Enzymatic transesterification/esterification processing systems and processes employing lipases immobilzed on hydrophobic resins

Abstract

Disclosed are processing systems and processes for carrying out enzymatic batchwise or continuous process for the production of fatty acid alkyl esters for use in the biofuels, food, cosmetics, pharmaceuticals and detergents industries.

1 . A processing system for the transesterification/esterification of a fatty acid source with an alcohol, to form fatty acid alkyl esters, comprising:
 a reaction vessel configured for reacting a reaction medium including a fatty acid source and at least one of an alcohol and an alcohol donor in the presence of an immobilized lipase preparation, wherein the immobilized lipase preparation comprises at least one lipase immobilized on a hydrophobic porous support and wherein said processing system is configured for passing the reaction medium through said immobilized lipase preparation in a direction at least partially opposed to gravity.   
     
     
         2 . The processing system according to  claim 1 , wherein said reaction vessel is configured for providing an expanded or fluidized bed of said immobilized lipase preparation. 
     
     
         3 . The processing system according to  claim 1  or  claim 2 , wherein said reaction vessel comprises a vessel inlet port and a vessel outlet port, and wherein said vessel inlet port is at a location lower than that of said vessel outlet port. 
     
     
         4 . The processing system according to any one of  claims 1  to  3 , wherein said reaction vessel comprises a stirring system for stirring the reaction medium and said immobilized lipase preparation within the reaction vessel. 
     
     
         5 . The processing system according to any one of  claims 1  to  4 , wherein said reaction vessel comprises the immobilized lipase preparation, at least during operation of said processing system for the production of said fatty acid alkyl esters. 
     
     
         6 . The processing system according any one of  claims 1  to  5 , wherein said reaction vessel comprises the fatty acid source and the at least one of an alcohol and an alcohol donor, at least during operation of said processing system for the production of said fatty acid alkyl esters. 
     
     
         7 . The processing system according to any one of  claims 1  to  6 , wherein said reaction medium comprises at least one of an aqueous alkaline buffer solution and water, said water being at least one of free water and mixed with a polyol or polyols, at least during operation of said processing system for the production of said fatty acid alkyl esters. 
     
     
         8 . The processing system according to any one of  claims 1  to  7 , wherein said reaction medium comprises a mixture, said processing system comprising a pre-reaction vessel in selective fluid communication with said reaction vessel via said vessel inlet port, said pre-reaction vessel being configured for premixing at least the fatty acid source and the at least one of an alcohol and an alcohol donor to form said mixture, and for selectively delivering said mixture to said reaction vessel at least during operation of said processing system for the production of said fatty acid alkyl esters. 
     
     
         9 . The processing system according to  claim 8 , further comprising a supply of fatty acid source in selective fluid communication with said pre-reaction vessel and configured for selectively delivering the fatty acid source to said pre-reaction vessel at least during said operation of said processing system, and an alcohol source in selective fluid communication with said pre-reaction vessel and configured for selectively delivering the at least one of an alcohol and an alcohol donor to said pre-reaction vessel at least during said operation of said processing system. 
     
     
         10 . The processing system according to  claim 8  or  claim 9 , further optionally comprising at least one of an aqueous buffer source and a water source in selective fluid communication with said pre-reaction vessel and configured for selectively delivering the at least one of an aqueous alkaline buffer solution and water, free or mixed with a polyol/polyols, to said pre-reaction vessel, to be included in said reaction mixture at least during said operation of said processing system. 
     
     
         11 . The processing system according to  claims 8  to  10 , configured for selectively delivering one or more of the fatty acid source and the at least one of an alcohol and an alcohol donor to said pre-reaction vessel in a continuous manner or in discrete batches at least during said operation of said processing system. 
     
     
         12 . The processing system according to any one of  claims 8  to  11 , configured for selectively delivering the at least one of an aqueous alkaline buffer solution and water, free or mixed with a polyol/polyols, to said pre-reaction vessel in a continuous manner or in discrete batches at least during said operation of said processing system. 
     
     
         13 . The processing system according to any one of  claims 8  to  12 , wherein said pre-reaction vessel is configured for selectively delivering said mixture to said reaction vessel in a continuous manner or in discrete batches at least during said operation of said processing system. 
     
     
         14 . The processing system according to any one of  claims 1  to  13 , the processing system being configured for selectively and directly delivering to said reaction vessel at least one of the fatty acid source; and/or the at least one of an alcohol and an alcohol donor; and/or the at least one of an aqueous alkaline buffer solution and water, free or mixed with a polyol/polyols. 
     
     
         15 . The processing system according to any one of  claims 1  to  14 , wherein said reaction vessel comprises a thermal regulation processing system configured for maintaining the reaction medium in said reaction vessel within a selected temperature range. 
     
     
         16 . The processing system according to any one of  claims 1  to  15 , further comprising a retaining arrangement configured for retaining the immobilized lipase preparation within said reaction vessel at least during operation of said processing system. 
     
     
         17 . The processing system according to  claim 16 , wherein said retaining arrangement is at one or both of said reaction vessel outlet and said reaction vessel inlet. 
     
     
         18 . The processing system according to any one of  claims 1  to  17 , further comprising a product separation vessel in selective fluid communication with said reaction vessel, said processing system being configured for selectively delivering a reaction mixture including reaction products from said reaction vessel to said product separation vessel, and wherein said product separation vessel is configured for selectively separating a yield of the fatty acid alkyl esters from the reaction mixture delivered thereto. 
     
     
         19 . The processing system according to  claim 18 , wherein said product separation vessel comprises one of a centrifuge, coalescer and gravity separation processing system. 
     
     
         20 . The processing system according to any one of  claims 18  and  19 , wherein said reaction vessel is configured for selectively delivering said reaction mixture to said product separation vessel in a continuous manner or in discrete batches at least during said operation of said processing system. 
     
     
         21 . The processing system according to any one of  claims 18  to  20 , configured for selectively dispensing said yield of fatty acid alkyl esters from said product separation vessel. 
     
     
         22 . The processing system according to  claim 21 , configured for selectively delivering said yield of fatty acid alkyl esters from said product separation vessel in a continuous manner or in discrete batches. 
     
     
         23 . The processing system according to any one of  claims 18  to  22 , wherein said processing system is configured for increasing said yield of the fatty acid alkyl esters from the reaction mixture delivered to said product separation vessel. 
     
     
         24 . The processing system according to  claim 23 , wherein said processing system is configured for selectively rerouting said yield of the fatty acid alkyl esters to said reaction vessel to further increase said yield of the fatty acid alkyl esters from the reaction mixture subsequently delivered to said product separation vessel. 
     
     
         25 . The processing system according to  claim 23  or  claim 24 , wherein said processing system is configured for selectively rerouting said yield of the fatty acid alkyl esters to one or more auxiliary reactor modules, wherein each said auxiliary reactor module comprises an auxiliary reactor vessel and an auxiliary product separation vessel, wherein said further increased yield of the fatty acid alkyl esters is selectively subsequently delivered via a respective said auxiliary product separation vessel. 
     
     
         26 . The processing system according to  claim 25 , wherein each said auxiliary reaction vessel is configured for reacting said yield of the fatty acid alkyl esters in the presence of an immobilized lipase preparation, wherein the immobilized lipase preparation comprises at least one lipase immobilized on a hydrophobic porous support and wherein said processing system is configured for passing the reaction medium through said immobilized lipase preparation in the respective said auxiliary reaction vessel in a direction at least partially opposed to gravity. 
     
     
         27 . The processing system according to any one of  claims 1  to  26 , wherein said processing system is configured for selectively outputting and rerouting a reaction mixture including said reaction products back to said reaction vessel for further processing therein for enhancing yield of said fatty acid alkyl esters. 
     
     
         28 . The processing system according to any one of  claims 18  to  27 , wherein said processing system is configured for selectively outputting and rerouting a reaction mixture including said reaction products back to said reaction vessel and for selectively subsequently outputting and delivering a modified reaction mixture including reaction products to said product separation vessel, and wherein said product separation vessel is configured for selectively separating a yield of the fatty acid alkyl esters from the reaction mixture delivered thereto. 
     
     
         29 . The processing system according to  claim 27  or  claim 28 , wherein said processing system is configured for rerouting the reaction mixture through said reaction vessel in a direction at least partially opposed to gravity. 
     
     
         30 . The processing system according to any one of  claims 25  to  29 , wherein said processing system is configured for selectively outputting and rerouting a reaction mixture provided by each said auxiliary reaction vessel back to the respective said auxiliary reaction vessel for enhancing yield of said fatty acid alkyl esters. 
     
     
         31 . The processing system according to any one of  claims 25  to  30 , wherein said processing system is configured for selectively outputting and rerouting a reaction mixture including said reaction products provided by the respective said auxiliary reaction vessel back to the respective said auxiliary reaction vessel and for selectively subsequently outputting and delivering a modified reaction mixture including reaction products from the respective said auxiliary reaction vessel to the respective said auxiliary product separation vessel, and wherein the respective said auxiliary product separation vessel is configured for selectively separating a yield of the fatty acid alkyl esters from the reaction mixture delivered thereto. 
     
     
         32 . The processing system according to  claim 30  or  claim 31 , wherein said processing system is configured for passing the reaction products through each said auxiliary reaction vessel in a direction at least partially opposed to gravity. 
     
     
         33 . A process for the transesterification/esterification of a fatty acid source with an alcohol, to form fatty acid alkyl esters, comprising reacting a reaction medium including a fatty acid source and an alcohol or an alcohol donor in the presence of an immobilized lipase preparation, wherein the immobilized lipase preparation comprises at least one lipase immobilized on a hydrophobic porous support and the reaction medium optionally stirred and contains at least one of an aqueous alkaline buffer solution and water, free or mixed with a polyol/polyols, and wherein the reaction medium is passed through said immobilized lipase preparation in a direction at least partially opposed to gravity. 
     
     
         34 . A process according to  claim 33 , wherein said reaction provides reaction products including said fatty acid alkyl esters. 
     
     
         35 . A process according to  claim 34 , further comprising the step of selectively directly recirculating said reaction products to said immobilized lipase preparation. 
     
     
         36 . A process according to  claim 35 , wherein in said recirculating step, said reaction products are passed through said immobilized lipase preparation in a direction at least partially opposed to gravity. 
     
     
         37 . A process according to  claim 35  or  claim 36 , comprising repeating said step of selectively directly recirculating reaction products of said reaction to said immobilized lipase preparation a plurality of times. 
     
     
         38 . A process according to any one of  claims 34  to  37 , further comprising the step of selectively separating fatty acid alkyl esters from said reaction products. 
     
     
         39 . A process according to any one of  claims 33  to  38 , wherein upon adding the said aqueous alkaline buffer solution the pH of the reaction medium containing the oil feedstock is from about 5 to about 11, respectively upon adding said water which is in the form of a water solution of at least one of dissolved salts and polyol/polyols the pH of the reaction medium containing the oil feedstock is from about 3 to about 11. 
     
     
         40 . A process according to any one of  claims 33  to  39 , wherein said at least one of aqueous alkaline buffer solution and water is contained at a quantity of at least 0.01% wt. of the fatty acid source, particularly 2% wt. of the fatty acid source, more particularly 5% wt. of the fatty acid source. 
     
     
         41 . A process according to any one of  claims 33  to  40 , wherein said alcohol is a short-chain alcohol, specifically C 1 -C 6  alkyl alcohol, more specifically C 1 -C 4  alkyl alcohol, particularly methanol or ethanol, or said alcohol is a medium-chain fatty alcohol (C 6 -C 10 ) or long-chain fatty alcohol (C 12 -C 22 ). 
     
     
         42 . A process according to any one of  claims 33  to  41 , wherein said alcohol donor is a mono-alkyl ester, such as methyl acetate or a di-alkyl carbonate, such as di-methyl carbonate, serving also as a source for mild alkaline reagent in the reaction medium. 
     
     
         43 . A process according to any one of  claims 33  to  42 , wherein said at least one lipase is a lipase derived from any one  Rhizomucor miehei, Pseudomonas  sp.,  Rhizopus niveus, Mucor javanicus, Rhizopus oryzae, Aspergillus niger, Penicillium camembertii, Alcaligenes  sp.,  Acromobacter  sp.,  Burkholderia  sp.,  Thermomyces lanuginosus, Chromobacterium viscosum, Candida antarctica B, Candida rugosa, Candida antarctica A, papaya  seeds and pancreatin. 
     
     
         44 . A process according to any one of  claims 33  to  43 , wherein said immobilized lipase is capable of catalyzing the esterification of free fatty acids to yield fatty acid alkyl esters and water as by-product, and the transesterification of triglycerides and partial glycerides to yield fatty acid alkyl esters and glycerol as by-product. 
     
     
         45 . A process according to any one of  claims 33  to  44 , wherein said lipase preparation comprises at least two lipases which can be each separately immobilized on a hydrophobic support or co-immobilized on the same hydrophobic support, and wherein said lipases possess identical or different regio-specificity or selectivity to fatty acyl groups. 
     
     
         46 . A process according to any one of  claims 33  to  45 , wherein said support is any one of hydrophobic aliphatic polymer-based support and hydrophobic aromatic polymer-based support. 
     
     
         47 . A process according to any one of  claims 33  to  46 , wherein said support is porous or non-porous inorganic support, which can be hydrophobic or is coated with hydrophobic organic material. 
     
     
         48 . A process according to any one of  claims 33  to  47 , wherein said alkaline buffer solution is added to said fatty acid source in a premixing stage or directly to the reaction medium. 
     
     
         49 . A process according to any one of  claims 33  to  48 , wherein said fatty acid source is any one of plant oil, animal fat, algal oil, fish oil, waste oil, grease trap and any mixtures thereof. 
     
     
         50 . A process according to any one of  claims 33  to  49 , wherein said fatty acid source comprises free fatty acids, mono-, di- or tri-glycerides, their mixtures at any ratio, in the absence or presence of other minor fatty acid derivatives such as phospholipids and wax esters, more specifically said fatty acid source is unrefined, refined, bleached, deodorized or any of their combinations. 
     
     
         51 . A process according to any one of  claims 33  to  50 , wherein said alcohol is methanol and said resulting fatty acid esters are fatty acid methyl esters (FAME—Biodiesel). 
     
     
         52 . A process according to any one of  claims 33  to  51 , wherein the reaction is carried out at a temperature between 0° C. and 100° C., specifically between 20-30° C. 
     
     
         53 . A process according to any one of  claims 33  to  52 , conducted in the processing system of any one of  claims 1  to  32 .