Economic and environmental evaluation of landfill gas utilisation: A multi-period optimisation approach for low carbon regions

Abstract

Landfill gas (LFG) is composed essentially of the most problematic greenhouse gases (GHGs) namely methane (50%) and carbon dioxide (45%). However, due to its methane content, LFG can be utilised as a renewable energy source, but utilising LFG is met with a lot of challenges such as choice for LFG grade (low, medium or high grade), LFG utilisation equipment (gas engines, gas turbines etc.) and product type (electricity, heat etc.). The study estimates LFG capture and develops tool for the utilisation of LFG as a renewable energy resource. The Intergovernmental Panel on Climate Change model outcome shows that an average annual LFG capture of 17,200 tonnes was obtained for Iskandar Malaysia and the optimal results indicate that the LFG is best utilised as a medium grade LFG for combined heat and power generation using steam turbines. The profitability evaluation shows that mean annual profit of US$5.6 million has been achieved with a payback period of 12.3 years and net present value of US$111 million, which is reasonable because the project can be classified as medium to large-scale. Additionally, the study provides insight into the viability of various LFG utilisation technologies and strategies for waste disposal to landfill.