Document Type : Research Article
Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr I.R. IRAN
Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), Tehran, I.R. IRAN
This paper presents a biogas water vapor reforming system for hydrogen production. The biogas mixture contains a large percentage of methane and carbon dioxide and small amounts of other gases. Thermodynamic modeling (energy and exergy) is performed on the proposed system, and a study on the effect of various system parameters such as temperature and the molar ratio of carbon dioxide to methane in the biogas mixture on hydrogen production, energy, and exergy efficiency of the whole system has been done in this paper. The results show that the increase in steam reforming reactors in a constant molar ratio of carbon dioxide to methane in the biogas mixture increases hydrogen production and the energy and exergy efficiency of the system. However, increasing the molar ratio of carbon dioxide to methane in the biogas mixture at high temperatures reduces hydrogen production per mole of methane. As a result, the energy and exergy efficiency of the whole system is reduced. Also, the highest energy and exergy efficiency of the entire system in the conditions where the amount of hydrogen production is maximum is 52% and 42%, respectively.