Method for recovering butanol waste liquid

Abstract

The invention relates to a butanol waste liquid recovery method, which comprises: providing a waste liquid produced by using propylene, hydrogen and carbon monoxide as raw materials to prepare n-butanol through a carbonylation reaction, the waste liquid comprising butyraldehyde, butyric acid, n-butanol, C8 alcohol, butyl butyrate, C12 and a heavy component substance; the waste liquid is subjected to light component removal through a light component removal tower, butyraldehyde is collected at the tower top, and light component removal liquid is obtained at the tower kettle; the light component removal liquid is subjected to heavy component removal through a heavy component removal tower, heavy component removal liquid is obtained at the tower top, and C8 alcohol, C12 and heavy component substances are collected at the tower kettle; mixing the de-heavy liquid with alkali liquor for neutralization reaction, and washing the reaction liquid with water to obtain an organic phase; enabling the organic phase to pass through an n-butyl alcohol rectifying tower, collecting n-butyl alcohol at the tower top, and obtaining kettle liquid at the tower kettle; the kettle liquid passes through a butyl butyrate rectifying tower, and butyl butyrate is obtained at the tower top; carrying out hydrogenation reaction on butyl butyrate under the action of a hydrogenation catalyst, and collecting n-butyl alcohol. According to the recovery method, useful components in the waste liquid are effectively recovered.

Description

Technical Field

[0001] This application relates to the field of waste liquid recovery technology, and in particular to a method for recovering butanol waste liquid. Background Technology

[0002] Current industrial processes for producing n-butanol mainly include homogeneous hydroformylation and aqueous hydroformylation. Homogeneous hydroformylation is more widely used industrially. This process uses a rhodium metal complex as a catalyst to carbonylate carbon monoxide, hydrogen, and propylene to produce n-butyraldehyde, which is then further hydrogenated to produce n-butanol. This carbonylation reaction and the hydrogenation of n-butyraldehyde generate a mixed butanol waste liquid, which, by mass percentage, contains at least 8%–10% butyraldehyde, 2%–5% butyric acid, 8%–10% n-butanol, 1%–3% C8 alcohol, 20%–30% butyl butyrate, 40%–50% C12 and other heavy components, and 0.8%–1% water. Due to its complex composition, direct distillation separation and recovery of this mixed butanol waste liquid is difficult, the process is lengthy, the quality of the recovered product is poor, and the return on investment is relatively low. Currently, most companies treat it primarily by burning fuel oil, which is extremely wasteful of energy and does not conform to the concept of green environmental protection.

[0003] Therefore, it is necessary to improve traditional technologies. Summary of the Invention

[0004] Based on this, this application provides a method for recovering butanol waste liquid that can shorten the process flow and effectively recover useful components.

[0005] The technical solution to the above-mentioned technical problems in this application is as follows.

[0006] The first aspect of this application provides a method for recovering butanol waste liquid, comprising the following steps:

[0007] The waste liquid produced from the carbonylation reaction of propylene, hydrogen and carbon monoxide to prepare n-butanol is provided. The waste liquid includes butyraldehyde, butyric acid, n-butanol, C8 alcohol, butyl butyrate, C12 and heavy components.

[0008] The waste liquid is passed through a light-light removal tower to remove light-light substances. Butyraldehyde is collected at the top of the tower, and the light-light removed liquid is obtained at the bottom of the tower.

[0009] The light liquid is passed through a heavy liquid removal tower for heavy liquid removal. The heavy liquid is obtained at the top of the tower, and C8 alcohol, C12 alcohol and heavy components are collected at the bottom of the tower.

[0010] The de-heavy liquid and the alkaline solution are mixed for a neutralization reaction, and the reaction solution is washed with water to obtain an organic phase;

[0011] The organic phase is passed through a n-butanol distillation column, where n-butanol is collected at the top of the column and bottom liquid is obtained from the bottom of the column.

[0012] The liquid in the reactor was passed through a butyl butyrate distillation column, and butyl butyrate was obtained at the top of the column.

[0013] The butyl butyrate was subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst, and n-butanol was collected.

[0014] In some embodiments, a method for recovering butanol waste liquid is provided, wherein the recovery method satisfies at least one of the following characteristics:

[0015] (1) The alkaline solution includes sodium hydroxide solution;

[0016] (2) The temperature of the neutralization reaction is 20℃~40℃.

[0017] In some embodiments, a method for recovering butanol waste liquid is provided, wherein the recovery method satisfies at least one of the following characteristics:

[0018] (1) The mass concentration of the sodium hydroxide solution is 10%~50%;

[0019] (2) The temperature of the neutralization reaction is 20℃~30℃;

[0020] (3) The mixing of the deweighting liquid and the alkali solution includes: adding the alkali solution dropwise to the deweighting liquid.

[0021] In some embodiments, the method for recovering butanol waste liquid includes a hydrogenation catalyst comprising at least one of a copper-zinc-aluminum catalyst and a copper-manganese-aluminum catalyst.

[0022] In some embodiments, the method for recovering butanol waste liquid involves carrying out the hydrogenation reaction in a fixed-bed reactor at a temperature of 170°C to 230°C, a pressure of 0.6 MPa to 2.0 MPa, and a feed space velocity of 0.10 h⁻¹. -1 ~0.25h -1 The hydrogen-to-ester ratio is 60-100:1.

[0023] In some embodiments, the method for recovering butanol waste liquid involves atmospheric distillation for removing light components, with the top temperature of the light component removal column being 40°C to 75°C, the bottom temperature being 126°C to 165°C, and the reflux ratio being 3 to 4:1.

[0024] In some embodiments, the method for recovering butanol waste liquid includes a deweighting tower with a pressure of -0.098 MPa to -0.095 MPa, a top temperature of 55°C to 91°C, a bottom temperature of 84°C to 145°C, and a reflux ratio of 4 to 5:1.

[0025] In some embodiments, the method for recovering butanol waste liquid includes a butanol distillation column with a pressure of -0.095 MPa to -0.090 MPa, a top temperature of 55°C to 62°C, a bottom temperature of 65°C to 90°C, and a reflux ratio of 3 to 4:1.

[0026] In some embodiments, the method for recovering butanol waste liquid includes a butyrate distillation column with a pressure of -0.098 MPa to -0.095 MPa, a top temperature of 86°C to 90°C, a bottom temperature of 95°C to 120°C, and a reflux ratio of 3 to 4:1.

[0027] In some embodiments, the method for recovering butanol waste liquid includes, by mass percentage: 8%~10% butyraldehyde, 2%~5% butyric acid, 8%~10% n-butanol, 1%~3% C8 alcohol, 20%~30% butyl butyrate, 40%~50% C12 and heavy components, and 0.8%~1% water.

[0028] The method for recovering butanol waste liquid disclosed in this application involves sequentially removing light and heavy components from the waste liquid generated from the carbonylation reaction of propylene, hydrogen, and carbon monoxide to prepare n-butanol. This separates n-butanol, butyric acid, and butyl butyrate from butyraldehyde, C8 alcohol, C12 alcohol, and heavy components in the resulting de-heavy liquid, effectively avoiding the influence of unknown heavy components on the subsequent distillation process of n-butanol and butyl butyrate. An alkaline solution is used to neutralize the de-heavy liquid, causing butyric acid to form a salt and reducing its acid value, effectively preventing butyric acid from affecting the activity of the hydrogenation catalyst and achieving butyric acid separation. The organic phase obtained by washing the neutralization reaction solution with water is then sequentially passed through a n-butanol distillation column and a butyl butyrate distillation column to collect n-butanol and improve the purity of butyl butyrate. The higher-purity butyl butyrate is then subjected to a hydrogenation reaction. The interaction between these steps effectively improves the conversion rate of butyl butyrate and the selectivity of n-butanol. Meanwhile, butyraldehyde can be collected at the top of the light component removal tower, and the bottom liquid of the heavy component removal tower can be sold directly as fusel oil, effectively recovering the useful components in the waste liquid. Moreover, the recovery process is simple and the process is relatively short. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive.

[0030] It should also be understood that this application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various alterations or modifications without departing from the spirit of this application, and the resulting equivalent forms also fall within the protection scope of this application. For example, features described or illustrated as part of one embodiment can be combined in a suitable manner in another embodiment to produce new embodiments. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of this application; it should be understood that this application can be implemented without one or more of these details.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for descriptive purposes only and is not intended to be limiting of the application.

[0032] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0033] In this application, the terms "multiple", "various", "multiple times", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0034] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0035] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0036] In this document, terms such as "preferred," "better," "more suitable," and "ideal" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0037] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0038] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0039] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0040] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0041] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0042] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0043] In this application, the terms "room temperature" or "normal temperature" generally refer to 4℃~35℃, for example, 20℃±5℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10℃~30℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20℃~30℃.

[0044] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0045] All references to documents mentioned in this application are incorporated herein by reference as if each document were individually incorporated by reference. Unless they conflict with the inventive purpose and / or technical solution of this application, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. When citing documents in this application, examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0046] The mass or weight of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship of mass or weight between the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass or weight mentioned in the embodiments of this application can be units known in the chemical industry, such as μg, mg, g, and kg.

[0047] Studies have found that butyric acid is present in butanol waste liquid, which can poison the hydrogenation catalyst. At the same time, the composition of butanol waste liquid is complex, and direct hydrogenation will affect the conversion rate of component hydrogenation and the selectivity of products. Furthermore, it is difficult to separate high-content n-butanol in the later stage.

[0048] One embodiment of this application provides a method for recovering butanol waste liquid, comprising the following steps:

[0049] Step S100: Provide waste liquid generated from the carbonylation reaction of propylene, hydrogen and carbon monoxide to prepare n-butanol. The waste liquid includes butyraldehyde, butyric acid, n-butanol, C8 alcohol, butyl butyrate, C12 and heavy components.

[0050] Step S200: The waste liquid is passed through a light-light removal tower to remove light-light substances. Butyraldehyde is collected at the top of the tower, and the light-light removal liquid is obtained at the bottom of the tower.

[0051] Step S300: The light liquid is passed through a heavy liquid removal tower for heavy liquid removal. The heavy liquid is obtained at the top of the tower, and the C8 alcohol, C12 alcohol and heavy components are collected at the bottom of the tower.

[0052] Step S400: Mix the de-heavy liquid and the alkaline solution for neutralization reaction, and wash the reaction solution with water to obtain the organic phase;

[0053] Step S500: The organic phase is passed through a n-butanol distillation column, n-butanol is collected at the top of the column, and bottom liquid is obtained from the bottom of the column;

[0054] Step S600: Pass the bottom liquid through a butyl butyrate distillation column to obtain butyl butyrate at the top of the column;

[0055] Step S700: Butyl butyrate is hydrogenated in the presence of a hydrogenation catalyst, and n-butanol is collected.

[0056] It is understandable that in step S200, the waste liquid is passed through a light-light component removal tower for light component removal. The top of the tower collects light components including butyraldehyde and those with boiling points lower than butyraldehyde, while other components remain in the bottom of the tower, resulting in a light-light component removal liquid, including n-butanol, butyric acid, butyl butyrate, and other unknown heavy components. In step S300, the light-light component removal liquid is passed through a heavy component removal tower for heavy component removal. The top of the tower yields a heavy component removal liquid containing n-butanol, butyric acid, and butyl butyrate. C8 alcohol, C12 alcohol, and heavy components remain in the bottom of the tower. This bottom liquid can be sold directly as fusel oil. In step S400, the heavy component removal liquid and alkali solution are mixed for neutralization. In step S500, butyric acid reacts to form a salt, which is then washed with water and exists in the aqueous phase. At this point, the organic phase includes n-butanol and butyl butyrate. In step S600, the organic phase is passed through a n-butanol distillation column, where n-butanol is collected at the top of the column, and a bottom liquid containing butyl butyrate is obtained at the bottom. In step S700, the bottom liquid is passed through a butyl butyrate distillation column to obtain butyl butyrate with higher purity. In step S700, the butyl butyrate with higher purity is hydrogenated under the action of a hydrogenation catalyst. By combining the interactions between the above steps, the conversion rate of butyl butyrate and the selectivity of the product n-butanol can be effectively improved.

[0057] In some examples, in step S100, the butanol waste liquid comprises, by mass percentage: 8%~10% butyraldehyde, 2%~5% butyric acid, 8%~10% n-butanol, 1%~3% C8 alcohol, 20%~30% butyl butyrate, 40%~50% C12 and heavy components, and 0.8%~1% water.

[0058] In some of these examples, in step S200, the removal of light components is carried out by atmospheric distillation.

[0059] In some examples, in step S200, the top temperature of the light-weight removal column is 40°C to 75°C. Optionally, the bottom temperature is 126°C to 165°C. Optionally, the reflux ratio is 3 to 4:1.

[0060] It is understood that in step S200, the top temperature of the light-weight product removal column includes, but is not limited to, 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 73℃, 74℃, and 75℃; the bottom temperature includes, but is not limited to, 126℃, 128℃, 130℃, 132℃, 135℃, 138℃, 140℃, 142℃, 145℃, 148℃, 150℃, 152℃, 155℃, 158℃, 160℃, 162℃, and 165℃; and the reflux ratio includes, but is not limited to, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, and 4:1. In some examples, the range can be defined by any two of these point values ​​as endpoints, and the same applies below.

[0061] In some of these examples, in step S300, deweighting is performed using negative pressure distillation.

[0062] In some examples, in step S300, the pressure of the deweighting column is -0.098 MPa to -0.095 MPa. Optionally, the column top temperature is 55℃ to 91℃. Optionally, the column bottom temperature is 84℃ to 145℃. Optionally, the reflux ratio is 4 to 5:1.

[0063] It is understood that in step S300, the pressure of the deweighting tower includes, but is not limited to, -0.098 MPa, -0.097 MPa, -0.098 MPa, and -0.095 MPa; the tower top temperature includes, but is not limited to, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, and 91℃; the tower bottom temperature includes, but is not limited to, 84℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, and 145℃; and the reflux ratio includes, but is not limited to, 4:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1, 4.5:1, 4.6:1, 4.7:1, 4.8:1, 4.9:1, and 5:1.

[0064] In some examples, in step S400, the alkaline solution comprises a sodium hydroxide solution. Optionally, the mass concentration of the sodium hydroxide solution is 10% to 50%. It is understood that the mass concentration of the sodium hydroxide solution includes, but is not limited to, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, and 50%. Optionally, the mass concentration of the sodium hydroxide solution is 20% to 50%.

[0065] In some examples, the neutralization reaction temperature in step S400 is 20°C to 40°C. Alternatively, the neutralization reaction temperature is 20°C to 30°C.

[0066] In some examples, step S400, mixing the de-heavy liquid and the alkali solution, includes adding the alkali solution dropwise to the de-heavy liquid. Optionally, the alkali solution is added dropwise while the de-heavy liquid is being stirred.

[0067] By controlling the concentration of the alkali solution and using a dropwise addition method to carry out the neutralization reaction at room temperature, the risk of saponification reaction during the hydrolysis of butyl butyrate can be effectively reduced, ensuring that butyl butyrate does not decompose excessively, thereby effectively improving the conversion rate of butyl butyrate.

[0068] In some of these examples, in step S400, a neutralization reaction is carried out in a batch reactor.

[0069] In some examples, in step S400, after the acid value of the upper oil phase of the neutralization reaction solution is ≤1 mgKOH / g, water is added for washing, and the phase is allowed to stand and separate. After the pH value of the aqueous phase is 7~8, the aqueous phase is removed to obtain the organic phase.

[0070] In some examples, in step S500, the pressure of the n-butanol distillation column is -0.095 MPa to -0.090 MPa. Optionally, the top temperature is 55°C to 62°C. Optionally, the bottom temperature is 65°C to 90°C. Optionally, the reflux ratio is 3 to 4:1.

[0071] It is understood that in step S500, the pressure of the n-butanol distillation column includes, but is not limited to, -0.095 MPa, -0.094 MPa, -0.093 MPa, -0.092 MPa, -0.091 MPa, and -0.090 MPa; the column top temperature includes, but is not limited to, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, and 62℃; the column bottom temperature includes, but is not limited to, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃, and 90℃; and the reflux ratio includes, but is not limited to, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, and 4:1.

[0072] In some examples, in step S600, the pressure of the butyl butyrate distillation column is -0.098 MPa to -0.095 MPa. Optionally, the top temperature is 86°C to 90°C. Optionally, the bottom temperature is 95°C to 120°C. Optionally, the reflux ratio is 3 to 4:1.

[0073] It is understood that in step S600, the pressure of the butyl butyrate distillation column includes, but is not limited to, -0.098 MPa, -0.097 MPa, -0.098 MPa, and -0.095 MPa; the top temperature includes, but is not limited to, 86℃, 87℃, 88℃, 89℃, and 90℃; the bottom temperature includes, but is not limited to, 95℃, 98℃, 100℃, 102℃, 105℃, 108℃, 110℃, 112℃, 115℃, 118℃, and 120℃; and the reflux ratio includes, but is not limited to, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, and 4:1.

[0074] In some examples, in step S700, the hydrogenation catalyst includes at least one of a copper-zinc-aluminum catalyst and a copper-manganese-aluminum catalyst. Optionally, the hydrogenation catalyst includes a copper-manganese-aluminum columnar solid catalyst.

[0075] In some examples, in step S700, the hydrogenation reaction is carried out in a fixed-bed reactor. Optionally, the temperature of the hydrogenation reaction is 170°C to 230°C. Optionally, the pressure is 0.6 MPa to 2.0 MPa. Optionally, the feed space velocity is 0.10 h⁻¹. -1 ~0.25 h -1 Optionally, the hydrogen-to-ester ratio is 60 to 100:1.

[0076] It is understood that in step S700, the temperature of the hydrogenation reaction includes, but is not limited to, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃, and 230℃; the pressure includes, but is not limited to, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 1.1 MPa, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, and 2 MPa; and the feed space velocity includes, but is not limited to, 0.10 h⁻¹. -1 0.12 h -1 0.15 h -1 0.18 h -1 0.2 h -1 0.22 h -1 0.25 h -1 The hydrogen-to-ester ratio includes, but is not limited to, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, and 100:1.

[0077] In some examples, step S700, before the hydrogenation reaction, further includes: preheating and vaporizing butyl butyrate; optionally, the preheating and vaporization temperature is 170°C to 180°C.

[0078] The above-mentioned method for recovering butanol waste liquid can effectively recover the useful components in the waste liquid, and the recovery process is simple and the process is short.

[0079] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0080] The mixed butanol waste liquid used in the following examples and comparative examples is derived from the waste liquid produced by the carbonylation reaction process of propylene, hydrogen, and carbon monoxide to produce n-butanol. By mass percentage, the butanol waste liquid includes: butyraldehyde 8%~10%, butyric acid 2%~5%, n-butanol 8%~10%, C8 alcohol 1%~3%, butyl butyrate 20%~30%, C12 and heavy components 40%~50%, and water 0.8%~1%.

[0081] "Normal temperature" refers to 20℃~30℃.

[0082] Example 1

[0083] Step 1: The mixed butanol waste liquid first passes through a light component removal distillation column. Atmospheric pressure distillation is used, with the column top temperature controlled at 75℃, the column bottom temperature at 165℃, and the reflux ratio at 3:1. The n-butyraldehyde and other light components are separated from the column top and collected. The column bottom yields a light component removal liquid containing n-butanol, a small amount of butyric acid, butyl butyrate, and other unknown heavy components.

[0084] Step 2: Pump the above-mentioned light liquid into the heavy liquid removal column and use negative pressure distillation, controlling the negative pressure to -0.095 MPa, the column top temperature to 91℃, the column bottom temperature to 145℃, and the reflux ratio to 5:1; the heavy liquid containing n-butanol, butyric acid, and butyl butyrate and other components is separated from the column top; the column bottom liquid can be sold directly as fusel oil.

[0085] Step 3: Pump the above-mentioned de-heavy liquid into a batch reactor, start stirring and gradually add a 10% sodium hydroxide solution. Carry out the acid-base neutralization reaction at room temperature. When the acid value of the upper oil phase is ≤1mgKOH / g, add 30% of its mass of process water and wash twice. Let it stand for 3 hours to separate into layers. When the pH value of the lower aqueous phase is 7~8, drain the lower aqueous phase. The upper layer is an organic phase containing butanol and butyl butyrate.

[0086] Step 4: Pump the above organic phase into the n-butanol distillation column, control the negative pressure to -0.090 MPa, the top temperature to 62℃, the bottom temperature to 90℃, and the reflux ratio to 3:1; n-butanol with a purity of 99% is separated from the top of the column, with a yield of 90%; the bottom liquid of the n-butanol column is obtained.

[0087] Step 5: Pump the bottom liquid of the above n-butanol column into the butyl butyrate distillation column, control the negative pressure to -0.095 MPa, the top temperature of the column to 90℃, the bottom temperature of the column to 120℃, and the reflux ratio to 3:1; butyl butyrate with a purity of 99% is separated from the top of the column, with a yield of 90%.

[0088] Step Six: The fixed-bed reactor has a bed height-to-diameter ratio of 45:1. The amount of copper-manganese-aluminum columnar solid catalyst added is 15% of the bed volume. The butyl butyrate is first vaporized in a preheater at a controlled temperature of 170°C. Butyrate and hydrogen are then piped to the fixed-bed reactor, maintaining the reaction temperature at 170°C, the system reaction pressure at 0.6 MPa, and the butyl butyrate feed space velocity at 0.25 h⁻¹. -1 The hydrogen-to-ester ratio was 90:1. Under continuous operation under these conditions, the conversion rate of butyl butyrate was 85.5%, and the selectivity for n-butanol was 91.3%.

[0089] Example 2

[0090] Step 1: The mixed butanol waste liquid first passes through a light component removal distillation column. Atmospheric pressure distillation is used, with the column top temperature controlled at 75℃, the column bottom temperature at 165℃, and the reflux ratio at 4:1. The n-butyraldehyde and other light components are separated at the top of the column and collected. The column bottom yields a light component removal liquid containing n-butanol, a small amount of butyric acid, butyl butyrate, and other unknown heavy components.

[0091] Step 2: Pump the above-mentioned light liquid into the heavy liquid removal column and use negative pressure distillation, controlling the negative pressure to -0.095 MPa, the column top temperature to 91℃, the column bottom temperature to 145℃, and the reflux ratio to 4:1; the heavy liquid containing n-butanol, butyric acid, and butyl butyrate and other components is separated from the column top; the column bottom liquid can be sold directly as fusel oil.

[0092] Step 3: Pump the above-mentioned de-heavy liquid into a batch reactor, start stirring and gradually add a 20% sodium hydroxide solution. Carry out an acid-base neutralization reaction at room temperature. When the acid value of the upper oil phase is ≤1mgKOH / g, add 30% of its mass of process water and wash twice. Let it stand for 3 hours to separate into layers. When the pH value of the lower aqueous phase is 7~8, drain the lower aqueous phase. The upper layer is an organic phase containing butanol and butyl butyrate.

[0093] Step 4: Pump the above organic phase into the n-butanol distillation column, control the negative pressure to -0.090 MPa, the top temperature to 62℃, the bottom temperature to 90℃, and the reflux ratio to 4:1; n-butanol with a purity of 99% is separated from the top of the column, with a yield of 95%; the bottom liquid of the n-butanol column is obtained.

[0094] Step 5: Pump the bottom liquid of the above n-butanol column into the butyl butyrate distillation column, control the negative pressure to -0.095 MPa, the top temperature of the column to 90℃, the bottom temperature of the column to 120℃, and the reflux ratio to 4:1. butyl butyrate with a purity of 99% is separated from the top of the column, with a yield of 90%.

[0095] Step Six: The fixed-bed reactor has a bed height-to-diameter ratio of 45:1. The amount of copper-manganese-aluminum columnar solid catalyst added is 15% of the bed volume. The butyl butyrate is first vaporized in a preheater at a controlled temperature of 170°C. The butyl butyrate and hydrogen are then piped to the fixed-bed reactor, with the reaction temperature controlled at 180°C. The system reaction pressure is 1 MPa, and the butyl butyrate feed space velocity is 0.2 h⁻¹. -1 The hydrogen-to-ester ratio was 80:1. Under continuous operation under these conditions, the conversion rate of butyl butyrate was 89.5%, and the selectivity for n-butanol was 93.4%.

[0096] Example 3

[0097] The difference from Example 2 is as follows:

[0098] In step three, the mass concentration of the sodium hydroxide solution is 30%.

[0099] In step six, the preheater temperature is controlled at 180℃, and butyl butyrate and hydrogen are transported to the fixed-bed reactor through pipelines. The reaction temperature is controlled at 200℃, the system reaction pressure is 1 MPa, and the butyl butyrate feed space velocity is 0.1 h⁻¹. -1 The hydrogen-to-ester ratio is 60:1.

[0100] Example 4

[0101] The difference from Example 3 is that in step three, the mass concentration of the sodium hydroxide solution is 50%.

[0102] Example 5

[0103] The difference from Example 4 is that in step six, the system reaction pressure is 2 MPa.

[0104] Example 6

[0105] The difference from Example 4 is that in step six, the hydrogenation catalyst is a copper-zinc-aluminum columnar solid catalyst.

[0106] Example 7

[0107] The difference from Example 3 is that in step three, a sodium hydroxide solution of equal mass concentration is directly pumped into a batch reactor and an acid-base neutralization reaction is carried out at 40°C.

[0108] Comparative Example 1

[0109] The difference from Example 4 is that step three is omitted, and step four involves pumping the de-heavy liquid into the n-butanol distillation column.

[0110] Comparative Example 2

[0111] The difference from Example 4 is that steps one through five are omitted; the mixed butanol waste liquid is directly vaporized in a preheater, with the preheater temperature controlled at 180°C; butyl butyrate and hydrogen are transported to a fixed-bed reactor via pipeline, with the reaction temperature controlled at 200°C; the system reaction pressure is 1 MPa; and the butyl butyrate feed space velocity is 0.1 h⁻¹. -1 The hydrogen-to-ester ratio is 60:1.

[0112] The yield and purity of n-butanol separated in step four, the yield and purity of butyl butyrate separated in step five, the conversion rate of butyl butyrate in step six, and the purity of n-butanol obtained in each embodiment and comparative example are shown in Table 1, with all units being "%".

[0113] Table 1

[0114]

[0115] In Table 1, the yield and purity in the "Step 4" column refer to the yield and purity of the n-butanol separated in Step 4, the yield and purity in the "Step 5" column refer to the yield and purity of the butyl butyrate separated in Step 5, and the conversion and selectivity in the "Step 6" column refer to the conversion of the butyl butyrate in Step 6 and the purity of the obtained n-butanol.

[0116] A comparison of Comparative Example 1 and Example 4 shows that the addition of the neutralization and washing step can significantly improve the conversion rate of butyl butyrate and the selectivity of n-butanol in the subsequent hydrogenation reaction.

[0117] Comparing Comparative Example 2 with Example 4, it can be seen that when the mixed butanol waste liquid is directly fed into the hydrogenation reaction without distillation, the conversion rate of butyl butyrate and the selectivity of n-butanol are significantly reduced.

[0118] A comparison of Example 7 and Example 3 shows that the stepwise addition of alkali solution in step 3 is superior to direct mixing, and the reduction of the neutralization temperature effectively reduces the hydrolysis and saponification reaction of butyl butyrate.

[0119] A comparison of Example 6 and Example 4 shows that the catalytic effect of the copper-manganese-aluminum hydrogenation catalyst is better than that of the copper-zinc-aluminum hydrogenation catalyst.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A method for recovering butanol waste liquid, characterized in that, Includes the following steps: The waste liquid produced from the carbonylation reaction of propylene, hydrogen and carbon monoxide to prepare n-butanol is provided. The waste liquid includes butyraldehyde, butyric acid, n-butanol, C8 alcohol, butyl butyrate, C12 and heavy components. The waste liquid is passed through a light-light removal tower to remove light-light substances. Butyraldehyde is collected at the top of the tower, and the light-light removed liquid is obtained at the bottom of the tower. The light liquid is passed through a heavy liquid removal tower for heavy liquid removal. The heavy liquid is obtained at the top of the tower, and C8 alcohol, C12 alcohol and heavy components are collected at the bottom of the tower. The de-heavy liquid and the alkaline solution are mixed for a neutralization reaction, and the reaction solution is washed with water to obtain an organic phase; The organic phase is passed through a n-butanol distillation column, where n-butanol is collected at the top of the column and bottom liquid is obtained from the bottom of the column. The liquid in the reactor was passed through a butyl butyrate distillation column, and butyl butyrate was obtained at the top of the column. The butyl butyrate was subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst, and n-butanol was collected.

2. The method for recovering butanol waste liquid as described in claim 1, characterized in that, The recycling method satisfies at least one of the following characteristics: (1) The alkaline solution includes sodium hydroxide solution; (2) The temperature of the neutralization reaction is 20℃~40℃.

3. The method for recovering butanol waste liquid as described in claim 2, characterized in that, The recycling method satisfies at least one of the following characteristics: (1) The mass concentration of the sodium hydroxide solution is 10%~50%; (2) The temperature of the neutralization reaction is 20℃~30℃; (3) The mixing of the deweighting liquid and the alkali solution includes: adding the alkali solution dropwise to the deweighting liquid.

4. The method for recovering butanol waste liquid as described in claim 1, characterized in that, The hydrogenation catalyst includes at least one of copper-zinc-aluminum catalyst and copper-manganese-aluminum catalyst.

5. The method for recovering butanol waste liquid as described in claim 1, characterized in that, The hydrogenation reaction is carried out in a fixed-bed reactor at a temperature of 170°C to 230°C, a pressure of 0.6 MPa to 2.0 MPa, and a feed space velocity of 0.10 h⁻¹. -1 ~0.25 h -1 The hydrogen-to-ester ratio is 60-100:

1.

6. The method for recovering butanol waste liquid according to any one of claims 1 to 5, characterized in that, The removal of light components is carried out by atmospheric distillation. The top temperature of the light component removal column is 40℃~75℃, the bottom temperature is 126℃~165℃, and the reflux ratio is 3~4:

1.

7. The method for recovering butanol waste liquid according to any one of claims 1 to 5, characterized in that, The pressure of the deweight removal tower is -0.098 MPa to -0.095 MPa, the top temperature is 55℃ to 91℃, the bottom temperature is 84℃ to 145℃, and the reflux ratio is 4 to 5:

1.

8. The method for recovering butanol waste liquid according to any one of claims 1 to 5, characterized in that, The pressure of the n-butanol distillation column is -0.095 MPa to -0.090 MPa, the top temperature is 55℃ to 62℃, the bottom temperature is 65℃ to 90℃, and the reflux ratio is 3 to 4:

1.

9. The method for recovering butanol waste liquid according to any one of claims 1 to 5, characterized in that, The pressure of the butyl butyrate distillation column is -0.098 MPa to -0.095 MPa, the top temperature is 86℃ to 90℃, the bottom temperature is 95℃ to 120℃, and the reflux ratio is 3 to 4:

1.

10. The method for recovering butanol waste liquid according to any one of claims 1 to 5, characterized in that, The butanol waste liquid comprises, by mass percentage: 8%~10% butyraldehyde, 2%~5% butyric acid, 8%~10% n-butanol, 1%~3% C8 alcohol, 20%~30% butyl butyrate, 40%~50% C12 and other heavy components, and 0.8%~1% water.

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