Biodiesel cold filtration process
View Patent ↗An improved biodiesel production process includes the steps of processing a feedstock to produce biodiesel, cooling the biodiesel so as to form sediment, and filtering the biodiesel to remove the sediment. The resulting biodiesel from the cold filtration process avoids problems of sediment formation during storage and transportation.
1. A method for removing impurities from biodiesel, comprising:
producing biodiesel from a feedstock using a process with temperatures exceeding 38° C., with the biodiesel meeting ASTM D6751-06 specification; then
cooling the biodiesel to a temperature of less than 38° C. using a cooling system to form particulates of impurities; and then
filtering the cooled biodiesel to remove the particulates;
wherein the cooling system is an economizer.
2. The method of claim 1 whereby the biodiesel is cooled to a temperature of between 4-38° C.
3. A method for removing impurities from biodiesel, comprising:
producing biodiesel from a feedstock using a process with temperatures exceeding 38° C., with the biodiesel meeting ASTM D6751-06 specification; then
cooling the biodiesel to a temperature of less than 38° C. using a cooling system to form particulates of impurities; and then
filtering the cooled biodiesel to remove the particulates;
wherein the cooling step is performed in multiple stages using a series of heat exchangers.
4. The method of claim 3 further comprising periodically cleaning the heat exchangers by running un-cooled biodiesel through the heat exchangers without supplying cooling fluid to the exchangers.
5. The method of claim 3 wherein a first cooling stage reduces the biodiesel temperature to approximately between 93-105° C., a second cooling stage further reduces the biodiesel temperature to approximately between 26-33° C., and a third cooling stage further reduces the biodiesel temperature to at least between 18-24° C.
6. The method of claim 1 wherein the filtering step includes multiple stages.
7. The method of claim 6 wherein a first filtering stage includes the addition of an adsorbent to the biodiesel.
8. The method of claim 7 whereby the adsorbent is selected from the group consisting of diatomaceous earth, silica, sand, and mixtures thereof.
9. The method of claim 8 wherein the adsorbent is diatomaceous earth.
10. The method of claim 9 wherein the diatomaceous earth is between 0.1% to 0.25% by weight of the biodiesel.
11. The method of claim 7 wherein the first filtration stage includes a leaf filter.
12. The method of claim 7 wherein a second filtration stage includes a sock filter.
13. A method for improving the quality of biodiesel fuel, comprising:
pretreating a supply of triglycerides to remove impurities; and then
converting the triglycerides into a mixture of methyl esters and glycerin in a process that includes a heating step; and then
removing the glycerin from the mixture; and then
cooling the methyl esters to a temperature of less than about 38° C. using a cooling system so as to form particles of non-methyl esters; and then
filtering the methyl esters through at least one filter to remove the non-methyl ester particles and thereby produce improved biodiesel fuel;
wherein the cooling is accomplished in a series of heat exchangers.
14. The method of claim 13 wherein the filtering is accomplished through a series of filters.
15. The method of claim 13 further comprising adding an adsorbent to the methyl esters after cooling and before filtering to form a slurry.
16. The method of claim 15 wherein the adsorbent is diatomaceous earth.
17. The method of claim 15 wherein the slurry is filtered through a leaf filter to remove particles from the biodiesel.
18. The method of claim 17 wherein the biodiesel is further filtered through a sock filter to remove particles.
19. The method of claim 13 further comprising winterizing the filtered methyl esters.
20. The method of claim 19 further comprising fractionating the winterized methyl esters.
21. The method of claim 13 wherein the methyl esters meet ASTM D6751 specifications or greater before cooling.
22. An improved biodiesel production process, comprising:
processing triglycerides in a process that includes a heating step to produce biodiesel; then
cooling the biodiesel with at least one heat exchanger so as to precipitate out particulates; then
filtering the cooled biodiesel to remove the particulates; and
periodically cleaning the heat exchanger by passing the uncooled biodiesel through the heat exchanger without supplying coolant to the heat exchanger.
23. The process of claim 22 further comprising restoring coolant flow to the heat exchanger after the cleaning step and recycling the biodiesel used for cleaning to the heat exchanger for cooling.
24. The process of claim 22 further comprising adding an adsorbent to the cooled biodiesel prior to filtration.
25. The process of claim 24 wherein the adsorbent is diatomaceous earth.
26. The process of claim 22 wherein the filtering step utilizes a pressure leaf filter.
27. A method for removing impurities from biodiesel, comprising:
producing biodiesel from a feedstock using a process with temperatures exceeding 38° C., with the biodiesel meeting ASTM D6751-06 specification; then
cooling the biodiesel to a temperature of less than 38° C. using a cooling system to form particulates of impurities; and then
filtering the cooled biodiesel to remove the particulates;
wherein the cooling system is a cooling water exchanger.
28. A method for removing impurities from biodiesel, comprising:
producing biodiesel from a feedstock using a process with temperatures exceeding 38° C., with the biodiesel meeting ASTM D6751-06 specification; then
cooling the biodiesel to a temperature of less than 38° C. using a cooling system to form particulates of impurities; and then
filtering the cooled biodiesel to remove the particulates;
wherein the cooling system is a cooling water recirculation loop.
29. A method for improving the quality of biodiesel fuel, comprising:
cooling the biodiesel that has completed the manufacturing process and which meets the requirements of ASTM D6751-06 to a temperature of less than 38° C. using a cooling system so as to form particles of non-methyl esters contained within the biodiesel; and then
filtering the biodiesel through at least one filter to remove the non-methyl ester particles and thereby produce improved biodiesel fuel;
wherein the cooling step is performed in multiple stages using a series of heat exchangers.
30. The method of claim 29 whereby the biodiesel is cooled to a temperature of between 4-38° C.
31. The method of claim 29 wherein the filtering step includes multiple stages.
32. The method of claim 31 wherein a first filtering stage includes the addition of an adsorbent to the biodiesel.
33. The method of claim 32 whereby the adsorbent is selected from the group consisting of diatomaceous earth, silica, sand, and mixtures thereof.
34. The method of claim 33 wherein the adsorbent is diatomaceous earth.
35. The method of claim 34 wherein the diatomaceous earth is between 0.1% to 0.25% by weight of the biodiesel.
36. The method of claim 31 wherein the first filtration stage includes a leaf filter.
37. The method of claim 31 wherein a second filtration stage includes a sock filter.