Waste-to-hydrogen: Recycling HCl to produce H2 and Cl2

Abstract

Coal-fired power plants are the most common form of power generation in many regions, which continuously produce waste heat and hydrogen chloride (HCl) flue gas. To address this issue, a novel Cu-Cl hydrogen pro duction cycle is modeled to recycle industrial waste heat and exhaust HCl and to produce hydrogen, realizing the waste-to-hydrogen (WtH) process. To complement the process analysis, a gate-to-gate life cycle emission analysis and gate-to-grave cost-benefit analysis have been performed to evaluate the commercial feasibility and en vironmental impacts. The final results of the product cost and life cycle CO2 emission of this Cu-Cl cycle are 2.8 US dollars/kg H2 and 8.7 kg CO2/kg H2, respectively. Cu-Cl cycle offers an economically competitive option compared with the steam methane reforming (SMR) hydrogen production process if taking the benefit of Cl2 into account. The life cycle CO2 emission of the Cu-Cl cycle is less than other existing processes, as the process can consume a considerable amount of HCl gas, which is regarded as greenhouse gas as well. The proposed process is shown to be a promising alternative to conventional hydrogen production processes