A Review on Pyrolysis of Different Feedstocks: Effect of Catalysts and Metal Loading

In this review work catalytic pyrolysis has been studied for different feedstocks. Through this study, the application of catalyst has been observed in terms of bio-oil, bio-gas, and bio-char yields for biomass and other feedstocks. It has been observed from this study that the maximum gas yield is 26.5% when zeolite catalyst is used with a ratio of 1:10 (catalyst: feedstock, wt./wt.). In case of molybdenum catalysts, it has been quantified that the gas yield percent is higher than others. When molybdenum catalysts are combined with zeolite, the highest gas yield has been found at 23.9% when the molybdenum and zeolite has been mixed with a ratio of 1:10. The structural behavior of the catalyst controls the yield of bio-oil, bio-gas, and biochar. The cracking of the C–C bond is facelifted due to the Brønsted acid site modification. The desorption and breakage of C–H due to Lewis’s acid sites. Due to the desorption of hydrogen Lewis’s acid sites dehydrogenation reaction increases. The reconfiguration increases due to the desorption of hydrogen. On the other hand, the selectivity of light olefins increases due to Brønsted acid sites. The solid (bio-char) yield has been found more in Y-zeolite. The solid yield for ferrite has been found around 40% of the total yield. The ZSM-11 catalyst has been observed to contribute 40% while the ZSM-5 catalyst has generated solid yield below 20%.