Hydrogen element flow and economic analyses of a coal direct chemical looping hydrogen generation process

Abstract

Abstract Coal direct chemical looping hydrogen generation (CDCLHG) is known as an attractive technique that converts coal into high purity H2 with inherent CO2 separation. In this paper, a CDCLHG system is developed and modeled. According to the prediction results, hydrogen element flow and economic performance of the CDCLHG system are researched. The study demonstrate that utilization efficiency of hydrogen element is 51.89%. By economic analysis, the results indicate that the calculated H2 producing cost of the CDCLHG system is 11.55 CNY/kg with coal price of 797 CNY/t and Fe based oxygen carrier price of 1986 CNY/t. Sensitivities to variables such as coal price, oxygen carrier price, water price and operating labor are researched. Coal price represents the most important sensitivity, while the sensitivity to water price and operating labor is relatively small. Additionally, H2 production from the CDCLHG process is only 3.0% more expensive than H2 production from natural gas chemical looping reforming with Fe based oxygen carrier. The CDCLHG process therefore appears to be an ideal option to obtain competitive hydrogen production.