Thermodynamic and economic analysis of a solar-biomass gasification system with the production of methanol and electricity

Abstract

The thermodynamic and economic performances of a solar-biomass gasification polygeneration system are investigated in this work. In the system, the collected high-temperature concentrated solar energy with a new beam-down optical configuration is used to drive biomass gasification, the cotton stalk is selected as the feedstock, and the produced syngas is fed into a methanol synthesis reactor for methanol production. In addition, the un-reacted syngas and the system waste heat are efficiently utilized via a combined cycle to generate electricity. The designed methanol production and power capacities are 51.2×103 tons/year and 32.7 MWe, respectively. The numerical simulation of the polygeneration system is implemented. The on-design energy efficiency of the system reaches to 51.89% with the exergy efficiency of 51.23%. According to the system off-design evaluation within a typical year, the annual averaged system efficiency is up to 48.35% with the monthly efficiency in a range of 46.65%-49.05%, and the levelized cost of methanol is 361.88 $/ton. The solar-biomass gasification polygeneration system with methanol and electricity production achieve favorable thermodynamic and economic performances, which contributes to reducing CO2 emission and provides an alternative way for efficiently utilizing the abundant renewable energies of solar and biomass resources.