催化轻汽油醚化原料预处理的方法

Pretreating methods for feed of catalytic light gasoline etherification

关键词:  催化轻汽油醚化工艺  金属阳离子  氮化物  萃取  吸附  预加氢 

Key words:  FCC light gasoline etherification process  metal cation  nitrides  extraction  adsorption  pre-hydrogenation

摘要:

催化轻汽油醚化工艺是提高车用汽油质量的清洁汽油生产工艺。介绍了催化轻汽油原料中金属阳离子和氮化物对醚化催化剂的危害,探讨了包括萃取法、吸附法、预加氢法在内的对金属阳离子和氮化物的脱除方法。对于萃取法,脱氧水或除盐水是目前最广泛采用的萃取剂,而填料塔或筛板塔是最常用的水洗设备,当采用新型微萃取深度分离设备时,可大幅度降低水洗水用量；对于吸附法,阳离子交换树脂做为吸附剂在国内已有工业化应用,当用作吸附剂时,催化轻汽油不应单独而应与甲醇按一定的醇烯比混合后再进入净化器,否则因烯烃聚合引起的温升将导致吸附剂失活；预加氢方法只能将非碱性氮化物转化为碱性氮化物,需要与其他方法配合使用才能脱除醚化原料中的有害杂质。进一步开发适用性强、环境友好的萃取剂、吸附剂或预加氢催化剂,对进一步降低设备和操作费用具有重要意义。 

Abstract:

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.