The fast pyrolysis of Chlorella vulgaris was carried out in a quartz tube reactor under different pyrolysis temperature levels. The product fractional yields, gaseous products and the evaluation method based on heating value and energy consumption were analyzed in order to obtain the optimal condition to produce syngas. The results indicated that the higher the pyrolysis temperature level was, the higher the bio-fuel yield was. 900 degrees C is the best temperature to obtain the maximum bio-fuel yield (91.09%, wt.%). And the highest emission of CO and H-2 were achieved under the pyrolysis temperature of 800 and 900 degrees C, respectively. According to the evaluation method based on heating value and energy consumption, there was a significant impact on the syngas production under different pyrolysis temperatures. Furthermore, the evaluation method based on energy consumption indicated that 800 degrees C was the optimal pyrolysis temperature to produce syngas. (c) 2013 Elsevier Ltd. All rights reserved.