Strategic use of CO2 for co-pyrolysis of swine manure and coal for energy recovery and waste disposal

Here in this study, the genuine role of CO2 in co-pyrolysis of swine manure and coal was mainly investigated to increase the thermal efficiency of the thermo-chemical process. The TGA test of swine manure and coal revealed that the CO2 co-feeding impact on any reactions (≤740 °C) between CO2 and the sample surface (i.e., heterogeneous reaction) should be excluded. A batch-type co-pyrolysis revealed two genuine CO2 co-feeding impacts on co-pyrolysis of swine manure and coal. First, CO2 can be an additional source for C and O through a plausible reaction between pyrolytic oil and CO2, which led to the enhanced generation of CO by the conversion of volatile organic carbons (VOCs) evolved from thermal deconstruction of pyrolytic substrate. Second, CO2 expedite the thermal cracking of VOCs, which also resulted in the more generation of H2 and CH4. Two genuine roles of CO2 in co-pyrolysis of swine manure and coal occurred independently. All experimental findings will be directly applicable to the gasification process since pyrolysis is an intermediate step for the gasification.