Method for treating waste liquid in production of 3-methyl-3-butene-1-ol

Abstract

The invention provides a method for producing waste liquid in production of 3-methyl-3-butene-1-alcohol, which comprises the following steps: (1) enriching 3-methyl-2-ene-1, 5-pentanediol and an isomer DIOL of 3-methyl-2-ene-1, 5-pentanediol through a separation process of the waste liquid to obtain a light component material; (2) carrying out hydrotreating on the light component material obtained in the step (1), and carrying out DIOL hydrogenation to obtain a crude product of a target product 3-methyl-1, 5-pentanediol MPD; and (3) refining the hydrogenated crude product to obtain MPD. According to the present invention, the 3-methylene-1, 5-pentanediol and the isomer thereof in the 3-methyl-3-butene-1-alcohol process waste liquid can be recovered, and the treated wastewater can be subjected to low-cost treatment by using the existing wastewater treatment facility in the park.

Description

Technical Field

[0001] The invention relates to the technical field of three wastes treatment, and in particular to a method for treating waste liquid in the production of 3-methyl-3-butene-1-ol, and also comprises a method for treating waste water. Background Art

[0002] 3-Methyl-3-butene-1-ol is the initiator of synthesizing the side chain of the third generation of polycarboxylate superplasticizer for concrete - TPEG polyether. The TPEG polyether synthesized from this raw material plays a decisive role in the quality and performance of polycarboxylate superplasticizer products, making it have the advantages of strong cement particle dispersion retention ability, low dosage, high water reduction rate, good reinforcement effect, durability, no corrosion of steel bars and environmental friendliness. In addition, 3-methyl-3-butene-1-ol can be isomerized into isopentenol, which is used as the main raw material for synthesizing the precursor of biomimetic pesticide "pyrethroid" - methyl (ethyl) benzyl benzoate, and is also the main raw material for artificial synthesis of citral, and can be further synthesized from it L-menthol and its derivatives, ionone flavors, carotenoids and vitamin A flavors, nutrients, etc.

[0003] There are many process schemes for synthesizing 3-methyl-3-butene-1-ol reported at home and abroad. The U.S. patent US2335027A first disclosed a method for synthesizing 3-methyl-3-butene-1-ol by thermal addition of formaldehyde and isobutylene.

[0004] British patent GB1205397 reported the preparation of 3-methyl-3-butene-1-ol from isobutylene and gaseous polyformaldehyde at low temperature of 20 to 80°C and catalyzed by tin tetrachloride, but there were problems with low reaction conversion rate, selectivity and product yield.

[0005] US patent US4028424 and other publications report that the target product is prepared from isobutylene and polyformaldehyde at 250°C and 240 atmospheres using sodium monohydrogen phosphate and sodium dihydrogen phosphate as catalysts in tert-butyl alcohol or methanol solvent. The high temperature and high pressure reaction requires large equipment investment and complex process operation.

[0006] In summary, the current implementation plan for 3-methyl-3-butene-1-ol is mainly to prepare it by Prins reaction of isobutylene and formaldehyde in the presence of a catalyst. The process of this reaction requires harsh conditions such as high temperature of 200-250°C and high pressure of more than 20MPa. The overall reaction yield is low, and a large amount of organic waste liquid and high-salt wastewater are generated in the semi-life, and the treatment cost is high, which greatly increases the cost of the equipment and the environmental protection pressure of the enterprise.

[0007] Although there are few public reports that mention treatment plans for the organic waste liquid and high-salt wastewater associated with this process, the chemical industry has mature treatment methods for the above three wastes, namely, organic waste liquid is generally treated by direct incineration, while high-salt wastewater is generally treated by concentration and crystallization.

[0008] However, we should note that the organic wastewater of this process contains a considerable amount of unsaturated diols, namely 3-methyl-2-ene-1,5-pentanediol and its isomers (hereinafter referred to as DIOL), with the following structural formula:

[0009] US patent US4079088 discloses a process for preparing ISPO from DIOL, in which isobutylene and DIOL are mixed and reacted at a temperature of 200°C to 450°C to prepare ISPO (3-methyl-3-butene-1-ol), but the yield is low, only 10% to 32%, which limits the industrial application of this technology.

[0010] In contrast, it would be a better choice to obtain 3-methyl-1,5-pentanediol (hereinafter referred to as MPD) by directly hydrogenating DIOL after recycling. In particular, considering that the methyl side chains in the structure of 3-methyl-1,5-pentanediol (MPD) give it many unique properties such as non-crystalline and hydrophobicity, it is used to prepare polyester resins with special properties, alkyd resins for coatings, etc., giving polyurethane excellent softness, high transparency and compatibility.

[0011] At the same time, it should be noted that the wastewater of this process faces a greater risk when treated by the concentrated crystallization salt extraction process, that is, the wastewater contains a large number of heavy components that are highly compatible with water, resulting in the by-product salt obtained by evaporation and crystallization having a purity that is difficult to meet the requirements for external sales, or can only be treated at a very low price. In short, the above treatment method is very uneconomical for commercially operated equipment.

[0012] In summary, it is necessary to develop a process for treating waste liquid and wastewater in the production of 3-methyl-3-butene-1-ol. Summary of the invention

[0013] In order to solve the above technical problems, the present invention provides a method for treating waste liquid in the production of 3-methyl-3-butene-1-ol, which can realize the recovery of 3-methylene-1,5-pentanediol and its isomers in the 3-methyl-3-butene-1-ol process waste liquid.

[0014] The present invention also provides a method for treating wastewater in the production of 3-methyl-3-butene-1-ol, and the treated wastewater can be treated at low cost by utilizing existing wastewater treatment facilities in the park.

[0015] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0016] A method for treating waste liquid in the production of 3-methyl-3-butene-1-ol comprises the following steps:

[0017] (1) The waste liquid generated in the process of refining and separating the 3-methyl-3-butene-1-ol product is subjected to a separation process to enrich 3-methyl-2-ene-1,5-pentanediol and its isomer DIOL to obtain a light component material;

[0018] (2) subjecting the light component material obtained in (1) to hydrogenation treatment, wherein 3-methyl-2-ene-1,5-pentanediol and its isomer DIOL are hydrogenated to obtain a crude product MPD containing 3-methyl-1,5-pentanediol;

[0019] (3) refining the crude product after hydrogenation to obtain 3-methyl-1,5-pentanediol MPD;

[0020] Optionally, the method further comprises the following steps:

[0021] Step (4) evaporating and concentrating the wastewater generated in the process of refining and separating the 3-methyl-3-butene-1-ol product to obtain concentrated wastewater;

[0022] (5) extracting the concentrated wastewater with an extractant, and obtaining an extracted oil phase containing DIOL, which is returned to the 3-methyl-3-butene-1-ol device for recovery and reprocessing;

[0023] (6) The extracted water phase and the evaporated water obtained by evaporation and concentration are mixed and then enter the Fenton and / or CWAO and / or biochemical water treatment system for treatment.

[0024] The waste liquid described in the present invention is produced during the refining and separation process of 3-methyl-3-butene-1-ol product, and contains 1-5wt% of water, 1-10wt% of light component impurities (including but not limited to low-carbon chain alcohols such as n-butanol, isopentanol, isopropanol, and n-propanol), 20-30wt% of ISPO, 30-40wt% of DIOL, and 20-40wt% of heavy component impurities.

[0025] The wastewater of the present invention comprises 1-10% organic salt (including but not limited to sodium formate, potassium formate, sodium acetate, potassium acetate, etc.), 0.5-2wt% DIOL, 1-5% polymer with a molecular weight of more than 300, and the rest is water.

[0026] Considering the high boiling point of DIOL, the separation process of the present invention needs to be carried out under high vacuum conditions, preferably at 500-2000 paA and 100-180°C. The supporting equipment is conventional separation equipment in the chemical industry, including but not limited to flash tanks, distillation kettles, thin film evaporators, screw devolatilizers, horizontal self-cleaning devolatilizers, etc., and preferably a thin film evaporator is used.

[0027] The hydroprocessing of the present invention can use the known catalysts used in the hydrogenation of carbon-carbon double bonds, for example, nickel, Raney nickel, palladium, Raney cobalt, platinum, ruthenium, etc. From the viewpoint of easy handling and economy, among these hydrogenation catalysts, Raney nickel is particularly preferably used. Relative to the total amount of the reaction liquid in the reactor, the amount of the hydrogenation catalyst is usually preferably in the range of 0.01 to 5% by mass, and more preferably in the range of 0.1 to 1% by mass. The reaction temperature is not particularly limited, but from the viewpoint of the activity, economy and operability of the hydrogenation catalyst, it is usually preferably in the range of 40 to 200°C, and more preferably in the range of 50 to 120°C. The reaction pressure is not particularly limited, but from the viewpoint of operability, safety, reaction efficiency and economy, it is usually preferably in the range of 0 to 10MPa (gauge pressure), and more preferably in the range of 1 to 5MPa (gauge pressure). The reaction time is usually preferably in the range of 1 to 50 hours, and more preferably in the range of 2 to 20 hours. In addition, the present invention can be implemented under any conditions in the presence or absence of a solvent.

[0028] The refining process of step (3) of the present invention adopts a high vacuum double-tower distillation system. Considering that the hydrogenation products MPD and DIOL have very similar boiling points, in order to obtain qualified MPD products in the refining process, it is necessary to strictly control the content of DIOL in the refined raw material, and the content of DIOL in the refined raw material is less than 0.5wt%, more preferably less than 0.1wt%. The light removal tower has 30 to 60 theoretical plates, an operating pressure of 5 to 15hPaA, a tower bottom temperature of 130 to 180°C, and a reflux ratio of 5 to 50. The product tower has 10 to 40 theoretical plates, an operating pressure of 5 to 20hPaA, a tower bottom temperature of 140 to 180°C, and a reflux ratio of 1 to 5.

[0029] The evaporation concentration process described in step (4) of the present invention can use well-known equipment technology, including but not limited to distillation, scraper evaporation, single-effect or multi-effect evaporator and MVR, etc. Considering the composition characteristics of the wastewater and in order to reduce operating costs, MVR is preferably used, wherein the evaporation concentration ratio is controlled at 1 to 20 times, preferably 3 to 6 times.

[0030] The specific implementation scheme of the extraction process described in step (5) of the present invention is not strictly limited, including but not limited to extraction tanks, continuous extractors and rotary disc extraction towers, etc. The extractant can be selected to use carbon four and above alcohol substances, including but not limited to n-butanol, n-octanol, isopentanol, isopentanol, isopentanol, isopentanol, etc., but considering that no new impurities are introduced into the system and the investment is increased by adding separation equipment to remove new impurities, the extractant is preferably ISPO, and the extraction feed mass ratio is ISPO: concentrated wastewater = 0.1-10:10, and the extraction temperature is 30-70°C. The extracted water phase obtained after extraction can be mixed with the evaporated condensed water and treated by Fenton and / or CWAO and / or biochemical in the park.

[0031] Through the above-mentioned treatment process, the recovery of 3-methylene-1,5-pentanediol and its isomers in the 3-methyl-3-butene-1-ol process waste liquid was achieved. In addition, the treated wastewater can be treated at a low cost using the existing wastewater treatment facilities in the park, greatly improving the profitability of commercial operation equipment.

[0032] Description of the drawings: Figure 1 A schematic diagram of the process of the present invention is shown in FIG. DETAILED DESCRIPTION

[0033] The following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0034] Waste liquid and wastewater: generated during the purification process of the reaction product of formaldehyde and isobutylene to prepare isopentenol.

[0035] Analytical methods:

[0036] Gas chromatograph: Agilent 7890, chromatographic column wax (conversion rate, selectivity determination), inlet temperature: 300 ° C; split ratio 50:1; carrier gas flow rate: 52.8 ml / min; heating program: maintain at 150 ° C for 10 min, increase to 260 ° C at a rate of 10 ° C / min, maintain for 5 min, detector temperature: 280 ° C.

[0037] Example 1

[0038] The waste liquid contains: 3.4wt% water, 6.2wt% light impurities, 21.6wt% ISPO, 38.8wt% DIOL, and the rest is 30wt% heavy impurities.

[0039] The wastewater contains: 7.9% organic salt, 1.1wt% DIOL, 2.6% polymer with molecular weight above 300, and the rest is water.

[0040] like Figure 1 As shown, the waste liquid is first treated by a thin film evaporator to recover DIOL, with an operating pressure of 1500paA and an evaporation temperature of 150°C; the DIOL obtained by evaporation is subjected to kettle hydrogenation to obtain a crude MPD product, with a Raney catalyst addition amount of 1wt%, an operating temperature of 120°C, an operating pressure of 4MpaG, and a reaction time of 10 hours, and the DIOL content in the crude MPD product is 0.08wt%; the crude MPD product is refined by a high vacuum double-tower distillation system, with a light-removal tower with 40 theoretical plates, an operating pressure of 10hpaA, a bottom temperature of 160°C, a reflux ratio of 20, and a product tower with 20 theoretical plates, an operating pressure of 10hpaA, a bottom temperature of 150°C, and a reflux ratio of 2, to obtain a MPD product with a purity of 99.5wt% (product index requirement>98%).

[0041] The wastewater is evaporated and concentrated by MVR, and concentrated wastewater is obtained after being concentrated 6 times; the concentrated wastewater is extracted using an extraction tank, with ISPO as the extractant, the extraction feed mass ratio is ISPO: concentrated wastewater = 1:5, the extraction temperature is 60°C, DIOL is enriched in the extracted oil phase, and returned to the upstream device separation process for recycling, and the extracted water phase is mixed with the evaporated condensed water and treated using the park's biochemical system.

[0042] Example 2

[0043] The waste liquid contains: water 5wt%, light component impurities 1.1wt%, ISPO

[0044] 29.8wt%, DIOL 30.1wt%, heavy impurities 34wt%.

[0045] The wastewater contains: 1.2% organic salt, 1.95wt% DIOL, 4.98% polymers with a molecular weight of more than 300, and the rest is water.

[0046] The waste liquid is first processed by a screw devolatilizer to recover DIOL, with an operating pressure of 500 paA and an evaporation temperature of 100°C; the evaporated DIOL is subjected to kettle hydrogenation to obtain a crude MPD product, with a Raney catalyst addition amount of 0.5wt%, an operating temperature of 50°C, an operating pressure of 5MpaG, and a reaction time of 20 hours, and the DIOL content in the crude MPD product is 0.02wt%; the crude MPD product is refined by a high vacuum double-tower distillation system, with a light-removal tower having 60 theoretical plates, an operating pressure of 5hpaA, a tower bottom temperature of 130°C, a reflux ratio of 50, and a product tower having 10 theoretical plates, an operating pressure of 5hpaA, a tower bottom temperature of 140°C, and a reflux ratio of 1, to obtain a MPD product with qualified purity.

[0047] The wastewater is evaporated and concentrated by MVR, and concentrated wastewater is obtained after being concentrated 3 times; the concentrated wastewater is extracted by an extraction tank, with ISPO as the extractant, the extraction feed mass ratio is ISPO: concentrated wastewater = 0.1:10, the extraction temperature is 70°C, DIOL is enriched in the extraction oil phase, and returned to the upstream device separation process for recycling, and the extraction water phase is mixed with the evaporated condensed water and treated by the park biochemical system.

[0048] Example 3

[0049] The waste liquid contains: 1.1 wt% of water, 10 wt% of light impurities, 26.7 wt% of ISPO, 34.2 wt% of DIOL, and 28 wt% of heavy impurities.

[0050] The wastewater contains: 10% organic salt, 0.5wt% DIOL, 1% polymer with a molecular weight of more than 300, and the rest is water.

[0051] The waste liquid is first treated in a distillation kettle to recover DIOL, with an operating pressure of 2000 paA and an evaporation temperature of 180°C; the evaporated DIOL is subjected to kettle hydrogenation to obtain a crude MPD product, with a Raney catalyst addition amount of 0.1 wt%, an operating temperature of 100°C, an operating pressure of 1 MpaG, and a reaction time of 2 hours, and the DIOL content in the crude MPD product is 0.1 wt%; the crude MPD product is refined by a high vacuum double-tower distillation system, with a lightness removal tower having 30 theoretical plates, an operating pressure of 15 hpaA, a tower bottom temperature of 180°C, a reflux ratio of 5, and a product tower having 40 theoretical plates, an operating pressure of 20 hpaA, a tower bottom temperature of 180°C, and a reflux ratio of 5, to obtain a MPD product with qualified purity.

[0052] The wastewater is evaporated and concentrated by MVR, and concentrated wastewater is obtained after being concentrated 4 times; the concentrated wastewater is extracted by an extraction tank, with ISPO as the extractant, the extraction feed mass ratio is ISPO: concentrated wastewater = 10:10, the extraction temperature is 30°C, DIOL is enriched in the extraction oil phase, and returned to the upstream device separation process for recycling, and the extraction water phase is mixed with the evaporated condensed water and treated by the park biochemical system.

Claims

1. A method for treating waste liquid in the production of 3-methyl-3-butene-1-ol, comprising the following steps: (1) The waste liquid is subjected to a separation process to enrich 3-methyl-2-ene-1,5-pentanediol and its isomer DIOL to obtain a light component material; (2) subjecting the light component material obtained in (1) to hydrogenation treatment, wherein DIOL is hydrogenated to obtain a crude product of target product 3-methyl-1,5-pentanediol MPD; (3) The crude product after hydrogenation is refined to obtain MPD; Optionally, the method further comprises the following steps: Step (4) evaporating and concentrating the wastewater generated in the process of refining and separating the 3-methyl-3-butene-1-ol product to obtain concentrated wastewater; (5) extracting the concentrated wastewater with an extractant, and obtaining an extracted oil phase containing DIOL, which is returned to an upstream device for recovery; (6) The extracted water phase and the evaporated water obtained by evaporation and concentration are mixed and then enter the Fenton and / or CWAO and / or biochemical water treatment system for treatment.

2. The method according to claim 1, characterized in that: The waste liquid is produced during the refining and separation process of 3-methyl-3-butene-1-ol product, and contains 1-5wt% of water, 1-10wt% of light component impurities, 20-30wt% of 3-methyl-3-butene-1-ol ISPO, 30-40wt% of DIOL, and 20-40wt% of heavy component impurities.

3. The method according to claim 1, characterized in that: The wastewater contains 1-10% organic salt, 0.5-2wt% DIOL, 1-5% high polymer with molecular weight above 300, and the rest is water.

4. The method according to any one of claims 1 to 3, characterized in that: The separation process in step (1) needs to be carried out under high vacuum conditions, preferably at 500-2000 paA and 100-180° C. The equipment is conventional separation equipment in the chemical industry, including but not limited to flash tanks, distillation kettles, thin film evaporators, screw devolatilizers, horizontal self-cleaning devolatilizers, and preferably thin film evaporators.

5. The method according to any one of claims 1 to 4, characterized in that: The catalyst used for the hydrogenation treatment in step (2) includes one or more of nickel, Raney nickel, palladium, Raney cobalt, platinum and ruthenium, preferably Raney nickel; the amount of the catalyst used is in the range of 0.01 to 5% by mass, preferably in the range of 0.1 to 1% by mass, relative to the total amount of the reaction liquid in the reactor.

6. The method according to any one of claims 1 to 5, characterized in that: The reaction temperature of the hydrotreatment in step (2) is in the range of 40 to 200° C., preferably in the range of 50 to 120° C.; and / or, the reaction pressure is in the range of 0 to 10 MPa, preferably in the range of 1 to 5 MPa; and / or, the reaction time is in the range of 1 to 50 hours, preferably in the range of 2 to 20 hours.

7. The method according to any one of claims 1 to 6, characterized in that The refining process in step (3) adopts a high vacuum double-tower distillation system comprising a dehydrogenation tower and a product tower to control the content of DIOL in the refined raw material to be less than 0.5%, preferably less than 0.1%.

8. The method according to claim 7, characterized in that The light removal tower has 30 to 60 theoretical plates, an operating pressure of 5 to 15 hPaA, a bottom temperature of 130 to 180°C, and a reflux ratio of 5 to 50; and / or the product tower has 10 to 40 theoretical plates, an operating pressure of 5 to 20 hPaA, a bottom temperature of 140 to 180°C, and a reflux ratio of 1 to 5.

9. The method according to any one of claims 1 to 8, characterized in that: In the step (4), the evaporation concentration ratio of the evaporation concentration step is controlled at 1 to 20 times, preferably 3 to 6 times.

10. The method according to any one of claims 1 to 9, characterized in that: In the step (5), the extraction agent used in the extraction process is an alcohol substance with carbon content of 4 or above, preferably n-butanol, n-octanol, isopentanol, isopentanol, isopentanol, and isopentanol, and isopentanol is more preferred, and / or the extraction feed ratio is extractant: concentrated wastewater = 0.1-10:10, and the extraction temperature is 30-70°C.

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