Retrofitting hetrotrophically cultivated algae biomass as pyrolytic feedstock for biogas, bio-char and bio-oil production encompassing biorefinery

摘要

Algal biomass grown hetrotrophically in domestic wastewater was evaluated as pyrolytic feedstock for harnessing biogas, bio-oil and bio-char. Freshly harvested microalgae (MA) and lipid extracted microalgae (LEMA) were pyrolysed in packed bed reactor in the presence and absence of sand as additive. MA (without sand additive) depicted higher biogas (420 ml/g; 800 degrees C; 3 h) and bio-oil (0.70 ml/g; 500 degrees C; 3 h). Sand addition enhanced biogas production (210 ml/g; 600 degrees C; 2 h) in LEMA operation. The composition of bio-gas and bio-oil was found to depend on the nature of feedstock as well as the process conditions viz., pyrolytic-temperature, retention time and presence of additive. Sand additive improved the H-2 composition while pyrolytic temperature increment caused a decline in CO2 fraction. Bio-char productivity increased with increasing temperature specifically with LEMA. Integration of thermo-chemical process with microalgae cultivation showed to yield multiple resources and accounts for environmental sustainability in the bio-refinery framework. (C) 2014 Elsevier Ltd. All rights reserved.