Catalytic esterification of fatty acids using solid acid catalysts generated from biochar and activated carbon

dc.contributor.author	Kastner, JR	en
dc.contributor.author	Miller, J	en
dc.contributor.author	Geller, DP	en
dc.contributor.author	Locklin, J	en
dc.contributor.author	Keith, LH	en
dc.contributor.author	Johnson, T	en
dc.date.accessioned	2014-06-06T06:51:40Z
dc.date.available	2014-06-06T06:51:40Z
dc.date.issued	2012	en
dc.identifier.issn	09205861	en
dc.identifier.uri	http://dx.doi.org/10.1016/j.cattod.2012.02.006	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/5628
dc.subject	Biochar	en
dc.subject	Biodiesel	en
dc.subject	Biorefinery co-product	en
dc.subject	Carbon supported catalysts	en
dc.subject	Free fatty acids	en
dc.subject	Heterogeneous	en
dc.subject	Re-useable	en
dc.subject	Solid acid catalyst	en
dc.subject.other	Biochar	en
dc.subject.other	Biorefineries	en
dc.subject.other	Carbon supported catalyst	en
dc.subject.other	Free fatty acid	en
dc.subject.other	Heterogeneous	en
dc.subject.other	Re-useable	en
dc.subject.other	Solid acid catalysts	en
dc.subject.other	Activated carbon	en
dc.subject.other	Biodiesel	en
dc.subject.other	Catalyst deactivation	en
dc.subject.other	Catalyst regeneration	en
dc.subject.other	Catalyst supports	en
dc.subject.other	Esterification	en
dc.subject.other	Esters	en
dc.subject.other	Flood control	en
dc.subject.other	Functional groups	en
dc.subject.other	Methanol	en
dc.subject.other	Reaction rates	en
dc.subject.other	Stearic acid	en
dc.subject.other	Sulfur	en
dc.subject.other	Vegetable oils	en
dc.subject.other	Catalyst activity	en
dc.title	Catalytic esterification of fatty acids using solid acid catalysts generated from biochar and activated carbon	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.cattod.2012.02.006	en
heal.publicationDate	2012	en
heal.abstract	Reusable, solid acid carbon supported catalysts were generated from biomass by pyrolysis (400-500 °C) to generate a soft to hard carbon backbone (i.e., biochar) for addition of acidic functional groups. Acid catalysts were synthesized by sulfonating the biochar and wood derived activated carbon using concentrated H 2SO 4 at 100, 150 and 200 °C (12 h) and gaseous SO 3 (23 °C). Attenuated Total Reflectance, sulfur, and NH 3-TPD analysis of the sulfonated carbons indicated the presence of -SO 3H groups on the 100 °C sulfonated biochar and activated carbon (AC), with higher active site densities (SO 3H density) for the SO 3 sulfonated material. The sulfonated carbons were tested for their ability to esterify free fatty acids with methanol in blends with vegetable oil and animal fat (5-15 wt.% FFA). Esterification of the fatty acids was typically complete (∼90-100% conversion) within 30-60 min at 55-60 °C (large methanol excess), but decreased with lower methanol to oil ratios using the biochar catalysts (e.g., 70%, 6 h, 20:1). Solid acid catalysts derived from wood based activated carbon had significantly higher activity compared to the biochar derived catalysts (e.g., 97%, 6 h, 6:1). Of the synthesized biochar catalysts, 400 °C pyrolyzedpine chip biochar, sulfonated at 100 °C, resulted in the highest reaction rate and lowest reduction in conversion (or deactivation) when reused multiple times. Drying the biochar catalysts for 1 h at 125 °C between uses maintained esterification activity, allowing the catalysts to be reused up to 7 cycles. For the SO 3 sulfonated AC catalyst, such a regeneration step was not required, as the fractional conversion of palmitic and stearic acid (5% FFA, 10:1, 3 h) remained >90% after 6 cycles. © 2012 Elsevier B.V. All rights reserved.	en
heal.journalName	Catalysis Today	en
dc.identifier.issue	1	en
dc.identifier.volume	190	en
dc.identifier.doi	10.1016/j.cattod.2012.02.006	en
dc.identifier.spage	122	en
dc.identifier.epage	132	en