Ecological footprint of bio-based diesel under climate change conditions toward sustainable palm oil industry and alternative energy development in Thailand

Thailand has set a maximum biodiesel production target of 11.0 million liters per day in 2037; biodiesels produced from fatty acid methyl ester from palm oil is blended with fossil diesel. The alternative biodiesels include bio-hydrogenated diesel and partially hydrogenated fatty acid methyl ester which can have higher blending percentages with fossil diesel. The total land and water ecosystem requirements for providing resources and absorbing emissions including cropland, energy, the forest, and built-up land for biodiesel production were assessed by ecological footprint to support the sustainable development of the biodiesel production target while considering climate change. In the existing condition, with production at 4.28 million liters per day, the ecological footprints of fatty acid methyl ester, hydrogenated fatty acid methyl ester, and bio-hydrogenated diesel were 5.46, 5.51, and 4.09 million global hectare/year, respectively. Water and cropland were the major sources accounting for 67 % and 14 %, respectively. For the production of 11.0 million liters per day under Representative Concentration Pathway 8.5, with maximization of fresh fruit bunches productivity and oil percentage, the ecological footprints of fatty acid methyl ester, hydrogenated fatty acid methyl ester, and bio-hydrogenated diesel were 9.38, 9.89, and 7.29 million global hectare/year, respectively, whereas for business-as-usual fresh fruit bunch productivity and oil percentage, these values increased to 14.5, 15.0, and 11.3 million global hectare/year, respectively. When only fatty acid methyl ester is used, the plantation area must be increased by between 741,862 and 802,281 ha. Increase in yield of oil palm plantation, percentage palm oil, and promotion of bio-hydrogenated diesel production should be implemented to decrease the amount of resources used for bio-based diesel production.