二步法催化高酸值大豆油制备生物柴油

PREPARATION OF BIODIESEL FROM SOYBEAN OIL WITH HIGH ACID VALUE BY TWO-STEP CATALYZED PROCESS

采用两步法催化高酸值大豆油制备生物柴油。第一步在固定床反应器中,以002CR型阳离子交换树脂为催化剂,高酸值大豆油中游离脂肪酸和甲醇酯化生成脂肪酸甲酯(生物柴油);然后用氢氧化钾催化油中的甘油三酯和甲醇进行酯交换。结果表明,最佳酯化条件为:醇酸摩尔比2∶1,反应温度60℃,进料速度3 mL/min。该条件下大豆油酸值可降至1 mgKOH/g以下。酯交换条件为:催化剂用量1.5%,醇油摩尔比6∶1,反应温度65℃。产品技术指标达到我国0#柴油(GB252-1994优级品)的要求。

Two - step catalyzed process was adopted to prepare biodiesel from Soybean oil with high acid value. Free fatty acid of Soybean oil with high acid value was esterified with methanol catalyzed by cationic exchange resin 002CR which filled in a packed reactor in the first step,and then triglyceride（TG） of soybean oil was transesterified with methanol catalyzed by potassium hydroxide. Results showed that the optimal esterification conditions were：the ratio of methanol to fatty acid was 2 ： 1 ,reaction temperature was 60 ℃ ,dosage of reactant was 3 mL/min. Under this condition,the acid value of soybean oil was under 1 mgKOH/g. Transesterification was performed at 1.5 0% of potassium hydroxide , 65 ℃ of reaction temperature,60 min of reaction time,and 6 ： 1 of mole ratio of methanol to TG, and the quality of the product reached the standard of GB252 -1994.