Biochemical methane potential assessment of municipal solid waste generated in Asian cities: A case study of Karachi, Pakistan

Municipal solid waste (MSW) generation rate in Asian cities is exponentially increasing with rise in urbanization and commercial activities. Beside this, the cities in developing Asia are deficient in adequate waste management and facing energy shortage as well. The ineffectual waste management practice is one of the main causative factors behind the negative repercussions on public health and environment. This paper provides an estimation of power generation potential along with economic and environmental benefits of biochemical methane pro-duction from MSW. The biochemical methane potential (BMP) test of the MSW generated in Karachi, Pakistan was conducted by using the fresh synthetic waste sample. Through the analysis of the results obtained in this study and available data of the MSW generation (quantity, organic fraction and moisture content) in Karachi it is estimated that, every year about 5600 tons of methane are being wasted to atmosphere adding enormous share in global climate change. This study estimated that, about 63 MWe electric power can be generated by establishing biowaste digestion plants with power generation facilities in the city. The generated power can contribute 2.1% share in daily power supply and 21% power shortage can be reduced as well. Additionally, about 401.3 million-PKRs (2.6 million-US$) revenue can be earned every year by selling the power generated by utilizing the MSW in waste to energy plants. Moreover, 0.13 Mt CO2-eq/annum greenhouse effect caused by methane emissions from open disposal of MSW can be eliminated.