Reduction of emission and exergy destruction in low-temperature heat-fired hydrogen production

Abstract

Steam methane reforming (SMR) consumes a tremendous amount of energy, typically provided by the combustion of natural gas, which leads to carbon emissions. Previous studies have explored methods to replace fossil fuel combustion with SMR, but most these studies have not considered the temperature of the heat transferred. In this study, we attempted to fill this gap in the thermal analysis of external heat-fired SMR. Specifically, the use of waste heat from gas turbines (SMR-GT) and chemical looping combustion (SMR-CLC) was analyzed considering heat transfer modes and temperature ranges using a multizone model. Our results show that the SMR-GT reduces exergy destruction by 37.8% owing to a lower radiative heat transfer rate. SMR-CLC reduces CO2 emissions by 99.9%, making it the most eco-friendly option. Increasing the temperature improved exergy efficiency by 7% in the GT and 17% in the CLC for SMR. ？ 2024 Hydrogen Energy Publications LLC