An Assessment of Gasification of Lipid-Extracted Algae by Thermodynamic Simulation

Abstract

Thermodynamic simulation of gasification of Nannochloropsis gaditana (after lipid extraction and before lipid extraction) over a wide range of temperatures (800 – 1400 ^oC) was performed in this study. The reactor temperature variation with respect to the O₂ to fuel ratio and the syngas composition with temperature were evaluated for gasification performance. The results showed the H₂/CO ratio for lipid-extracted algae (LEA) was very similar to the gasification behavior of raw algae (RA) before lipid extraction. Only a slight variation was observed for the lower heating value (9.2 MJ/Nm3 for RA and 8.9 MJ/Nm³ for LEA at 1000 ^oC) of the syngas from the two feedstocks. The H₂/CO ratio for both RA and LEA remained almost the same over the range of temperatures (800-1400 oC) under consideration. The cold gas efficiency was found between 82 % to 75 % for RA and 75 % to 69 % for LEA at 1000 ^oC and 1400 ^oC respectively. As the overall gasification performance did not degrade significantly after extraction of lipid from algae, the LEA holds remarkable potential as a gasification feedstock in a biorefinery set up.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 59-63