Production of renewable aromatics and heterocycles by catalytic pyrolysis of biomass resources using rhenium and tin promoted ZSM-5 zeolite catalysts

Abstract The purpose of this study is to investigate the effects of rhenium and tin loading (between 0 and 5% by impregnation method) on a ZSM-5 zeolite catalyst as well as the product distribution and aromatic yield under different catalytic conditions. A biomass to catalyst ratio of 5–20 is also considered. Due to its feed characteristics, beechwood was selected as the biomass resource, and the catalytic pyrolysis process was chosen, for it is an economic process. For a better analysis of the product distribution, all product samples were identified using gas chromatography coupled with mass spectrometry. Responses then were analyzed utilizing the full factorial method. The models obtained for high-economic-value produced aromatic and heterocyclic production had R-Sq. of 92.89 and 96.81 %, respectively, indicating the validity of the proposed models. The results clearly show that by changing the parameters, valuable heterocyclic compounds can be synthesized with acceptable yields. According to the study, the highest aromatic selectivity belongs to catalytic loadings of 1.58 % rhenium and 3% tin resulted in selectivity of 51.27 for aromatic compounds. Moreover, the catalytic loading of 3% rhenium and 3% tin resulted in the highest selectivity with a rate of 24.62 for heterocyclic compounds.