(2016) Energy Conversion and Management_Carbon dioxide assisted co-pyrolysis of coal and ligno-cellulosic biomass

Cho S.-H., Lee J., Kim K.-H., Jeon Y.J., Kwon E.E.

(Elsevier Ltd) Energy Conversion and Management ISSN: 1968904 Vol.118 Issue. Article No. DOI: 10.1016/j.enconman.2016.03.093

This work mechanistically investigated the influence of CO₂ in co-pyrolysis of sub-bituminous coal and main constituents of ligno-cellulosic biomass (cellulose and hemicellulose). Our experimental work identified the crucial role of CO₂ in co-pyrolysis of coal and biomass. For example, CO₂ not only enhanced the thermal cracking behavior of VOCs evolved from the thermal degradation of a carbonaceous solid sample (i.e., sub-bituminous coal, cellulose, and xylan) via blocking the addition reaction, but also directly reacted with VOCs and CO₂. The genuine effects induced by CO₂ led to a significant reduction of condensable hydrocarbons (i.e., tar), which directly lead to a significant enhancement of syngas production and modification of ratio of CO to H₂: the ratio of CO to H₂ was increased approximately ∼1200% at 680 °C in pyrolysis of coal in the CO₂ environment and the ratio of CO to H₂ was adjustable by means of using a different amount of CO₂ during the pyrolysis process of carbonaceous samples. Furthermore, the identified role of CO₂ would be applicable to the in-situ air pollution control in various industrial applications, such as steelworks. Lastly, the identified role of CO₂ in pyrolysis will be applied in the gasification process since pyrolysis is the intermediate step for the gasification process. © 2016 Elsevier Ltd. All rights reserved.

This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIP) (No. 2014RA1A004893 ). The third author also acknowledges partial support made by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (No. 2009-0093848 ).