Important aspects for the planning of biogas energy plants: Malatya case study

Abstract

Conventional energy use causes various environmental impacts of global warming. Also, as a result, renewable energy sources are more beneficial because they generate virtually no emissions. Biogas is historically recognized as a by-product of the anaerobic (oxygen-free) decomposition of agricultural waste. One of the most critical issues for biogas plants in electricity production is the economically and environmentally safe disposal of vast volumes of digestate. In this study, an extensive pathway for the establishment of a large-scale biogas energy plant was presented. Under these lightings, a case plant built in Akcadag-Malatya was investigated from the techno-economic point of view. The case plant was built to generate heat and power as well as solid and liquid fertilizer. The produced biogas and methane were respectively recorded as 229,49 m(3)/h and 139,08 m(3)/h. It was determined that electricity generation in an amount of 5,256,000 kWh per year from the digested feedstock was available with the maximum power capacity of 625 kWh. The annual and daily heat energy outputs were calculated as 6,482,400 kWh and 640 kWh, respectively. The solid and liquid fertilizers were respectively determined as 40,891.03 t/a and 5,152.74 t/a. According to the results, total investment costs per the produced electricity for the biogas energy plant were calculated as 1451.53 (sic)/kWh. The payback period was calculated as 2.22 with a net present value of 944,714.44 (sic). CO2 emissions have been reduced by 14,105 tons per year thanks to the co-generation system.