Biogas is a gaseous by-product generated from anaerobic digestion (AD) of palm oil mill effluent (POME). As a renewable energy resource, one of the commercial uses of biogas in the Malaysian palm oil industry is as a supplementary fuel in biomass boilers. This approach adopts a co-firing concept, offers an immediate and low-cost investment option for a direct and clean conversion of biogas to steam and electricity via an existing combined heat and power (CHP) plant available at palm oil mills (Nasrin et al. 2014 and Loh et al., 2014). Biogas is added as a partial substitute fuel in oil palm biomass boilers.