A COMPARATIVE STUDY OF GASES GENERATED FROM SIMULANT THERMAL DEGRADATION OF AUTOTROPHIC AND HETEROTROPHIC Chlorella

Both autotrophically growing Chlorella cells with chlorophyll and heterotrophically growingChlorella cells without chlorophyll have been obtained by cell culture through controlling the supply of or-ganic and inorganic carbon and nitrogen.The content of protein in the cells of autotrophic algae is 5times as high as that in the cells of heterotrophic algae.On the contrary,the content of crude lipid in thelatter is 4.4 times as high as that in the former.The gas productive rate of autotrophic algal cells is a littlebit higher than that of heterotrophic algal cells,and the gases mainly contain CO2,while theheterotrophic algal cells produce hydrocarbon gas at a much higher rate.With the rise of temperature,both kinds of cells display the rapid drop in the acid/alkane ratio of the gas components.Their ratios ofnormal and isomeric alkanes are all above 1.The ratio of ethane to ethyleme increases regularly with therising temperature.Therefore,it may be taken as one of the indexes for identifying the maturity of suchnatural gases.In particular,the comparative study has revealed that the actual potential ofmicroplanktonic algae in producing oil and natural gas should be much greater than what people haverecognized before.