| 摘要 |
There are disclosed processes for separating waxes of different melting points from a room temperature amorphous or liquid hydrocarbon mixture in an energy conservative manner by selectively causing precipitation of crystallized waxes. The processes involve the use of a selected co-solvent totally miscible with light and intermediate hydrocarbons from a group consisting of acetone, ketene, propanone, 2-propanone, methanol, ethanol, isopropanol, N-propanol, acetic acid, formic acid, and propionic acid or combinations thereof as a precipitating agent. Hydrocarbon mixtures, especially those with elevated pour points are first diluted by solvents such as toluene and/or methylethyl ketone which must be free of any significant quantity of the aforesaid co-solvents. The diluted hydrocarbon mixture at above 50 degrees F. is mixed with one or more of such selected co-solvents in a ratio preferably between 1:1 and 10:1 by weight to the heavy hydrocarbon content of the mixture; five minutes or more without artificial cooling is allowed to permit crystallization of waxes which are removed in solid form by a physical process such as filtering, settling, or the like. By controlling the amount and nature of the selected co-solvent and by including or excluding water or brine with the co-solvent, valuable waxes of high melting point may be selectively separated, or all waxes may be removed indiscriminately; performing the separation process in several stages of adding co-solvent and/or water permits selecting out more valuable high melting point waxes first before succeeding stages reduce the wax content of the remaining liquid hydrocarbon to minimal values to enhance its value.
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