工业硫酸催化酯化合成生物柴油性能的研究

Study on properties of biodiesel synthesized by catalytic esterification with sulfuric acid

以各种植物油厂的下脚油、高脂肪酸厂的废弃产物和甲醇为原料,以工业硫酸为催化剂,催化合成生物柴油。考察了醇油体积比、催化剂用量、反应时间以及温度对酯化率的影响,确定了最佳反应条件:醇油体积比1∶1,催化剂用量0.6g,反应温度65～75℃,反应时间6h。在此条件下,酯化率达到95.5%。将产物进行常压蒸馏、水洗,得到柴油粗产品。再将柴油粗产品在-0.095～-0.085MPa真空度下减压蒸馏精制,收集170～210℃范围内的馏分。其精制所得产品酸值低,且收率高达90%以上。制得的生物柴油的基本性质如密度、黏度、闪点等基本符合美国现有的生物柴油标准,且与石化矿物柴油性质接近。

Biodiesel is catalytic synthesized using variety of leftover oils of vegetable oil factory, waste products of high fatty acid plant and methanol as raw materials, and industrial sulfuric acid as catalyst. The effects of volume ratio of methanol to oil, amount of catalyst, reaction time and temperature on the esterification rate are investigated. The optimum reaction conditions are determined as follows= volume of methanol to oil ratio of 1 ： 1, amount of catalyst 0.6 g, reaction temperature 65 to 75 ℃, reaction time 6 h. Under these conditions, the esterification rate can reach 95.5 %. The product is atmospheric distilla- ted and washed, and crude diesel product is got. Then the crude diesel product is distillated in -0. 095 to -0. 085 MPa vacuum and 170 to 210℃range of fractions is collected. The acid value of refined product is low, and the yield up to 90%. The basic properties of biodiesel, such as density, viscosity, flash point, etc. , are in line with existing US biodiesel standards, and close to those of mineral and petrochemicals diesel.