Removal of free fatty acids from acid oil by esterification with cation exchange resin

采用阳离子交换树脂为催化剂研究了酸性油脂的酯化脱酸工艺。分别筛选了001x4,001x7,d113,Hd-8,Cd-552等几种型号的树脂,其中以Cd-552催化效果最好。研究了反应时间、醇酸摩尔比和酸性油脂中催化剂质量分数对Cd-552催化酯化脱酸效果的影响。在醇酸摩尔比30∶1,反应温度60℃,树脂质量分数5%和反应时间5 H的工艺条件下,酸性油脂经Cd-552催化酯化脱酸后,酸值从10.97 Mg/g降低到0.689 Mg/g。反应后树脂易分离,能够循环使用,有效地解决了传统的脱酸催化剂不足,对以酸性油脂为原料的生物柴油的生产具有应用前景。Using acidic cation exchange resins as a solid esterification catalyst,the removal of free fatty acids(FFA) from acid oil by esterification with methanol was researched.The resins such as 001×4,001×7,D113,HD-8,CD-552 were selected for the experiments.The results show that the resin CD-552 is the best catalyst for FFA reduction.The effects of reaction time,mole ratio of alcohol to FFA and mass fraction of catalyst in acid oil on acid reduction by esterification with CD-552 were investigated.Under the reaction conditions: molar ratio of alcohol to FFA 30 ∶1,reaction temperature 60 ℃,catalyst mass fraction 5% and reaction time 5 h,the acid number of the oil is reduced from 10.97 mg/g to 0.689 mg/g after removal of free fatty acids from acid oil by esterification with CD-552.It indicates that the resin is easy to be separated and recycled,which overcomes the deficiency of traditional FFA reduction catalyst,and has a good application prospects for producing biodiesel by using acid oil as raw material