Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 Issue 5 (Special Issue) 2021 07 23 Investigation of hydrogen production process by partial oxidation of natural gas in a large non-catalytic reformer and comparison with methane steam reforming process in a small catalytic reformer Investigation of hydrogen production process by partial oxidation of natural gas in a large non-catalytic reformer and comparison with methane steam reforming process in a small catalytic reformer 3275 3292 4235 10.22060/mej.2021.18268.6788 FA Seyed Behzad Haghi 1Department of Energy system engineering, Islamic Azad University, North Tehran Branch, Tehran, Iran Gholamreza Salehi Department of Mechanical engineering, Islamic Azad University, Central Tehran Branch, Tehran, Iran Masoud Torabi Azad , Faculty of Marine Science and Technology, Islamic Azad University, North Tehran Branch, Tehran, Iran 0000-0001-9571-8813 Ali Lohrasbi Nichkouhi Department of Mechanical engineering, Islamic Azad University, Nowshahr Branch, Nowshahr, Iran Journal Article 2020 04 13 In the first part of the research, non-catalytic natural gas reformer is investigated numerically. The governing equations include the mass equation, the species equation with eddy dissipation concept modeling using GRI-1.2 mechanism, the momentum and energy equation with Reynolds-averaged Navier–Stokes turbulence model. The results show that increasing the pressure promotes conversion of CH4 into hydrogen, but from pressure 3 MPa and above, hydrogen production remains almost constant. Also, if the ratio of oxygen to natural gas increases to 0.66, the temperature increases and the concentration of CH4 in the exhaust gas decreases In addition, as the ratio of water vapor to natural gas increases, the temperature in the reformer decreases and the H2/CO (synthetic gas) ratio in the output increases. In the next section, methane steam reforming is examined to overcome the hot spot problem in these reformers. The mass, Brinkman, component and energy transport equation are used for the multi-tube catalytic reformer. The effects of inlet temperature of heating tubes, CH4/H2O ratio and configuration of heating tubes have been investigated. The results show that increasing the inlet temperature of the heating tubes, the CH4/H2O ratio up to 0.25 and the number of heating tubes, increase methane reforming. In the first part of the research, non-catalytic natural gas reformer is investigated numerically. The governing equations include the mass equation, the species equation with eddy dissipation concept modeling using GRI-1.2 mechanism, the momentum and energy equation with Reynolds-averaged Navier–Stokes turbulence model. The results show that increasing the pressure promotes conversion of CH4 into hydrogen, but from pressure 3 MPa and above, hydrogen production remains almost constant. Also, if the ratio of oxygen to natural gas increases to 0.66, the temperature increases and the concentration of CH4 in the exhaust gas decreases In addition, as the ratio of water vapor to natural gas increases, the temperature in the reformer decreases and the H2/CO (synthetic gas) ratio in the output increases. In the next section, methane steam reforming is examined to overcome the hot spot problem in these reformers. The mass, Brinkman, component and energy transport equation are used for the multi-tube catalytic reformer. The effects of inlet temperature of heating tubes, CH4/H2O ratio and configuration of heating tubes have been investigated. The results show that increasing the inlet temperature of the heating tubes, the CH4/H2O ratio up to 0.25 and the number of heating tubes, increase methane reforming.

https://mej.aut.ac.ir/article_4235_8ccfb1140664a5fa63177fb6e07352f0.pdf