Pretreating methods for feed of catalytic light gasoline etherification

FCC light gasoline etherification process is a clean production process to improve quality of motor gasoline. The harmfulness of metal cations, nitrogen compounds in the gasoline feed to etherification catalyst was introduced. The methods for removing these harmful impurities including extraction, adsorption, pre-hydrogenation were discussed. For extraction, deaerated water or desalted water is currently the most widely used extraction agent, and packing tower or sieve plate tower is the most commonly used washing equipment. When water wash device adopts new micro-extraction highly efficient separation equipment, the washing water consumption could be greatly reduced. For adsorption, cation exchange resin as adsorbent has been applied in domestic industry. When used as adsorbent, light catalytic gasoline feed should not enter the purifier separately, but should enter the purifier mixed with methanol according to certain methanol to olefins ratio. Otherwise the adsorbent will be deactivated by the temperature rise caused by olefin polymerization. The pre-hydrogenation method can only change the non-basic nitrogen compounds into the basic nitrogen compounds, which should be combined with other methods to remove the harmful materials. It has very important significance for further developing environmentally friendly extraction agent, adsorbent or hydrogenation catalyst with high adaptability to reduce the equipment and operating costs.