Assessment of Waste to Energy Potential in the Central Zone of Afghanistan

The central zone of Afghanistan has enough cattle to be considered for generating biogas. The cattle population in the zone was 634,524, 647,229 and 633,362 heads in 2012-13, 2014-15 and 2016-17, respectively. As a result of field experiments, the fresh manure generation of cattle in the zone is 19 kg head-1 day-1, fraction recoverable of the generated cattle manure is 80% and the proportion of dry matter of the manure is 23.7%. Based on these manure parameters, about 834,320, 851,026 and 832,792 tons of dry matter recoverable could be generated in the mentioned three years, respectively. By using a biogas digester, this dry matter recoverable could be enough for generating about 86,769,319, 88,506,691 and 86,610,419 m3 of biogas in 2012-13, 2014-15 and 2016-17, respectively. The amount of generated biogas is equivalent of 1,735, 1,770 and 1,732 TJ of energy in the mentioned years, respectively. In the case study of Kabul province, it was found that till now biogas plants are not constructed in the zone. For financial evaluation of biogas utilization, a dairy of 24 cattle was selected. It was determined that the manure from 24 cattle can generate about 9 m3 per day (3,285 m3 per year) of biogas in a 24 m3 DSAC-Model biogas digester. By comparing biogas energy value from the equivalent energy of LPG, biogas has value of 66,521.25 Afg per year (978 USD per year). By considering the requirements of cooking and lighting of a family of 8 members, the generated biogas (9 m3/day) in the mentioned dairy farm can be enough for two families. Considering the situation of the zone DSAC-Model biogas plant was considered suitable among various types of it. The techno-financial analyze result was quite attractive. For this case, the NPV was 2,664.6 USD, B/C 2.37, IRR was 33% and the discounted payback period (PP) was 4.09 years (4 years and about one month). As all these financial indicators are in the acceptable range, therefore the biogas generation with DSAC-Model biogas plant in the central zone of Afghanistan is beneficent.