Process for making biodiesel from crude tall oil

• US 20070130820A1
• Filed: 11/16/2006
• Published: 06/14/2007
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York)
• Inventors: Omori, Shigetoshi, Shastri, Shiri, Marda, Swapnil, Chatterjee, Siddharth
• Granted Patent: US 7,695,532 B2
• Time in Patent Office: Days
• US Class Current: 44/306
• CPC Class Codes: C10G 2300/1011 Biomass
• CPC Class Codes: C10L 1/026 for compression ignition
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 30/20 using bio-feedstock

Abstract

A process of making biodiesel from crude tall oil by reacting crude tall oil with a C₁-C₆ alkanol in the presence of an acid catalyst or by reacting crude tall oil with an acyl halide in the presence of a C₁-C₆ alkanol. The reaction product of either of these reactions is separated into a suspension liquid by the addition of a polar liquid. The biodiesel product is recovered from the suspension liquid by addition of an organic solvent which produces a polar liquid phase and an organic liquid phase. The biodiesel is recovered from the organic liquid phase by evaporating the organic solvent, which is recovered for use in subsequent separation processes, and vacuum distilling off the product biodiesel from the organic solvent-free organic liquid phase.

Claims

1. A process of making biodiesel comprising reacting crude tall oil with a C₁-C₆ alkanol in the presence of an acid catalyst to produce a biodiesel reaction product.

2. A process in accordance with claim 1 wherein said crude tall oil is reacted with said C₁-C₆ alkanol by reflexing a mixture of said crude tall oil and said C₁-C₆ alkanol, at a temperature of at least about the boiling temperature of said C₁-C₆ alkanol, in the presence of said acid catalyst.

3. A process in accordance with claim 1 wherein said crude tall oil is reacted with said C₁-C₆ alkanol by contacting said crude tall oil with said C₁-C₆ alkanol, in the presence of said acid catalyst, in a closed system at a temperature of at least about the boiling temperature of at least about the boiling temperature of said C₁-C₆ alkanol.

4. A process in accordance with claim 2 wherein said reflux is conducted at a temperature in the range of between about 55°

C. and about 120°

C. over a period of no more than about 2 hours.

5. A process in accordance with claim 4 wherein said reflux occurs at a temperature in the range of about 60°

C. and about 110°

C. over a period of between about 1 hour and 2 hours.

6. A process in accordance with claim 5 wherein said reflux is conducted at a temperature in the range of between about 65°

C. and about 100°

C. for a period of about 1 hour.

7. A process in accordance with claim 3 wherein said contact occurs at a temperature in the range of between about 55°

C. and about 90°

C. for a period of no more than about 2 hours.

8. A process in accordance with claim 1 wherein said C₁-C₆ alkanol is methanol, ethanol or propanol and said acid catalyst is sulfuric acid or hydrochloric acid.

9. A process in accordance with claim 8 wherein said C₁-C₆ alkanol is methanol and said acid catalyst is sulfuric acid.

10. A process in accordance with claim 2 comprising the step of refluxing said mixture in the presence of a water absorbing agent.

15. A process in accordance with claim 1 wherein said biodiesel reaction product is (a) contacted with a volume of a polar liquid at least equal to the volume of said biodiesel reaction product wherein a suspension liquid is formed;

(b) contacting said suspension liquid with an organic solvent whereby a two-phase liquid mixture, an organic liquid phase and a polar liquid phase, is obtained;

(c) removing and recovering said organic solvent from said organic phase by evaporation; and

(d) recovering said biodiesel by vacuum distillation of said organic solvent-free product of step (c).

17. A process in accordance with claim 15 wherein said polar liquid is water;

said polar liquid phase is an aqueous phase;

said extracting agent is ethyl acetate, methylene chloride, ethylene chloride, chloroform, hexane, ether or petroleum ether; and

said water is added to said biodiesel reaction product in a volume of up to about three times the volume of said biodiesel reaction product.

19. A process in accordance with claim 17 wherein said aqueous phase obtained in said step (b) is contacted at least once with said organic solvent wherein a two-phase liquid mixture is formed and wherein said organic phase in each of said organic solvent contacting steps is added to said organic liquid phase prior to said step (c).

21. A process in accordance with claim 19 wherein said volume of water added to said biodiesel reaction product in said step (a) is about double the volume of said biodiesel reaction product;

said organic solvent added in said step (b) is ethyl acetate; and

said step (b) includes said first contact of said ethyl acetate with said biodiesel reaction product and two additional contacts of said aqueous phase with said ethyl acetate.

11. A process of making biodiesel comprising reacting crude tall oil with an acyl halide in the presence of a C₁-C₆ alkanol to produce a biodiesel reaction product.

12. A process in accordance with claim 11 wherein said reaction of said crude tall oil and said acyl halide occurs by slow addition of said acyl halide to said crude tall oil in said C₁-C₆ alkanol at reduced temperature in a closed system followed by heating at a temperature of said C₁-C₆ alkanol for no more than about 2 hours.

13. A process of in accordance with claim 12 wherein said acyl halide is added to said crude tall oil in said C₁-C₆ alkanol at a temperature in the range of between about −

10°

C. and about 10°

C. and said heating occurs at a temperature in the range between 25°

C. and about 100°

C. over a period of between about 30 minutes and about 2 hours.

14. A process in accordance with claim 11 wherein said acyl halide is acetyl chloride or acetyl bromide and said C₁-C₆ alkanol is methanol, ethanol or propanol.

16. A process in accordance with claim 11 wherein said biodiesel reaction product is (a) contacted with a volume of a polar liquid at least equal to the volume of said biodiesel reaction product wherein a suspension liquid is obtained;

(b) contacting said suspension liquid with an organic solvent whereby a two-phase liquid mixture, an organic liquid phase and a polar liquid phase, is obtained;

(c) removing and recovering said organic solvent from said organic phase by evaporation; and

(d) recovering said biodiesel by vacuum distillation of said organic solvent-free product of step (c).

18. A process in accordance with claim 16 wherein said polar liquid is water;

said polar liquid phase is an aqueous phase;

said extracting agent is ethyl acetate, methylene chloride, ethylene chloride, chloroform, hexane, ether or petroleum ether; and

said water is added to said biodiesel reaction product in a volume of up to about three times the volume of said biodiesel reaction product.

20. A process in accordance with claim 18 wherein said aqueous phase obtained in said step (b) is contacted at least once with said organic solvent wherein a two-phase liquid mixture is formed and wherein said organic phase in each of said organic solvent contacting steps is added to said organic liquid phase prior to said step (c).

22. A process in accordance with claim 20 wherein said volume of water added to said biodiesel reaction product in said step (a) is about double the volume of said biodiesel reaction product;

said organic solvent added in said step (b) is ethyl acetate; and

said step (b) includes said first contact of said ethyl acetate with said biodiesel reaction product and two additional contacts of said aqueous phase with said ethyl acetate.