The Effect of Microwave and Alkaline Treatment on Biogas Production from Organic Fraction of Municipal Solid Waste

Abstract

Background: Renewable energy sources have received increased interest from the international community with biomass being one of the oldest and the most promising ones. In the concept of exploitation of solid organic waste residues, the present study investigates the pre-treatment and biogas fermentation potential of the solid organic waste. Solid organic waste is the solid waste generated houses of leftovers. Organic Fraction of Municipal Solid Waste (OFMSW) is the most solid organic waste material resource for obtaining energy. Therefore, it is necessary to apply a convenient pretreatment method to increase the biogas yield. Microwave pretreatment method assists to break down hard OFMSW for improved degradation of solid organic waste and releasing of biogas. General Objective: Evaluating the production of biogas from OFMSW using microwave radiation and sodium hydroxide treatment. Methodology: The Biogas test is one method that can be used to estimate the amount of biogas that could be produced from anaerobically digesting organic waste at mesophilic temperatures. A known quantity of organics based on the volatile solids fraction is added to OFMSW inoculum. The mixture is anaerobically digested until biogas production ceases, during which time the quantity and quality of biogas produced is measured. - Alkaline treatment (NaOH). - Microwave treatment power operated at 2450 MHz and 450 W. - Combined treatment (Microwave _Alkaline). Results: In both pretreatment methods, remarkable findings were obtained as biogas concentration. The maximum produced total biogas amount of 3L was achieved after ten minutes of pretreatment time in 300 mL of 2% NaOH solution (w/v) at microwave power of 450 W with 60 g OFMSW. The results suggest that microwave and microwave-alkali pretreatment can increase total biogas production. Conclusion 1. A long-time (25 min) microwave treatment can improve the reducing biogas yield greatly for the hydrolysis of OFMSW, but leads to high sugar loss during the pretreatment. 2. Combined microwave-alkaline treatment at near room temperature, the time of biological process was shortened to 120 hour and the efficiency of NaOH pretreatment was enhanced. 3. The combined pretreatment process is favorable for further development and application of biological pretreatment.