Pyrolysis of lignin
View Patent ↗One aspect of the present invention relates to a method of modifying thermoplastic properties of lignin rich biomass to reduce agglomeration during any subsequent pyrolysis. The method comprises providing a lignin rich biomass and treating the lignin rich biomass with an alkali metal hydroxide or an alkaline earth metal hydroxide under conditions effective to reduce agglomeration, during any subsequent pyrolysis, compared to when the lignin rich biomass is not subjected to said treating. Also disclosed is a method of fast pyrolysis using the product of this method of modifying the thermoplastic properties of lignin rich biomass.
1. A method of fast pyrolysis, said method comprising:
(a) providing a technical lignin;
(b) treating the technical lignin with an alkali metal hydroxide or an alkaline earth metal hydroxide in an amount of from over 4% (w/w) to 20% (w/w) under conditions effective to reduce agglomeration, during pyrolysis, compared to when the technical lignin is not subjected to said treating; and
(c) pyrolyzing the treated technical lignin in continuous mode for 1 to 3 hours to produce pyrolysis products.
2. The method according to claim 1 , wherein the technical lignin is produced by a process selected from the group consisting of organosolv process, supercritical hydrolysis, enzymatic hydrolysis, acid hydrolysis, alkaline extraction, solvent extraction, ionic-liquid extraction, and aprotic solvent extraction.
3. The method according to claim 1 , wherein the alkali metal hydroxide or the alkaline earth metal hydroxide is selected from the group consisting of Ca(OH) 2 , NaOH, KOH, and Mg(OH) 2 .
4. The method according to claim 1 , wherein said pyrolyzing is carried out in a fluidized bed reactor.
5. The method according to claim 1 , wherein said treating comprises:
mixing the technical lignin and the alkali metal hydroxide or the alkaline earth metal hydroxide to form an aqueous mixture having a moisture content and
reducing the moisture content of the mixture.
6. The method according to claim 1 , wherein said pyrolyzing is carried out at temperatures of 450° C. to 600° C.
7. The method according to claim 1 further comprising:
reducing or removing particulate matter in the pyrolysis product.
8. The method according to claim 7 further comprising:
condensing vapor products from the pyrolysis product following said reducing or removing.
9. The method according to claim 8 further comprising:
fractionating the pyrolysis product following said reducing or removing.
10. The method according to claim 9 , wherein said fractionating comprises:
separating the pyrolysis product into separate bio-oil and light gas fractions.
11. The method according to claim 10 , wherein said bio-oil is rich in phenolic monomers.
12. The method according to claim 1 , wherein said treating is carried out without heating.
13. The method according to claim 1 , wherein said treating is carried out at room temperature.