CO2 effects on catalytic pyrolysis of yard trimming over concrete waste

Abstract

Syngas itself can be directly combusted as fuel and adopted as a versatile raw feedstock in many chemical industries. Nonetheless, the fossil-based resources are mainly being converted into syngas via the thermo-chemical process with substantial emissions of anthropogenic CO2, which is one of main factors deteriorating the usefulness of syngas. Thus, it is desirable to obtain syngas through sustainable conversion techniques and a carbon neutral feedstock. To achieve the noted grand challenges, suppressing CO2 formation during the synthesis of syngas by transforming CO2 into a combustible matter (CO2-to-fuel) is of great importance since it offers a precautious measure for fortifying energy security in the most countries and abating catastrophic consequences arising from global warming. To this end, this study was aimed to introduce a sustainable conversion of syngas through pyrolysis of municipal solid waste (MSW). Specifically, pyrolysis of yard trimming was investigated as a case study because it is one of the main MSW components. To offer an environmentally benign platform for producing syngas, CO2 was fed during pyrolysis of yard trimming, and the functional effectiveness of CO2 was mainly scrutinized. All experimental observations offered that reduction of CO2 and simultaneous oxidation of volatile pyrolysates coming from yard trimming thermolysis were achieved, which resulted in the enhanced formation of CO. In addition, catalytic pyrolysis was examined to expedite reaction rates using a concrete waste because the demolition waste is one of main inorganic MSW components. The effectiveness of CO2 was remarkably enhanced from catalytic pyrolysis over concrete. Conclusively, this study suggested that both the organic/inorganic MSW components could be valorized through the concept of waste-to-energy in conjunction with CO2-to-fuel.