Abstract:

Biodiesel was prepared by esterification of cottonseed oil crude fatty acids with methanol and with sulfuric acid as catalyst.Three fractions of the biodiesel (230—260℃, 230—310℃ and 260—310℃) were collected by vacuum distillation at an absolute pressure of 2000 Pa.The densities, viscosities and solidifying points of the fractions were determined.At the same time, the composition of the biodiesel was analyzed with gas chromatography and mass spectrometry (GC-MS).It was found that the solidifying points of two fractions (230—260℃ and 230—310℃) met the national standard of 0^# diesel, and the fraction of 260—310℃ could be used as fuel for low-speed engines.

Key words:

生物柴油, 酯化, 减压蒸馏, 气/质联用, 馏分成分

摘要：

使用浓硫酸催化棉油毛酸与甲醇的酯化反应制备脂肪酸甲酯即生物柴油。通过减压蒸馏，在0.002 MPa的压力下， 分别收集230～260℃、230～310℃和260～310℃ 3个馏分段的生物柴油，测定其密度、黏度、冷凝点。同时，通过气相色谱-质谱联用仪对生物柴油的成分及其含量进行分析。发现230～260℃和230～310℃两馏分段的馏出率分别达到53.27%和64.76%，且凝点指标均达到我国0^#柴油的标准。260～310℃馏分段柴油的馏出率为10.52%，凝点为5℃，可作为中、低速柴油机的燃料使用。

关键词:

生物柴油, 酯化, 减压蒸馏, 气/质联用, 馏分成分