Feasibility Study of Composting and Anaerobic Digestion Plant at Community Scale in Malaysia

Malaysia is in a transition state towards a more developed country which stresses on sustainable development. The Malaysia government has introduced several policies related to the installation of renewable energy to secure its energy demand, which has an annual growth rate of 8.1%. In the Iskandar region in Johor, low-carbon development projects have been continuously implemented under the low-carbon society blueprint for Iskandar Malaysia. The selected village, Layang-Layang, is located within a palm oil plantation and is part of Malaysia rural transformation centre (RTC) project where a community-composting pilot plant was successfully set up in 2016. This study analysed the environmental and economic performance of the community-composting project. A total of four scenarios is analysed regarding their environmental performance (greenhouse gas emission) and the economic returns of investment. Scenario A served as the baseline study where all the municipal waste is sent to a landfill site. Scenario B involved the current pilot-scale composting plant practised by 100 residents in Layang-Layang. Scenario C considered the scaled-up composting scenario (3000 residents) based on the data from scenario A and B in Layang-Layang. Scenario D considered the treatment of the municipal wastes (3000 residents) to generate biogas via anaerobic digestion (AD) where the digestate was used for composting. In this study, co-composting of food waste from a residential area with the green waste from the plantation showed a reduction potential of 96.79% (Scenario C) on greenhouse gas (GHG) emission as compared to the landfill (Scenario A) and a reduction of 99.67% on GHG emission for the integrated AD and composting system (Scenario D). The scaled-up composting in scenario C was more attractive for investment as compared to scenario D. Scenario C showed a shorter minimal year for the return of investment (3.09 years) as compared to Scenario D (6.17 years) with electricity generation from biogas. Graphical Abstract