Emissions of CH4 and CO2 from Wastewater of Palm Oil Mills: A Real Contribution to Increase the Greenhouse Gas and Its Potential as Renewable Energy Sources

Abstract

Palm oil mill effluent (POME) treatment in Indonesia is still predominant using an open pond system. This system has the weakness of the unknown and uncontrollable value of greenhouse gas (GHG) emissions into the atmosphere. This study estimated GHG emissions (CH4 and CO2) from anaerobic ponds and their potential as a renewable energy source and obtain GHG emission conversion coefficients for each kg of COD POME and ton of crude palm oil (CPO). Gas samples were collected using a closed static chamber. GHG sample concentration testing was done using Gas Chromatography with a flame ionization detector (FID) and thermal conductivity detector (TCD). The results showed that the emission rate of CH4 and CO2 in the anaerobic pond POME treatment was relatively high, 261.93 and 595.99 g/m2/day, respectively, equivalent to 48.572 t CO2-eq/day or 14,571.5 t CO2-eq/year. CO2 emissions were greater than two times CH4 emissions, both spatially and temporally. There was a process of facultative biodegradation, aerobic and or anaerobic process according to the biotic-abiotic environment and the levels of organic components in the substrate. In anaerobic ponds, the optimal requirements for the biodegradation process tended to be unfulfilled, so the emission rate of CH4 was less than CO2. The GHG conversion coefficient was obtained, namely each kg of COD from POME emitted 6.266 kg CO2-eq of GHG; for each m3 of POME emitted by 0.163 t CO2-eq of GHG; and 0.556 t CO2-eq/t CPO. The maximum potential for POME to energy conversion was 1.045 MWe with a power capacity of 8,603 MWh/year.

Biomass Fuel Production through Fermentation of Lysinibacillus sp. LC 556247 in Various Ratios of Palm Oil Mill Effluent and Empty Fruit Bunch

“…Utilization of agricultural waste, such as palm oil mill waste, into biomass fuel using naturally occurring microbes is sustainable rather than leaving the waste in open spaces such as open ponding systems without extensive treatment. The obsolete open ponding system causes uncontrollable greenhouse gas (GHG) emissions into the atmosphere [53]. The commercially available pellet has a low CEV of 17.35 MJ/kg when compared to the product from the Group 4 biomass fuel.…”

Application of the Hydrodeoxygenation of Black Soldier Fly Larvae Lipids in Green Diesel Production

“…Three generations of biofuels-1, edible plant parts [2,3]; 2, non-edible plant parts [4]; and 3, algal photosynthetic microorganisms [5]-have been developed and extensively investigated for use in future energy resources. However, each has encountered its own challenges, such as food-feed-fuel competition [6], deforestation [7], large amounts of land use [8], and high-water consumption [9,10]. Such paradoxical situations can exacerbate climate change and potentially lead to food security issues [11].…”