TY - JOUR
T1 - Process improvements for the supercritical in situ transesterification of carbonized algal biomass
AU - Levine, Robert B.
AU - Bollas, Alexandra
AU - Savage, Phillip E.
N1 - Funding Information:
R.B.L. acknowledges financial support from a NSF Graduate Research Fellowship and a University of Michigan Graham Environmental Sustainability Institute Fellowship . We also gratefully acknowledge financial support from the University of Michigan College of Engineering and from the US National Science Foundation ( CBET-1133439 ).
PY - 2013/5
Y1 - 2013/5
N2 - This work focuses on the production of biodiesel from wet, lipid-rich algal biomass using a two-step process involving hydrothermal carbonization (HTC) and supercritical in situ transesterification (SC-IST). Algal hydrochars produced by HTC were reacted in supercritical ethanol to determine the effects of reaction temperature, time, ethanol loading, water content, and pressure on the yield of fatty acid ethyl esters (FAEE). Reaction temperatures above 275. °C resulted in substantial thermal decomposition of unsaturated FAEE, thereby reducing yields. At 275. °C, time and ethanol loading had a positive impact on FAEE yield while increasing reaction water content and pressure reduced yields. FAEE yields as high as 79% with a 5:1 ethanol:fatty acid (EtOH:FA) molar ratio (150. min) and 89% with a 20:1 EtOH:FA molar ratio (180. min) were achieved. This work demonstrates that nearly all lipids within algal hydrochars can be converted into biodiesel through SC-IST with only a small excess of alcohol.
AB - This work focuses on the production of biodiesel from wet, lipid-rich algal biomass using a two-step process involving hydrothermal carbonization (HTC) and supercritical in situ transesterification (SC-IST). Algal hydrochars produced by HTC were reacted in supercritical ethanol to determine the effects of reaction temperature, time, ethanol loading, water content, and pressure on the yield of fatty acid ethyl esters (FAEE). Reaction temperatures above 275. °C resulted in substantial thermal decomposition of unsaturated FAEE, thereby reducing yields. At 275. °C, time and ethanol loading had a positive impact on FAEE yield while increasing reaction water content and pressure reduced yields. FAEE yields as high as 79% with a 5:1 ethanol:fatty acid (EtOH:FA) molar ratio (150. min) and 89% with a 20:1 EtOH:FA molar ratio (180. min) were achieved. This work demonstrates that nearly all lipids within algal hydrochars can be converted into biodiesel through SC-IST with only a small excess of alcohol.
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U2 - 10.1016/j.biortech.2013.03.022
DO - 10.1016/j.biortech.2013.03.022
M3 - Article
C2 - 23567731
AN - SCOPUS:84876344264
SN - 0960-8524
VL - 136
SP - 556
EP - 564
JO - Bioresource technology
JF - Bioresource technology
ER -
