The selection of raw materials is the cost-wise strategy for biodiesel to compete with diesel. The raw material used in the second generation of biodiesel production is non-edible oil which contains high free fatty acids (FFA). Palm Fatty Acid Distillate (PFAD); the by-product of crude palm oil (CPO) industry has a high potential as the amount is abundant in Indonesia. The objective of this study is to compare the catalytic activity of esterification reaction using self-synthesized sulphated alumina and a sulphuric acid catalyst against the reduction of FFA. The reaction was carried out in a three-necked flask, at a temperature of 60C, 7 hours of reaction time and rotation speed of 400 rpm. The results showed that the maximum FFA conversion of PFAD esterification reactions over sulphated alumina was 84%, achieved at methanol to oil ratio of 1.7 (v/v), catalyst to PFAD ratio of 12 % (w/w) and reaction time of 7 hours. Meanwhile, the optimum conditions for PFAD esterification usingsulphuric acid catalyst are methanol to oil volume ratio of 1.5; catalyst to PFAD ratio of 7.4 wt.% and 3 hours of reaction time. 99.34% of FFA conversion was achieved with the homogeneous catalyst.

原材料的选择是生物柴油与柴油竞争的成本策略。第二代生物柴油生产所用的原料是含有高游离脂肪酸（FFA）的非食用油。棕榈脂肪酸馏出物 (PFAD)；原棕油 (CPO) 行业的副产品具有很高的潜力，因为印度尼西亚的数量丰富。本研究的目的是比较使用自合成硫酸化氧化铝和硫酸催化剂的酯化反应对 FFA 还原的催化活性。反应在三颈烧瓶中进行，温度60℃，反应时间7小时，转速400rpm。结果表明，在甲醇油比为 1 时，硫酸氧化铝上 PFAD 酯化反应的最大 FFA 转化率为 84%。7 (v/v)，催化剂与 PFAD 的比率为 12% (w/w)，反应时间为 7 小时。同时，使用硫酸催化剂进行PFAD酯化的最佳条件是甲醇与油的体积比为1.5；催化剂与 PFAD 的比例为 7.4 wt.%，反应时间为 3 小时。使用均相催化剂实现了 99.34% 的 FFA 转化率。