Abstract: A process for purifying linear paraffins in which a hydrocarbon feedstream containing linear paraffins contaminated with aromatics, sulfur-, nitrogen-, and oxygen-containing compounds, and color bodies, and also containing up to about 5 wt % desorbent from effluent recycle, is contacted with a solid adsorbent such as a NaX zeolite or zeolite MgY; after adsorption the adsorbent is desorbed with an alkyl-substituted aromatic desorbent, such as toluene. As the adsorent bed is being desorbed, the initial effluent from the adsorption cycle will contain levels of desorbent and may be recycled to the hydrocarbon feedstream. Previous to the removal of impurities from the adsorbent by desorption, the desorbent displaces interstitial linear paraffins which are also recycled to the hydrocarbon feedstream.

Abstract: A process for purifying linear paraffins in which a hydrocarbon stream containing linear paraffins contaminated with aromatics, sulfur-, nitrogen-, and oxygen-containing compounds, and color bodies, but essentially free of olefins, is contacted with a solid absorbent such as a NaX zeolite or zeolite MgY. After adsorption the adsorbent is desorbed with an alkyl- substituted aromatic desorbent, such as tuluene. The initial effluent from the adsorb cycle, which will contain a high concentration of residual desorbent, is recycled to a desorbent recovery system. The level of desorbent in the adsorber effluent is monitored on a real time basis until the desorbent level of the adsorber effluent declines from a plateau level, i.e., a 100% plateau level, that correlates with the level of impurities, particularly the aromatic impurities in the feed, which is an indication of aromatics breakthrough, thereby signaling the need to switch the adsorbent beds.