Catalytic and Non-Catalytic Co-Pyrolysis of Corn Stalk and Polystyrene with a focus on Liquid Yield and Quality

Abstract

In this study non-catalytic and catalytic co-pyrolysis of Corn Stalk (CS) and Polystyrene (PS) was conducted in a fixed bed reactor at 500C (selected based on TGA results) to evaluate the effect of feedstock blend ratio, catalyst to feedstock ratio (CFR) and mode of catalyst addition. CS and PS were co pyrolyzed in various proportions that is 1:0, 1:3, 1:1, 3:1, 0:1. Increasing PS in mixture showed positive synergy in case of liquid oil with maximum synergy evidenced at CS to PS ratio of 1:3. Whereas, direct comparison between in-situ and ex-situ using HZSM-5 Catalyst, under identical conditions revealed that In-situ yielded more liquid oil and mono aromatics hydrocarbon (MAH) yet less poly aromatic hydrocarbons (PAH) and acids which was attributed to difference in residence time of pyrolysis vapors. However increasing CFR in twain modes led to decrease in overall MAH and oxygenates and increase in PAH and acids. With regard to aromatics selectivity, maximum selectivity to BTEX and negligible selectivity to styrene was noticed at ex-situ CFR of 1. In comparison to non-catalytic, catalytic yield less MAH so further physical analysis of non-catalytic was carried out which elucidated liquid oil encompasses properties close to conventional fossil fuels.