高酸值油料一步法制备生物柴油研究

DIRECTLY CONVERT PALM FATTY ACID DISTILLATE TO BIODIESEL IN ESTERIFICATION PROCESS

以酸值123.04 mg KOH/g的棕榈油脱臭馏出物(PFAD)为原料,在带压反应器中,用浓硫酸为催化剂,采用一步法催化酯化反应制备生物柴油。重点研究反应温度、反应时间、催化剂用量和醇油比等因素对酯化和酯交换反应的影响。结果表明,提高反应温度能促进酯化反应和酯交换反应,使高酸值原料经一次反应直接转化为目的产物——脂肪酸甲酯,从而缩短制备流程,降低成本,强化酯化反应进行,提高脂肪酸甲酯收率。当催化剂用量为0.5%(质量分数)、醇油物质的量之比7∶1、在130℃反应90 min后,生物柴油的最高收率达到88.1%。较之酸碱两步法催化高酸值油料制备生物柴油能显著缩短反应时间、简化工艺流程、降低生产成本。

The palm fatty acid distillate(PFAD)with the high acid value of 123.04 mg KOH/g was converted directly into biodiesel in a pressurized reactor using sulfuric acid as catalyst. The main factors affecting the yield of biodiesel such as the molar ratio of methanol to PFAD,reaction time,reaction temperature and catalyst dosage are studied. The results showed that the yield of biodiesel increased notably in the enhanced acid catalyzed esterification process by raising the reaction temperature. And the marked advantage for this process is to convert PFAD into biodiesel in one-step reaction in less time at low cost compare with the traditional two-step method. The highest biodiesel yield was 88.1% obtained at the optimum conditions:catalyst sulfuric acid loading of 0.5% wt,molar ratio of methanol to PFAD is 7∶1,react at 130 oC for 90 min.