IMPROVED PROCESS CONTROL OF PROCESS FOR PURIFICATION OF LINEAR PARAFFINS

摘要

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 adsorbent such as an NaX zeolite or zeolite MgY. After adsorption the adsorbent is desorbed with an alkyl-substituted aromatic desorbent, such as toluene. 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.