Malaysia is the world’s second largest producer of palm oil. In 2019, a total of 19.86 million tonnes of crude palm oil (CPO) was produced from 98.28 million tonnes of fresh fruit bunches (FFB) processed by 452 palm oil mills, with an export earnings of RM63.73 billion from 5.90 million hectares of oil palm planted areas (MPOB, 2020). During palm oil extraction, a wastewater stream, palm oil mill effluent (POME), is generated abundantly. Based on the POME: FFB mass ratio of 0.67:1, the industry could generate an approximate 65 million tonnes of POME in a year. The anaerobic digestion (AD) of POME, through a series of open ponding system (Figure 1), emits biogas – a greenhouse gas (GHG) of about 65% methane (Loh et al., 2017), which is untapped and then released into the atmosphere. If otherwise it is produced and trapped, it becomes a replenishable energy source for the country.