Double-stage chemical looping combustion combined with sorption enhanced natural gas steam reforming process for hydrogen and power cogeneration: Thermodynamic investigation

作者：Zhu, Lin^*; Xie, Na; Jiang, Peng; Li, Luling; Chen, Hu

来源：Chemical Engineering Research and Design, 2016, 114: 247-257.

DOI：10.1016/j.cherd.2016.08.024

• Double-stage cogeneration system
• Chemical looping combustion
• Sorption-enhanced steam reforming
• Thermodynamic analysis
• Cascade utilization of energy

Chemical looping combustion (CLC) is a high efficiency and clean power generation system. With the principle of energy cascade utilization and methodology of system integration, a cogeneration system for hydrogen and power from natural gas was proposed by thermally coupling high-pressure (HP) and low-pressure (LP) double-stage CLC and sorption-enhanced steam reforming unit. The effects of operating parameters on the different performances indicators (including product gas concentration, H-2 yield, and CH4 conversion) were investigated. The proposed novel process and a benchmark cogeneration process (i.e., natural gas CLC combustion unit along with sorption-enhanced steam reforming process) were both evaluated and compared from a thermodynamic point of view. @@@ Results show that increasing the Fuel(Hp)/C and Fuel(LP)/C ratio (i.e., natural gas as fuel for HP/LP-CLC divided by the feed molar flow for reformer ratio) leads significantly in improving the H-2 yield and CH4 conversion. The addition of Ca-based sorbent and steam in reformer also has positive impacts on system performances. Under the conditions of Fuel(HP)/C = 0.42 and Fuel(LP)/C = 0.70, the novel process has a H-2 concentration of 92%, H-2 yield of 3.64, and CH4 conversion of 75%, while for the benchmark process, the H-2 concentration is 89%, H-2 yield is 3.55, and has a CH4 conversion of 69%. In addition, the optimized process minimizes exergy destruction and increases exergy efficiency over 6% when compared to the base-case system.

• 出版日期2016-10
• 单位西南石油大学