Utilization of carbon dioxide in coal gasification - An experimental study

Abstract

Utilization of coal in the current energy sector requires implementation of highly-efficient technologies to meet the dual targets of increased energy-efficiency and reduced carbon footprint. Efforts are being made to develop gasification systems with lower unit emissions of carbon dioxide and other contaminants, capable of handling various feedstocks and flexible in terms of products generated (synthesis gas, hydrogen, heat and electricity). The utilization of captured carbon dioxide and waste heat in industrial processes are considered to further contribute to the advancements in energy-efficient and low-emission technological solutions. This paper presents the experimental results on the incorporation of carbon dioxide into the valorization cycle as a reactant in coal gasification. Tests were performed on a laboratory scale moving bed gasifier using three system configurations with various simulated waste heat utilization scenarios. The temperature range covered 700, 800 and 900°C and the gasification agents used were carbon dioxide, oxygen and the mixture of 30 vol.% carbon dioxide in oxygen. The combined effect of the process parameters applied on the efficiency of coal processing in terms of the gas yields, composition and calorific value was studied and the experimental data were explored using Principal Component Analysis.