[VIP专享]伯伯版本专英长到死论文翻译(生物柴油)

in the bottom layer. This work also appeared as three papers [50-52]: these patents and papers are very similar to the earlier procedures described in the above text [45]. The same ionic liquids were also used to transesterify waste oil [53] or soyabean oil [54] with methanol to give biodiesel. An acidic anionic ionic liquid, 1-H-3-methylimidazolium hydrogensulfate, was shown to catalyze the reaction of rapeseed oil with methanol to give biodiesel [55].EXPERIMENTAL

Animal fat (specifically lard; 1.0 g), methanol (2.0 g), and an ionic liquid (0.25 g; selected from 1 to 7) (see Fig. 3 for structures) were placed in a microwave tube with a magnetic stirrer, and heated to the desired temperature (see Tables 2-4) for 30 min in a CEM Discover microwave reactor. The mixture was then cooled to room temperature and was observed to be biphasic. The two layers were each analyzed by [sup.1]H NMR spectroscopy: the upper (product) layer was dissolved in CD[Cl.sub.3] and the lower layer was obtained in methanol; the lower methanol layer was isolated, the methanol removed in vacuo, and [CD.sub.3]OD added. The yield was determined by comparing the integration of the -[OCH.sup.2]- group in the glyceryl residue in the triglyceride with the -[OCH.sub.3] group in the FAME (biodiesel). The

upper

methyl oleate (product) layer was decanted, and the dissolved methanol was removed by distillation at 120 [degrees]C or by heating to 60 [degrees]C at 1 mm Hg pressure. The product was found to be free of ionic liquid catalyst by [sup.1]H NMR spectroscopy.Base-catalyzed reactions

The base-catalyzed reactions (see Table 4) were carried out by adding the ionic liquid catalyst to the alcohol and triglyceride mixture, followed by heating at the required temperature. A disadvantage of the base-catalyzed reactions is that, when applied to fatty acids (as opposed to esters), a salt is formed which renders the base catalyst inactive. For transesterification, however, the ionic liquid, methanol, and glycerol form a separate phase from the biodiesel. The ionic liquid catalyst can then be separated from the alcohols (methanol and glycerol) by distillation or vacuum distillation. The catalyst could be then recycled and reused.