Process analysis for ammonia-based CO2 capture in ironmaking industry

Abstract

Abstract In this work, low concentrated ammonia solution (up to ∼10 wt.%) was used to capture from blast furnace gas (BFG), compared to exhausted gas from power plant have a high CO2 concentration(up to ∼23 vol.%). Pilot plant with processing capacity of 50 Nm3-BFG/hr was built at POSCO in late 2008. Changing the operating conditions in pilot test with the absorption and regeneration temperature, circulating flow-rate of ammonia solution between absorber and stripper, the side stream ratio of columns for removing the slipped ammonia, and then collect the data such as gas flow rates, concentration of gas. Based on the collected data, we analyze the results such as CO2 removal efficiency, purity of recovered CO2 and consumed utilities (steam, cooling water, …). Through the analysis of results, we will find the main factors affecting the operation of ammonia-based CO2 capture process and design CO2 capture plant with the capacity of 1000 Nm3-BFG/hr.