Hydrogen Production from Ventilation Air Methane in a Dual-Loop Chemical Looping Process

详细信息    查看全文

• 作者：Yongxing Zhang ; Elham Doroodchi ; Behdad Moghtaderi ; Xiaojuan Han ; Yushan Liu
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：May 19, 2016
• 年：2016
• 卷：30
• 期：5
• 页码：4372-4380
• 全文大小：501K
• 年卷期：0
• ISSN：1520-5029

文摘

A dual-loop chemical looping process is proposed to produce hydrogen from ventilation air methane (VAM). It mainly consists of two loops, an oxygen removal loop and a hydrogen production loop. The oxygen removal loop is a Cu-based chemical looping air separation process, in which the oxygen content is separated through the reversible reaction 4CuO ⇄ 2Cu₂O + O₂ + 263.2 kJ/mol.The oxygen-depleted stream is subsequently fed into the hydrogen production loop, where the ultra-low-concentration methane is reformed into highly pure hydrogen. In light of the thermodynamics and experimental results, the oxygen removal temperature should be in the range of 300–400 °C in order to commence the oxidation of Cu₂O at a proper kinetics rate while the catalytic combustion of VAM and reduction of copper oxides with methane are inhibited. Two configurations are proposed, and the thermodynamic performance is evaluated by a case study with methane concentration of 0.5 vol%. It was found that the proposed system was able to produce high-purity hydrogen from VAM, and the hydrogen efficiency was as high as 40.4%. If pure O₂ is considered as a byproduct, the energy demand was 0.32 kWh/m³ O₂, which is significantly lower than the energy demand of conventional cryogenic systems. In addition, a parametric study was conducted to determine the effect of the varying operational parameters, and hence the most suitable values for the parameters are given.