Thermodynamic analysis of a tri-generation system driven by biomass direct chemical looping combustion process

Chemical looping process (CLP) is a promising technology for in-situ CO2 capture without energy penalty. Direct CLP has more compact structure, favorable economic competitiveness, and larger reduction of exergy loss compared to syngas CLP. In this work, a novel biomass direct chemical looping combustion (CLC) driven tri-generation system for the production of cooling, heating, and power is proposed. The proposed system contains a direct CLC section as the prime mover, two gas turbines and an organic Rankine cycle for power generation, an absorption chiller for cooling production, and two heat exchangers to generate heat. First, a thorough thermodynamic analysis is implemented to assess the energy and exergy efficiencies of the proposed system under evaluated design conditions, as well as identify the exergy loss distribution. Second, Sensitivity analysis is conducted to investigate the effects of major operating parameters on the system performances. Third, the performances of the proposed system are compared to syngas CLC based tri-generation system. Thermodynamic analysis results show that the proposed system has high energy efficiency of 90.92% and exergy efficiency of 33.82%. The largest exergy loss takes place in the air reactor, accounting for 34.42% of total exergy loss, followed by fuel reactor and absorption chiller, which are 30.09% and 15.37%, respectively. Besides, the proposed system has better thermodynamic performances than syngas CLC driven tri-generation, whose energy and exergy efficiencies are 69% and 23.4%, respectively.

Automated summary

The study proposed a novel biomass direct chemical looping combustion driven tri-generation system with high energy and exergy efficiencies, which was compared with syngas CLC driven systems.