GHG analysis of the production of crude palm oil considering the conversion of agricultural wastes to by-products

The oils and fats world production are predominantly championed by two (2) main oils which are palm oil and soybean oil. Even though these commodities are categorized as oils, these crops are basically agricultural crops which generate abundant wastes along their supply chain. The oil palm supply chain churns out huge amounts of biomass and water wastes. Greenhouse gas (GHG) analysis was conducted for four (4) different pathways practiced by the Malaysian oil palm industry which analyses the GHG emissions of these pathways and also included the recycling of the wastes. The GHG emissions from for land use change (LUC) from logged over forest, oil palm fresh fruit bunch production and biogas were 2095, 618, 916 kg CO(2)eq/kg CPO respectively. The recycling of pressed mesocarp fiber (PMF) and palm kernel shell (PKS) as fuel displaced 2.5 kWh/kg PMF and 3.6 kWh/kg PKS of fossil energy giving a GHG reduction of 1.5 kg CO(2)eq /kg PMF and 2.2 kg CO(2)eq/kg PKS, respectively. The empty fruit bunch (EFB) applied at the plantations for mulching as fertilizer substitute gave a GHG savings of 3.3 kg CO(2)eq/t EFB. EFB used as boiler fuel displaced 2.0 kWh/ kg EFB of electricity with a GHG savings of 1.1 kg CO(2)eq/t EFB. Palm oil mill effluent (POME), wastewater of the milling process emits biogas during the anaerobic treatment, when captured and utilized as energy, displaces 2.7 kWh/m(3) biogas of non-renewable energy with GHG savings of 13.4 kg CO(2)eq/m(3) biogas. Pathway one (1) with LUC from logged over forest, biogas emissions and biomass utilization as fuels and fertilizer substitute showed the worst environmental performance while pathway 4 with no LUC, biogas capture and utilization of biomass as fuels showed the best environmental performance to produce crude palm oil. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.