Catalytic pyrolysis of straw biomasses (wheat, flax, oat and barley) and the comparison of their product yields

In this study, the pyrolysis of several Canadian straw biomasses was studied using a thermogravimetric analyzer and a bench-scale horizontal fixed-bed reactor, in order to better understand the devolatilization process and to obtain information about the product yields of these biomasses. The straw biomasses were converted through pyrolysis performed in a fixed-bed reactor at temperatures of 500 °C to study the influence of the feedstock on product yields. The effects of various catalysts on product yields are also discussed. When using zeolite catalysts, the bio-oil and bio-char yields of the straw pyrolysis were increased to 46.44% and 38.77%, respectively, while the bio-gas yield was decreased to 13.65%. The use of catalyst zeolite ZY-SS had the most significant effect on overall bio-oil and bio-char yields, increasing the bio-oil yield by about 2% and the bio-char yield by 8%. This catalyst had the most significant effect on the pyrolysis of flax straw, where the bio-oil yield was increased to 46.44%. In the pyrolysis of oat straw, the use of the catalyst consistently decreased the bio-gas yield; however, the bio-oil yield increased the most significantly (43.32%) with the use of catalyst zeolite ZY-NS. The use of zeolite ZY-NS also increased the bio-oil yield during the pyrolysis of barley straw (43.03%).