Study On The Integrative Transformation Of Xinjiang Cottonseed Oil Deodorizing Distillate

Distillates of oil deodorization are the byproducts of this oil refining process, and consist mainly of natural Vitamin E( tocopherols), sterols, free fatty acids, glycerides. Natural tocopherols, phytosterol and fatty acid methyl ester can be obtained from cottonseed oil deodorizing distillate(CODD). The purpose of the thesis is to study technics of the integrative transformation of Xinjiang CODD .That is using only a catalyst to promote the simultaneous reactions of nonα-tocopherols, glycerides, free fatty acids, and methyl alcohol in CODD. Then highα-tocopherol content in nature tocopherols and phytosterol were obtained by means of specific adsorption and crystallization alkalinity respectively. The mainly studies are as follows:We prepared highly catalytic SO₄^2-/ZrO₂-MoO3 solid acid catalyst, SO₄^2-/ZrO₂-V₂O₅ solid acid catalyst, supported Br nsted acidic ionic liquids, and carbon-based solid acid catalyst in the integrative transformation of CODD. This study shows that these catalysts exhibited optimal catalytic activity to simulaneous methylation, methyl esterification and transesterification for the integrative transformation of CODD.The optimal conditions for these catalysts preparation were then determined, then the characterization and detection were studied. These catalysts were well stable and could be reused more than six times.The technics of integrative transformation of CODD were studied respectively. Under optimal integrative transformation conditions: reaction temperature,250～280℃; catalyst amount, 10% (w/w); reaction time, 3～5h; methanol-to-oil ratio, 3:1～4:1; the yield of tocopherols reach 75% above;content ofα-tocopherol in tocopherol reach 87% above; methyl esterification rate reach 94% above; transesterification rate reach 84% above.After adsorption and desorption of the product from integrative transformation of CODD using basic polymeric adsorbent disposed, the purity and the yield of tocopherols were 75.68% and 87.77%, the content ofα-tocopherol in tocopherol was about 90.00%.Using the adsorption by-product that is concentrated solution after separating tocopheryls by means of specific adsorption as material, the optimal conditions for crystallization are: the solvent of absolute ethyl alcohol; material-to- the solvent ratio, 1:5(w/ v); the crystallization temperature, -5℃; the crystallization time , 36 h. Under the optimal crystallization conditions, the experiment results showed the yield and the purity of phytosterol were 62.64% and 62.56% respectively. The melting range and IR spectra of rude phytosterol were studied. That showed there are mainlyβ-sitosterol and a few campesterol. It was agreeded with documents published.