Evaluation of PtPd-modified Zeolite Catalysts (ZSM-5, Beta, USY) for Pyrolysis of Jatropha Waste

Abstract

Fast pyrolysis with three typical modified zeolite catalysts was evaluated to produce bio-oil from Jatropha waste. Jatropha waste was pyrolyzed in a stainless-steel reactor at 600 under N2 gas flow. The aromatic hydrocarbon selectivity in the bio-oil was in the order: PtPd/ZSM(30) (73.7 %) PtPd/Beta(22.5) (68.6 %) PtPd/USY(20) (48.7 %), where the weight ratio of Jatropha/catalyst was 1. In addition, catalyst regeneration was carried out to study the catalyst efficiency. The analysis of fresh and regenerated catalysts by XRD, NH3-TPD, and TG/DTG, as well as product selectivity and surface properties showed that coke deposition and removal were associated with the zeolite structure and surface acid property. Due to pore size regulation, H-ZSM-5 with 10-membered ring (10 MR) could promote the pyrolysis reaction on the outside surface rather than in the inside channels. In USY zeolite with 12 MR, the reaction could occur inside the channels, but the moderate acid nature resulted in only slightly developed coke formation, which could be removed, at least partly, after regeneration. In beta zeolite with 12 MR, the total amount of surface acidity was more than twice that of USY, which undergoes more condensed coke formation, and was more difficult to remove by regeneration than the coke over USY. Thus, under these pyrolysis conditions, PtPd/ZSM(30) seems to be a better candidate for pyrolysis of Jatropha waste compared to PtPd/Beta(22.5) and PtPd/USY(20).

Catalytic Cracking of LDPE Dissolved in Benzene Using Nickel-Impregnated Zeolites

“…Such observation is related to the 3D structure of the catalysts, ZSM-5-type zeolite, with 10-membered rings and the absence of cages at the channel intersections. These characteristics minimize the formation and further development of coke precursor inside the zeolite channels of ZSM-based zeolites …”

“…These characteristics minimize the formation and further development of coke precursor inside the zeolite channels of ZSM-based zeolites. 72 Upon comparison, Ni-Y has higher coke formation compared to that of Y. This is ascribed to the effect of higher acidity in Ni-Y compared to that in Y.…”