Thermal fractionation of biomass of non-lignocellulosic origin for multiple high-quality biofuels
Methods for production of multiple biofuels through thermal fractionation of biomass feedstocks are described. The products of said methods are also described.
1. A method of pyrolytic thermal fractionation of microalgae biomass comprising a protein component and a triglyceride component with or without an additional carbohydrate component, the method comprising:
(a) heating the microalgae biomass to a first volatilization temperature of a first component comprising at least one of proteins or carbohydrates, and holding the first volatilization temperature of the heated microalgae biomass constant for a first period of time until no further mass loss of the first component occurs, thereby producing a first volatilized vapor product derived from proteins and/or carbohydrates, wherein the first volatilization temperature is in the range of from 180° C. to 360° C.;
(b) removing and recovering the first volatilized vapor product from the microalgae biomass remaining from step (a);
(c) heating the microalgae biomass remaining from step (b) to a second volatilization temperature of a second component comprising triglycerides, and holding the second volatilization temperature of the heated microalgae biomass constant for a second period of time until no further mass loss of the second component occurs, thereby producing a second volatilized vapor product derived from the triglycerides, wherein the second volatilization temperature is in the range of from 370° C. to 500° C.; and
(d) removing and recovering the second volatilized vapor product from the microalgae biomass remaining from step (c).
2. The method of claim 1 , wherein step (a) comprises simultaneously volatilizing proteins and carbohydrates.
3. The method of claim 1 , wherein the second volatilized vapor product comprises one or more of: triglycerides, long chain fatty acids, di-glyceride, mono-glyceride, or hydrocarbons.
4. The method of claim 1 , wherein the first volatilized vapor product comprises one or more of: organic acids, furans, N-compounds, water, aldehydes, ketones, or phenols.
5. The method of claim 1 , wherein the first volatilization temperature is 320° C.
6. The method of claim 1 , wherein the second volatilization temperature is 420° C.
7. The method of claim 1 , wherein the microalgae biomass comprises Chlorella sp.
8. The method of claim 1 , wherein the microalgae biomass comprises Scenedesmus sp.
9. The method of claim 1 , wherein the first period of time is in the range of from 5 minutes to 30 minutes.
10. The method of claim 1 , wherein the second period of time is in the range of from 5 minutes to 30 minutes.
11. The method of claim 1 , wherein the first period of time is in the range of from 10 minutes to 15 minutes.
12. The method of claim 1 , wherein the second period of time is in the range of from 10 minutes to 15 minutes.
13. The method of claim 1 , further comprising combusting the first volatilized vapor product for recovery of process heat.
14. The method of claim 1 , further comprising passing the first volatilized vapor product through hydro-denitrification and hydro-deoxygenation processes to reduce nitrogen and oxygen content of products.
15. The method of claim 1 , further comprising subjecting the first volatilized vapor product to a downstream purification step to recover nitrogen- and/or oxygen-containing compounds.
16. The method of claim 1 , further comprising esterifying the second volatilized vapor product to produce fatty acid alkyl esters or biodiesel.
17. The method of claim 16 , wherein the esterification comprises gas-phase reactions with one or more alcohol vapors.
18. The method of claim 16 , wherein the esterification is conducted with a solid or mineral acid catalyst.
19. The method of claim 16 , wherein the esterification is conducted without a catalyst.