Study on the conversion of cyanobacteria of Taihu Lake water blooms to biofuels

A large amount of cyanobacteria of water blooms pose a considerable threat to the water ecological balance, as well as human health, which are intractable to deal with. The objective of this paper is to utilize cyanobacteria of water blooms in Taihu Lake (CTL) as bioenergy resource to obtain fuel precursors, and simultaneously provide a way to mitigate the environmental burdens of Taihu Lake. The conversion of CTL collected in 2010 summer to biofuels via direct pyrolysis, catalytic pyrolysis and transesterification was studied. The yield of organic bio-oil from direct pyrolysis (BODP) was 32.3 wt%, and 28.3% of the BODP were aromatic compounds. The catalytic pyrolysis over HZSM-5 produced 30.5 wt% organic bio-oil (BOCP), in which there were lower nitrogenous compound content (33.7% vs. 40.6%), lower oxygenic compound content (21.2% vs. 27.3%), and higher aromatic content (43.4% vs. 28.3%) compared to BODP, and the heat value of BOCP was as high as 32.60 MJ kg−1. The results demonstrate that the use of CTL, a potential environmental threat, to produce value-added fuel is an applicable approach to generate fuel precursors, especially via catalytic pyrolysis. The result might be helpful to find a possible strategy for use of byproducts of green tide as feedstock for bio-oil production, which should be beneficial for environmental protection and renewable energy development.