Improved process for 1, 3-butanediol

Abstract

An improved process for the preparation of low impurity 1, 3-butanediol, comprising: (a) subjecting acetaldehyde to an aldol condensation reaction in a reactor to produce butylaldehyde; (b) hydrogenating butanol in the hydrogenation reactor in the presence of a hydrogenation / dehydrogenation catalyst to produce a crude 1, 3-butanediol stream having an active hydrogenation / dehydrogenation catalyst content; (c) removing the catalyst in the crude 1, 3-butanediol stream or deactivating the catalyst in the crude 1, 3-butanediol stream; and (d) distilling the treated crude 1, 3-butanediol stream in a distillation unit to provide a purified 1, 3-butanediol product.

Description

[0001] Cross - reference to related applications

[0002] This international patent application claims priority to co - pending U.S. Provisional Patent Application Serial No. 63 / 416,815, filed on October 17, 2022, of the same title (Attorney Docket No. OQ - 212), the entire disclosure of which is hereby incorporated by reference. Technical field

[0003] The present invention relates to the manufacture of 1,3 - butanediol, and more particularly to high - purity products suitable for cosmetic applications or applications requiring low - odor substances. Background art

[0004] 1,3 - Butanediol is used in the manufacture of plasticizers, polyol esters, and cosmetics. It is typically produced by subjecting acetaldehyde to aldolization, hydrogenating aldol in the presence of a hydrogenation / dehydrogenation catalyst, and then purifying the crude product. Low - odor, high - purity products are required for cosmetic applications and are desirable in many other end - uses.

[0005] US 2003 / 0018224( Tsuji etc.) discloses various methods for preparing high - purity 1,3 - butanediol by hydrogenating aldol in the presence of a Raney Nickel catalyst and distilling the crude mixture. It is mentioned that relatively highly active Raney Nickel catalysts achieved the desired results. See paragraphs

[0086] ,

[0087] .

[0006] Tsuji U.S. Patent No. 6,376,725, etc. discloses a method for preparing high - purity 1,3 - butanediol with a small amount of by - products and low odor. The method includes adding a base to crude 1,3 - butanediol free of high - boiling substances, subjecting the mixture to heat treatment, and then distilling out 1,3 - butanediol; distilling out low - boiling substances from 1,3 - butanediol. See column 2, lines 1 - 9.

[0007] GB1205689 (Celanese) discloses a method for preparing low - odor 1,3 - butanediol, which includes distilling the product in a container made of stainless steel to avoid catalytic degradation of the product by iron oxides, etc. See page 1, column 2, lines 62 - 77.

[0008] US 2005 / 0154239( Windhorstet al.) disclose a method for preparing low-impurity 1,3-butanediol by using an acetaldehyde feed with a low acid content. The process is reported to achieve relatively high yields by minimizing by-products. See paragraph

[0018] .

[0009] Windhorst discloses a method for reducing the odor of 1,3-butanediol by treating the product with activated carbon.

[0010] Nishiguchi No. 5,345,004 of discloses a method for preparing cosmetic grade 1,3-butanediol with a small amount of by-products and low odor. The method removes crotonaldehyde from recycled acetaldehyde. Summary of the invention

[0011] The present invention provides an improved process for producing 1,3-butanediol (sometimes referred to herein as 1,3 BG) by eliminating sources of impurities to produce cosmetic grade, low odor 1,3 BG.

[0012] In the context of the present invention, it was found that very low levels of hydrogenation / dehydrogenation catalyst residues in the crude product stream, such as greater than 100 ppm of Raney nickel, catalyze Guerbet reactions during the purification of 1,3 BG and adversely affect product quality. Conventional catalyst removal processes, such as settling and filtration using conventionally used filtration systems, do not achieve the necessary reduction of previously used catalyst in the crude product. Without being bound by theory, it is apparent that the catalytic formation of key byproducts occurs via Guerbet reactions as shown in Scheme 1 below, Scheme 2 below, and the Examples that follow.

[0013]

[0014] Scheme 1: Guerbet reaction mechanism to produce Guerbet byproducts from primary / secondary alcohols

[0015] As can be seen from Scheme 1, Scheme 2 and the following examples, at elevated temperatures, in the presence of water and nickel, 1,3 BG decomposes with the release of hydrogen. Large amounts of 2-propanol, 2-butanol, 1-butanol, and large amounts of 4-hydroxy-2-butanone and methyl vinyl ketone were detected. These molecules are identified by the inventors herein as key intermediates in the formation pathways of various byproducts (including pyrans and other ethers). Without being limited to the structures shown, some representative impurities observed include the following:

[0016]

[0017] The conditions employed in the examples herein are the same and comparable to those employed in the purification section of a typical commercial unit.

[0018] Low levels of active hydrogenation / dehydrogenation catalysts in the crude product are responsible for this decomposition (no reaction occurs in the absence of a catalyst). The Guerbet reaction was first discovered in 1899 and was found to be relevant to diols in the 1960s. See M. Guerbet: Action of amyl alcohol of fermentation on its sodium derivative. In: Proceedings of the Academy of Sciences Band 128, 1899, S. 511-513. In the examples, it can be seen that the reaction is initiated and catalyzed by Ni. For general information on the Guerbet reaction, see GB 761296 (Esso Research and Engineering Co.), page 2, column 2, line 92 to page 3, column 1, line 32.

[0019] One aspect of the present invention provides a method for producing 1,3-butanediol, comprising:

[0020] (a) subjecting acetaldehyde to an aldol condensation reaction in a reactor to produce butanediol;

[0021] (b) hydrogenating the aldol in the presence of a hydrogenation / dehydrogenation catalyst in a hydrogenation reactor to produce a crude 1,3-butanediol stream having an active hydrogenation / dehydrogenation catalyst content greater than 100 ppm;

[0022] (c) removing or deactivating the catalyst in the crude 1,3-butanediol stream to provide a treated crude 1,3-butanediol stream having less than 100 ppm of active hydrogenation / dehydrogenation catalyst; and

[0023] (d) distilling the treated crude 1,3-butanediol stream in a distillation unit to provide a purified 1,3-butanediol product.

[0024] In another aspect of the present invention, an improved method for a continuous process for preparing such 1,3-butanediol is provided, which comprises hydrogenating aldol in the presence of a hydrogenation / dehydrogenation catalyst in a hydrogenation reactor to produce a crude 1,3-butanediol stream having an active hydrogenation / dehydrogenation catalyst content, and distilling the crude 1,3-butanediol stream in a distillation train to provide a purified 1,3-butanediol product, the improved method comprising removing the active catalyst in the crude 1,3-butanediol stream or deactivating the active catalyst in the crude 1,3-butanediol stream before distillation to provide a treated crude 1,3-butanediol stream having less active hydrogenation / dehydrogenation catalyst in the range of 0 to 750 ppm compared to the crude 1,3-butanediol stream before treatment, and distilling the treated crude 1,3-butanediol stream in the distillation train to provide a purified 1,3-butanediol product.

[0025] Further aspects and details are provided in the following discussion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic flow chart showing a typical continuous production process of 1,3-butanediol used in the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail herein with reference to the accompanying drawings for illustrative purposes only. The invention is defined in the appended claims. Unless otherwise indicated, the terms and symbols used herein have their ordinary meanings; for example, %, ppm and similar terms mean weight percent, parts per million (by weight), etc., unless otherwise indicated.

[0028] "Consisting essentially of" and similar terms refer to the listed components, excluding other components that would materially change the basic and novel characteristics of the composition, article, or process. Unless otherwise specified or apparent, a composition or article consists essentially of a stated or listed component when it includes more than 90% by weight of the stated or listed component. That is, the term excludes more than 10% of unlisted components. Any product disclosed and claimed herein may consist essentially of the stated components.

[0029] The "effective pore size" of a filter system refers to the ability of the filter system to filter out particles of a certain size. For example, a 0.20 micron (µm) rated filter system will remove particles larger than 0.2 µm in diameter from the filter stream.

[0030] Filter, filter system and similar terms refer to a single filter element or multiple filter elements, including filter elements arranged in series or in parallel characterized by an effective pore size. Such filters include, but are not limited to, blade systems, cartridge systems, bag systems, centrifugal systems, sedimentation systems, candle systems and / or magnetic systems. It is preferred to use a filter system with a primary filtration system, followed by a secondary filtration system or a gloss-enhancing filtration system with a smaller effective pore size. The primary filtration may consist of a sedimentation device with or without one or more filters of the above-disclosed type. The gloss-enhancing filtration system may include, but is not limited to, those systems described above. In addition, pre-coat materials may be added to enhance the filtering capacity of the primary and secondary systems. The pre-coat material may be of various types, including diatomaceous earth, perlite and / or cellulose. The gloss-enhancing filtration system preferably has an effective pore size less than or equal to 1 μm.

[0031] "Guerbet impurities" or "Guerbet byproducts" include 2-propanol, 2-butanol, 1-butanol, 4-hydroxy-2-butanone, methyl vinyl ketone, and byproducts generated from these molecules, such as pyrans and other ethers, representative byproducts include the following:

[0032]

[0033] As used herein, "hydrogenation / dehydrogenation catalyst" and similar terms refer to metal catalysts for hydrogenating and dehydrogenating organic compounds, including transition metal catalysts selected from the list of Ti, Zr, V, Nb, Cr, Mo, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd and Hg metals. The catalyst can be in the form of a fixed bed, optionally with the catalyst metal supported on a carrier, or the catalyst can be in the form of a slurry of a supported catalyst metal or a non-supported catalyst metal. Particularly preferred are Raney catalysts in the form of a slurry selected from Raney-Co, Raney-Ni, Raney-Cu, Raney-Fe, including metals that may be included in the Raney catalyst as a promoter during the manufacture of the Raney catalyst, especially Al, Zn and Cr, but not combined with Al, Zn and Cr.

[0034] A typical 1,3 BG process can be separated and simplified into three distinct steps. The first is the aldol condensation of acetaldehyde to produce 3-hydroxybutyraldehyde, the second is the hydrogenation of the latter to the corresponding crude diol, and the third is the purification of the crude 1,3-butanediol. The process can be carried out in batch mode, semi-continuous mode, or more preferably in a 100% continuous manner from acetaldehyde feeding to final purification of the product.

[0035] A simplified overall process flow for the continuous process of the present invention is as follows Figure 1 , which schematically shows an apparatus for producing 1,3-butanediol having a reactor, a purification column, and a removal unit as described below.

[0036] Aldol condensation reaction of acetaldehyde:

[0037] In describing this process, reference is made to Figure 1 The simplified process flow in the invention is as follows. The unit feeds acetaldehyde to an aldol condensation reactor A. 2% to 20% caustic is added to the reactor, more preferably 2% to 10% caustic. The aldol condensation reactor A is operated at a conversion rate of 10% to 90%, more preferably 20% to 80%, or even more preferably 22% to 62%. The conversion is controlled by typical process parameters known to those skilled in the art. The temperature is controlled at 30°F to 130°F, more preferably 50°F to 100°F, even more preferably 60°F to 90°F, for example 70°F to 85°F, and the reaction pressure is in the range of 20psig to 70psig, more preferably in the range of 30psig to 60psig, even more preferably in the range of 25psig to 50psig.

[0038] The reactor product is withdrawn and sent to a stripper column to remove light ends from the product stream. The Stripper B residue contains the intermediates that are fed to the hydrogenation portion of the unit.

[0039] Hydrogenation of butanediol:

[0040] Hydrogenation is accomplished using a metal-based catalyst, which is more preferably selected from the list of Ti, Zr, V, Nb, Cr, Mo, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd and Hg metals, and even more preferably selected from the list of Raney-Co, Raney-Ni, Raney-Cu, Raney-Fe or similar catalysts. The hydrogenation reactor C is typically operated at 150°F to 250°F, more preferably at 180°F to 230°F, even more preferably at 190°F to 220°F and 500psig to 800psig, more preferably 600psig to 750psig, even more preferably 650psig to 720psig. Hydrogen is fed to the reactor, and hydrogen can be passed through the reactor as a two-phase flow of, for example, an intermediate and an active hydrogenation catalyst. The hydrogenation product and some active hydrogenation catalyst come out of the reactor. Unreacted hydrogen is separated from the crude reaction mixture, while the liquid phase is sent to the catalyst separation system D. The active catalyst is usually removed by decanting and optionally by filtering. The crude reaction product continues to be purified E.

[0041] Purification (E):

[0042] The crude 1,3 BG after hydrogenation pretreatment contains light impurities and heavy impurities. The crude product usually contains a large amount of 1,3-butanediol in water, as well as some light fractions such as ethanol and / or butanol and / or crotonaldehyde and corresponding impurities. The heavy fraction impurities include 2,6-dimethyl-1,3-dioxane-4-ol (aldoxane), 2-ethyl-1,3-butanediol and / or 2,4-dimethyl-1,3-dioxane (BG acetal) and / or 3-hydroxybutyl acetate (BG monoacetate). Water can account for 50% to 90% of the crude product stream, suitably 60% to 80%, and even more suitably 65% ​​to 75%, with the remainder essentially consisting of 1,3-butanediol.

[0043] Impurities can be removed during the purification process by a series of towers. In one variation of the invention, the first purification step can include removing any light fraction impurities, including water. In another variation of the invention, the second purification step can include removing any heavy fractions, followed by a third step and / or a finishing step to provide odorless high-quality 1,3-butanediol. By means of the present invention, the corresponding purification step can include using a vacuum flasher.

[0044] According to the present invention, the catalyst separation unit (X,Figure 1 ):

[0045] However, according to the present invention, a catalyst removal / deactivation unit (X) is provided in addition to or instead of the above-mentioned catalyst separation train to reduce the active hydrogenation / dehydrogenation catalyst level to less than 1000 ppm, more preferably less than 500 ppm, even more preferably less than 150 ppm, less than 100 ppm before further purification of the treated crude 1,3-butanediol stream.

[0046] In order to pre-treat the crude reaction product to reduce the level of active hydrogenation / dehydrogenation catalyst, it is proposed as part of the present invention to utilize primary and secondary catalyst deactivation and / or removal systems.

[0047] The primary catalyst deactivation and / or removal system may include a filtration system, but is not limited to a vane system with or without a settling device, a cartridge system, a bag system, a centrifugal system, a sedimentation system, a candle system, and / or a magnetic system. The secondary catalyst deactivation system or the gloss enhancement filter system may include, but is not limited to, those mentioned above. In addition, a pre-coat material may be added to enhance the filtration capacity of the primary filtration system and the gloss enhancement filter system. The pre-coat material may be of various types, including diatomaceous earth, perlite, and / or cellulose.

[0048] Deactivating transition metal-based hydrogenation / dehydrogenation catalysts is another possible route to prevent the decomposition of the desired 1,3-butanediol and the formation of unwanted byproducts via the Guerbet reaction. Without being bound by theory, it is believed that the catalytic activity of the hydrogenation / dehydrogenation catalyst is limited by the active surface sites of the heterogeneous and / or homogeneous materials used as catalysts. Therefore, deactivation of the active sites can inhibit unwanted side reactions and is a core part of the present invention.

[0049] Deactivation can occur by contacting the catalyst with hypochlorite, nitrate-based or nitrite-based solutions, dissolved carbon monoxide, phosphine compounds, and / or any other component that may block the active surface for chemical and / or physical adsorption mechanisms. Contacting the crude process stream with the deactivating ions prevents further by-product formation. The crude process stream and / or process unit can be treated continuously or discontinuously to deactivate the transition metal catalyst present in unintended locations and / or intended locations.

[0050] According to the present invention, since impurities causing odor are reduced, the finishing step can be omitted.

[0051] Experimental example

[0052] 1. Formation of by-products:

[0053] A series of experiments were conducted to determine the effect of residual active hydrogenation / dehydrogenation catalyst on the formation of impurities in 1,3-butanediol during downstream processing of crude 1,3-butanediol.

[0054] General process

[0055] Under an inert gas atmosphere (Ar), 1,3-butanediol was dissolved in water (30 wt%) to represent a typical crude 1,3-butanediol stream and fed to a laboratory distillation apparatus equipped with a cooling trap, condensate collector and gas collector. The distillation temperature was maintained at 103°C.

[0056] The unit was run in aqueous 1,3-butanediol with varying amounts of hydrogenation / dehydrogenation catalyst (including a benchmark with no catalyst at all to study the effect of the latter).

[0057] Gases and condensates were collected and analyzed.

[0058] Table 1.1: Influence of the concentration of hydrogenation / dehydrogenation catalyst on the gas formation in 1,3-butanediol as an indicator for the decomposition Guerbet activity.

[0059]

[0060] [a] Since Ar was used as an inert gas, it was excluded from the results by calculation.

[0061] Table 1.2: Effect of the concentration of hydrogenation / dehydrogenation catalyst on the formation of representative by-products in 1,3-butanediol as an indicator for the decomposition Guerbet activity.

[0062]

[0063] Impurity generation is related to hydrogen generation according to the following scheme2:

[0064]

[0065] It can be seen that in the absence of an active hydrogenation / dehydrogenation catalyst, no impurities are generated, but at 1 wt % or 0.1 wt % of an active hydrogenation / dehydrogenation catalyst, the generation of byproducts is high enough to be detected by simple GC analysis, particularly 1-butanol and 2-butanol, which contain a relatively small amount of 4-hydroxy-2-butanone (4H2B). From the above scheme, it can be understood that 2-butanol may be derived from 4H2B. The generation of impurities is reduced when the catalyst is about 100 ppm in the mixture, and the generation of impurities is substantially absent when the catalyst is 10 ppm in the mixture.

[0066] Therefore, if the active catalyst is removed or deactivated to a level corresponding to less than 100 ppm of active catalyst before further processing of the crude product stream (distillation of the crude treated product at elevated temperature), impurity formation in industrial plants will be significantly improved.

[0067] Filter to prevent by-product formation: Filtration process:

[0068] Representative mixtures of 1,3BG and water were filtered using different effective pore size filter disks in the presence of 1% (w / w) transition metal catalyst. The material was passed through a single filter disk and exposed to the general process conditions used for byproduct formation described above. The distillate was collected and analyzed.

[0069] Table 2.1 Effect of filtration on reducing the formation of Guerbet by-products.

[0070]

[0071] [a] Reported as wt % by GC and KF titration; [b] Reported as wt% by GC

[0072] In the above examples, filter paper discs were used. It will be appreciated by those skilled in the art that a filtration system comprising polyester discs or tubes, polypropylene discs or tubes, or sintered metal discs or tubes may be used.

[0073] 3. Inactivation to prevent by-product formation

[0074] Typically, a mixture of 1,3 BG and water is exposed to deactivated and activated forms of the transition metal catalyst. Deactivation in the presence of excess deactivating ions relative to the transition metal catalyst shows differences in byproduct formation.

[0075] Inactivate Raney nickel using a NaOCl solution (8% to 10% aqueous solution)

[0076] Raney nickel (5 g) was added to a 250 mL round bottom flask containing water (35 g), and an 8% to 10% aqueous solution of NaClO (based on Raney nickel, about 100% excess, 150 g) was added over 10 minutes. During the addition, the temperature of the mixture increased from room temperature (~20 ° C) to 41 ° C. After complete addition, the mixture was stirred at 60 ° C for 1 hour.

[0077] Then, the mixture was cooled to room temperature, and the catalyst was filtered and washed with water. The deactivated catalyst was stored while moist before use.

[0078] Use NaNO 3 solution (10% aqueous solution) to inactivate Raney nickel

[0079] Raney nickel (20 g) was added to a 500 mL round-bottom flask filled with water (80 g), and NaNO was added over 25 min. 3 (About 6% excess based on Raney nickel, 300 g). During the addition, the temperature increased from room temperature (~20°C) to 33°C. After complete addition, the mixture was stirred at 60°C for 1 hour.

[0080] Then, the mixture was cooled to room temperature, and the catalyst was filtered and washed with water. The deactivated catalyst was stored while moist before use.

[0081] Table 3.1: Effect of deactivating hydrogenation / dehydrogenation catalysts on gas formation.

[0082]

[0083] [a] Ar was used as an inert gas; [b] Reported as gas phase wt% by GC; Reported as liquid fraction wt% by GC

[0084] Although the present invention has been described in detail, it will be readily understood by those skilled in the art that modifications within the spirit and scope of the present invention may be made. These modifications should also be considered as a part of the present invention. In conjunction with the above description including the Abstract of the Present Invention and Technical Background, in view of the above discussion, the relevant knowledge in the art and the references above, the disclosures thereof are incorporated herein by reference, and it is therefore considered unnecessary to further describe them. In addition, it should be understood from the above discussion that aspects of the present invention and parts of the various embodiments may be combined or interchanged in whole or in part. In addition, it will be understood by those of ordinary skill in the art that the above description is only by way of example and is not intended to limit the present invention.

Claims

1. A method for preparing 1,3-butanediol, comprising: include: (a) subjecting acetaldehyde to an aldol condensation reaction in a reactor to produce butanediol; (b) hydrogenating the aldol in the presence of a hydrogenation / dehydrogenation catalyst in a hydrogenation reactor to produce a crude 1,3-butanediol stream having an active hydrogenation / dehydrogenation catalyst content greater than 100 ppm; (c) removing or deactivating the catalyst in the crude 1,3-butanediol stream to provide a treated crude 1,3-butanediol stream having less than 100 ppm of active hydrogenation / dehydrogenation catalyst; and (d) distilling the treated crude 1,3-butanediol stream in a distillation unit to provide a purified 1,3-butanediol product.

2. The method of claim 1, wherein the hydrogenation / dehydrogenation catalyst comprises a transition metal hydrogenation / dehydrogenation catalyst.

3. The method of claim 2, wherein the hydrogenation / dehydrogenation catalyst comprises a transition metal hydrogenation / dehydrogenation catalyst selected from the group consisting of Ti, Zr, V, Nb, Cr, Mo, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd and Hg metals.

4. The method according to claim 3, wherein the hydrogenation / dehydrogenation catalyst is a Raney catalyst selected from Raney-Co, Raney-Ni, Raney-Cu, Raney-Fe, which optionally includes one or more of Al, Zn and Cr. The method according to claim 1 , wherein the hydrogenation / dehydrogenation catalyst is a Raney nickel catalyst.

6. The process according to any one of the preceding claims, wherein the hydrogenation / dehydrogenation catalyst is a slurry catalyst.

7. The process according to any one of the preceding claims, wherein the treated crude 1,3-butanediol stream contains less than 75 ppm of active hydrogenation / dehydrogenation catalyst.

8. The process of claim 7, wherein the treated crude 1,3-butanediol stream contains less than 50 ppm of active hydrogenation / dehydrogenation catalyst.

9. The process of claim 8, wherein the treated crude 1,3-butanediol stream contains less than 25 ppm of active hydrogenation / dehydrogenation catalyst.

10. The process of claim 9 wherein the treated crude 1,3-butanediol stream contains less than 12.5 ppm of active hydrogenation / dehydrogenation catalyst.

11. The method according to any one of the preceding claims, further comprising removing residual catalyst from surfaces of the distillation apparatus and / or deactivating residual catalyst.

12. The process of any one of the preceding claims, wherein the active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream is deactivated with a deactivating agent effective to block active catalytic sites on the hydrogenation / dehydrogenation catalyst.

13. The process of claim 12, wherein the active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream is deactivated with a molar excess of deactivating agent relative to the catalyst present.

14. A process according to claim 12 or claim 13, wherein deactivation of the catalyst in the crude 1,3-butanediol stream is carried out by contacting the catalyst with a deactivating agent selected from hypochlorite, a nitrate-based solution or a nitrite-based solution, dissolved carbon monoxide and a phosphine-based compound.

15. The process according to any one of the preceding claims, wherein the crude 1,3-butanediol stream containing residual active hydrogenation / dehydrogenation catalyst is filtered using a filtration system having an effective pore size of 0.01 μm to 1 μm.

16. The method of claim 15, wherein the filtration system is a leaf system, a cartridge system, a bag system, a centrifugal system, a sedimentation system, a candle system, a magnetic system, or a combination thereof.

17. A method according to claim 15 or claim 16, wherein the effective pore size of the filtration system is from 0.01 μm to 0.5 μm.

18. The method of claim 15 or claim 16, wherein the effective pore size of the filtration system is 0.01 μm to 0.25 μm.

19. The method of claim 15 or claim 16, wherein the effective pore size of the filtration system is 0.01 μm to 0.1 μm.

20. The process of any one of the preceding claims, wherein the purified 1,3-butanediol product has less than 1% Guerbet impurities.

21. The process of any one of the preceding claims, wherein the purified 1,3-butanediol product has less than 0.5% Guerbet impurities.

22. The process of any one of the preceding claims, wherein the purified 1,3-butanediol product has less than 0.25% Guerbet impurities.

23. The process of any one of the preceding claims, wherein the purified 1,3-butanediol product has 0% to 0.5% Guerbet impurities.

24. An improved method for a continuous process for preparing 1,3-butanediol, in which the continuous process for preparing such 1,3-butanediol comprises hydrogenating aldol in the presence of a hydrogenation / dehydrogenation catalyst in a hydrogenation reactor to produce a crude 1,3-butanediol stream having an active hydrogenation / dehydrogenation catalyst content, and distilling the crude 1,3-butanediol stream in a distillation apparatus to provide a purified 1,3-butanediol product, the improved method comprising removing or deactivating the active catalyst in the crude 1,3-butanediol stream before distillation to provide a treated crude 1,3-butanediol stream having less active hydrogenation / dehydrogenation catalyst in the range of 0 to 750 ppm compared to the crude 1,3-butanediol stream before treatment, and distilling the treated crude 1,3-butanediol stream in a distillation apparatus to provide a purified 1,3-butanediol product.

25. The improved process of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 500 ppm.

26. The improvement of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 250 ppm.

27. The improvement of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 100 ppm.

28. The improvement of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 50 ppm.

29. The improvement of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 25 ppm.

30. The improvement of claim 24 wherein the level of active hydrogenation / dehydrogenation catalyst in the treated crude 1,3-butanediol stream prior to distillation is in the range of 0 to 12.5 ppm.

31. The improved method according to claim 24, incorporating one or more features selected from claims 1 to claim 23.

32. A device for producing 1,3-butanediol, wherein include: (a) an aldol condensation reaction reactor, wherein the aldol condensation reaction reactor is used to perform an aldol condensation reaction on acetaldehyde to produce butyral; (b) a hydrogenation reactor connected to the aldol condensation reactor containing a slurry hydrogenation / dehydrogenation catalyst for hydrogenating the butanediol in the aldol condensation reactor, and the hydrogenation reactor is operable to provide a crude 1,3-butanediol stream containing an active hydrogenation / dehydrogenation catalyst; (c) a catalyst removal / deactivation unit coupled to the hydrogenation reactor and adapted to remove or deactivate active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream, effective to remove or deactivate active catalyst in the crude 1,3-butanediol stream to provide a treated crude 1,3-butanediol stream having less active hydrogenation / dehydrogenation catalyst in the range of 0 to 750 ppm compared to the crude 1,3-butanediol stream prior to treatment in the catalyst removal / deactivation unit; and (d) a distillation apparatus connected to the catalyst removal / deactivation unit, the distillation apparatus being used to purify the treated crude 1,3-butanediol product stream.

33. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has a content of active hydrogenation / dehydrogenation catalyst in the range of 0 to 500 ppm.

34. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has an active hydrogenation / dehydrogenation catalyst content in the range of 0 to 250 ppm.

35. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has a content of active hydrogenation / dehydrogenation catalyst in the range of 0 to 100 ppm.

36. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has a content of active hydrogenation / dehydrogenation catalyst in the range of 0 to 50 ppm.

37. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has an active hydrogenation / dehydrogenation catalyst content in the range of 0 to 25 ppm.

38. The apparatus of claim 32, wherein the catalyst removal / deactivation unit is operable to reduce the content of active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream such that the treated crude 1,3-butanediol stream has an active hydrogenation / dehydrogenation catalyst content in the range of 0 to 12.5 ppm.

39. The apparatus of any one of claims 32 to 38, wherein in the catalyst removal / deactivation unit, the crude 1,3-butanediol stream containing residual active hydrogenation / dehydrogenation catalyst is filtered using a primary filtration system and then filtered using a polishing filtration system.

40. The apparatus of any one of claims 32 to 39, wherein in the catalyst removal / deactivation unit, the crude 1,3-butanediol stream containing the residual active hydrogenation / dehydrogenation catalyst is filtered using a polishing filtration system having an effective pore size of 0.01 μm to 1 μm.

41. The device of claim 39 or claim 40, wherein the polishing filtration system is a blade system, a cartridge system, a bag system, a centrifugal system, a sedimentation system, a candle system, a magnetic system, or a combination thereof.

42. The apparatus of claim 39 or claim 40, wherein the polishing filtration system has an effective pore size of 0.01 μm to 0.5 μm.

43. The apparatus of claim 39 or claim 40, wherein the polishing filtration system has an effective pore size of 0.01 μm to 0.25 μm.

44. The apparatus of claim 39 or claim 40, wherein the polishing filtration system has an effective pore size of 0.01 μm to 0.1 μm.

45. The apparatus of any one of claims 32 to 44, wherein the active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream is deactivated in a catalyst removal / deactivation unit with a deactivating agent effective to block active catalytic sites on the hydrogenation / dehydrogenation catalyst.

46. ​​The apparatus of claim 45, wherein the active hydrogenation / dehydrogenation catalyst in the crude 1,3-butanediol stream is deactivated with a molar excess of deactivating agent relative to the catalyst present in the crude 1,3-butanediol stream.

47. An apparatus according to claim 45 or claim 46, wherein deactivation of the catalyst in the crude 1,3-butanediol stream is carried out by contacting the catalyst with a deactivating agent selected from the group consisting of hypochlorite, nitrate-based solutions or nitrite-based solutions, dissolved carbon monoxide, phosphine compounds, and combinations thereof.

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