KR20140131589A - Preparation of alpha, beta-unsaturated carboxylic acids and esters thereof - Google Patents

Abstract

The L-type zeolite, the modified L-type zeolite, or any combination thereof can be produced by catalytic conversion of an alpha, beta -unsaturated carboxylic acid and / or its ester through a reaction pathway including a dehydroxylation reaction and a selective esterification reaction ≪ / RTI > In some reaction paths, the dehydroxylation reaction and the esterification reaction can be carried out sequentially or simultaneously.

Description

PREPARATION OF ALPHA, BETA-UNSATURATED CARBOXYLIC ACIDS AND ESTERS THEREOF < RTI ID = 0.0 >

This application is a continuation-in-part of U. S. Application No. 61 / 608,053, filed March 7, 2012; U.S. Application No. 61 / 740,230, filed December 20, 2012; And U.S. Provisional Application No. 13 / 819,035, filed February 26, 2013.

The present invention relates to a process for preparing an alpha, beta -unsaturated carboxylic acids and / or esters thereof using catalysis.

Acrylic acid and its ester derivatives are important commercial chemicals used in the manufacture of polyacrylic acid esters, elastomers, superabsorbent polymers, floor polishes, adhesives, paints and the like. Historically, acrylic acid has been prepared by the hydroxycarboxylation of acetylene. This method uses nickel carbonyl and high pressure carbon monoxide, both of which are expensive and natural in nature. Other methods, such as the use of ethenone and ethylene cyanohydrin, have the same risks.

In an effort to reduce environmental impacts among others, lactic acid dehydroxylation has been investigated as a route for the production of acrylic acid since lactic acid can be derived from a renewable biological source such as sugar cane It is because. For the most part, solid catalysts have been investigated for use in both liquid phase and gaseous dehydroxylation reactions that convert lactic acid to acrylic acid. Certain solid catalysts that have been investigated include sodium phosphate supported on silica and weak acid supported on aluminosilicate or silica. It has been found that the dehydroxylation reaction carried out with some of these catalysts proceeds only at high temperatures in excess of 350 DEG C, which can add significant energy cost during scaling. Furthermore, many of the solid catalysts, including those mentioned above, showed poor selectivity to acrylic acid (i.e., multiple byproducts that need to be removed, which increases manufacturing costs) and low overall yields of the reaction. Therefore, the cost of producing acrylic acid through lactic acid dehydroxylation is still very high.

The present invention relates to a process for preparing an alpha, beta -unsaturated carboxylic acids and / or esters thereof using catalysis.

One embodiment of the present invention relates to a process for the production of an alpha -hydroxycarboxylic acid, an alpha -hydroxycarboxylic acid ester, a beta -hydroxycarboxylic acid, a beta -hydroxycarboxylic acid ester, an alpha -alkoxycarboxylic acid, Providing a composition comprising a reactant selected from the group consisting of alkoxycarboxylic acid esters, lactides, and any combination thereof; And performing a dehydroxylation reaction by contacting the composition with a dehydroxylation catalyst to produce a product comprising an alpha, beta -unsaturated carboxylic acid and / or an ester thereof, The dehydroxylation catalyst comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof.

Yet another embodiment of the present invention is a process for the preparation of an alpha -hydroxycarboxylic acid, an alpha -hydroxycarboxylic acid ester, a beta -hydroxycarboxylic acid, a beta -hydroxycarboxylic acid ester, an alpha -alkoxycarboxylic acid, providing a composition comprising a reactant selected from the group consisting of a? -alkoxycarboxylic acid ester, a lactide, and any combination thereof; And a step of simultaneously conducting an esterification reaction and a dehydroxylation reaction by contacting the composition with an alcohol and a catalyst to produce a product comprising an alpha, beta -unsaturated carboxylic acid ester, wherein the catalyst Comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof.

Yet another embodiment of the present invention provides a method of preparing a composition comprising: providing a composition comprising a reactant selected from the group consisting of? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid,? -Alkoxycarboxylic acid,? -Alkoxycarboxylic acid, and any combination thereof; Performing an esterification reaction by contacting the composition with an esterification catalyst and alcohol to produce an intermediate comprising an ester of the reactant; And a step of performing a dehydroxylation reaction by contacting an intermediate with a dehydroxylation catalyst to produce a product comprising an alpha, beta -unsaturated carboxylic acid ester, wherein the dehydroxylation catalyst Comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof.

Yet another embodiment of the present invention provides a method of preparing a composition comprising: providing a composition comprising a reactant selected from the group consisting of? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid,? -Alkoxycarboxylic acid,? -Alkoxycarboxylic acid, and any combination thereof; Performing an esterification reaction by contacting the composition with an alcohol to produce an intermediate comprising an ester of a reactant, wherein the esterification reaction is performed with an exogenous catalyst; And performing a dehydroxylation reaction by contacting an intermediate with a dehydroxylation catalyst to produce a product comprising an alpha, beta -unsaturated carboxylic acid ester, wherein the dehydroxylation catalyst Comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof.

Yet another embodiment of the present invention is a process for the preparation of an alpha -hydroxycarboxylic acid, an alpha -hydroxycarboxylic acid ester, a beta -hydroxycarboxylic acid, a beta -hydroxycarboxylic acid ester, an alpha -alkoxycarboxylic acid, providing a composition comprising a reactant selected from the group consisting of a? -alkoxycarboxylic acid ester, a lactide, and any combination thereof; And performing the dehydroxylation reaction by contacting the composition with a dehydroxylation catalyst in the presence of a carrier gas to produce a product comprising an alpha, beta -unsaturated carboxylic acid and / or an ester thereof Wherein the carrier gas comprises greater than about 90% carbon dioxide.

Another embodiment of the present invention is a process comprising producing acrylic acid or acrylic acid ester from a reactant derived from a fermentation process comprising a biological catalyst and a biological source, wherein the biological source is selected from the group consisting of glucose, sucrose, glycerol, Wherein the reactant is selected from the group consisting of? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Alkoxycarboxylic acid,? -Alkoxycarboxylic acid ester,? -Alkoxycarboxylic acid esters, lactides, and any combination thereof.

Another embodiment of the present invention is a process comprising producing acrylic acid or acrylic ester from a reactant through a chemical process comprising a chemical catalyst and a biological source, wherein the biological source is selected from the group consisting of glucose, sucrose, glycerol, Wherein the reactant is selected from the group consisting of? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Alkoxycarboxylic acid,? -Alkoxycarboxylic acid ester, A carboxylic acid, a beta -alkoxycarboxylic acid ester, a lactide, and any combination thereof.

Features and advantages of the present invention will become apparent to those of ordinary skill in the art by reading the following description of the preferred embodiments.

The following drawings are included to illustrate certain aspects of the invention and are not to be seen as exclusive examples. The present invention may be considered as equivalents to the various modifications, adaptations, combinations, and forms and functions that come within the purview of the ordinary skill in the art.
Figure 1 illustrates a non-limiting example of some of the other reaction pathways described herein.
Figure 2 provides an exemplary system schematic for use in preparing an alpha, beta -unsaturated carboxylic acid and / or ester thereof in accordance with at least some embodiments of the present invention.
Figure 3 provides a chemical route for the conversion of triglycerides to acrylic acid using a chemical catalyst.
Figure 4 provides a chemical pathway for converting glucose to acrylic acid using a chemical catalyst.
Figure 5 provides conversion percentages and selectivities of reactions performed with L-type zeolites in accordance with at least some embodiments of the present invention.
Figure 6 provides conversion percentages and selectivities of reactions performed with L-type zeolites and regenerated L-type zeolites in accordance with at least some embodiments of the present invention.
Figure 7 provides conversion percentages and selectivities of reactions performed with L-type zeolites in accordance with at least some embodiments of the present invention.

The present invention relates to a process for preparing an alpha, beta -unsaturated carboxylic acids and / or esters thereof using catalysis.

The present invention is based, in at least some examples, on the L-type zeolite catalysts which selectively (i. E., High conversion percentages) and selectively produce an alpha, beta -unsaturated carboxylic acid (e.g., acrylic acid) and / or an ester thereof from a lactic acid- Lt; / RTI > As exemplified herein, surprisingly, in some embodiments, L-type catalysts are found to more effectively and selectively prepare an alpha, beta -unsaturated carboxylic acid (e.g., acrylic acid) and / or an ester thereof from a lactic acid-like reactant lost. As a result, the reaction pathways and catalysts described herein are provided, in some embodiments, to produce acrylic acid from lactic acid on an industrial scale in a cost-effective and naturally-friendly manner.

It is to be understood that when "about" is used before the numerical value herein, "about" In some ranges of numerical ranges, it should be noted that some of the lower limits listed may be greater than some of the upper limits listed. Ordinarily the skilled artisan will recognize that the selected subset will need to select an upper limit that exceeds the selected lower limit.

As used herein, the term "reaction pathway" refers to a reaction or series of reactions for converting a reactant into a product comprising an alpha, beta -unsaturated carboxylic acid or ester thereof, wherein the intermediate is a reaction or a series of reactions As shown in FIG. In some embodiments, the reaction path of the present invention may comprise a dehydroxylation reaction using a dehydroxylation catalyst comprising an L-type zeolite. In some embodiments, the reaction pathway of the present invention may further comprise an esterification reaction.

As used herein, the term "dehydroxylation reaction" refers to the removal of water from the reactants. The term " dehydroxylation reaction "is also known in the art as" dehydration reaction ".

Figure 1 illustrates a non-limiting example of some other reaction pathway of the present invention. For example, in some embodiments shown in reaction path 1 of Figure 1, starting with a starting composition comprising the reactants, the reaction pathway of the present invention is obtained via esterification reaction (1A), an intermediate comprising an ester of the reactant , Followed by a dehydroxylation reaction (1B) to obtain a product comprising an ester of an alpha, beta -unsaturated carboxylic acid. In another embodiment, shown in reaction path 2 of Figure 1, starting with a starting composition comprising the reactant, the reaction pathway of the present invention is via reaction (2A) with an intermediate containing an alpha, beta -unsaturated carboxylic acid And then obtaining a product comprising an ester of an alpha, beta -unsaturated carboxylic acid via esterification reaction (2B). In another embodiment, shown in reaction path 3 of Figure 1, starting with a starting composition comprising the reactant, the reaction pathway of the present invention comprises an alpha, beta -unsaturated carboxylic acid via a dehydroxylation reaction (3) To obtain the product. In another embodiment, shown in Reaction Route 4 of Figure 1, starting with the starting composition comprising the reactants, the reaction pathway of the present invention comprises the simultaneous dehydroxylation and esterification reactions (4) To obtain a product comprising an ester of a carboxylic acid.

Reactants suitable for use with the reaction pathways of the present invention include, but are not limited to,? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Hydroxycarboxylic acid,? -Hydroxycarboxylic acid ester,? -Alkoxycarboxylic acid, alkoxycarboxylic acid esters, and the like, and any combinations thereof. Suitable esters mentioned above may be C ₁ -C ₁₀ alkyl esters. Specific examples of the reactants include lactic acid, salts of lactic acid (e.g., its calcium, ammonium, magnesium, sodium, and potassium salts), alkyl esters of lactic acid, lactide, methyl lactate, butyl lactate, 3-hydroxypropionic acid, 3 But are not limited to, an alkyl ester of hydroxypropionic acid, methyl 3-hydroxypropionate, butyl 3-hydroxypropionate, lactamide, and any combination thereof. In some embodiments, the reactants may be in the form of a solid, liquid, melt or gas. Further, the reactants may be substantially pure chiral reactants or racemic mixtures of chiral reactants such as D (-) lactic acid, L (+) lactic acid, DD lactide, LLactide, racemic mixture of D / L lactic acid, Or a racemic mixture of D / L lactide.

Reactants suitable for use with the reaction pathways of the present invention may be prepared by any known method. In some embodiments, the reactants may be biologically-derived, chemically-derived, or a combination thereof. Examples of biologically-derived reactants can be found in International Patent Application No. PCT / US11 / 50707, entitled " Catalytic Dehydroxylation of Lactic Acid and Lactic Acid Esters ", the entirety of which is incorporated herein by reference. As a non-limiting example, lactic acid may be fermented broth prepared from a microorganism that uses and / or metabolizes sucrose, glucose, etc. from sugarcane, beets, whey, etc. (for example, acid-resistant allogenic lactic acid bacteria) (e.g., ammonium lactate) present in the broth.

In some embodiments, the [alpha] -hydroxycarboxylic acids (e.g., lactic acid and derivatives thereof) described herein can be obtained from a fermentation broth. In some embodiments, the fermentation broth described herein can be derived from a culture of bacterial species comprising E. coli and Bacillus coagulans selected to produce lactic acid on a commercial scale. In some embodiments, the fermentation broth described herein may be derived from a culture of a filamentous fungi species selected for lactic acid production. In some embodiments, the fermentation broth described herein may be derived from yeast species known to be capable of producing lactic acid on an industrial scale. Suitable microorganisms for producing lactic acid on a commercial scale include, in some embodiments, Escherichia coli, Bacillus coagulans , Lactobacillus delbruckii , L. bulgaricus , Lactobacillus, L. thermophilus , L. leichmanni , L. casei , L. fermentii , Streptococcus thermophilus , Streptococcus thermophilus , Streptococcus thermophilus , S. lactis , S. faecalils , Pediococcus sp , Leuconostoc sp , Bifidobacterium sp , Rhizopus oryzae, ( Rhizopus oryzae ) and many yeast species in industrial applications. Those of ordinary skill in the art having benefit of the present invention will recognize any suitable combination of the foregoing teachings.

The fermentation process to produce an a-hydroxycarboxylic acid, such as lactic acid, may in some embodiments be a batch process, a continuous process, or a mix process thereof. A number of carbohydrate materials derived from natural sources can be used as feedstock with the fermentation of the a-hydroxycarboxylic acids described herein. For example, sucrose from sugarcane and beets, lactose from glucose, hydrolyzed starch, whey containing maltose and dextrose, glycerol from the biodiesel industry, and combinations thereof, Lt; RTI ID = 0.0 > of < / RTI > The microorganisms can be made to have the ability to use the pentose sugars derived from the hydrolysis of cellulose biomass to prepare the [alpha] -hydroxycarboxylic acids described herein. In some embodiments, microorganisms having the ability to use both a 6-carbon containing sugar such as glucose and a 5-carbon containing saccharide such as xylose simultaneously in the production of lactic acid are preferred biocatalysts in fermentation production of lactic acid. In some embodiments, the hydrolyzate derived from the inexpensively available cellulosic material contains both the C-5 carbon and the C-6 carbon containing sugar and the C-5 carbon and the C-6 carbon containing saccharide in the manufacture of lactic acid Biocatalysts that can be used simultaneously are highly desirable in that they produce low-cost lactic acid suitable for conversion to acrylic acid and acrylic acid esters.

In some embodiments, the fermentation broth for the production of lactic acid may comprise acid-resistant homologous lactic acid bacteria. By "homologous" it is meant that the bacterial strain produces substantially only lactic acid as the fermentation product. Acid-resistant allogenic lactic acid bacteria are generally isolated from corn-soaked water in commercial corn milling. Acid resistant microorganisms that can be grown at elevated temperatures may be preferred in some embodiments. In some preferred embodiments, microorganisms capable of producing at least 4 g of lactic acid per liter of fermentation fluid (and more preferably 50 g of lactic acid per liter) can be used in the fermentation process described herein.

In some embodiments, the fermentation broth may be used after various unit operations such as filtration, acidification, polishing, and concentration are made at various times of manufacture, or after processing by one or more of the above-described unit operations. In some embodiments, if the fermentation broth contains about 6 to about 20% lactic acid on a weight / weight (w / w) basis, the lactic acid may be recovered in a concentrated form. Recovery of the lactic acid in concentrated form from the fermentation broth can be accomplished by a plurality of methods and / or a combination of methods known in the art.

In the fermentation process described herein, at least one alkali material (for _{example, NaOH, CaCO 3, (NH} 4) 2 CO 3, NH 4 HCO 3. NH 4 OH, KOH, or a any combination of a) the growth medium Lt; RTI ID = 0.0 > alkaline < / RTI > With the addition of ammonium hydroxide to the fermentation medium, ammonium lactate can be accumulated in the fermentation broth. Since ammonium lactate has a high solubility in aqueous solution, it can have an increased concentration in the fermentation broth. One method for obtaining lactic acid from a fermentation broth containing ammonium lactate is to remove lactic acid from the fermentation broth after microfiltration and ultrafiltration of the fermentation broth by continuous ion exchange (CIX), virtual mobile layer chromatography (SMB), bipolar membrane electrodialysis (EDBM) Ion exchange, or liquid-liquid extraction. Samples from fixed bed ion exchange can, in some embodiments, undergo bipolar electrodialysis to obtain lactic acid in the form of a concentrated free acid.

In some embodiments, the reactants (e. G., Lactic acid mil lactic acid esters) are reacted with biological sources (e. G., Glucose, sucrose, and glycerol) via one or more chemical processes using chemical catalysts without involving any fermentation processes using biocatalysts. ). ≪ / RTI > For example, lactic acid and lactic acid esters derived from biological sources can be prepared from acrylic acid and acrylic acid esters via dehydroxylation and esterification, as described above.

In another example, glycerol may be used as a starting material and a lactic acid and then acrylic acid may be prepared using a chemical process that does not involve any fermentation process (e.g., FIG. 3). The worldwide production of biodiesel by trans-esterification of fatty acid esters derived from vegetable oils has increased several fold over the last few decades to partially replace the use of fossil-hazardous diesel fuel. Glycerol, a by-product from the biodiesel industry, may be suitable as a starting material for the production of acrylic acid and acrylic esters according to the process described in the present invention, or may be a preferred starting material in some embodiments.

For example, one approach to preparing lactic acid from glycerol is to use a thermochemical conversion of glycerol to lactic acid via an intermediate compound such as glyceraldehyde, 2-hydroxypropanal and pyruvic aldehyde at temperatures above about 550 < 0 & Process can be used. However, thermochemical conversion processes can cause significant degradation of the pyruvic aldehyde and lactic acid at these elevated temperatures, thereby resulting in reduced selectivity for lactic acid production. In some instances, the use of chemical catalysts mediating the dehydrogenation reaction responsible for the production of lactic acid may allow a reduction in temperature, thereby improving selectivity and reducing degradation. In some instances, the heterogeneous catalyst may be recovered and reused multiple times, may not require buffering, and may be easily modified to operate on a continuous flow process instead of a batch process to increase throughput and turnaround time Thus, heterogeneous catalysts may be preferred. This advantage can be converted to a significant reduction in operating costs and waste disposal.

Suitable heterogeneous catalysts for dialing glycerol with lactic acid may include metals including, but not limited to, nickel, cobalt, copper, platinum, palladium, ruthenium, rhodium and any combination thereof. In some embodiments, the heterogeneous catalyst may be optionally supported on a support, including, but not limited to, carbon, silica, alumina, titania, zirconia, zeolite and the like. In some embodiments, the reaction mixture may further comprise additional hydrogen or oxygen. In some embodiments, the selected catalyst may be used without additional hydrogen or oxygen.

In some embodiments, the heterogeneous catalyst comprising metals may be used in the presence of, but not limited to, alkali components, including alkali, alkaline earth metal hydrates, solid bases, and combinations thereof. In some preferred embodiments, the conversion of glycerol to lactic acid may use a copper based catalyst with a base promoter, but no reducing agent or oxidizing agent is used in a single port reaction.

In some embodiments, acrylic acid may be prepared from sucrose. In some instances, sucrose can be hydrolyzed to produce glucose and fructose. In some instances, fructose could be converted directly to lactic acid in near stoichiometric yield using a chemical catalyst, but conversion of glucose to lactic acid was observed to yield a yield of about 64%. Thus, some embodiments include hydrolyzing sucrose to obtain glucose and fructose; Isomerizing glucose to obtain fructose; And conversion of the mixed fructose to lactic acid using a chemical catalyst. Similarly, some embodiments include hydrolyzing starch to obtain glucose; Isomerizing glucose to obtain fructose; And conversion of the mixed fructose to lactic acid using a chemical catalyst.

Conversion of fructose (from a mixed or separate source) to lactic acid using a chemical catalyst can be achieved by the reaction of dihydroxyacetone (DHA) with dihydroxyacetone (DHA) by reverse-aldol reaction of fructose, Glyceraldehyde (GLY), which in turn can be converted to pyruvic aldehyde (PAL) by dehydration and rearrangement. The PAL can be further converted into the desired alkyl lactate or lactic acid under the action of a Lewis acid in an alcohol-containing solution or water. Thereafter, in some embodiments, lactic acid and alkyl lactates can be converted to acrylic acid and acrylate esters using a zeolite catalyst at about 330 < 0 > C.

Lewis acidic zeolites, such as Sn-Beta, surprisingly showed high activity and selectivity for the conversion of sucrose, glucose and fructose to esters of lactic acid. In some embodiments, the solid Lewis acidic catalyst may comprise a zeotype material, and in some embodiments may include, for example, Sn, Pb, Ge, Ti, Zr and / or < RTI ID = 0.0 > Hf. ≪ / RTI > For example, the solid Lewis acidic catalyst may comprise an oleophilic material and tetravalent Sn and / or tetravalent Ti.

Examples of suitable zeolitic materials may include, but are not limited to, the structural forms BEA, MFI, MEL, MTW, MOR, LTL or FAU, such as zeolite beta and ZSM-5. Other examples of suitable dendritic materials may include TS-1. These various examples of the dendritic material may be Lewis acidic porous amorphous materials, and in some embodiments may preferably have a structural type of MCM-41 or SBA-15.

The reaction for preparing lactic acid from sucrose, glucose and fructose may be carried out in batch mode or in a fluidized reactor at a temperature of from about 50 ° C to about 300 ° C, preferably from about 100 ° C to about 220 ° C, and most preferably from about 140 ° C Deg.] C to about 200 < 0 > C.

Referring back to the reaction path of the present invention, in some embodiments, the starting composition described herein may comprise a reactant and a solvent. Suitable solvents for use with the reactants described herein include water, alcohols such as methanol, ethanol, propanol, iso-propanol, n-propanol, butanol, iso-butanol, n-butanol, But are not limited to, tetrahydrofuran, tetrahydrofuran, methylene chloride, toluene, xylene, and the like, and any combinations thereof. In some embodiments, the solvent may be in a supercritical state.

In some embodiments, the initiator compositions described herein are prepared from a lower limit of about 5 wt%, 10 wt%, 15 wt%, 25 wt%, or 50 wt% based on the weight of the starting composition to about 95 wt% The concentration can range from any lower limit to any upper limit, and the concentration can range from any upper limit to any upper limit, Includes any subset. In some embodiments, the initiator compositions described herein are prepared from a lower limit of about 5 wt%, 10 wt%, 15 wt%, 25 wt%, or 50 wt% based on the weight of the starting composition to about 95 wt% The solvent may comprise a solvent in a concentration ranging from an upper limit value in the range of from about 1% by weight to about 90% by weight, 85% by weight, 75% by weight, or 50% by weight and the concentration may range from any lower limit to any upper limit, Includes any subset.

In some embodiments, where the reactant comprises an ester (e. G., An ester of lactic acid), the initiator composition described herein may be present in an amount of about 1 wt%, 2 wt%, 3 wt%, or 4 wt% % Water content in the upper limit of about 10 wt.%, 9 wt.%, 8 wt.%, 7 wt.%, 6 wt.%, Or 5 wt.% Based on the weight of the starting composition from the lower limit of% May range from any lower limit to any upper limit and includes any subset therebetween. As a non-limiting example, the starting composition may comprise methyl lactate, methanol, and water, wherein the water content is from about 3.5% to about 5% by weight relative to the weight of the starting composition. As a non-limiting example, the starting composition may comprise butyl lactate, butanol and water, wherein the water content is from about 1% to about 5% by weight, based on the weight of the starting composition.

In some embodiments, the starting compositions described herein may be subjected to one or more additional processing steps prior to starting the reaction pathway of the present invention. The forecourt of the additional process steps may include, but is not limited to, filtration, acidification, crystallization, pervaporation, electrodialysis, ion exchange, liquid-liquid extraction, and virtual mobile phase chromatography. As a non-limiting example, an additional process step may be used to enrich the lactic acid content and remove impurities from the fermentation broth from which the lactic acid is prepared.

Some of the reactions described herein involve contacting the reactants and / or intermediates with a catalyst (e.g., a dehydroxylation reaction and / or an esterification reaction). In some embodiments, contacting is effected within the system (e.g., introducing the starting composition into the reactor holding the catalyst), outside the system (mixing the catalyst into the starting composition prior to introduction into the reactor) Lt; / RTI > The systems and processes are described in greater detail herein.

In some embodiments, the dehydroxylation reaction useful in the reaction pathways of the present invention involves contacting the reactants and / or intermediates with the dehydroxylation catalysts described herein. In some embodiments, the dehydroxylation catalysts described herein can be liquid, solid, or a combination thereof. In some embodiments, the reactants and / or intermediates may be in a vapor phase and / or a liquid phase. As a non-limiting example, in some embodiments, the dehydroxylation reaction useful in the reaction path of the present invention may involve contacting the reactants and / or intermediates in a vapor phase with a solid dehydroxylation catalyst.

In some embodiments, the dehydroxylation catalysts suitable for use with the present invention include zeolites, modified zeolites, acid catalysts, weak acid catalysts, strong acid catalysts, neutral catalysts, base catalysts, ion exchange catalysts, zeolites, And any combination thereof. In some embodiments, preferred dehydroxylation catalysts can include, but are not limited to, L-type zeolites and / or modified zeolites. As used herein, zeolites refer to microporous solids and medium aluminosilicate members, also known as "molecular sieves ". Zeolites general molecular formula _{M x / n [(AlO 2} ) x (SiO 2) y] zH having a ₂ O, where n is the charge of the metal cation (M), M is typically Na ^+, K ⁺ or Ca ²⁺ , And z is the number of moles of highly fluctuating water. Examples of the zeolite may be a light (natrolite) with sodium of the formula _{Na 2 Al 2 Si 3 O 10} · 2H 2 O. As used herein, the term "modified zeolite " refers to a zeolite modified by (1) an inorganic salt and / or by impregnation with an oxide and / or (2) ion exchange.

The zeolite is believed to contain channels (also known as voids or pores) occupied by cation and water molecules. Without being bound by theory, it is believed that the dehydroxylation reaction performed in the presence of the zeolite can be advantageously made in the channel of the zeolite. Thus, the size of the channel affects, inter alia, the diffusion rate of the chemical through it, thus affecting the selectivity and conversion efficiency of the dehydroxylation reaction. In some embodiments, the diameter of the channels in the zeolite catalyst suitable for use with the dehydroxylation reactions disclosed herein can be from about 1 to about 20 A, more preferably from about 5 to about 10 A, ≪ / RTI >

Suitable zeolites for use as the dehydroxylation catalysts described herein can be derived from naturally-occurring materials and / or can be chemically synthesized. Further, zeolites suitable for use as the dehydroxylation catalysts described herein can, in some embodiments, have a crystal structure corresponding to L-type zeolite, Y-type zeolite, X-type zeolite, Lt; / RTI > Other types of zeolites such as A, X, Y, and L are different in their composition, pore volume, and / or channel structure. The A- and X-type zeolites have a Si-Al molar ratio of about 1 and a tetrahedral aluminosilicate skeleton. The Y-type zeolite has a molar ratio of Si to Al of about 1.5 to about 3.0 and a skeletal phase similar to the skeletal phase of the X-type zeolite. The L-type zeolite has a molar ratio of Si to Al of about 3.0 and a one-dimensional pore size of about 0.71 nm, resulting in a cavity of about 0.48 nm x 1.24 nm x 1.07 nm.

In some embodiments, the modified zeolite may be prepared by performing ion exchange with a zeolite. In some embodiments, modified zeolites suitable for use as the dehydroxylation catalyst described herein may have associated ions therewith, such ions being H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ . Mg ²⁺ , Ca ²⁺ , La ²⁺ , La ³⁺ , Ce ²⁺ , Ce ³⁺ , Ce ⁴⁺ , Sm ²⁺ , Sm ³⁺ , Eu ²⁺ , Eu ³⁺ , But are not limited thereto. As described herein, "[ion associated] - [crystal structure] -type zeolite" is used to abbreviate a specific zeolite and / or modified zeolite. For example, L-type zeolites with potassium ions associated with them are abbreviated as KL-type zeolites. In another example, the X-type zeolite with potassium and sodium ions contained therein is abbreviated as Na / KX-type zeolite. In some embodiments, the L-type zeolite can be modified by techniques such as calcination, ion exchange, an initial wet impregnation method, a hydrotreating with steam, any mixing method thereof, and any combination thereof.

In some embodiments, the modified zeolite suitable for use as the dehydroxylation catalyst described herein may have more than one cation associated therewith. In certain embodiments, a modified zeolite suitable for use as the dehydroxylation catalyst described herein may comprise a first cation and a second cation, wherein the molar ratio of the first cation to the second cation is from about 1: 100: 1, 500: 1, 100: 1, 1000: 1, 1: 500, 1: 100, 1:50, 1:10, 1: 5, 1: 3, 1: The molar ratio may be in the range of an upper limit of 50: 1, 10: 1, 5: 1, 3: 1, 2: 1, or 1: 1 wherein the molar ratio may range from any lower limit to any upper limit, ≪ / RTI > As a non-limiting example, a modified zeolite suitable for use as the dehydroxylation catalyst described herein may include, in some embodiments, H / Na-L-type zeolite, Li / Na-X-type zeolite, Na / KY -Form zeolite, and any combination thereof. As a non-limiting example, a modified zeolite suitable for use as the dehydroxylation catalyst described herein may, in some embodiments, be Na / KL-type zeolite, Na / KY-type zeolite, and / Type zeolite, wherein the ratio of sodium ion to potassium ion is at least about 1:10.

It is contemplated that in some embodiments where the H ^& lt ^{; + &} gt ^; on zeolite is not exchanged and the H ^& lt ^{; + &} gt ^; phase is exchanged on the zeolite, the catalytic acidity of the prepared modified zeolite may be reduced. The scale of the reduction in acidity can be determined through appropriate experimentation. For example, ASTM (American Society for Testing and Materials) D4824 can be used to determine the acidity of a modified zeolite. Briefly, this experiment uses ammonia chemisorption to determine the acidity of the modified zeolite, where a volumetric measurement system is used to obtain the amount of chemisorbed ammonia.

In some embodiments, the modified zeolite may be a zeolite impregnated with an inorganic salt and / or an oxide thereof. In some embodiments, inorganic salts suitable for use in making the modified zeolites described herein include, but are not limited to, phosphates, sulphates, molybdates, tungstates, tinates, antimonates, and the like, and calcium, sodium, magnesium, aluminum, , And any combination thereof. The term " cation " Non-limiting way of example, in some embodiments, the modified zeolite is sodium phosphate (e.g., monosodium phosphate (NaH ₂ PO _4), disodium phosphate (Na ₂ HPO _4), and trisodium phosphate (Na ₃ PO ₄₎₎ , Potassium phosphate compounds, sodium aluminum phosphate compounds (e.g. Na ₈ Al ₂ (OH) ₂ (PO ₄ ) ₄ ), and any combination thereof.

In some embodiments, a modified zeolite suitable for use as the dehydroxylation catalyst described herein is a zeolite having a weight per gram of zeolite modified from the lower limit of about 0.1, 0.2, or 0.4 mmol per gram of modified zeolite At a concentration in the range of 1.0 mmol, 0.8 mmol, or 0.6 mmol upper limit, the concentration can range from any lower limit to any upper limit and any concentration between them It also includes a subset. As a non-limiting example, an impregnated L-type zeolite suitable for use with the dehydroxylation reaction described herein may be a Na / KL-type zeolite impregnated with a sodium phosphate compound, wherein the ratio of sodium ions is about More than 1:10.

One of ordinary skill in the art will recognize additional steps to prepare the modified zeolite by ion exchange and / or impregnation. For example, above all, drying and / or calcination may be necessary to remove water from the pores and / or convert the salt to an oxide. Furthermore, and above all, proper storage may be necessary to prevent the modified zeolite from being at least partially inactivated during the storage process. As used herein, the term " calcined "refers to a process in which a zeolite catalyst undergoes a thermal treatment process to remove volatile fractions in the presence of air.

Suitable acid catalysts for use as the dehydroxylation catalysts described herein may be liquid, solid or a combination thereof. Examples of suitable liquid acid catalysts for use as the dehydroxylation catalysts described herein include, but are not limited to, sulfuric acid, hydrogen fluoride, phosphoric acid, paratoluene sulfonic acid, and the like, and any combination thereof Do not.

In some embodiments, the solid acid catalyst is contacted with a solution containing a hydroxide or hydrated hydroxide of a metal corresponding to Group 4 of the periodic table with a sulforous component, calcining the mixture between about 350 ° C and about 800 ° C . ≪ / RTI > In some embodiments, the solid acid catalyst may be higher than the acidity of 100% sulfuric acid. In some embodiments, the solid acid catalyst may be more preferred than the liquid acid catalyst because, among other things, the solid acid catalyst may exhibit higher catalytic capabilities and lower causticity, which can be easily removed at the end of the reaction This is because it has advantages.

Suitable weak acid catalysts for use as the dehydroxylation catalysts described herein include titania catalysts, SiO ₂ / H ₃ PO ₄ catalysts, Al ₂ O ₃ catalysts (eg, Al ₂ O ₃ .HF catalysts), Nb ₂ O ₃ / SO ₄ ^-2 catalyst, a Nb ₂ O ₅ .H ₂ O catalyst, a phosphotungstic acid catalyst, a phosphomolybdic acid catalyst, a silicomolybdic acid catalyst, a silicotungstic acid catalyst, an acidic polyvinylpyridine hydrogen chloride catalyst Commercially available PVPH ⁺ Cl ^- ®), hydrated acidic silica catalysts (eg, ECS-3® available from Engelhard), and the like, and any combinations thereof.

Suitable basic catalysts for use as the dehydroxylation catalysts described herein include ammonia, polyvinylpyridine, metal hydroxides, Zr (OH) ₄ , amines of the general formula NR ¹ R ² R ³ wherein R ¹ , R ² , R ³ is independently selected from hydrogen, a hydrocarbon containing from 1 to 20 carbon atoms, a side chain group or functional group including, but not limited to, alkyl and / or aryl groups containing from 1 to 20 carbon atoms, etc. and But is not limited to, any combination thereof. In some embodiments, ammonium lactate can be advantageously used as a reactant for the production of acrylic acid because, when undergoing a high temperature treatment, the ammonium lactate decomposes to release ammonia (basic catalyst) and lactic acid.

Suitable solid oxides for use as the de-hydroxylated catalyst described herein, TiO2 (for example, Ti-0720® available purchased from _{Engelhard), ZrO 2, Al 2} O 3, SiO 2, ZnO 2, SnO 2, WO 3 _{, MnO 2, Fe 2 O 3} , V 2 O 5, SiO 2 / Al 2 O 3, ZrO 2 / WO 3, ZrO 2 / Fe 2 O 3, ZrO 2 / MnO 2 , etc., and include his any combination of But are not limited thereto. The above discussion of ion exchange and immersion in relation to L-type zeolites will be fully applied to solid oxides.

A solid dehydroxylation catalyst suitable for use as the dehydroxylation catalyst described herein, in some embodiments, has a high surface area. In some embodiments, a solid dehydroxylation catalyst suitable for use as the dehydroxylation catalyst described herein has a surface area of at least about 100 m ² / g. In some embodiments, the solid dehydroxylation catalyst suitable for use as the dehydroxylation catalyst described herein has a catalytic activity of about 100 m ² / g, 125 m ² / g, 150 m ² / g, or 200 m ² / g may have a surface area ranging from a lower limit of about 500 m ² / g, 400 m ² / g, 300 m ² / g, or 250 m ² / g, Up to an upper limit, and includes any subset therebetween.

In some embodiments, the dehydroxylation catalyst described herein can be present in the dehydroxylation reaction described herein at a molar ratio of catalyst to reactant / intermediate of at least about 1: 1000. In some embodiments, the dehydroxylation catalysts described herein are from about 1: 1000, 1: 500, or 1: 250 to about 1: 1. 1: 10, or 1: 100 in the molar ratio of catalyst to reactant / intermediate, wherein the molar ratio ranges from any lower limit to any upper limit value And includes any arbitrary subset thereof.

In some embodiments, the dehydroxylation reaction may use more than one of the dehydroxylation catalyst types described herein. In some embodiments, the weight ratio of the two dehydroxylation catalysts may be greater than about 1:10. In some embodiments, the weight ratio of the two dehydroxylation catalysts can range from a lower limit of about 1: 10, 1: 5, 1: 3 or 1: 1 to about 10: 1, 5: 1, 3: 1, where the weight ratio can range from any lower limit to any upper limit and includes any subset of them. Those of ordinary skill in the art having the benefit of this disclosure will appreciate the expansion of this ratio to the three or more dehydroxylation catalysts described herein.

In some embodiments, the dehydroxylation reaction useful in the reaction path of the present invention is carried out at a temperature ranging from a lower limit of about 100 DEG C, 150 DEG C, or 200 DEG C to about 500 DEG C, 400 DEG C, or an upper limit of 350 DEG C Where the temperature can range from any lower limit to any upper limit and includes any subset of them.

Polymerization inhibitors can be used in conjunction with the dehydroxylation reactions described herein to prevent polymerization of the alpha, beta -unsaturated carboxylic acids or esters thereof prepared according to the reaction pathways. In some embodiments, the polymerization inhibitor may be introduced into the reaction pathway of the present invention, for example, in the starting composition, during the dehydroxylation reaction, during the esterification reaction, and any combination thereof. Examples of polymerization inhibitors may include, but are not limited to, 4-methoxyphenol, 2,6-di-tert-butyl-4-methylphenol, sterically hindered phenols and the like.

In some instances, the dehydroxylation reaction of the present invention may be carried out in the absence of any dehydroxylation catalyst described herein and in the presence of an inert solid support such as a glass, ceramic, porcelain, or metallic material present in the reaction vessel Lt; / RTI > In some embodiments, the supercritical solvent may be useful in the starting composition for the dehydroxylation reaction performed in the absence of the dehydroxylation catalyst described herein.

In some embodiments, the esterification reaction useful in the reaction pathways of the present invention may involve contacting the reactants and / or intermediates with an alcohol (as reactant and / or solvent) and an esterification catalyst as described herein.

In some embodiments, the esterification reaction can be carried out in the presence of an alcohol as a solvent and / or as a reactant. In some embodiments, examples of suitable alcohols include alkyl alcohols such as C ₁ -C ₂₀ alcohols such as methanol, ethanol, propanol, iso-propanol, n-propanol, butanol, iso-butanol, (E.g., cyclohexanol, cyclopentanol, and the like), and alcohols (e.g., cyclohexanol, cyclohexanol, cyclohexanol, But is not limited to, any combination thereof.

In some embodiments, the fermentation broth described herein containing a salt of an alpha -hydroxycarboxylic acid (e.g., ammonium lactate) as described herein can be used as a reactant for the esterification reaction. The use of such salts may require a two-step esterification reaction, for example, decomposing ammonium lactate into ammonia and lactic acid, and then reacting the lactic acid with the alcohol described herein. Since all of these two stages of esterification reaction steps are reversible and can reach equilibrium, in some embodiments, excess reactants can be used and / or the products are continuously removed to minimize the adverse reaction and improve the overall yield .

In some embodiments, the esterification reactions described herein may be performed, among other things, in a batch process or a reactive distillation process. In the esterification reaction described herein, an esterification catalyst may be used, including the process described above to improve the efficiency of the esterification process. In some embodiments, the catalyst may be a homogeneous catalyst or a non-homogeneous catalyst. A homogeneous catalyst suitable for enhancing the rate of the esterification process of the present invention may, in some embodiments, include, but is not limited to, a strong inorganic acid, a strong organic acid, and any combination thereof. In some preferred embodiments, the homogeneous catalyst for use with the esterification reaction described herein may be hydrochloric acid. Non-uniform catalysts suitable for enhancing the rate of the esterification process of the present invention include, in some embodiments, cationic resin catalysts such as the AMBERLYST-15 catalyst (strong acid, sulfonic acid, crosslinked styrenedivinyl available from Rohm and Haas But are not limited to, macroscopic polymeric resins based on benzene copolymers. In some embodiments, the esterification catalysts described herein may comprise a mixture of a tin salt and an aluminate, wherein the tin salt is reacted with an aluminum salt to form and / or form a stannous aluminate A first tin ion can be provided. In some embodiments, the esterification catalysts described herein may comprise a mixture of a primary tin salt, an aluminate, and finely divided sand. In some embodiments, the esterification catalyst described herein may comprise gas CO ₂ .

The rate of the esterification reaction can be varied by many different methods. For example, an increase in the concentration of the catalyst, an increase in the ratio of alcohol to lactic acid, and / or an increase in temperature may be used to increase the rate of esterification. One of ordinary skill in the art having the benefit of this disclosure has the problem that when changing the rate of the esterification reaction, for example, the volatility reactants such as some alcohols may evaporate in increasing the temperature, which can be solved using a cooler .

In some embodiments, the pressure of the esterification reaction described herein may range from about 1 atmosphere to about 10 atmospheres. For example, this pressure should be sufficient to maintain the aluminum lactate and alcohol in the liquid phase in the reaction mixture.

In some embodiments where an ammonium lactate reactant is used, the molar ratio of alcohol to ammonium lactate in the esterification reaction may be from about 1: 1 to about 10: 1, more preferably from about 1: 1 to about 5: 1, and includes any subset thereof.

In some embodiments, the efficiency of the esterification reaction can be influenced by the amount of water present. In some embodiments, the desiccant may be used in the esterification reactions described herein to reduce the water content. In some embodiments, the desiccant may extract water from the vapor phase during the recovery of the alcohol. In some embodiments, the desiccant may function by adsorption absorption of water into the desiccant. Preferred desiccants do not absorb alcohol, especially the alcohol used in the esterification reaction. In some embodiments, the desiccant may be an inert porous component. Exemplary desiccants may include, but are not limited to, diatomaceous earth, molecular sieves, zeolites, and the like, and any combination thereof. Commercially available components having a surface area of about 12 cm ² / g to 20 cm ² / g may, in some embodiments, be suitable for use as a desiccant.

Controlling the water content in the esterification reaction can also be achieved and / or improved by using a hydrophilic pervaporation membrane. The use of a pervaporation membrane in the esterification process can advantageously provide multiple functions, including, but not limited to, helping to control the water content, minimizing adverse reactions, and helping to separate the lactic acid ester by distillation have.

Controlling the water content in the esterification reaction can also be achieved and / or improved by using an azeotroping agent such as benzene.

In some embodiments, any combination of the recited ones can be used to control the water content in the esterification reaction process described herein.

In some embodiments using ammonium lactate reactants, ammonia can be released during the esterification reaction. In some embodiments, the esterification reaction can be performed at a high temperature reflux and the inert gas can be used to remove ammonia from the cooler. In some embodiments, the ammonia released during the downstream process of the fermentation broth containing ammonium lactate is condensed, compressed and reused as a source of alkali into the fermentation vessel to maintain the pH of the microorganism growth medium.

On a large scale, reactive distillation, in some embodiments, can be used in conjunction with resin-esterification catalysis to minimize the adverse reaction of the esterification reaction as described above, thereby providing high purity with purity close to 100% theoretical yield Can be prepared. In some embodiments, the lactic acid may be dissolved (or dispersed) in the alcohol and then passed through a reaction zone having a packed bed of the esterification catalyst. The product stream from the outlet of the reaction zone contains excess alcohol and the desired end product which can then be fed into the distillation column to separate and purify the formed ester. Lactic acid esters with high boiling points can, in some embodiments, be separated from the alcohol via fractional distillation.

In some embodiments, the esterification catalysts described herein may be liquid, solid, or a combination thereof. In some embodiments, the reactants and / or intermediates may be in a vapor phase and / or a liquid phase. In some embodiments, suitable esterification catalysts for use with the reaction pathways of the present invention include ion exchange resins, aluminum silicate compounds (e.g., zeolites and / or modified zeolites described herein), and the like, and any combinations thereof But is not limited thereto.

Under certain circumstances, the esterification reaction can be carried out in the absence of any external catalyst. The esterification reaction in the absence of an external catalyst is preferred. As used herein, the term "external catalyst" refers to a chemical that is added to any chemical reaction from an external source to lower the activation energy required for the chemical reaction and to improve the overall rate of the chemical reaction. The term "external catalyst" is used to distinguish a situation where some of the components of the chemical reaction may themselves act as catalysts. The esterification reaction may, in some embodiments, be carried out without the addition of any external catalyst, as described in International Application No. PCT / US11 / 50707, entitled " Catalytic Dehydration of Lactic Acid and Lactic Acid Esters & , The entirety of which is incorporated herein by reference. For example, in some embodiments, the fermentation broth can be heated to about 100 < 0 > C in the presence of the appropriate alcohol without the addition of any external catalyst to achieve formation of the lactic acid ester.

Examples of ion exchange resins suitable for use with the esterification reactions described herein include, in some embodiments, AMBERLYST® products such as AMBERLYST® 70 (a strong acid ion exchange resin available from Rohm and Haas, and Dow Chemicals) But is not limited thereto.

In some embodiments, the esterification reactants and the dehydroxylation reactants can be used in the same reaction vessel to enable the co-reaction path of the present invention (e.g., reaction path 4 of FIG. 1).

In some embodiments, the esterification reactants and the dehydroxylation reactants can be used sequentially in two different reaction vessels to enable the sequential reaction path of the present invention (e.g., reaction path 1 or 2 in Figure 1) . Alternatively, the dehydroxylation reaction and the esterification reaction can be carried out sequentially in the same reactor. For example, reaction path 1 can be carried out such that the top of the reaction chamber contains an esterification catalyst, the bottom of the reaction chamber contains a dehydroxylation catalyst, and the two catalysts are separated by an inactive material have. Reactants with appropriate alcohols, in some embodiments, may be introduced into the top of the reaction chamber. As the reactants pass through the esterification catalyst, the reactants are esterified and the formed ester passes through the inert material and reaches the bottom of the reaction chamber where the dehydroxylation reaction takes place and the ester of the?,? - unsaturated carboxylic acid The formation of acrylate esters for lactic acid reactants, for example.

In some embodiments, the dehydroxylation catalyst can occupy the top of the reaction vessel, and the esterification catalyst occupies the bottom of the reaction vessel, between which the inactive material, which may be suitable to perform reaction path 2, . For example, the reactants can be fed to the top of the reactor, after which the alpha, beta -unsaturated carboxylic acids produced in the top of the reaction vessel can pass through the inert material, enter the bottom of the reactor, An ester of an alpha, beta -unsaturated carboxylic acid can be prepared in contact with an alcohol, which can be collected at the bottom of the reactor. In some embodiments, the alcohol may be in the vapor phase. In some embodiments, if the dehydroxylation catalyst and the esterification catalyst are the same, both the top and bottom of the reactor are filled with catalyst and the inactive material disposed therebetween may be optional.

In some embodiments, the esterification reaction and the dehydroxylation reaction may occur simultaneously in the same reaction vessel as described in reaction path 4. In some embodiments for achieving a co-reaction, the reactants comprising the desired alcohol may be simultaneously introduced to the top of the reactor vessel and the corresponding ester of the alpha, beta -unsaturated carboxylic acid may be collected at the bottom of the reactor vessel .

In some embodiments, aluminum silicate compounds (e.g., zeolites and / or modified zeolites) may function both as esterification and dehydroxylation catalysts. In some embodiments, catalysts that function both as esterification and dehydroxylation catalysts can be used in the sequential reaction path of the present invention (e.g., reaction pathways 1 and 2 of Figure 1) or in the co-reaction pathway of the present invention 1 reaction path 4) can be used.

In some embodiments, the esterification reaction useful in the reaction path of the present invention is carried out at a temperature ranging from a lower limit of about 50 ° C, 100 ° C, 150 ° C, or 200 ° C to an upper limit of about 500 ° C, 400 ° C, or 350 ° C Where the temperature can range from any lower limit to any upper limit and includes any subset therebetween.

In some embodiments, the reaction pathway of the present invention may be used to prepare an alpha, beta -unsaturated carboxylic acid or ester thereof. Examples of alpha, beta -unsaturated carboxylic acids or esters thereof may include, but are not limited to, acrylic acid, alkyl esters of acrylic acid (e.g., methyl acrylate and butyl acrylate), and the like, and any combinations thereof.

Surprisingly, it has been found that the use of butyl lactate in the starting composition reduces the formation of unwanted by-products seen in the use of other alkyl lactates such as methyl lactate, and butyl lactate is preferably converted to acrylic acid rather than butyl acrylate .

In some embodiments, the reaction pathway of the present invention can produce an aldehyde (e.g., acetaldehyde). Thus, the reaction pathway may optionally further comprise an oxidation reaction to convert acetaldehyde to acetic acid.

In some embodiments, the reaction pathway of the present invention is at least about 40%, in some embodiments at least about 50%, in some embodiments at least about 55%, in some embodiments at least about 60%, in some embodiments at least about 65% In some embodiments, at least about 70%, in some embodiments at least about 75%, in some embodiments at least about 80%, in some embodiments at least about 85%, in some embodiments at least about 90% , In some embodiments greater than about 95%, in some embodiments greater than about 98%, or in some embodiments greater than about 99%.

In some embodiments, the selectivity of the reaction pathway of the present invention is in an amount greater than or equal to 40 mole percent of the product, in some embodiments greater than or equal to 50 mole percent, in some embodiments greater than or equal to 55 mole percent, , In some embodiments in an amount greater than or equal to 65 mole percent, in some embodiments in an amount greater than or equal to 70 mole percent, in some embodiments in an amount greater than or equal to 75 mole percent, in some embodiments less than or equal to 80 mole percent, In some embodiments greater than or equal to 85 mole percent, in some embodiments greater than or equal to 90 mole percent, in some embodiments greater than 95 mole percent, in some embodiments greater than 98 mole percent, or in some embodiments less than 99 mole percent / RTI > unsaturated carboxylic acids and / or their esters in an amount of at least < RTI ID = 0.0 > 1% < / RTI >

The conversion efficiency and / or selectivity of the reaction pathway may depend, among other things, on the temperature, the concentration of reactants and / or intermediates, and / or the reactants and / or intermediates used to calcine the composition of the catalyst, dehydroxylation and / And the duration of contact between the dehydroxylation and / or esterification catalyst.

In some instances, it has been observed that reactor metallurgy can have a negative impact on acrylic acid selectivity in the lactic acid dehydroxylation reaction. Without being bound by theory, it is believed that the lactic acid feed can cause corrosion of the reactor walls, resulting in leaching of the metal components from the reactor walls. For example, when a stainless steel reactor is used in a dehydroxylation reaction, metal components such as nickel, chromium and iron can be leached into the product stream and / or accumulated on the dehydroxylation catalyst , Which can be detected, for example, using inductively coupled plasma (ICP) analysis. The leached metal can act as a catalyst capable of forming a by-product. For example, the nickel released from the walls of a stainless steel reactor can act as a hydrogenation catalyst, leading to the formation of propionic acid from acrylic acid. Similarly, iron released from the walls of a stainless steel reactor can function as a dicarboxylation catalyst, leading to the formation of acetaldehyde. In addition, some of the components leached from the reactor wall can lead to polymerization of lactic acid and acrylic acid. Thus, in some embodiments, the reactor material may be selected to be corrosion resistant to any of the products formed through the dehydroxylation reaction with the feed or catalyst. Examples of suitable reactor materials capable of alleviating unwanted catalytic reactions include, but are not limited to, titanium, silanized stainless steel, quartz, and the like. Reactors with reduced corrosion levels are provided for higher selectivity for acrylic acid and to reduce byproduct formation.

As a non-limiting example, similar to Reaction Routes 2 and 3 illustrated in FIG. 1, some embodiments are illustrated by reaction of a dehydrocyclization catalyst comprising L-type zeolite with a starting composition as described herein, / RTI > unsaturated carboxylic acids and / or esters thereof, in order to produce the alpha, beta -unsaturated carboxylic acids and / or their esters. When an alpha, beta -unsaturated carboxylic acid is prepared, some embodiments may further comprise performing the esterification reaction by contacting the esterification catalyst and the alcohol with an alpha, beta -unsaturated carboxylic acid, beta -unsaturated carboxylic acid ester. Specifically, in some embodiments, the starting composition may comprise lactic acid, and then the product of the dehydroxylation reaction may comprise acrylic acid, and the product of the esterification reaction may include an acrylic acid ester .

As another non-limiting example, similar to Reaction Route 1 illustrated in Figure 1, some embodiments include esterification reactions by contacting the esterification reaction with an initiator composition comprising an esterification catalyst and an alcohol as described herein, To thereby produce an ester derivative; To carry out the dehydroxylation reaction secondarily by contacting the ester derivative with a dehydroxylation catalyst comprising an L-type zeolite, thereby preparing an alpha, beta -unsaturated carboxylic acid ester. Specifically, in some embodiments, the starting composition may comprise lactic acid, the product of the esterification reaction may comprise a lactic acid ester, and the product of the dehydroxylation reaction may comprise an acrylic acid ester.

As another non-limiting example, similar to Reaction Route 4 as illustrated in Figure 1, some embodiments include contacting a catalyst comprising L-zeolite and an alcohol with a starting composition comprising the carboxylic acid derivative described herein To carry out the hydroxylation reaction and the esterification reaction simultaneously, thereby preparing an?,? - unsaturated carboxylic acid ester. Specifically, in some embodiments, the starting composition may comprise lactic acid, and the common dehydroxylation reaction and esterification reaction may comprise an acrylic acid ester.

Any suitable system may be used in conjunction with performing the reaction pathways of the present invention. In some embodiments, a system suitable for use in conjunction with performing the reaction pathways of the present invention may include a reactor and may optionally include at least one preheater (e.g., to preheat the starting composition, solvent, reactants, etc.) ), Pumps, heat exchangers, coolers, material handling equipment, and the like, and any combination thereof. Examples of suitable reactors include batch reactors, plug-flow reactors, continuously-stirred tank reactors, packed-bed reactors, slurry reactors, but are not limited to, reactors, fixed-bed reactors, fluidized-bed reactors, and the like. The reactor may, in some embodiments, be single-staged or multi-staged. Further, the reaction path of the present invention may, in some embodiments, be performed batch-wise, semi-continuously, continuously, or any combination thereof.

As described above, the reaction path or a portion thereof may be carried out in a liquid phase and / or a vapor phase. Thus, carrier gas (e.g., argon, nitrogen, carbon dioxide, etc.) may be used in conjunction with the reaction pathways and / or systems described herein. In some embodiments, the reaction path, or a portion thereof, may be performed in a liquid phase and / or a vapor phase, and in some embodiments substantially a single inert gas (e.g., a carrier gas comprised of a single carrier gas in excess of about 90% Of an inert gas. In some embodiments, the reaction path, or a portion thereof, may be performed in a liquid phase and / or vapor, and in some embodiments may be substantially carbon dioxide (e.g., a carrier gas comprised of carbon dioxide in excess of about 90%).

In some embodiments, the reaction path of the present invention has a weight hourly space velocity ("WHSV") of from about 0.2 hr ^-1 to about 1.5 hr ^-1 , or preferably from about 0.5 hr ^-1 to about 1.2 hr ^-1 Speed.

In some embodiments, the product of the reaction pathway of the present invention is a reaction product of an alpha, beta -unsaturated carboxylic acid and / or ester thereof, and other components (e.g., solvent, polymerization inhibitor, byproduct, unreacted reactant, / RTI > and / or an esterification catalyst). Thus, the products of the reaction pathway of the present invention can be separated and / or purified into the components of the product (including mixtures of components). In some embodiments, the solvent is separated from the product of the reaction pathway of the present invention and can be regenerated for reuse. The regenerating solvent can advantageously produce less waste and can reduce the cost of producing the alpha, beta -unsaturated carboxylic acid and / or its esters.

Suitable techniques for separation and / or purification include, but are not limited to, distillation, extraction, reactive extraction, adsorption, absorption, stripping, crystallization, evaporation, sublimation, diffusion separation, adsorption bubble separation, membrane separation, fluid- Combinations thereof, but are not limited thereto.

Those of ordinary skill in the art having the benefit of this disclosure will recognize that at least some of the various dehydroxylation and / or esterification catalysts described herein can be regenerated either in situ or ex situ . For example, in some embodiments, the zeolite and / or the modified zeolite may be regenerated at elevated temperatures in the presence of oxygen (e. G., Air or oxygen diluted in an inert gas).

For a better understanding of the present invention, the following examples of preferred or exemplary embodiments are provided. The following examples should not be read in any way to limit or define the scope of the invention.

Example

1. Abbreviations and calculations

Table 1 provides equations for some calculations used throughout the Examples section.

Liquid Spatio-Temporal Rate ("LHSV")

Gas hourly space velocity ("GHSV")

Weight hourly space velocity ("WHSV")

Reactant Conversion ("Cnv _X ")

Product selectivity ("Sel _Y ")

here:
C represents a catalyst;
mL _c represents the volume of the catalyst;
mL represents the volume of the liquid;
X represents the reactant;
Y represents the component of the product;
F _lf is the liquid flow rate (mL / h);
F _gf is the gas flow rate (mL / h);
V _C is the volume of _C in the reactor;
G _X is the mass of X;
G _C is the mass of _C in the reactor;
[X] _in is the molar concentration of X _in the starting composition;
[X] _out is the molar concentration of X in the outlet flow; And
[Y] _out is the molar concentration of Y in the outlet flow.

II. catalyst

A plurality of catalysts were prepared in the following manner. The catalysts used in the examples presented herein are described in W.R. Grace Company or TOSOH USA, Inc. and subjected to appropriate chemical modification as required.

"HY-type zeolite" was prepared as a 1/16 "pellet with a SiO ₂ : Al ₂ O ₃ ratio of 6: 1 and a Na ₂ O content of 0.28% .HY type zeolite was calcined at 500 ° C. for 3 hours And stored in sealed vials in a desiccator until use.

The "Na-Y-type zeolite" was prepared as a 1/16 "extrudate with a 5: 1 ratio of SiO ₂ : Al ₂ O ₃ and 13 wt% Na ₂ O. The Na- And stored as described in the HY-type zeolite.

"K ⁴ / Na-Y-type zeolite" was prepared by quadrupling the Na-Y-type zeolite with aqueous KCl solution. 30 g of Na-Y zeolite (pulverized and filtered to 20-60 mesh particle size) was slowly added to 150 mL of 2M KCl solution and the suspension was stirred for 2 hours in a Rotavapor at 60 ° C. The flask was removed and the supernatant was replaced with fresh KCl solution for 2 ^nd exchange. The same procedure was repeated two more times. The resulting sample was washed multiple times until Cl ^- was absent, and initially dried at 30 < 0 > C and 60 < 0 > C for 2 hours at 2-3 mmHg. The catalyst was transferred to a vacuum oven, allowed to stand overnight at 110 ° C, calcined at 500 ° C for 3 hours, and stored in a previously used desiccator.

"KL-type zeolite" was prepared to have a SiO ₂ : Al ₂ O ₃ ratio of 7: 9 and a K ₂ O content of 14.4 dry weight percent. The KL-type zeolite was pulverized and squeezed to a size of 20 to 60 mesh. The zeolite material was calcined as described above for the HY-type zeolite.

"Li / KL-type zeolite" was prepared by treating 15 g of KL-type zeolite with 150 mL of 1 M LiCl solution at 30 DEG C overnight. The resulting sample was washed a number of times until no Cl ^- was removed and initially dried at 30 ° C and 60 ° C at 2 to 3 mmHg for 4 hours. The catalyst was further dried in a vacuum oven at 110 DEG C and finally calcined at 450 DEG C for 3 hours.

"Na / KL-type zeolite" was prepared by slowly adding 200 mL of 1M NaCl aqueous solution to 15 g of KL-type zeolite. The suspension was stirred at 30 < 0 > C for 6 hours. After removing the supernatant, the solid was washed several times until Cl- was cleared. After drying under vacuum, the catalyst was calcined at 450 DEG C for 3 hours as described for the H-Y-type zeolite.

The "Na ² / KL-type zeolite" was prepared in the same manner as the Na / KL-type zeolite, but after the first exchange, the zeolite was treated as the second part of the fresh NaCl solution.

The "Na ³ / KL-type zeolite" was prepared in the same manner as the Na ² / KL-type zeolite, but after the second exchange, the zeolite was treated with the third part of the fresh NaCl solution.

The "Na ⁴ / KL-type zeolite" was prepared in the same manner as the Na ³ / KL-type zeolite, but after the third exchange, the zeolite was treated with the fourth part of the fresh NaCl solution.

"(7.1% Na ₂ HPO ₄ ) / KL-type zeolite" was prepared by an initial wetting method using KL-type zeolite. According to this method, a solution of Na ₂ HPO ₄ .7H ₂ O (2.164 g Na ₂ HPO _{4 in} 13 mL deionized water) was added slowly to 13 g of KL-type zeolite. The resulting slurry was kept in a sealed beaker for 2 hours. Subsequently, the impregnated solids were transferred to a conventional oven and dried overnight at 120 < 0 > C.

"(7.1% Na ₂ HPO ₄ ) / Na ³ / KL-type zeolite" was prepared in the same manner as (7.1% Na ₂ HPO ₄ ) / KL-type zeolite using Na ³ / KL-type zeolite.

"(2.13% Na ₂ HPO ₄ ) / KL-type zeolite" was prepared in the same manner as (7.1% Na ₂ HPO ₄ ) / KL-type zeolite using less Na ₂ HPO ₄ .

"(3.55% Na ₂ HPO ₄ ) / KL-type zeolite" was prepared in the same manner as (7.1% Na ₂ HPO ₄ ) / KL-type zeolite using less Na ₂ HPO ₄ .

"(14.0% Na ₂ HPO ₄ ) / KL-type zeolite" was prepared in the same manner as (7.1% Na ₂ HPO ₄ ) / KL-type zeolite using more Na ₂ HPO ₄ .

III. Reaction protocol

Reaction protocol I (continuous vapor phase dehydroxylation of methyl lactate). The reaction was carried out in a fixed bed reactor system by passing the starting composition on the vapor phase (described in each of the following examples below) through a solid catalyst (described in each of the following examples). A specific illustration of the reactor system is shown in Figure 2 and is further described below. The reactor was made of 1/2 "/ 12" stainless steel tubing, with three 10 μm stainless steel filters at the bottom of the tube serving as a support for the catalyst layer. A 10.5 mL catalyst was packed in the middle of the reactor using a GC column packing vibrator. The top of the reactor receives four identical inlet filters, thereby providing an 8 mL porous stainless steel contact area for pre-evaporation and / or gas-liquid mixing. The reactor tube was placed in a column heater (Flatron CH 30) equipped with a high output heating tape (Omega, 470 W, Part # STH051-060). The temperature of the reactor was monitored by a thermocouple coupled to the outer wall of the reactor tube and the temperature of the reactor was controlled by a temperature controller (M-260, J-KEM Scientific model). The liquid hourly space velocity ("LHSV") was varied from about 0.50 h- ¹ to about 1.10 h- ¹ (based on 10.5 mL catalyst volume and about 0.1 to about 0.2 mL / min liquid flow rate). Nitrogen flow rates were varied at 4.4 and 5.6 mL / min.

Reaction protocol II (continuous vapor phase dehydroxylation of butyl lactate). The reaction was carried out by methods and systems similar to those described for the methyl lactate dehydroxylation. The liquid hourly space velocity ("LHSV") was held constant at 1.2 h ^-1 (based on 5 mL catalyst volume and 0.1 mL / min liquid flow rate). The nitrogen flow rate was also kept constant at 5.0 mL / min.

Reaction protocol III (continuous vapor phase dehydroxylation of lactic acid). The reaction was carried out by methods and systems similar to those described for the methyl lactate dehydroxylation. The reactor is made of 5/16 "/ 6" stainless steel tubing and the catalyst is held between two plugs of quartz sand (50-70 mesh particle size). In this set of experiments, the liquid hourly space velocity ("LHSV") was varied from about 0.48 h ^-1 to about 2.4 h ^-1 (based on a 0.04 cc / min liquid flow rate, from about 1 cc to about 7 cc For a range of catalyst volumes). Specific reaction parameters are listed below for each individual embodiment.

Fixed bed reactor system. Referring to Figure 2, the system is identified as four separate sections AD. Section A is a gas control comprising two separate channels for the replacement gas and the purge gas. The alternative gas channel provides a catalyst pre-process gas, such as ammonia and carbon dioxide, and the purge gas channel provides a nitrogen flow in the range of 2 to 30 mL / min. As shown in section A, each of the purge gas channel and the alternate gas channel has bidirectional on-off valves 2-1 and 2-2, respectively, and mass flow controllers 1 and 2 Respectively. Furthermore, the purge gas channel includes a three-way valve 3-1.

Section B is provided for liquid phase capture and consists of two circuits. The first circuit is used to introduce the liquid reactant into the system, and includes a moving flask (4-1) and a reactant reservoir (4-2). The reactants in the moving flask (4-1) can be moved to the reactant flask (4-2) by the positive pressure of the inert gas. In this system, all of the reservoirs are pressurized to 8 psi by nitrogen, enabling smooth operation of the pump 5. The reaction flask (4-2) was also placed on a balance for continuous monitoring of the reactants added over time. The second circuit is used to introduce a liquid solvent into the system and includes a solvent flask (4-3). The reactants and / or the solvent are transferred to the pump 5 through the three-way selector valve 3-2. Thereafter, the liquid reactants and / or the solvent are led to the reactor 7 or the reactant reservoir 4-2 respectively by the three-way valves 3-3 and 3-4. This is set so that the solvent used will purify the various transfer lines or transfer the reactants to the reactor (7).

Section C is reactor 7 in a column heater having a controlled temperature, as described above. The second thermocouple can be coupled to the reactor for precise monitoring of the reactor temperature.

Section D consists of a spring-loaded back pressure regulator 8, an in-line condenser 9 and a collection flask 11 (a glass flask coated in this system) do. The temperature of the collecting flask 11 was maintained at 4 DEG C in order to efficiently retain all products having a low boiling point. The dry ice trap 12 is located after the collection flask 11 to quench all products with low boiling points.

IV. Experiment

Dehydroxylation of lactic acid in water solvent. The starting composition of 40% lactic acid / 60% water was reacted with the various catalysts listed in Table 2 in vapor phase at 320 DEG C for 4 hours according to the above reaction protocol III (KL-type zeolites reacted at 320 DEG C for 2 hours ). In this section, it will be appreciated that the reaction time refers to the time it takes for the starting composition to pass / pass or pass through the bed of catalyst particles as opposed to a fixed sample of the starting material and catalyst particles. Further, conversion and selectivity measurements are based on samples of the product collected at reaction time as opposed to the total product collected over the entire reaction time.

As shown in Table 2, the Y-type zeolite shows high lactic acid conversion at very low acrylic acid selectivity of less than 13%. In contrast, both KL-type zeolite and Na ³ / KL-type zeolite show good lactic acid conversion of about 65% and high acrylic acid selectivity of about 50%. Li / KL-type zeolites increased lactic acid conversion, but produced significantly more acetaldehyde. On the other hand, the impregnated zeolite, 7.1% Na ₂ HPO ₄ / KL-type zeolite, increased lactate conversion and reduced the acetaldehyde product compared to the parent KL-type zeolite.

catalyst
Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid H-Y-type zeolite 98.3 59.7 NA 0.00 Na-Y-type zeolite 73.6 43.7 NA 19.5 K / Na-Y-type zeolite 98.5 11.1 NA 7.8 K-L-type zeolite 69.3 22.3 NA 35.9 Na ³ / KL-type zeolite 70.6 27.1 NA 36.3 Li / K-L-type zeolite 86.8 51.3 3.1 28.7 7.1% Na ₂ HPO ₄ / KL-type
Zeolite 71.7 11.7 4.2 39.9

Dehydroxylation of lactic acid in water solvent. The starting composition of 40% D, L-lactic acid / 60% water with 100 ppm of the polymerization inhibitor 4-methoxyphenol was reacted with the various catalysts listed in Table 3 in vapor phase at 320 DEG C for 4 hours according to the above reaction protocol III . As can be seen from the results in Table 3, among the catalysts tested in this experiment, the HSZ-500TM KOD1S, L-type zeolite catalyst showed a decrease in conversion level but had a higher selectivity for acrylic acid.

catalyst*
Lactate conversion
% Selectivity (mol%) Acetaldehyde Acrylic acid HSZ-920 ^TM HOD1A
(Beta zeolite) 99.6 59.5 0.2 HSZ-930 ^TM HOD1S
(Beta zeolite) 99.9 73.8 0.5 HSZ-500 ^TM KOD1S
(L-type zeolite) 74.7 21.8 35.4 HSZ-640 ^TM HOD1A
(Mordenite zeolite) 98.2 68.2 1.6 HSZ-330 ^TM HUD1A
(Y-type zeolite) 98.3 59.7 0.0 HSZ-360 ^TM HUD1C
(Y-type zeolite) 99.2 71.4 1.2

Each of these zeolite catalysts was purchased from TOSOH USA, Inc. The catalysts were used without any modification.

Dehydroxylation of lactic acid in water solvent. The starting composition of 40% D, L-lactic acid / 60% water with 100 ppm of the polymerization inhibitor 4-methoxyphenol was reacted with the various catalysts listed in Table 4 in vapor phase at 320 DEG C for 4 hours according to the above reaction protocol III .

As shown in Table 4, small cation-modified zeolites could have higher conversion rates, but the selectivity to acrylic acid appeared to be negatively affected by large and small cations. Thus, zeolites modified with sodium ions may be preferred in some embodiments.

catalyst
Lactate conversion
% Selectivity (mol%) Acetaldehyde Acrylic acid Cs ³ / KL-type zeolite 57.9 22.6 24.2 Na ³ / KL-type zeolite 70.6 27.1 36.3 Li ³ / KL-type zeolite 72.9 51.8 29

Dehydroxylation - impregnation amount of lactic acid in water solvent (1). The starting composition of 40 wt% lactic acid by weight with respect to water was reacted with the various catalysts listed in Table 5 on the vapor phase at 330 DEG C according to the above-described reaction protocol III.

As shown in Table 5, the gradual increase in the amount of Na ₂ HPO ₄ supported on the base KL zeolite system reduced by-products acetaldehyde and propionic acid, while improving both conversion and selectivity. For this catalyst system, 7.1% loading appears to be the optimal range for Na ₂ HPO ₄ impregnation.

catalyst
Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid K-L-type zeolite 80.1 19.7 8.4 33.5 2.1% Na ₂ HPO ₄ / KL-type
Zeolite 81.2 14.9 6.6 32.3 3.6% Na ₂ HPO ₄ / KL-type
Zeolite 81 12.6 4.2 31.1 7.1% Na ₂ HPO ₄ / KL-type
Zeolite 82.3 11 5.0 31.9 14.0% Na ₂ HPO ₄ / KL-type
Zeolite 79.9 15.3 5.3 32.2

Dehydroxylation - impregnation amount of lactic acid in water solvent (2). The starting composition of 40 wt% lactic acid by weight based on the weight of water was reacted with the various catalysts listed in Table 6 on the vapor at 340 DEG C according to the above reaction protocol III.

As shown in Table 6, impregnation appears to result in a catalyst system with higher conversion rates. However, the amount of Na ₂ HPO ₄ supported on the base Na ³ / KL zeolite system seemed to affect the conversion and selectivity and significantly reduced by-product acetaldehyde. For this catalyst system, 7.1% loading appears to be the optimal range for Na ₂ HPO ₄ impregnation.

catalyst
Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid Na ³ / KL-type zeolite 80.6 31.1 5.2 46.7 1.4% Na ₂ HPO ₄ / Na ³ / KL-type
Zeolite 90.8 22.2 4.3 37.6 7.1% Na ₂ HPO ₄ / Na ³ / KL-type
Zeolite 87.3 14.9 3.0 40.7 10.7% Na ₂ HPO ₄ / Na ³ / KL-type
Zeolite 86.4 14.7 6.5 40.2 14% Na ₂ HPO ₄ / Na ³ / KL-type
Zeolite 85.8 15.2 6.9 39.8

Dehydroxylation of Lactic Acid in Water Solvents - Catalyst Stability. The starting composition of 40% lactic acid / 60% water was reacted with the various catalysts listed in Table 7 on a steam basis at 340 占 폚 for 4 hours in accordance with the above reaction protocol III. To determine the tendency of each catalyst to lose activity over time, the product was analyzed every 1 hour of the 4 hour reaction.

As shown in Table 7, both KL zeolite and Na ³ / KL-type zeolite show progressively weakening activity and selectivity over time, but less for Na ³ / KL-type zeolite. In contrast, Na ₂ HPO ₄ with the impregnation appears to stabilize both the conversion and selectivity, as shown in 7.1% Na ₂ HPO ₄ / KL- zeolite and _{7.1% Na 2 HPO 4 / Na} 3 / KL- zeolite catalyst . Both partial Na exchange and Na ₂ HPO ₄ impregnation (ie, 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite) appear to have synergistic effects that result in high and stable conversion at high and stable selectivity to acrylic acid.

catalyst
time
(city) Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid
Tosoh KL

One 86.06 13.69 1.7 40.81 2 79.80 16.70 2.2 39.69 3 76.79 15.27 2.9 38.62 4 76.19 12.31 3.0 32.98
Na3 / KL-type
Zeolite
One 83.49 29.73 4.4 50.87 2 83.87 29.20 4.5 45.10 3 77.89 32.73 5.6 46.65 4 77.32 32.80 6.4 44.28 7.1%
Na ₂ HPO ₄ / KL-type
Zeolite One 85.07 12.94 5.3 34.31 2 83.42 14.52 6.8 36.89 3 82.78 14.38 7.2 35.94 4 83.39 14.60 7.7 34.46 7.1%
Na ₂ HPO ₄ / Na ³ / KL-type
Zeolite One 90.22 14.60 2.7 39.85 2 87.58 14.58 2.9 41.64 3 86.56 15.27 3.0 40.94 4 84.65 15.23 3.4 40.41

Dehydroxylation of Lactic Acid in Water Solvents - Temperature Effect. Starting compositions having varying concentrations of lactic acid ("LA ") in water listed in Table 8 with 100 ppm of 4-methoxyphenol were added to the reaction mixture at 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite.

As shown in Table 8, for the 40% lactic acid starting composition, increasing the temperature resulted in an increase in both conversion and selectivity. In contrast, in the case of the 30% and 20% lactic acid starting compositions, increasing the temperature seems to increase the conversion but reduce the selectivity to acrylic acid, increasing the temperature to 340 [deg.] C for samples with a starting concentration of 20% lactic acid In the case, it seems to be quite abrupt.

Initial lactic acid concentration Temperature
(° C) Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid
20%
320 78.6 13.8 8.0 43.7 330 85.9 16.3 8.3 45.2 340 92.5 15.3 13.4 32.3
30%
320 73.5 15.5 8.0 41.7 330 80.3 16.9 8.6 40.1 340 89.0 17.7 11.3 40.2
40%
320 67.3 10.8 4.1 30.5 330 77.5 14.7 5.6 37.9 340 87.3 14.9 3.0 40.7

Effect of Dehydroxylation - Lactic Acid Concentration of Lactic Acid in Water Solvents. Starting compositions having an initial concentration of 50% and 60% lactic acid in the water listed in Table 9 were added to the reaction mixture at various temperatures listed in Table 9 on a steam basis for 5 hours (7.1% Na ₂ HPO ₄ ) / Na ³ / KL-type zeolite.

As shown in Table 9, increasing the temperature increased the conversion, but the selectivity changed from the higher temperature to the minimum. Furthermore, increasing the initial lactic acid concentration has minimal effect on conversion and selectivity at these temperatures, at least at these concentrations.

Initial lactic acid concentration
Temperature
(° C) Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid
50%
340 78.9 18.6 3.8 42.4 350 86.7 22.0 5.5 47.3 360 93.6 22.4 8.6 45.0
60%
340 79.8 20.4 8.3 46.3 350 85.4 23.5 8.3 47.9 360 93.9 23.3 14.3 44.8

Dehydroxylation of Lactic Acid in Water Solvents - Effect of Reactant Flow Rate. The starting composition of 40% lactic acid / 60% water was reacted in vapor phase with Na ³ / KL-type zeolite at 320 ° C for 3 hours according to the above reaction protocol III, wherein the liquid flow rate of the starting composition Speed ("WHSV").

As shown in Table 10, increasing the lactic acid space velocity (i.e., increasing the reactant flow rate) leads to a reduction in conversion and a significant improvement in acrylic acid selectivity.

WHSV
(g _X / g _C / h) Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid 0.600 70.6 27.1 0.0 36.3 1.200 54.1 32.9 0.0 49.9 1.500 50.9 33.0 0.0 52.8

Dehydroxylation of Lactic Acid in Water Solvents - Effect of Carrier Gas Flow Rate. The starting composition of 40% lactic acid / 60% water was reacted in vapor phase with Na ³ / KL-type zeolite at 320 ° C for 3 hours according to the above reaction protocol III, wherein the liquid flow rate of the argon carrier gas As well.

As shown in Table 11, increasing the carrier gas flow appears to reduce acetaldehyde and propionic acid formation while maintaining acrylic acid selectivity.

Argon flow rate
(mL / min) Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid 5 70.6 27.1 Not measured 36.3 10 78.4 22.2 4.1 34.4 20 79.0 16.4 2.2 37.5 30 81.6 14.6 2.8 36.7 40 79.0 10.8 1.3 37.1

Dehydroxylation - Solvent Effect of Lactic Acid in Solvents. The starting compositions listed in Table 12 were reacted with Na ³ / KL-type zeolite on a steam basis at 340 ° C for 4 hours according to the above reaction protocol III.

As shown in Table 12, the Na ³ / KL-type zeolite undergoes a catalytic esterification reaction. Furthermore, the addition of alcohol in the starting composition has minimal effect on conversion, but appears to dramatically reduce selectivity for acrylic acid.

start
Composition
Lactic acid
transform
% Selectivity (mol%) Acetaldehyde Acrylate * MOPAE *** Lacate ** Acrylic acid Propionic acid 30% LA 70% water 90.5 22.4 0 0 0 33.4 13.7 30% LA 65% MeOH 5% water 92.2 14.9 1.6 1.0 20.8 23.0 6.8 30% LA 65% EtOH 5% water 93.5 15.9 0.4 0 10.1 20.2 5

* Methyl acrylate or ethyl acrylate for methanol ("MeOH") and ethanol ("EtOH" respectively).

** Methyl lactate or ethyl lactate for methanol and ethanol, respectively.

*** 2-Methoxypropionic acid methyl ester or 2-ethoxypropionic acid ethyl ester for methanol and ethanol respectively.

Dehydroxylation of Lactic Acid in Water Solvents - Effect of Catalyst Volume. The starting composition of 20% lactic acid / 80% water was reacted in vapor phase with 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite for 4 hours at 330 ° C according to the above reaction protocol III, Lt; / RTI >

As shown in Table 13, increasing the amount of catalyst appears to increase the conversion. Excess catalyst, however, appears to reduce selectivity.

Catalyst (mL)
Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid One 67.8 17.3 5.4 47.2 2 85.9 16.3 8.3 45.2 3 96.4 14.1 3.6 49.5 4 98.4 17.0 5.3 43.9 5 99.2 9.0 3.4 40.9 6 99.6 15.9 7.1 20.4 7 99.9 17.3 5.3 27.0

Dehydroxylation of Lactic Acid in Water Solvents - Catalytic Activity Consumption. The starting composition of 20% lactic acid / 80% water was reacted in vapor phase over 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite at 330 ° C. for 96 hours according to the above reaction protocol III (FIG. As a measure of the tendency of each catalyst to lose activity over time, the product was analyzed periodically over 96 hours each.

As shown in FIG. 5, the 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite has a constant lactic acid conversion over 50 hours and an acrylic acid selectivity of about 70% or more.

Dehydroxylation of lactic acid in water solvent - Lactic acid source. The starting composition having a 20% or 30% concentration of lactic acid was reacted with 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite on a steam basis at 330 ° C according to the above reaction protocol III for 4 hours. Lactic acid was derived from one of (1) synthetic lactic acid (purchased from Sigma-Aldrich, TCI or Alfa Aesar) and (2) raw-derived lactic acid (purchased from ADM Coporation). The raw-derived lactic acid is derived from the biological fermentation of sugars. Bovine-derived lactic acid in two different grades (USP-American Pharmacological Association; FCC-US FDA) was used in this experiment (Table 14).

Initial lactic acid concentration Lactic acid source Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid
20% synthesis 85.9 16.3 8.3 45.2 Raw-USP rating 83.1 21.0 5.8 51.1 Raw-FCC rating 81.6 20.5 7.7 49.9
30%
synthesis 80.3 16.9 8.6 40.1 Raw-USP rating 75.9 20.9 5.6 46.6 Raw-FCC rating 83.4 20.8 7.5 47.8

Dehydroxylation - Catalytic Effect of Butyl Lactate in Butanol - Water Solvents. The starting composition of 50% butyl lactate / 45% butanol / 5% water was reacted with the various catalysts listed in Table 15 at 300 占 폚 for 4 hours according to the above reaction protocol II.

As shown in Table 15, increasing the amount of Na ⁺ associated with the catalyst (ie, more Na ⁺ exchange) increases the selectivity for acrylic acid, and this effect is also present in Li ⁺ exchanged catalysts.

catalyst Butyl lactate conversion
% Selectivity (mol%) Acetaldehyde Butyl acrylate Propionic acid Acrylic acid KL-type
Zeolite 42.6 5.9 1.5 2.4 16.7 Na / KL-type
Zeolite 49.3 10.8 1.9 3.4 30.3 Na ² / KL-type
Zeolite 45.8 15.0 2.0 5.3 39.2 Na ³ / KL-type
Zeolite 53.2 17.5 1.9 3.7 42.9 Na ⁴ / KL-type
Zeolite 54.0 14.2 1.8 3.4 38.4

Dehydroxylation of Butyl Lactate in Butanol - Water Solvent - Water Effect. The starting compositions listed in Table 16 were reacted with Na ³ / KL-type zeolite on a steam basis at 300 ° C for 4 hours according to the above reaction protocol II.

As shown in Table 16, in a solvent system containing water, increasing the water content increases acrylic acid selectivity. Thus, for these reaction parameters, the optimum range of water content can be approximately from about 5 to about 10%, which results in stabilization of the catalytic activity at the temperature tested.

start
Composition Butyl lactate conversion
% Selectivity (mol%) Acetaldehyde Butyl acrylate Propionic acid Acrylic acid 50% butyl lactate
50% butanol
0% water 39.3 16.4 2.5 4.8 37.6 50% butyl lactate
49% butanol
1% water 45.7 12.5 1.7 3.6 29.1 50% butyl lactate
47.5% butanol
2.5% water 55.0 15.8 2.1 3.6 38.5 50% butyl lactate
46.5% butanol
3.5% water 55.9 12.0 1.5 2.8 31.7 50% butyl lactate
45% butanol
5% water 53.2 17.5 1.9 3.7 42.9 50% butyl lactate
40% butanol
10% water 51.0 17.0 1.9 2.0 44.3

Dehydroxylation of Butyl Lactate in Butanol - Water Solvents - Temperature Effect. The starting composition of 50% butyl lactate / 45% butanol / 5% water was reacted with Na ³ / KL-type zeolite on the steam for 4 hours at the temperatures listed in Table 17 according to the above reaction protocol II.

As shown in Table 17, increasing the temperature above 280 DEG C seems to increase butyl lactate conversion and acrylic acid selectivity.

Temperature
(° C) Butyl lactate conversion
% Selectivity (mol%) Acetaldehyde Butyl acrylate Propionic acid Acrylic acid 280 32.8 10.1 0 3.0 24.6 290 33.6 10.8 0 2.5 28.3 300 53.2 17.5 1.9 3.7 42.9 310 49.3 17.0 3.2 4.6 49.7 320 50.7 18.2 3.6 4.8 52.5

Dehydroxylation of Butyl Lactate in Butanol - Water Solvent - Effect of Reactant Flow Rate. The starting composition of 50% butyl lactate / 45% butanol / 5% water was reacted with Na ³ / KL-type zeolite on a steam basis at 300 ° C. for 4 hours according to the above reaction protocol II. The flow rate of the starting composition was adjusted to obtain the LHSV listed in Table 18.

As shown in Table 18, increasing LHSV appears to have minimal effect on acrylic acid selectivity, but butyl lactate conversion appears to be dropping. However, the optimum LHSV for acrylic acid selectivity appears to be from about 2 hr < ^-1 > to about 3 hr < ^-1 >.

LHSV
(h ^-1 ) Butyl lactate conversion
% Selectivity (mol%) Acetaldehyde Butyl acrylate Propionic acid Acrylic acid 1.5 41.8 18.7 3.2 4.8 57.9 2 34.7 19.7 2.6 5.0 60.1 3 25.9 19.9 1.9 4.9 59.3 6 14.5 19.4 0 0 56.9

Dehydroxylation of lactic acid in water solvent - Catalytic activity after regeneration. The starting composition of 20% lactic acid / 80% water was reacted in vapor phase on 7.1% Na ₂ HPO ₄ / Na ³ / KL-type zeolite for 96 hours at 330 ° C. according to the above reaction protocol III (FIG. 6) It was regenerated with air for 3 hours. As a measure of the propensity of the catalyst for activity after regeneration, the products were analyzed periodically over a 72 hour reaction. As shown in FIG. 6, more than 70% of the normal state conversion was successfully restored. However, steady state acrylic acid selectivity has been reduced by more than about 50%, since temperatures below the temperature required to burn the deposited coke due to equipment limitations are used for regeneration.

Dehydroxylation of methyl-lactate in a methanol-water solvent. The starting compositions listed in Table 19 were reacted with Na ³ / KL-type zeolite in a vapor phase at 300 ° C for 4 hours according to the above reaction protocol I.

As shown in Table 19, as the water concentration increases, the acrylic acid selectivity increases. The byproduct, methoxypropionic acid, also decreased with increasing water concentration.

Starting composition
Methyl lactate conversion
% Selectivity (mol%) Acetaldehyde Methyl acrylate Methoxy
Propionic acid Acrylic acid 50% methyl lactate
45% methanol
5% water 41.3 13.7 16.2 12.7 20.5 50% methyl lactate
40% methanol
10% water 40.6 14.2 18.0 13.8 28.8 50% methyl lactate
30% methanol
20% water 39.8 14.8 12.8 7.8 35.3

Dehydroxylation of Lactic Acid in Water Solvents - Catalytic Activity with Binder. The starting composition containing 20% strength lactic acid was reacted with the calcined or non-calcined catalysts listed in Table 20 at 330 占 폚 for 5 hours in the vapor phase according to the above reaction protocol III. Catalyst HSZ-500 ^TM KOD1C (L-type zeolite available from TOSOH USA, Inc.) was used as is or calcined at 450 占 폚. Clay-A was used as a binder in this experiment. The clay-A binders used in this experiment differ from the silacar binders in all other experiments described herein.

The results shown in Table 20 show that comparing those containing calcined and non-calcined catalysts with clay-A shows that they can have the smallest effect on the conversion rate but reduce the selectivity of acrylic acid and the by-product acetaldehyde Lt; / RTI > This may be due to the modification of the acidic or basic sites on the catalyst during the calcination process.

catalyst Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid Non-calcined 80.1 23.8 9.8 36.0 Calcined 84.8 33.0 4.4 32.4

Effect of dehydroxylation of lactic acid in water solvent - carrier gas composition. The starting composition containing 20% strength lactic acid was reacted with the various catalysts listed in Table 21 for 5 hours at 330 占 폚 in the vapor phase using the carrier gas listed in Table 21 according to the above reaction protocol III.

The results shown in Table 21 show that the use of carbon dioxide as the carrier gas improved both the stable conversion percent and acrylic acid selectivity of the two modified L-type zeolites tested, especially 7.1% Na ₂ HPO ₄ / NA-3 ^rd Ex Lt; RTI ID = 0.0 > acetaldehyde < / RTI > by-product to KL. Figure 7 shows comparative data on 20% aqueous lactic acid conversion and acrylic acid selectivity for 7.1% Na ₂ HPO ₄ / NA-3 ^rd Ex KL using CO ₂ and argon or nitrogen as the carrier gas in the course of 100 hours present.

Carrier gas
catalyst
Lactate conversion
% Selectivity (mol%) Acetaldehyde Propionic acid Acrylic acid argon
Na-3 ^rd exchanged KL 91.5 35.8 7.0 50.2 7.1% Na ₂ HPO ₄ / Na-3 ^rd exchanged KL 80.2 17.4 11.2 51.8 CO ₂
Na-3 ^rd exchanged KL 92.3 29.4 9.1 49.3 7.1% Na ₂ HPO ₄ / Na-3 ^rd exchanged KL 85.5 16.8 6.0 59.1

Measurement of corrosion of stainless steel reactor walls. In this experiment, the corrosion extent of the stainless steel reactor walls by lactic acid was monitored during four consecutive days of operation of the stainless steel catalytic reactor with L-type zeolite catalyst. A solution of lactic acid (20% w / v) was used as the feed. The temperature of the reactor was maintained at 330 ° C and nitrogen was used as the carrier gas. The reactor was operated in continuous mode and acrylic acid was collected daily. At the end of the fourth day, the acrylic acid fraction, the lactic acid feed, the unused catalyst, and the catalyst used were analyzed daily for the presence of each level of metal in each of these samples shown in Table 22. The results indicate that the L-type zeolite catalyst possesses a significant concentration of metal leached from the stainless steel reactor in the dehydroxylation reaction.

metal
Amount (mg / kg) Lactic acid
Supply Acrylic acid
1 day Acrylic acid
2 days Acrylic acid
3 days Acrylic acid
4 days unused
catalyst Used
catalyst Iron (Fe) 0.3 131.0 113.4 82.4 4.2 144 24565 Nickel (Ni) - 15.4 12.9 10.5 1.2 2 4317 Chromium (Cr) - 33.7 30.4 0.9 0.9 2 6850

In this lactic acid dehydroxylation experiment, acetaldehyde and propionic acid were detected as by-products, and their molar selectivity was also determined during the 4 day experimental period. The results shown in Table 23 indicate that the molar selectivity to acetaldehyde and propionic acid was increased during the course of the 4 day experiment, thereby indicating a decrease in selectivity for acrylic acid.

product
% Mol selectivity 1 day 2 days 3 days 4 days Acetaldehyde 11.3 10.56 11.61 14.4 Propionic acid 4 5.8 7.9 22.9

The above examples illustrate that a plurality of catalysts based on L-form zeolites and modified zeolites can be used for the preparation of alpha, beta -unsaturated carboxylic acids and / or esters thereof.

Accordingly, the present invention is well suited to attaining the objects and effects inherent therein as well as the objects and effects mentioned. It is to be understood that the particular embodiments disclosed above are for illustrative purposes only and that the invention can be modified and practiced otherwise but may be modified and practiced in the equivalent manner obvious to those of ordinary skill in the art having the benefit of the teachings herein. Further, the invention is not limited to the specific details of the structure or design shown herein other than those described in the following claims. It is therefore evident that the specific exemplary embodiments disclosed above may be varied, combined, or modified, all of which are considered to be within the scope and spirit of the invention. The invention illustratively disclosed herein may suitably be carried out in the absence of any components not specifically disclosed herein and / or any optional components disclosed herein. Compositions and methods are described as "comprising," "comprising, " or" comprising ", the various components and steps, wherein the compositions and methods are "essentially composed," " ". All numbers and ranges disclosed above may vary in some amounts. When a numerical range having a lower limit and an upper limit is disclosed, any included range falling within the range is specifically disclosed. In particular, all ranges of values disclosed herein (in the form of "about a to about b", or equivalently, "about a to b", or equivalently, "about a to b"), It should be understood that all numbers and ranges are presented. In addition, the term in a claim has its usual ordinary meaning unless explicitly and explicitly defined by the patentee. Also, as used in the claims, an indefinite article such as "a" or "an" is defined herein to mean one or more than one element of introduction. If there are contradictions in the use of words or terms in one or more patent documents or non-patent documents which may be included herein by reference and hereby incorporated by reference, the definitions consistent with this specification should be borrowed.

Claims (73)

hydroxycarboxylic acid esters,? -hydroxycarboxylic acid esters,? -alkoxycarboxylic acid,? -alkoxycarboxylic acid esters,? -alkoxycarboxylic acid,? -alkoxycarboxylic acid esters,? -hydroxy carboxylic acid esters,? -hydroxycarboxylic acid esters,? -hydroxycarboxylic acid esters, ≪ / RTI > and any combination thereof; And
In order to produce a product comprising an alpha, beta -unsaturated carboxylic acid and / or an ester thereof, at least one selected from the group consisting of L-type zeolite, modified L-type zeolite, Performing a dehydroxylation reaction by contacting the composition with a miscration catalyst
≪ / RTI > The method according to claim 1,
performing an esterification reaction by contacting the product with an esterification catalyst and an alcohol to produce a second product comprising an alpha, beta -unsaturated carboxylic acid ester,
≪ / RTI > 3. The method of claim 2,
Wherein the dehydroxylation catalyst and the esterification catalyst are the same. The method according to claim 2 or 3,
Wherein the dehydroxylation reaction and the esterification reaction are carried out simultaneously. The method according to claim 2 or 3,
Wherein the dehydroxylation reaction and the esterification reaction are carried out sequentially. 6. The method according to any one of claims 2 to 5,
Wherein the dehydroxylation reaction and the esterification reaction are carried out in a single reaction vessel. 6. The method according to any one of claims 2 to 5,
Wherein the esterification reaction is carried out in a reactor vessel comprising a reactor material comprising at least one selected from the group consisting of titanium, silanized stainless steel, quartz, and any combination thereof. 8. The method according to any one of claims 2 to 7,
Wherein the alcohol is at least one selected from the group consisting of C ₁ -C ₂₀ alcohols, aryl alcohols, cyclic alcohols, and any combination thereof. 9. The method according to any one of claims 2 to 8,
The alcohol is selected from the group consisting of methanol, ethanol, propanol, iso-propanol, n-propanol, butanol, iso-butanol, n-butanol, 2-ethylhexanol, iso-nonanol, , Cyclohexanol, cyclopentanol, and any combination thereof. ≪ Desc / Clms Page number 14 > 10. The method according to any one of claims 2 to 9,
Wherein the esterification reaction takes place in the presence of a carrier gas comprising greater than about 90% carbon dioxide. 11. The method according to any one of claims 1 to 5 and 8 to 10,
Wherein the dehydroxylation reaction is carried out in a reactor vessel comprising a reactor material comprising at least one selected from the group consisting of titanium, silanized stainless steel, quartz, and any combination thereof. The method according to claim 6,
Wherein the single reaction vessel comprises a reactor material comprising at least one selected from the group consisting of titanium, silanized stainless steel, quartz, and any combination thereof. 13. The method according to any one of claims 1 to 12,
Wherein the dehydroxylation reaction occurs in the presence of a carrier gas comprising greater than about 90% carbon dioxide. 14. The method according to any one of claims 1 to 13,
Wherein the reactants are in the vapor phase and the dehydroxylation catalyst is in the solid phase. 15. The method according to any one of claims 1 to 14,
The dehydroxylation catalyst further comprises at least one selected from the group consisting of zeolites, acid catalysts, weak acid catalysts, strong acid catalysts, neutral catalysts, basic catalysts and any combination thereof in addition to the solid oxides, L-type zeolites Way. 16. The method according to any one of claims 1 to 15,
The modified L-type zeolite comprises at least one inorganic salt comprising at least one selected from the group consisting of phosphates, sulphates, molybdates, tungstates, tinates, antimonates, and any combination thereof and / ≪ / RTI > 17. The method of claim 16,
Wherein the inorganic salts and / or oxides thereof are present in modified L-type zeolites at a concentration of from about 0.1 mmol / g modified zeolite to about 1.0 mmol / g modified zeolite. 18. The method according to claim 16 or 17,
Wherein the inorganic salt comprises at least one selected from the group consisting of monosodium phosphate, disodium phosphate, and trisodium phosphate, potassium phosphate, sodium aluminum phosphate compound, and any combination thereof. 19. The method according to any one of claims 1 to 18,
Characterized in that the modified L-type zeolite undergoes at least one ion exchange. 20. The method according to any one of claims 1 to 19,
Modified L-type zeolites include H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ . Mg ²⁺ , Ca ²⁺ , La ²⁺ , La ³⁺ , Ce ²⁺ , Ce ³⁺ , Ce ⁴⁺ , Sm ²⁺ , Sm ³⁺ , Eu ²⁺ , Eu ³⁺ , Lt; RTI ID = 0.0 > of: < / RTI > 21. The method according to any one of claims 1 to 20,
Wherein the modified L-type zeolite is a Na / KL-type zeolite having a ratio of sodium ions to potassium ions of about 1:10 or greater. 22. The method according to any one of claims 1 to 21,
Wherein the conversion efficiency is at least about 75%. 23. The method according to any one of claims 1 to 22,
Wherein the conversion efficiency is greater than or equal to about 90%. 24. The method according to any one of claims 1 to 23,
Characterized in that the product comprises at least about 60 mole% of alpha, beta -unsaturated carboxylic acids and / or esters thereof. 25. The method according to any one of claims 1 to 24.
Wherein the reactant is lactide. 26. The method according to any one of claims 1 to 25,
Wherein the reactants are biologically-derived. 27. The method according to any one of claims 1 to 26,
Wherein the dehydroxylation reaction is carried out in the presence of a polymerization inhibitor. 28. The method according to any one of claims 1 to 27,
Wherein the composition further comprises a solvent. 29. The method of claim 28,
≪ / RTI > further comprising the step of regenerating the solvent after the dehydroxylation reaction. providing a composition comprising a reactant selected from the group consisting of? -hydroxycarboxylic acid,? -hydroxycarboxylic acid,? -alkoxycarboxylic acid,? -alkoxycarboxylic acid, and any combination thereof;
Performing an esterification reaction by contacting the composition with an esterification catalyst and alcohol to produce an intermediate comprising an ester of the reactant; And
In order to produce a product comprising an alpha, beta -unsaturated carboxylic acid ester, a dehydroxylation catalyst comprising at least one selected from the group consisting of L-type zeolite, modified L-type zeolite, and any combination thereof, To carry out the dehydroxylation reaction
≪ / RTI > 31. The method of claim 30,
Wherein the dehydroxylation reaction and / or the esterification reaction occurs in the presence of a carrier gas substantially comprising carbon dioxide. 32. The method according to claim 30 or 31,
Characterized in that the dehydroxylation and / or esterification reaction is carried out in a reactor vessel comprising a reactor material comprising at least one selected from the group consisting of titanium, silanized stainless steel, quartz and any combination thereof Way. 33. The method according to any one of claims 30 to 32,
Wherein the dehydroxylation catalyst and the esterification catalyst are the same. 34. The method according to any one of claims 30 to 33,
Wherein the alcohol is at least one selected from the group consisting of C ₁ -C ₂₀ alcohols, aryl alcohols, cyclic alcohols, and any combination thereof. 35. The method according to any one of claims 30 to 34,
The alcohol is selected from the group consisting of methanol, ethanol, propanol, iso-propanol, n-propanol, butanol, iso-butanol, n-butanol, 2-ethylhexanol, iso-nonanol, , Cyclohexanol, cyclopentanol, and any combination thereof. ≪ Desc / Clms Page number 14 > 36. The method according to any one of claims 30 to 35,
Wherein the modified L-type zeolite comprises at least one inorganic salt comprising at least one selected from the group consisting of phosphates, sulfates, molybdates, tungstates, tinates, antimonates, and any combination thereof and / ≪ / RTI > 37. The method according to any one of claims 30-36,
Wherein the inorganic salts and / or oxides thereof are present in modified L-type zeolites at a concentration of from about 0.1 mmol / g modified zeolite to about 1.0 mmol / g modified zeolite. 37. The method according to any one of claims 30 to 37,
Wherein the inorganic salt comprises at least one selected from the group consisting of monosodium phosphate, disodium phosphate, and trisodium phosphate, potassium phosphate, sodium aluminum phosphate compound, and any combination thereof. 39. The method according to any one of claims 30-38,
Characterized in that the modified L-type zeolite undergoes at least one ion exchange. 40. The method according to any one of claims 30-39,
Modified L-type zeolites include H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ . Mg ²⁺ , Ca ²⁺ , La ²⁺ , La ³⁺ , Ce ²⁺ , Ce ³⁺ , Ce ⁴⁺ , Sm ²⁺ , Sm ³⁺ , Eu ²⁺ , Eu ³⁺ , Lt; RTI ID = 0.0 > of: < / RTI > 41. The method according to any one of claims 30 to 40,
Wherein the modified L-type zeolite is a Na / KL-type zeolite having a ratio of sodium ions to potassium ions of about 1:10 or greater. 42. The method according to any one of claims 30-41,
Wherein the conversion efficiency is at least about 75%. 43. The method according to any one of claims 30 to 42,
Wherein the conversion efficiency is greater than or equal to about 90%. 44. The method according to any one of claims 30 to 43,
Characterized in that the product comprises at least about 60 mol% of an alpha, beta -unsaturated carboxylic acid ester. 45. The method according to any one of claims 30-44,
Wherein the dehydroxylation reaction is carried out in the presence of a polymerization inhibitor. 46. The method according to any one of claims 30-45,
Wherein the reactants are biologically-derived. 46. The method according to any one of claims 30-46,
Wherein the composition further comprises a solvent. 49. The method of claim 47,
≪ / RTI > further comprising the step of regenerating the solvent after the dehydroxylation reaction. hydroxycarboxylic acid esters,? -hydroxycarboxylic acid esters,? -alkoxycarboxylic acid,? -alkoxycarboxylic acid esters,? -alkoxycarboxylic acid,? -alkoxycarboxylic acid esters,? -hydroxy carboxylic acid esters,? -hydroxycarboxylic acid esters,? -hydroxycarboxylic acid esters, ≪ / RTI > and any combination thereof; And
In order to produce a product comprising an alpha, beta -unsaturated carboxylic acid and / or ester thereof, the dehydroxylation is carried out by contacting the composition with a dehydroxylation catalyst in the presence of a carrier gas comprising greater than about 90% Performing a misfire reaction
≪ / RTI > 50. The method of claim 49,
performing an esterification reaction by contacting the product with an esterification catalyst and an alcohol to produce a second product comprising an alpha, beta -unsaturated carboxylic acid ester,
≪ / RTI > 51. The method of claim 50,
Wherein the esterification reaction takes place in the presence of a carrier gas. A method for producing acrylic acid or acrylic acid ester from a sugar, said method comprising:
(a) catalytic conversion of sugar to lactic acid or alkyl lactate; And
(b) catalytically converting the lactic acid or alkyl lactate obtained in step (a) into acrylic acid or acrylic acid ester
≪ / RTI > 53. The method of claim 52,
Further comprising the step of purifying the acrylic acid or acrylic acid ester obtained in the step (b). 54. The method of claim 52 or 53,
Wherein the catalytic conversion of the sugar is mediated by a first chemical catalyst. 55. The method of claim 54,
Wherein the first chemical catalyst is a dehydroxylation catalyst. 56. The method of claim 55,
Wherein the dehydroxylation catalyst comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof. 57. The method of claim 56,
The modified L-type zeolite comprises at least one inorganic salt comprising at least one selected from the group consisting of phosphates, sulphates, molybdates, tungstates, tinates, antimonates, and any combination thereof and / ≪ / RTI > 57. The method of claim 56 or 57,
Characterized in that the modified L-type zeolite undergoes at least one ion exchange. 62. The method of any one of claims 56 to 58,
Modified L-type zeolites include H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ . Mg ²⁺ , Ca ²⁺ , La ²⁺ , La ³⁺ , Ce ²⁺ , Ce ³⁺ , Ce ⁴⁺ , Sm ²⁺ , Sm ³⁺ , Eu ²⁺ , Eu ³⁺ , Lt; RTI ID = 0.0 > of: < / RTI > 60. The method according to any one of claims 55 to 59,
The dehydroxylation catalyst further comprises at least one selected from the group consisting of zeolites, acid catalysts, weak acid catalysts, strong acid catalysts, neutral catalysts, basic catalysts and any combination thereof in addition to the solid oxides, L-type zeolites Way. 60. The method according to any one of claims 52 to 60,
Wherein the catalytic conversion of lactic acid or alkyl lactate is mediated by a second chemical catalyst. 62. The method of claim 61,
And the second chemical catalyst is an esterification catalyst. A process for the production of acrylic acid or acrylic esters from glycerol, said process comprising:
(a) catalytically converting glycerol to lactic acid or alkyl lactate; And
(b) catalytically converting the lactic acid or alkyl lactate obtained in step (a) into acrylic acid or acrylic acid ester
≪ / RTI > 64. The method of claim 63,
Further comprising the step of purifying the acrylic acid or acrylic acid ester obtained in the step (b). 65. The method of claim 63 or 64,
Characterized in that the catalytic conversion of glycerol is mediated by a first chemical catalyst. 66. The method of claim 65,
Wherein the first chemical catalyst is a dehydroxylation catalyst. 67. The method of claim 66,
Wherein the dehydroxylation catalyst comprises at least one selected from the group consisting of L-type zeolites, modified L-type zeolites, and any combination thereof. 68. The method of claim 67,
The modified L-type zeolite comprises at least one inorganic salt comprising at least one selected from the group consisting of phosphates, sulphates, molybdates, tungstates, tinates, antimonates, and any combination thereof and / ≪ / RTI > 69. The method of claim 67 or 68,
Characterized in that the modified L-type zeolite undergoes at least one ion exchange. 71. The method according to any one of claims 67 to 69,
Modified L-type zeolites include H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ . Mg ²⁺ , Ca ²⁺ , La ²⁺ , La ³⁺ , Ce ²⁺ , Ce ³⁺ , Ce ⁴⁺ , Sm ²⁺ , Sm ³⁺ , Eu ²⁺ , Eu ³⁺ , Lt; RTI ID = 0.0 > of: < / RTI > A method according to any one of claims 66 to 70,
The dehydroxylation catalyst further comprises at least one selected from the group consisting of zeolites, acid catalysts, weak acid catalysts, strong acid catalysts, neutral catalysts, basic catalysts and any combination thereof in addition to the solid oxides, L-type zeolites Way. 72. The method according to any one of claims 63 to 71,
Wherein the catalytic conversion of lactic acid or alkyl lactate is mediated by a second chemical catalyst. 73. The method of claim 72,
And the second chemical catalyst is an esterification catalyst.

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