Exergetic Analysis of a Microalgae Gasifier with an Integrated Solar Dryer
Ephraim Taktak Bello, Abba B. Muhammad, Fasiu A. Oluwole
Abstract
Renewable energy sources are rapidly substituting fossil fuels. In this paper, energy and e xergy analyses of microalgae biomass to synthetic gas production is presented. First and second laws of thermodynamics analyses were conducted on three energy systems: solar dryer; combustor; and a gasifier. Exergy analysis was performed on three heat media to investigate the energy conversion performance of each energy system within range of 10-50% humidity. The tests were carried out on three conditions: product gas having high concentrations of carbon monoxide and hydrogen gases; gasification begins at 1000 0C; and complete combustion with no ash formation. According to the results obtained, moisture content in microalgae biomass has negligible effect on the exit temperature of synthetic gas from gasification chamber. The exergy loss analysis in solar dryer show lower values compared to a combustor and gasifier. The gasifier chamber is least energy efficient system with exergy loss value of 5.4KJ/Kg at 50% humidity compared to 3.4KJ/Kg and 3.1KJ/Kg at 50% humidity levels for solar dryer and combustor respectively.