Exergy analysis of synthetic natural gas production method from biomass

The paper presents the results of exergy analysis for a biomass-to-synthetic natural gas (SNG) conversion process. The presented study is based on wood gasification, which is analysed for different gasification conditions like temperature and/or pressure. The analysed temperature was varied in the range from 650 to 800 °C and the pressure range was from 1 to 15 bar. The main process units of biomass-to-SNG conversion technology are gasifier, gas cleaning, synthesis gas compression, CH4 synthesis and final SNG conditioning. The results showed that the largest exergy losses take place in the biomass gasifier, CH4 synthesis part and CO2 capture unit. The overall exergetic efficiency of the biomass-to-SNG process was estimated in the range of about 69.5–71.8%.