Simultaneous synthesis and purification of a fatty acid monoester biodiesel fuel

Abstract

Simultaneous synthesis and purification of a fatty acid monoester biodiesel fuel from a triacylglycerol feedstock is described. In an exemplary method, the triacylglycerol feedstock is continuously contacted with a catalytic chromatographic bed comprising a first (solid phase) basic catalyst through a first port of a simulated moving bed chromatographic apparatus. A monohydric alcohol and optional second (mobile phase) basic catalyst is continuously contacted with the catalytic chromatographic bed through a second port and pumped in a first direction toward the triacylglycerol feedstock to contact the triacylglycerol in a reaction zone of the catalytic chromatographic bed where the fatty acid monoester and glycerol coproduct are formed. The fatty acid monoester is removed from the reaction zone through a product port of the simulated moving bed apparatus. Segments of the catalytic chromatographic bed are incrementally moved in a second direction, opposite the first direction, and the glycerol is removed from a raffinate port located opposite the product port of the apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates one embodiment of a simulated moving bed chromatographic apparatus configured with a basic catalytic chromatographic bed material (strong base resin) and its use in a process for synthesizing fatty acid monoesters and glycerol coproduct and simultaneously purifying fatty acid monoesters and glycerol coproduct by chromatographic separation.

FIG. 2 diagrammatically illustrates another embodiment of a simulated moving bed chromatographic apparatus for simultaneously synthesizing fatty acid monoesters from acylglycerols and purifying them from coproducts, configured with a basic catalytic chromatographic bed material. FIG. 2a illustrates the position of ports at a first time and FIG. 2b illustrates the position of the ports at a second, step time.

FIG. 3 illustrates an embodiment of a simulated moving bed apparatus configured for simultaneously synthesizing and purifying a fatty acid monoester and purifying it from coproducts with an acidic catalytic chromatographic bed in which the acidic catalyst has been converted to the basic form by treatment with an alkali solution.

FIG. 4 illustrates an embodiment of a simulated moving bed apparatus configured for simultaneously synthesizing and purifying a fatty acid monoester from acylglycerols and purifying it from coproducts with a hydrophobic chromatographic bed material.

FIG. 5 illustrates an embodiment of a simulated moving bed apparatus configured for simultaneously synthesizing fatty acid methyl esters from acylglycerols and purifying it from coproduct glycerol by adsorptive/desorptive separation.

FIG. 6 illustrates the elution profile of a pulse test from example 5.1 using a single column loaded with Sybron MP600 strong base resin from Bayer (Pittsburg, Pa.).

FIG. 7 illustrates the elution profile of a pulse test from example 5.2 using a single column loaded with PA308 strong base resin from Mitsubishi (Tokyo, Japan),

FIG. 8 illustrates the elution profile of a pulse test from example 5.3 using a single column loaded with weak base resin SD2 from Dow Chemical Co. (Midland, Mich.).

FIG. 9 illustrates the elution profile of a pulse test from example 5.4 using a single column loaded with Spherical Silica (Makall Group Inc., Quindao, China).

FIG. 10 illustrates the elution profile of a pulse test from example 5.5 using a single column loaded with Spherical Alumina (LaChemCo, Gramercy, La.).

FIG. 11 illustrates the elution profile of a pulse test from example 5.6 using a single column loaded with Spherical Alumina (LaChemCo, Gramercy, La.).

FIG. 12 illustrates the elution profile of a pulse test from example 5.7 using a single column loaded with a nonfunctional resin SP 70 (Mitsubishi, Tokyo, Japan).

FIG. 13 illustrates the elution profile of a pulse test from example 5.8 using a single column loaded with strong acid resin Sybron K2629 (Bayer, Pittsburg, Pa.).

Claims

1. A process for simultaneously synthesizing and purifying a fatty acid monoester and glycerol comprising: contacting a chromatographic bed material with an acylglycerol feedstock, a monohydric alcohol and a first catalyst to form the fatty acid monoester while simultaneously separating a fraction enriched with the fatty acid monoester from a fraction enriched with glycerol by sorbent chromatography over the chromatographic bed material.

2. The process of claim 1 wherein the sorbent chromatography comprises a chromatographic separation.

3. The process of claim 1 wherein the sorbent chromatography comprises an adsorptive/desorptive separation.

4. The process of claim 1 wherein the chromatographic bed material is a catalytic chromatographic bed material containing the first catalyst.

5. The process of claim 4 wherein the catalytic chromatographic bed material comprises a strong base resin.

6. The process of claim 4 further including simultaneously contacting the catalytic chromatographic bed with a second catalyst.

7. The process of claim 6 wherein the second catalyst comprises a basic compound.

8. The process of claim 7 wherein the basic compound comprises a hydroxide salt.

9. The process according to claim 8 wherein the hydroxide salt is present in amount of 0.0050 to 5 weight percent of the amount of monohydric alcohol.

10. The process according to claim 9 wherein the hydroxide salt is present in amount of 0.0050-0.2 weight percent of the amount of monohydric alcohol.

11. The process according to claim 8 wherein the amount of fatty acid monoester produced is at least 98 mole percent of the amount of fatty acid moieties in the acylglycerol feedstock.

12. The process of claim 6 wherein the second catalyst is contacted with the monohydric alcohol prior to contacting the chromatographic bed and acylglycerol feedstock.

13. The process of claim 1 wherein the monohydric alcohol is selected from the group consisting of methanol and ethanol.

14. The process of claim 1 wherein the acylglycerol comprises a triacylglycerol obtained from an oilseed plant.

15. The process of claim 1, wherein none of the reactants are in a vapor phase.

16. The process of claim 1 wherein the chromatographic bed material is contained within a simulated moving bed apparatus.

17. The process of claim 16 wherein the simulated moving bed apparatus comprises a plurality of movable column segments connected in sequential fluid series and including in order, an eluent port to introduce the monohydric alcohol into the apparatus to contact the chromatographic bed material, a raffinate port to remove the glycerol from the apparatus, a feed port to introduce the acylglycerol into the apparatus to contact the chromatographic bed material, and a product port to remove the fatty acid monoester from the apparatus.

18. The process of claim 17 wherein the column segments are sequentially connected in a circular series.

19. The process of claim 18 wherein the monohydric alcohol flows through the simulated moving bed apparatus in a first flow direction and the column segments are collectively moved in a second direction opposite the first direction.

20. The process of claim 16 wherein the simulated moving bed apparatus comprises a plurality of column segments sequentially fluidly interconnected by moveable ports that include in order, an eluent port to introduce the monohydric alcohol into the apparatus to contact the chromatographic bed material, a raffinate port to remove the glycerol from the apparatus, a feed port to introduce the acylglycerol into the apparatus to contact the chromatographic bed material, and a product port to remove the fatty acid monoester from the apparatus.

21. The process of claim 20 wherein the moveable ports are moved in a circular sequence relative to the column segments.

22. The process of claim 20 wherein the monohydric alcohol is introduced into the simulated moving bed apparatus in a first flow direction and the moveable ports are collectively moved to adjacent column segments in the same direction to simulate movement of the bed segments in a second direction opposite the first direction.

23. The process of claim 1, wherein the contacting of the chromatographic bed material with the monohydric alcohol, acylglycerol feedstock and first catalyst with simultaneous sorbent chromatographic separation are conducted continuously with removal of the glycerol enriched effluent and removal of fatty acid monoester enriched effluent.

24. The process of claim 4 wherein the acylglycerol feedstock is contacted with the catalytic chromatographic bed material in a first zone and the glycerol is withdrawn from a second zone different than the first.

25. The process of claim 24 further including contacting the catalytic chromatographic bed with the monohydric alcohol in a third zone located upstream of the first and second zones with respect to a flow direction of the monohydric alcohol.

26. The process of claim 25 further including contacting the catalytic chromatographic bed with the monohydric alcohol in the absence of any other catalyst in a fourth zone located between the first zone and the third zone.

27. A process for simultaneously synthesizing and purifying a fatty acid monoester comprising, in a simulated moving bed apparatus comprising a plurality of column segments sequentially connected in series and containing a catalytic chromatographic bed material, simultaneously continuously: a. feeding an acylglycerol feedstock into the apparatus at a feed port position to contact the chromatographic bed material at a column segment in a first zone;b. feeding a monohydric alcohol eluent reactant into the apparatus at an eluent port position to contact the chromatographic bed material at a column segment in a second zone;c. flowing the monohydric alcohol eluent reactant in a first direction toward the first zone to contact the acylglycerol feedstock and moving the plurality of column segments in a second direction opposite the first direction;d. removing a first effluent enriched in the fatty acid monoester from a product port positioned within the first zone and downstream of the feed port position with respect to the first direction; ande. removing a second effluent enriched in glycerol from a raffinate port position in the second zone upstream of the feed port with respect to the first direction.

28. A biodiesel fuel production facility comprising a simulated moving bed apparatus configured to operate any one of the processes according to any one of claims 1-16.

29. The process according to claim 27 wherein the chromatographic bed material serves two roles simultaneously, a first role as a solid phase catalyst and a second role as the stationary phase for sorbent chromatography.

30. The process according to claim 27 wherein the monohydric alcohol serves as both a reactant and an eluant.

31. A process for simultaneously synthesizing and purifying glycerol comprising, contacting a chromatographic bed material with an acylglycerol feedstock, a monohydric alcohol and a first catalyst to form glycerol while simultaneously separating a fraction enriched with the glycerol from a fraction enriched with fatty acid methyl ester by sorbent chromatography over the chromatographic bed material.

32. The process of claim 31 further including incorporating the glycerol to form compositions selected from the group consisting of salt brine additives, rock salt treatments, magnesium chloride treatments, non-chloride highway anti-icers, sand treatments, freeze conditioners for particulate products, freeze conditioners for coal, freeze conditioners for ores, fire resistant hydraulic fluids, engine coolants, oil well fluids, gas well fluids, agricultural anti-icing applications, airplane lavatory fluids and recreational vehicle lavatory fluids.

33. The process of claim 31 further including chemically modifying the glycerol to form compositions selected from the group consisting of propylene glycol, ethylene glycol, methanol, 2-propanol, glycerol, lactic acid, glyceric acid, sodium lactate, epichlorohydrin, acrolein, and sodium glycerate.

34. The process according to claim 31, wherein the glycerol comprises a raffinate having a chloride content not greater than 300 parts per million.

35. The process according to claim 31, wherein the glycerol comprises raffinate having a chloride content not greater than 100 parts per million.

36. The process of claim 4 wherein the catalytic chromatographic bed material is selected from the group consisting of a strong base resin, a weak base resin, a strong acid resin, a weak acid resin, a nonfunctional resin, and a nonfunctional solid.