Research On Natural Gas Hydrogenation Cogeneration Process Based On Double Chemical Chain Combustion Coupled Steam Reforming

The clean and efficient use of natural gas is an effective measure to optimize energy development structure.Hydrogen and energy production both are important way to achieve the green transformation of natural gas.However,the huge energy consumption of traditional hydrogen production,and the heavy power loss of generate electricity have the bad effect on the development of processes.Besides,the two production processes have the well-known negative impact on the environment.Based on the principle of energy cascade utilization and methodology of system integration,the integration of the clean and efficient chemical-looping combustion power generation system with no consumption of CO2 capture and steam reforming hydrogen production technology which shows high H2 yield and CO2 absorption rate is proposed and investigated with natural gas as raw material.In this new system,high-/low-pressure chemical-looping system are applied into supply hydrogen production and absorbent regeneration,respectively.The double-stage chemical-looping combustion power generation coupled steam enhanced-reforming hydrogen production system(D-CLC-SER),chemical-looping combustion power generation coupled steam enhanced reforming hydrogen production system(CLC-SER),chemical-looping combustion to power generation system(CLC-P),and the steam reforming to hydrogen production system(SE-SR)were simulated by Aspen Plus software.The effect of Ca-based sorbent,steam into reformer,natural gas as fuel or natural gas as fuel for HP-/LP-CLC to natural gas fed for reformer molar ratio(namely Ca/C,S/C,CFUEL/CH2,CFuel-HP/CH2 and CFuel-LP/CH2)on production concentration,H2 yield and energy generated were investigated.And the optimized operative conditions of the four processes were obtained.Based on the thermodynamical first law and the thermodynamical second law,the thermodynamic properties of the four processes were obtained:In CLC-P process,energy efficiency is 55.79%,exergy efficiency is 37.89%,the exergy loss rate is 45.30%;In SE-SR process,the hydrogen efficiency and yield are 65%,15%,respectively,energy efficiency is 23.52%,exergy efficiency is 89.18%,the exergy loss rate is 15.82%;In CLC-SER,the hydrogen efficiency and yield are 89%,17%,respectively,energy efficiency is 57.86%,exergy efficiency is 67.04%,the exergy loss rate is 29.34%;In D-CLC-SER,the hydrogen efficiency and yield are 92%,18%,respectively,energy efficiency is 66.50%,exergy efficiency is 72.72%,the exergy loss rate is 23.61%.