Experimental verification of the effectiveness of CO2 capture from flue gas after pulverised coal combustion

Abstract

This article presents experimental verification of CO₂ capture from flue gases generated in a pulverised coal-fired power boiler. The tests were carried out using a pilot-scale moving bed temperature swing adsorption system installed in an operating coal-fired power plant (Skawina Power Plant). Activated carbon in the form of beads was used as the adsorbent due to its developed microporous structure, large specific surface area and excellent mechanical resistance under conditions of continuous circulation. The installation enables treatment of a flue gas stream with a volumetric flow rate of up to 50 m³/h. The supplied flue gas, composed mainly of N₂ and CO₂, was extracted downstream of the plant’s gas-cleaning system. Two recent measurement campaigns were analysed under variable inlet CO₂ concentrations (4.81–7.16 vol.%; it depends on the operation of the power plant, so it cannot be controlled by researchers), different flue gas flow rates and varying sorbent mass flow rates. Under quasi-steady-state operating conditions, a capture efficiency of 50–60% was achieved at an inlet CO₂ concentration of 6–7% by volume, with an average energy consumption of 55.3 MJ/kgCO₂. A second series of measurements confirmed the high sensitivity of capture efficiency to the ratio of sorbent mass flow rate to flue gas flow rate and to regeneration conditions. The results demonstrate the technical feasibility of moving bed temperature swing adsorption operation under actual coal-fired power plant conditions; however, significant optimisation of heat integration, process configuration and sorbent management is necessary to reduce energy requirements to a level compatible with industrial implementation.