PERFORMANCE AND ANALYSIS OF AGRICULTURAL FEEDSTOCKS, PRETREATMENT AND CO-DIGESTION FOR ANAEROBIC BIOENERGY PRODUCTION

Agricultural residues and livestock wastes represent important feedstocks for anaerobic digestion and renewable bioenergy production. This paper examines the feedstock characteristics, pretreatment approaches, and co-digestion strategies described in the thesis for conversion of agricultural waste into biogas. The reviewed feedstocks include rice straw and rice husk, wheat straw, corn stalks, sugarcane bagasse and press mud, banana pseudo-stem, vegetable waste, cattle dung and dairy effluent.Their suitability for digestion is influenced by physicochemical characteristics including volatile solids, moisture, pH, lignocellulosic composition and carbon-to-nitrogen ratio. Lignocellulosic residues present a hydrolysis limitation because cellulose and hemicellulose are protected within a lignin-hemicellulose structure. The thesis considers physical, chemical and biological pretreatment approaches to improve substrate accessibility.Co digestion is presented as a means of combining complementary feedstocks, improving nutrient balance and process stability. In the reported experimental results, mechanical shredding below 2 mm followed by 2% sodium hydroxide treatment at 70C for 60 minutes reduced lignin content by 24.5%, increased biogas yield by 42%, and reduced digestion time by 15 days. The reported feedstock analysis and pretreatment results support the use of agricultural waste mixtures and pretreatment as important components of anaerobic bioenergy production.