Parametric study was conducted to investigate the effect of variation of process conditions for single stage without recycle (SSWR) and double stage with permeate recycle (DSPR) on product purity, CH4 recovery and compression power requirement. In the study, achieving high CH4 recovery and product purity simultaneously could not be attained in SSWR configuration. The performance of DSPR yielded a better result but with higher membrane area and compression power. In the economic studies, increase in CO2 and feed pressure increased the gas processing cost (GPC) while increase in flow rate decrease GPC based on economies of scale. At optimized condition, the calculated GPC was $0.46/m3 of biomethane . The NPV, IRR and BCR for producing biomethane were R15,240,343, 22.41 % and 2.05 respectively with a break-even in the 5th year. Using CBG over gasoline, the end user saves 34 % of annual fuel cost.
|Title of host publication||WCECS 2015|
|Subtitle of host publication||Transactions on Engineering Technologies|
|Editors||S. I. Ao, H. Kim, M. Amouzegar|
|Publication status||Published - 2015|