An evaluation of hydrogen production from the perspective of using blast furnace gas and coke oven gas as feedstocks

Blast furnace (BF) is a large-scale reactor for producing hot metal where coke and coal are consumed as reducing agent and fuel, respectively. As a result, a large amount of CO(2) is liberated into the atmosphere. The blast furnace gas (BFG) and coke oven gas (COG) from the ironmaking process can be used for H(2) production in association with carbon capture and storage (CCS), thereby reducing CO(2) emissions. In this study thermodynamic analyses are performed to evaluate the feasibility of H(2) production from BFG and COG. Through the water gas shift reaction (WGSR) of BFG, almost all CO contained in BFG can be converted for H(2) production if the steam/CO (S/C) ratio is no less than unity and the temperature is at 200 degrees C, regardless of whether CO(2) is captured or not. The maximum H(2) production from WGSR is around 0.21 Nm(3) (Nm(3) BFG)(-1). Regarding H(2) production from COG, a two-stage reaction of partial oxidation (PDX) followed by WGSR is carried out. It is found the proper conditions for syngas formation from the PDX of COG is at the oxygen/fuel (O/F) ratio of 0.5 and the temperature range of 1000-1750 degrees C where the maximum syngas yield is 2.83 mol (mol hydrocarbons)(-1). When WGSR is subsequently applied, the maximum H(2) production from the two-stage reaction can reach 0.83 Nm(3) (Nm(3) COG)(-1). Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.