SIMULATION OF SORPTION ENHANCED CHEMICAL-LOOPING PROCESS FOR HYDROGEN PRODUCTION FROM BIOMASS

Abstract

This research focuses on improvement of sorption enhanced chemical-looping process for hydrogen production from biomass via theoretical method. Corn stover was applied as a raw material. Pyrolysis process was applied for the conversion of biomass to bio-oil before feeding to reforming process. Sorption enhanced chemical-looping is of interest in this work to investigate and develop its potential for hydrogen production. In this work, we firstly compared hydrogen production efficiency of four different reforming processes in terms of bio-oil conversion, hydrogen yield, hydrogen purity, and energy consumption. The simulation results show that sorption enhanced and sorption enhanced chemical-looping reforming processes are the optimal processes for hydrogen production, which can provide 100% bio-oil conversion, 169 g hydrogen/kg corn stover of hydrogen yield, 97% of hydrogen purity and 11.8 kW of energy consumption at reforming temperature of 550 Celsius degree, pressure of 1 bar, steam equivalence ratio (SER) of 5, NiO equivalence ratio (NER) of 0.1, and CaO equivalence ratio (CER) of 2. Furthermore, improvement of SE-CLR process was also studied with the goal to minimize amount of preheating and cooling units and reduce loss of heat from reactor by adiabatic operation. The results show that heat integration in modified SE-CLR process can provide 77.4 g hydrogen/kg corn stover of hydrogen yield, 77% of hydrogen purity and 5.64 kW of energy consumption. Moreover, preheating units used in the process were reduced from 8 to 3 and using 2 heat exchangers instead of feed water preheater and feed air preheater.