PROCESS FOR THE MANUFACTURE OF ACROLIN

Abstract

The present invention relates to a process for the production of high purity acrolein, compatible with industrial use, from an aqueous solution containing reuterin from fermentation, said process involving separation of suspended solids followed by transformation of reuterin into acrolein in a distillation column. The acrolein produced in the context of the present invention can be used in various downstream applications, in particular as a raw material for the production of acrylic acid and its derivatives, methionine and its derivatives or glutaraldehyde and its derivatives. The acrolein produced in the context of the invention can have a high content of bio-based carbon within the meaning of ASTM D6866 or EN 16640 standards when bio-based raw materials are used to obtain the aqueous solution of reuterin from fermentation. Figure 1

Description

Title of the invention: PROCESS FOR PRODUCING ACROLIN Technical field

[0001] The present invention relates to a process for manufacturing high purity acrolein, compatible with industrial use, from an aqueous solution of reuterin derived from fermentation, said process involving a transformation of reuterin into acrolein in a distillation column. The acrolein produced within the scope of the present invention can be used in various downstream applications, in particular as a raw material for the manufacture of acrylic acid and its derivatives, methionine and its derivatives or glutaraldehyde and its derivatives. The acrolein produced within the scope of the invention can have a high content of bio-sourced carbon within the meaning of ASTM D6866 or EN 16640 standards when bio-sourced raw materials are used to obtain the aqueous solution of reuterin derived from fermentation. Prior art and technical problem

[0002] Acrolein is the simplest of the unsaturated aldehydes. It is also called 2-propenal, acrylaldehyde or acrylic aldehyde. By its structure, acrolein has a high reactive power thanks to the presence of its two reactive functions which are capable of reacting individually or together. This is why acrolein finds numerous applications, notably as a synthesis intermediate. In particular, it is a key intermediate for the synthesis of methionine, which has established itself as a supplement to animal feed as a substitute for fish meal. Acrolein is a synthesis intermediate in the industrial production of acrylic acid by gas-phase oxidation of propylene.Acrolein also leads, by reaction with methyl vinyl ether and then hydrolysis, to glutaraldehyde which has numerous uses in leather tanning, as a biocide in oil drilling, during the treatment of cutting oils, or as a chemical disinfectant and sterilizer for hospital equipment.

[0003] Acrolein is most often used as an intermediate in the synthesis of derivatives which are synthesized on the producer's site due to the toxicity of the product which leads manufacturers to avoid the storage and transport of this chemical product.

[0004] The most commonly used acrolein production process is based on the gas-phase catalytic oxidation reaction of propylene with atmospheric oxygen. The acrolein thus obtained can then be directly integrated into an acrylic acid manufacturing process. When acrolein also serves as a raw material for the synthesis of methionine or for fine chemical reactions, a purification section makes it possible to eliminate the by-products of the reaction, mainly carbon oxides, acrylic acid, acetic acid and acetaldehyde, and to obtain high purity acrolein, compatible with industrial use, as described for example in US patents 6515187 or US 3433840.

[0005] The industrial production of acrolein is therefore highly dependent on the raw material propylene obtained by steam cracking or catalytic cracking of petroleum fractions. This raw material of fossil origin also contributes to the increase in the greenhouse effect. It therefore appears necessary to have a process for synthesizing acrolein that is not dependent on the propylene resource and uses another, preferably renewable, material. Such a process meets the criteria associated with the concept of green chemistry in the broader context of sustainable development. In addition, there is a strong market demand for synthetic intermediates such as acrolein, used to obtain numerous products, to be able to be obtained from bio-sourced raw materials, such as glycerol.

[0006] The term "bio-sourced" applied to a product means that the said product is derived from biomass. It is accepted according to the European standard EN 16935 that the bio-sourced content of a product can be expressed by measuring its bio-sourced carbon content. The standards ASTM D6866 or EN 16640 describe such methods for determining the bio-sourced carbon content in products from the measurement of the 14C content.

[0007] It is known, as described in document FR 2882052, that glycerol can lead to the production of acrolein by catalytic dehydration in the gas phase at high temperature. This reaction is accompanied by multiple side reactions which require numerous separation steps or which lead to rapid deactivation of the catalyst.

[0008] Gas-phase methods for preparing acrolein from glycerol require complex catalysts and the vaporization of large quantities of water, which results in a significant energy cost. They generally give average yields, of the order of 60 to 70%, and generate a variety of by-products, which complicates the purification of acrolein, preventing the industrial development of said routes in the past.

[0009] Document CN 1394839 relates to a process for preparing reuterin from glycerol. Reuterin is defined as 3-hydroxypropionaldehyde (3HPA), 3HPA hydrates, 3HPA dimers and 3HPA oligomers. The yields of the reaction are not given. Acrolein, an intermediate product of the reaction, is obtained by passing pure vaporized glycerol over a catalyst of the potassium sulfate or magnesium sulfate type.

[0010] It has long been known, as described in US 4692027, that reuterin can be obtained from glycerol using microorganisms and that acrolein can be obtained from reuterin in a homogeneous acid medium, for example in the presence of sulfuric acid as described by RH Hall and ES Stern (J. Chem. Soc., 1950, 490-498).

[0011] Document EP 1669457 describes the fermentation of glycerol into reuterin. The conversion is remarkably high, of the order of 98% as described in Example 2. Example 5 describes the transformation of reuterin into acrolein by the addition of a 35% solution of hydrochloric acid into the fermentation medium containing said reuterin. The acrolein obtained remains in the fermentation medium and is directly transformed to obtain other derivatives.

[0012] Document US 2012 / 0034665 describes a method for obtaining aldehydes by fermentation from glycerol using microorganisms. In Example 11, it is described that acrolein is obtained from a fermentation medium containing reuterin by acid hydrolysis in the presence of hydrochloric acid at elevated temperatures. The acrolein obtained by this method is quantified in the fermentation medium and is not isolated therefrom.

[0013] Thus, even if acrolein is obtained with a high yield, it remains in solution and requires numerous treatments of the reaction medium, such as the neutralization of homogeneous acid catalysts and purification steps, before being obtained with a high purity, compatible with industrial use, for example to make methionine or glutaraldehyde. These constraints can prevent industrial development.

[0014] Document EP 3339282 describes the extraction of reuterin from an aqueous solution using chitosan. The disadvantage of this method is that the chitosan must be washed in order to recover the reuterin, which generates additional volumes of water.

[0015] Document WO 2022 / 073014 describes a process for continuously obtaining acrolein directly from a fermentation medium, by dehydration of reuterin followed by fractional distillation at a pressure below atmospheric pressure and at a temperature between 37°C and 52.4°C to avoid degradation of microbial cells during this operation, which greatly limits the kinetics of the dehydration reaction of reuterin into acrolein and water.

[0016] The publication by S. Oehmke and AP. Zeng (Eng. Life Sci., 2015,15, 133-139) presents different methods for obtaining acrolein from reuterin. The most efficient is the dehydration of reuterin in the presence of an acid having a Hammet constant Ho of -1 followed by distillation. This method is described in paragraph 2.3.5 by using 500 mL of orthophosphoric acid and 777 mL of fermentation medium containing reuterin.

[0017] Document US 10047381 describes the possibility of obtaining reuterin by fermentation in the absence of glycerol. Example 1 relates to obtaining reuterin by fermentation in the absence of carbon sources other than carbon dioxide, not necessarily biosourced. Example 10 does not describe in detail the conditions for converting reuterin into acrolein other than by specifying that this is carried out using acid catalysis.

[0018] The inventors have now surprisingly discovered that it is possible to obtain acrolein from an aqueous solution of reuterin from fermentation by directly obtaining acrolein of high purity, compatible with industrial use. Typical weight specifications for the industrial use of acrolein as a synthesis intermediate are: purity >94%, acetaldehyde <2.5% and water <3.5%.

[0019] Consequently, the invention proposes to provide a simple and easy-to-implement solution for obtaining high-purity acrolein, compatible with industrial use, from an aqueous solution of reuterin resulting from fermentation without the addition of an acid catalyst and by operating directly in a distillation column. Summary of the invention

[0020] The proposed technical solution consists of obtaining high purity acrolein, compatible with industrial use, from an aqueous solution of reuterin resulting from fermentation, after separation of the suspended matter, by heating said aqueous solution free of suspended matter directly in a single distillation column.

[0021] According to a first aspect, the present invention relates to a process for manufacturing high-purity acrolein, compatible with industrial use, from an aqueous solution of reuterin resulting from fermentation, said process comprising the following steps:

[0022] - Subjecting said aqueous solution of reuterin resulting from fermentation to a step of separating suspended matter and obtaining an aqueous flow of reuterin freed from suspended matter,

[0023] - Submit said aqueous flow of reuterine freed from suspended matter to a distillation step leading to obtaining on the one hand, an aqueous stream low in reuterin and acrolein and, on the other hand, a stream of high purity acrolein.

[0024] The process for manufacturing high purity acrolein from an aqueous solution of reuterin resulting from fermentation, said process comprises the following steps: - Separate the suspended matter from said aqueous solution of reuterin resulting from fermentation in order to obtain an aqueous flow of reuterin free of suspended matter, - Introducing said aqueous stream of reuterin freed from suspended matter into a distillation column jointly carrying out the conversion of reuterin into acrolein and the separation by distillation leading to obtaining, on the one hand, an aqueous stream low in reuterin and acrolein, and on the other hand, a stream of high purity acrolein.

[0025] According to one embodiment, the fermentation host for obtaining the aqueous solution of reuterin resulting from fermentation is a bacterium, a yeast, a fungus, an algae, a cyanobacterium or a mixture of several of these elements.

[0026] According to one embodiment, the reuterin contained in the aqueous solution of reuterin resulting from fermentation has a biosourced carbon content measured according to the ASTM D6866 or EN 16640 standards greater than or equal to 5%, preferably greater than or equal to 10%, preferably greater than or equal to 25%, preferably greater than or equal to 33%, preferably greater than or equal to 50%, preferably greater than or equal to 66%, preferably greater than or equal to 75%, preferably greater than or equal to 90%, preferably greater than or equal to 95%, preferably greater than or equal to 98%, preferably greater than or equal to 99%, advantageously equal to 100%.

[0027] According to one embodiment, the separation of suspended matter from the aqueous solution of reuterin resulting from fermentation is carried out by filtration.

[0028] According to one embodiment, the separation of suspended matter from the aqueous solution of reuterin resulting from fermentation is carried out by centrifugation.

[0029] According to one embodiment, the aqueous stream of reuterin freed from suspended matter is treated in a single distillation column.

[0030] According to one embodiment, the aqueous stream low in reuterin and acrolein obtained after the distillation step is totally or partially recycled upstream of the process.

[0031] According to a second aspect, the invention relates to high purity acrolein, compatible with industrial use, obtained according to the process described above.

[0032] According to one embodiment, the high purity acrolein, compatible with industrial use, obtained according to the process is then transformed into methionine and its derivatives. The invention relates to the use of acrolein to obtain methionine and its derivatives.

[0033] According to one embodiment, the high purity acrolein, compatible with industrial use, obtained according to the process is then transformed into acid acrylic and its derivatives. The invention relates to the use of acrolein to obtain acrylic acid and its derivatives.

[0034] According to one embodiment, the high purity acrolein, compatible with industrial use, obtained according to the process is then transformed into glutaraldehyde and its derivatives. The invention relates to the use of acrolein to obtain glutaraldehyde and its derivatives.

[0035] According to one embodiment, the high-purity acrolein, compatible with industrial use, obtained according to the method has a bio-sourced carbon content measured according to the ASTM D6866 or EN 16640 standards greater than or equal to 5%, preferably greater than or equal to 10%, preferably greater than or equal to 25%, preferably greater than or equal to 33%, preferably greater than or equal to 50%, preferably greater than or equal to 66%, preferably greater than or equal to 75%, preferably greater than or equal to 90%, preferably greater than or equal to 95%, preferably greater than or equal to 98%, preferably greater than or equal to 99%, advantageously equal to 100%. The invention also relates to the various downstream applications of this high-purity acrolein, compatible with industrial use, having a bio-sourced carbon content.

[0036] The present invention meets the need expressed in the state of the art. It makes it possible to generate high-purity acrolein, compatible with industrial use, without using a complex and expensive process.

[0037] The invention will now be described in more detail in the following description.

[0038] The attached [Fig. 1] illustrates the principle diagram of a particular mode of the method according to the invention. Detailed description of the invention

[0039] The invention aims to produce on an industrial scale high-purity acrolein, compatible with industrial use, from an aqueous solution of reuterin resulting from fermentation by distillation, after separation of the suspended matter, using a simple and easy-to-implement process.

[0040] The invention consists in producing on an industrial scale high purity acrolein, compatible with industrial use, from an aqueous solution of reuterin resulting from fermentation by heating said solution, after separation of the suspended matter, in a single distillation column, thus generating a gaseous phase mainly composed of acrolein which is condensed to give a condensate rich in acrolein.

[0041] According to the invention, said process for obtaining high-purity acrolein, compatible with industrial use, comprises the following steps which can be carried out sequentially or simultaneously, each in a batch, semi-batch, continuous or semi-continuous manner:

[0042] - Subjecting said aqueous solution of reuterin resulting from fermentation to a step of separating suspended matter and obtaining an aqueous flow of reuterin freed from suspended matter,

[0043] - Submit said aqueous flow of reuterine freed from suspended matter to a distillation stage leading to obtaining on the one hand, an aqueous stream low in reuterin and acrolein and, on the other hand, a stream of high purity acrolein, compatible with industrial use.

[0044] According to various embodiments, said method comprises the following characteristics, where appropriate combined. The contents indicated are expressed by weight, unless otherwise indicated. Within the ranges of values indicated, the limits are included.

[0045] Optionally, the method according to the invention may include one or more additional steps, which may be carried out sequentially or simultaneously, each in a batch, semi-batch, continuous or semi-continuous manner, such as:

[0046] - Recovery of these separated suspended materials;

[0047] - Recycling of the liquid aqueous phase poor in reuterin and acrolein from the distillation column;

[0048] According to one embodiment, the reuterin content of the aqueous reuterin solution resulting from fermentation varies between 0.1% and 10%, preferably between 1.5% and 5%.

[0049] According to one embodiment, the pH of the aqueous solution of reuterin resulting from fermentation varies from 3 to 12, preferably from 4 to 7.

[0050] According to one embodiment, the content of suspended matter in the aqueous solution of reuterin resulting from fermentation varies between 0.1% and 5%, preferably between 0.5% and 1%.

[0051] There are different methods for separating liquid and solid phases from liquids. The two most common technologies are plate centrifugal separation and filtration.

[0052] According to one embodiment, the separation of suspended matter is carried out by filtration with filters having a pore size between 0.01 and 0.9 μm.

[0053] According to one embodiment, the separation of the suspended matter is carried out by filtration at a temperature varying from 20°C to 50°C, preferably from 25°C to 40°C.

[0054] The filters often used in these separations are so-called tangential filters. This tangential filtration is the preferred method because the membranes used for tangential filtration have a long service life and can be regenerated in the process. The membranes used for this type of filtration are generally polymer materials. Their disadvantage is that they cannot withstand basic pH values (pH >12) due to soda during membrane cleaning operations. In fact, we use preferably ceramic or graphite membranes. The filtration carried out is a tangential microfiltration on flat, cartridge, tubular or multi-tubular modules and preferably with multi-channel tubular modules.

[0055] According to one embodiment, the separation of suspended matter is carried out by centrifugation, for example by separation technology involving a plate separator.

[0056] According to one embodiment, the separation of the suspended matter is carried out by centrifugation at a temperature varying from 20°C to 80°C, preferably from 25°C to 40°C.

[0057] According to one embodiment, the suspended materials once separated are recovered by hydrothermal gasification, combustion or spreading.

[0058] According to one embodiment, the gas resulting from the gasification is composed of 40-70% methane, 5-20% hydrogen and 20-40% carbon dioxide.

[0059] According to one embodiment, the suspended materials are mixed with the water necessary for the hydrothermal treatment before introduction into the gasification.

[0060] According to the embodiment, the hydrothermal gasification is carried out at a temperature between 350°C and 450°C and a pressure of 25 MPa.

[0061] According to one embodiment of the invention, the aqueous flow of reuterin freed from suspended matter obtained has a reuterin content of between 0.1% and 10%, preferably between 1.5% and 5%.

[0062] According to one embodiment, the aqueous flow of reuterin freed from suspended matter is preheated before introduction into the distillation column using one or more tubular or spiral exchangers in series.

[0063] According to one embodiment, the preheating of the aqueous flow of reuterin freed from suspended matter is done by electricity, steam, by a heat transfer fluid such as mineral oil or by recycling the aqueous phase poor in reuterin and acrolein from the distillation column.

[0064] According to one embodiment of the invention, the aqueous stream of reuterin freed from suspended matter is treated in a single distillation column to obtain, on the one hand, an aqueous stream low in reuterin and acrolein and, on the other hand, a stream of high-purity acrolein, compatible with industrial use.

[0065] According to one embodiment of the invention, the distillation column is a distillation column which comprises an equivalent of 10 to 50 theoretical stages, preferably 20 and 30 theoretical stages.

[0066] According to one embodiment, the internals used for the column may be valve trays or perforated overflow trays, cross-flow trays such as Dual Flow, Ripple Trays, Turbo Grid Shell, or ordered packing such as structured packing, such as Sulzer's Mellapack 250X.

[0067] According to one embodiment of the invention, the distillation column is fed in the lower third of this column, preferably between the theoretical plates 3 to 10 counted from the column foot.

[0068] According to one embodiment, the distillation column operates continuously or discontinuously.

[0069] According to one embodiment of the invention, the column operates under a pressure ranging from 0.07 MPa to 0.5 MPa. The distillation is carried out in a pressure range from 0.07 MPa to 0.5 MPa.

[0070] According to one embodiment of the invention, the operating temperature at the bottom of the column is between 90°C and 150°C.

[0071] According to one embodiment, the residence time in the column bottom is between 0.2 h and 3 h, preferably between 0.5 h and 1 h.

[0072] According to one embodiment of the invention, the head stream of the column is high purity acrolein, compatible with industrial use. The weight specifications obtained are typically: purity >94%, acetaldehyde <2.5%; water <3.5%.

[0073] According to one embodiment of the invention, the column operates with a reflux ratio (flow rate of condensed liquid returned to the column / flow rate of high purity acrolein withdrawn) of between a mass ratio of 1 / 1 to 5 / 1, preferably 2 / 1 to 3 / 1.

[0074] According to one embodiment of the invention, high purity acrolein, compatible with industrial use, is obtained in liquid form after condensation using one or more tubular or spiral exchangers.

[0075] According to one embodiment of the invention, this condensation is carried out by an assembly comprising several tubular or spiral exchangers in series.

[0076] According to one embodiment of the invention, one or more polymerization inhibitors are added to the condenser or at the top of the column. One or more polymerization inhibitors are injected during the condensation of the high-purity acrolein stream.

[0077] According to one embodiment of the invention, the polymerization inhibitors used in the process according to the invention are chosen from the inhibitors conventionally used in existing industrial processes for the production of acrolein. These include phenolic derivatives such as hydroquinone (HQ) and its derivatives such as hydroquinone methyl ether (EMHQ), 2,6-di-terbutyl-4-methyl phenol (BHT) or 2,4-dimethyl-6-terbutyl phenol (Topanol A); phenothiazine and its derivatives; nitroxide compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (4-OH-TEMPO); and amine compounds such as paraphenylenediamine derivatives.

[0078] According to a preferred embodiment of the invention, at least one of said polymerization inhibitors is hydroquinone (HQ).

[0079] According to one embodiment of the invention, oxygen, air or air said to be depleted to 7% O2 is injected at the bottom of the distillation column in order to improve the effectiveness of the polymerization inhibitors.

[0080] According to a preferred embodiment of the invention, the quantity of oxygen injected at the bottom of the distillation column corresponds to a content of 0.12% to 0.5% relative to the quantity of organic vapor in the column.

[0081] According to one embodiment of the invention, the aqueous stream low in reuterin and acrolein resulting from the distillation is recycled at least or partially upstream of the process.

[0082] According to one embodiment, this liquid aqueous flow is cooled in an exchanger before being recycled.

[0083] According to one embodiment, this exchanger is also supplied counter-currently by an aqueous flow of reuterine freed from suspended matter supplying the distillation column.

[0084] According to one embodiment, the aqueous stream low in reuterin and acrolein resulting from the distillation is cooled to a temperature between 20°C and 40°C, preferably between 30°C and 37°C, then injected upstream of the fermentation reactor with or without make-up water containing a portion of the inorganic salts and other materials necessary for the fermentation.

[0085] According to one embodiment, a portion of the recycled aqueous flow is purged to a combustion or gasification treatment system.

[0086] According to one embodiment, the purge rate relative to the total flow rate of the recycling of the aqueous flow varies between 0.1% and 1%, preferably between 0.3% and 0.8%.

[0087] According to one embodiment, the steps of recovering the separated suspended matter and recycling the liquid aqueous phase low in reuterin and acrolein from the distillation column are each carried out in batch, semi-batch, continuous or semi-continuous mode.

[0088] According to one embodiment of the method according to the invention, the reuterin contained in the aqueous solution of reuterin resulting from fermentation has a biosourced carbon content measured according to the ASTM D6866 or EN 16640 standards greater than or equal to 5%, preferably greater than or equal to 10%, preferably greater than or equal to 25%, preferably greater than or equal to 33%, preferably greater than or equal to 50%, preferably greater than or equal to 66%, preferably greater than or equal to 75%, preferably greater than or equal to 90%, preferably greater than or equal to 95%, preferably greater than or equal to 98%, preferably greater than or equal to 99%, advantageously equal to 100%.

[0089] According to another aspect, the invention relates to high-purity acrolein, compatible with industrial use, obtained according to this embodiment and containing a biosourced carbon content measured according to the ASTM D6866 or EN 16640 standards. greater than or equal to 5%, preferably greater than or equal to 10%, preferably greater than or equal to 25%, preferably greater than or equal to 33%, preferably greater than or equal to 50%, preferably greater than or equal to 66%, preferably greater than or equal to 75%, preferably greater than or equal to 90%, preferably greater than or equal to 95%, preferably greater than or equal to 98%, preferably greater than or equal to 99%, advantageously equal to 100% and its various downstream applications.

[0090] The invention also relates to the use of high purity acrolein containing a biosourced carbon content for the manufacture of methionine as well as its derivatives having a biosourced carbon content originating at least in part from the biosourced carbon content of acrolein.

[0091] The invention also relates to the use of high purity acrolein containing a biosourced carbon content for the manufacture of glutaraldehyde as well as its derivatives having a biosourced carbon content originating at least in part from the biosourced carbon content of acrolein.

[0092] The invention also relates to the use of high purity acrolein containing a biosourced carbon content for the manufacture of acrylic acid as well as its derivatives having a biosourced carbon content originating at least in part from the biosourced carbon content of acrolein.

[0093] According to a particular embodiment corresponding to [Fig. 1], the process for manufacturing high-purity acrolein, compatible with industrial use, can then be described as follows:

[0094] The aqueous solution containing reuterin from the fermentation (2) from the fermentation reactor RI feeds a solid-liquid separator SI which makes it possible to obtain an aqueous stream containing reuterin (4) and the separated suspended matter (3). The stream (4) is preheated in an exchanger E1 by the aqueous stream poor in reuterin and acrolein from the distillation column (11). The stream (4) feeds a distillation column C1 which generates on the one hand at the bottom an aqueous stream poor in reuterin and acrolein (9) and on the other hand a gaseous phase of high purity acrolein, compatible with industrial use (5). The gaseous phase of high purity acrolein (5) is condensed by a condenser C2 onto which polymerization inhibitors (6) are also injected.A part of the condensed flow is returned as reflux (8) in the distillation column Cl and another part is withdrawn in the liquid form of high purity acrolein, compatible with industrial use (7). The aqueous flow poor in reuterin and acrolein (9) is divided between a flow (11) which, after heat exchange in the exchanger El, is recycled upstream of the fermentation reactor RI and serves as a water make-up in addition to the flow (1) which contains all the elements necessary to carry out the . fermentation and a stream (10). The stream (10) serves as make-up water to the gasifier G1 treating the separated suspended matter (3) to transform it into gas (16), salt (15) and water (12). The water produced can be recycled totally or partially upstream of the gasifier G1 (13). The water produced in the gasifier G1 can be purged by the stream (14).

[0095] The following examples illustrate the present invention without, however, limiting its scope. EXPERIMENTAL PART

[0096] The pH of the different aqueous solutions was measured using a Mettler Toledo Five Easy Plus immersion probe device.

[0097] Reuterin titers were determined by the colorimetric method adapted from S. Vollenweider et al. (J. Agric Food Chem, 2003, 51, 3287-3293).

[0098] The simulation results are obtained with ASPEN V 12.1 software implementing Uniquac / Hayden O Connell.

[0099] The reuterin solution from a fermentation used in the experimental examples (excluding simulation) was obtained from glycerol and has a biosourced carbon content measured according to the ASTM D6866 standard greater than 95%. It was previously filtered to obtain the aqueous solution containing reuterin free of suspended matter, the biosourced carbon content of which measured according to the ASTM D6866 standard is greater than 95%.

[0100] The acrolein obtained in the experimental examples (excluding simulation) has a biosourced carbon content measured according to the ASTM D6866 standard greater than 95%.

[0101] EXAMPLE 1: Comparison between acrolein obtained by oxidation of propylene and acrolein obtained from an aqueous solution of reuterin from fermentation

[0102] 200 g of aqueous solution of reuterin from fermentation at a titer of reuterine of 1.2% and whose pH is 6.9 were introduced into an autoclave reactor with mechanical stirring and equipped with a cooled separation bridge connected to a container to receive the condensate.

[0103] The autoclave under a pressure of 0.5 MPa is heated to 150 °C for 1 h. The resulting gas phase was condensed to obtain 1.71 g of acrolein, which corresponds to a yield of 94%. The resulting liquid aqueous phase contains 0.06% of reuterin and traces (<0.01%) of acrolein and has a pH of 6.9.

[0104] The table below expresses the contents of organic products obtained in this process and compares them to those typically obtained during the production of acrolein by oxidation of fossil propylene (conventional process). There are notable differences in the contents, in particular in acetaldehyde (6 times higher in the propylene oxidation process), in allyl alcohol (4 times lower in the process propylene oxidation process), into ethanol (absent from the propylene oxidation process), into furfuraldehyde and benzaldehyde (present only in the propylene oxidation process).

[0105] [Tables 1] Carbon compounds (w %) Process by oxidation of propylene Process according to example 1 Acrolein 96.50 95.89 Acetaldehyde 1.22 0.19 Acetic acid 0.33 0.27 Allyl alcohol 0.23 1.11 Acetone 0.03 0.02 Furfuraldehyde 0.02 - Benzaldehyde 0.04 - Ethanol - 1.19 Others 1.61 1.29

[0106] Table 1: Comparison of the organic compositions obtained in the process for obtaining acrolein by oxidation of propylene and according to the invention.

[0107] EXAMPLE 2: Distillation of an aqueous solution containing reuterin from fermentation

[0108] The distillation of an aqueous stream of reuterin freed from suspended matter achieves the conversion of reuterin into acrolein and by-products in the column boiler due to the operating temperature and the residence time in the latter (see Example 1). Water is also present in significant quantity because the reuterin is introduced in the aqueous phase (reuterin content typically around 2%, 1.7% in Example 1). The separation of the compounds in the column to obtain high-purity acrolein, compatible with industrial use, follows the laws of liquid-vapor equilibrium.

[0109] Example 2 shows the results of the distillation of a mixture after reaction in the distillation column, simulated with the ASPEN V 12.1 software and using Uniquac / Hayden O Connell. The simulated column has 25 theoretical stages, operates under atmospheric pressure and is fed to tray 20. The top product is completely condensed.

[0110] The products implemented in the simulation are: [YES] Water

[0112] ACO: acrolein

[0113] ACETALD: acetaldehyde

[0114] Acetone: acetone

[0115] AllylOH: allylic alcohol

[0116] ETOH: ethanol

[0117] [Tables2] Feed Phase High purity acrolein (column top) Low reuterin and acrolein flow (column bottom) Temperature °C 20 51.9 99.4 Pressure MPa 0.2 0.1 0.1 Mass flow kg / h 100 2.0 98.0 Mass fraction w% WATER 0.98 0.026 >0.99 ACO 0.0200 0.97 0.0005742 ACETALD 4.80E-05 0.002 3.52E-07 ACETONE 4.80E-06 0 4.89E-06 ALLYLOH 0.0001 0 0.0001 ETOH 0.0002 0.0000 0.0002

[0118] Table 2: Simulation of a distillation column operating at atmospheric pressure.

[0119] It is found that the acrolein at the top of the column has a purity >97%, an acetaldehyde content of 0.2% and a water content of 2.6%, which corresponds to high purity acrolein, compatible with industrial use.

[0120] Heavier impurities in terms of boiling point such as ethanol and allyl alcohol are found at the bottom of the column.

[0121]

Claims

Claims

1. A process for manufacturing high-purity acrolein from an aqueous solution of reuterin obtained from fermentation, said process comprising the following steps: - Separating the suspended matter from said aqueous solution of reuterin obtained from fermentation in order to obtain an aqueous stream of reuterin freed from suspended matter, - Introducing said aqueous stream of reuterin freed from suspended matter into a distillation column jointly carrying out the conversion of reuterin into acrolein and the separation by distillation leading to obtaining, on the one hand, an aqueous stream low in reuterin and acrolein, and on the other hand, a stream of high-purity acrolein in which the contents by weight are: acrolein >94%, acetaldehyde <2.5% and water <3.5%.

2. A method according to claim 1, wherein the reuterin solution from fermentation has a reuterin content by weight of between 0.1% and 10%, preferably between 1.5% and 5%.

3. A method according to claim 1 or 2, wherein the aqueous solution of reuterin from fermentation has a pH between 3 and 12, preferably between 4 and 7.

4. A method according to any preceding claim, wherein the separation of suspended matter from said aqueous solution of reuterin from fermentation is carried out by filtration.

5. A method according to any one of claims 1 to 3, wherein the separation of suspended matter from said aqueous solution of reuterin from fermentation is carried out by centrifugation.

6. Process according to any one of the preceding claims, in which the distillation is carried out between 90°C and 150°C at the bottom of the column.

7. A process according to any preceding claim, wherein the distillation is carried out in a pressure range of from 0.07 MPa to 0.5 MPa.

8. Method according to any one of the preceding claims, in which the distillation column comprises from 10 to 50 theoretical stages, preferably from 20 to 30 theoretical stages.

9. A method according to any preceding claim wherein the steps of separating suspended matter and distilling are each carried out batchwise or continuously.

10. A method according to any one of the preceding claims, wherein the suspended matter once separated is recovered by hydrothermal gasification, combustion or spreading.

11. A process according to any one of the preceding claims, wherein the aqueous stream low in reuterin and acrolein from the distillation column is recycled in whole or in part upstream of the process.

12. A method according to any preceding claim, wherein one or more polymerization inhibitors are injected during the condensation of the high purity acrolein stream.

13. A method according to claim 12, wherein one of the polymerization inhibitors is hydroquinone.

14. Acrolein obtained by the process according to any one of the preceding claims.

15. Use of acrolein according to claim 14 for the manufacture of methionine and its derivatives.

16. Use of acrolein according to claim 14 for the manufacture of glutaraldehyde and its derivatives.

17. Use of acrolein according to claim 14 for the manufacture of acrylic acid and its derivatives.

18. A method according to any one of claims 1 to 14, wherein the reuterin contained in the aqueous solution of reuterin resulting from fermentation has a biosourced carbon content, measured according to ASTM D6866 or EN 16640 standards, greater than or equal to 5%.

19. Acrolein obtained according to the process of claim 18 having a biosourced carbon content, measured according to the ASTM D6866 or EN 16640 standards, greater than or equal to 5%.

20. Use of acrolein according to claim 19 for the manufacture of methionine and its derivatives.

21. Use of acrolein according to claim 19 for the manufacture of glutaraldehyde and its derivatives.

22. Use of acrolein according to claim 19 for the manufacture of acrylic acid and its derivatives.

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