Improper discard of oil palm trunk and empty fruit bunch renders massive greenhouse gases. Turning these palm wastes into solid biofuels could aid in carbon reduction. The embodied environmental impacts of the solid biofuel densification process are neglected in carbon emission quantification studies applying Greenhouse Gas Protocol while the significance of classifying the system's direct and indirect carbon emissions were overlooked in those utilising life cycle assessment. Despite the prospect of both methodologies to complement their limitations for carbon emissions quantification, no study integrates both methodologies to investigate direct and indirect emissions systematically from a life cycle perspective. An integrated framework of life cycle assessment and Greenhouse Gas Protocol is developed to quantify the direct and indirect carbon emissions of oil palm trunk and empty fruit bunch densification from cradle-to-gate for three pellet plants in Indonesia and Malaysia. The emissions are categorised into three emission scopes: Scope 1, Scope 2, and Scope 3 according to the Greenhouse Gas Protocol, integrated with avoided emissions which are quantified via life cycle assessment. The pellet plants generate 534.7-732.3 kg CO2-eq/tonnepellet per hour, in which Scope 1 (i.e., direct emissions) is the major emission scope due to high emissions from wastewater production and drying fuel combustion. Washing equipment (169.2-439.0 kg CO2-eq/tonnepellet per hour) and burners (87.1-214.5 kg CO2-eq/tonnepellet per hour) are the hotspots found in the pellet plants. Producing empty fruit bunch pellets could reduce 62.0-74.1 % of emissions than landfilling the empty fruit bunch. Empty fruit bunch pellet and oil palm trunk pellet are recommended to co-fire with coal to phase down coal usage in achieving COP26 pledge. This study provides data-driven insights for quantifying carbon emissions through the integrated framework and could be a reference in future life cycle carbon footprint studies of the biomass densification process.
As a promising green and sustainable coating material, gum was extracted from durian seed to produce eutectogel, which the properties were tunable using natural deep eutectic solvent (NADES). Ten different eutectogels were successfully synthesized using durian seed gum (DSG) and xanthan gum (XG) gelators at different composition (5, 10, 15 %) to gel choline chloride-glucose (1:1), choline chloride-fructose (1:2) and betaine-glucose-water (1:1:1) NADESs. Results revealed that eutectogel was non-Newtonian and weak gel material with excellent thermostability up to 200 °C. When the gum content increased, the resulted eutectogel showed higher viscosity, yield stress, hardness, gumminess, adhesiveness, and weight holding capacity. In overall, choline chloride-fructose (1:2) NADES and 10 % of DSG formed an excellent eutectogel which remained stable and compatible upon 12 weeks of storage. It displayed superior viscoelastic, texture, gases and moisture barrier properties which were beneficial for food coating application. This eutectogel was able to extend the shelf life of fresh-cut apples during storage with lower weight loss and higher total phenolic content (TPC). The potential future of this well-characterized tunable DSG-derived eutectogel includes, but not limited to, food and pharmaceutical industries, smart sensing, flexible wearable electronics, water purification, supercapacitors and batteries.