Co-gasification behaviors of various coal-based solid fuels blends at initial stage of oxy-fuel Co-combustion

Abstract

The technology of oxy-fuel co-combustion is beneficial to consume the large amount of ultra-low volatile coal-based solid fuels (UCF). Moreover, the oxy-fuel co-combustion of various UCFs could also promote the development of coal-chemical industry and reduce the carbon emission in power plants. However, the co-gasification behaviors of various coal-based solid fuels blends at initial oxy-fuel co-firing stage are still vague, which need to be further studied. In the present, the co-gasification features of various coal-based solid fuels blends during initial oxy-fuel co-combustion process were investigated by oxy-fuel co-combustion system experimentally. The rise of O2 concentration could obtain low Brunner−Emmet−Teller surface area and high Barrett-Joyner-Halenda average pore owing to the collapse of internal structures. The nitrogen gases (X–N) yields show a decreasing trend with the UCF proportion raised. The increasing temperature could promote the gas release of sample. The ash droplets observed on the surface of blend were formed by reactions between oxygen and carbon on the sample surface in 3% O2/97% CO2 atmosphere, which are enlarged with temperature significantly. The present research could be beneficial for efficiency utilization of low-rank coal, together with the reduction of NOx emission and realization of carbon neutrality.