The method according to claim 9, used as such.

12. The method according to claim 9, wherein R'' = ethyl.

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