Theoretical study and parametric optimization of biomass based multi-generation energy system using exergy and exergoeconomic concepts

In this paper, a novel multi-generation system driven by biomass in order to produce producing power, pasteurized milk, hydrogen, oxygen and distillate water production is proposed and modeled. The system consists of three main subsystems: a gasifier, an S-CO2 Brayton cycle and a Multi effect distillation parallel feed (MED-PF) unit. Exergy and exergoeconomic analysis is performed for the proposed system based on mass and energy and cost balances, using the EES (engineering equation solver) software. A parametric analysis is conducted to find the effect of key decision variables (main compressor inlet temperature (TR1R), turbines inlet temperature (TR5R), main compressor inlet pressure (PR1R), intermediate pressure between HP and LP turbines (PR6R), producer gas mass fraction (MF), equivalence ratio(ER), compressors pressure ratio(Rp) and brine salinity(xRbR)) on the energy and exergy efficiencies as well as distillate flow and total product cost rate. The results show that at the base point thr energy and exergy efficiencies of the system are 65.51% and 43.61% respectively and the total product cost rate is 0.02268($/s).

Keywords:

multigeneration systems , energy , exergy , exergoeconomic , S-CO2 , gasifier , MED-PF desalination , pasteurization