Alpha alcohols
| 원료 | Aluminum powder; Ethylene |
| 생산물 | alpha alcohols |
| 적용 | A process for making even-numbered, straightchain alpha alcohols from ethylene, aluminum, hydrogen, solvents, air, and water. The process also produces byproducts of either high-purity alumina or alum. |
| 설명 | Description: Triethylaluminum preparation. Aluminum powder is slurried in a suitable solvent and hydrogenated with dry hydrogen in the presence of triethylaluminum. The hydrogenated product, diethylaluminum hydride, is contacted with ethylene to form triethylaluminum. Two moles of triethylaluminum are recycled to the hydrogenation step for every one mole that goes to the polymerization step. Growth. Triethylaluminum is reacted with ethylene to produce higher-molecular-weight alkylaluminums. The polymerization follows a Poisson distribution giving a mixture of alkyl chains from C2 through C22. The growth reaction is highly exothermic, and because of the violent reactivity of growth product and triethylaluminum with water, a hydrocarbon is used as the heat transfer medium. The reaction is conducted at high pressure and low temperature for optimum efficiency. Oxidation. Growth product is oxidized under carefully controlled conditions with dry air to produce alkoxide. The oxidation reaction is highly exothermic and produces small quantites of byproduct esters, ethers, acids and aldehydes which are removed along with excess solvent prior to hydrolysis. Hydrolysis. Purified alkoxide is reacted with water to produce a mixture of crude alcohols and alumina slurry. After a purification step, water is removed from the slurry by drying to produce high-purity 75% Al2O3 CATAPAL alumina. The hydrolysis can also be conducted using 98% sulfuric acid to produce a high-purity alum solution. Fractionation. The crude alcohols are dried and then distilled into individual pure component alcohols or two component blends. The high-molecular-weight alcohols are distilled under vacuum conditions. |