High yield of hydrocarbon gases resulting from pyrolysis of yellow heterotrophic and bacterially degradedChlorella protothecoides

Four kinds of cells ofChlorella protothecoides, green autotrophic cells, bacterially degraded green autotrophic cells, yellow heterotrophic cells and bacterially degraded yellow heterotrophic cells, were used to simulate thermal degradation and gas formation by heating without oxygen at 300°C for 100 h. The yield of pyrolysed hydrocarbon gases in yellow heterotrophic cells with bacterial degradation was 8.5 times higher than that of green autotrophic cells without bacterial degradation. The use of bacterially degraded yellow heterotrophic cells resulted in relatively more lipid and less protein. The results suggest that the hydrocarbon-producing potential of microplanktonic algae in nature may be greater than previously thought based on studies of green autotrophic cells.