Green electricity generation from biogas of cattle manure: An assessment of potential and feasibility in Pakistan

In several countries, organic or municipal solid wastes, such as cattle and buffalo manure, have become a serious political and environmental issue owing to organic waste incineration and garbage disposal. To overcome this problem, biogas production from manure, a green treatment that both contributes to the availability of sustainable energy and assists in reducing global warming, was considered. The current study was conducted on the generation of green electricity using cattle and buffalo manure in Pakistan. In 2021, Pakistan has generated 102.742-terawatt hour (TWh) of electricity collectively; biogas share in total production accounted for only 0.98%, which is approximately 1 TWh. Unfortunately, most of the electricity was generated from nonrenewable energy sources. One large animal produces 9–10 kg of manure per day. A system for manure collection can be developed; 30% of total manure produced every day by cattle and buffalo can be collected. Such a type of system is already used for the collection of poultry manure. Pakistan has been blessed with almost 42.4 million buffaloes and 51.5 million cattle. The annual collection of manure from cattle and buffalo at the rate of 30% will be 92.53 million tons. From this manure, approximately 4.63 billion m3of biogas can be produced and 70% can be collected, which will be 3.24 billion m3. Thus, Pakistan has the potential of generating 19.79 TWh of electricity per day from cattle and buffalo manure. Biogas has the potential to generate over 20% of Pakistan’s total electricity. At the farm level, 100 cattle ranches with 60% collected manure can create roughly 57% of their total consumed electricity. Slurry, a byproduct of anaerobic digestion, can be used as a biofertilizer in fields. It is possible to use cattle manure to make biogas, which is “made by fermentation of organic waste in the absence of oxygen.” It aids in the reduction of fossil fuel dependency, solid waste management, and air pollution control by lowering greenhouse gas emissions. Biogas contributes to the three pillars of sustainable development: economic, environmental, and social development. Biogas contributes significantly to the SDGs and other aspects of sustainable development.