EVALUATION AND SCRUBBING OF BIOGAS GENERATION FROM AGRICULTURAL WASTES AND WATER HYACINTH

Abstract

This study aimed to characterize anaerobic batch biodegradation of five co-digested mixtures in terms of methane yield and energy production as follows: Mixture 1 (potato waste + sugar beet leaves), mixture 2 (cattle dung), mixture 3 (water hyacinth + cattle dung), mixture 4 (rice straw + cattle dung + poultry droppings) and mixture 5 (bagasse + cattle dung). Effects of stirring, dry oxidation and water scrubbing processes on the biogas quality were also examined. The peak values of gas generation reached up to 0.344 and 0.476 L/L/day for control and handle stirring in case of mixture 5. The results showed significant differences in biogas production between control and stirring for different mixtures. The biogas generation increased by stirring with 60.33% compared to control. The highest values of CH4 were 75, 69.7 and 68.6% for mixtures 1, 5 and 3, respectively. The average CO2 ranged from 31.65 to 37.46%, while H2S contents ranged from 2017.6 to 2622.4 ppm. Average removal efficiencies of CO2 and H2S reached up to 94.84 and 97.2%, respectively. Upgrading biogas enriched it with methane content up to 95.71% and increased its calorific value up to 31.28 MJ/m3. It could be concluded that, the mixing and stirring as well as dry oxidation and water scrubbing processes have an important role and efficacy in the biogas production quantity and quality. Recycling of wastes and biogas production requires strong governmental support to be successful.