车用LPG有害杂质的鉴别与脱除

采用12种普通液化石油气进行行车试验，发现汽车的燃气器具内积聚粉末或碎屑，严重时造成蒸发器或电磁阀堵塞；蒸发器腔体内生成粘稠状液体；含水LPG冬季结冰可造成供气系统堵塞。检验证明：粉末的主要成分是单质硫；碎屑是金属腐蚀的硫化物；粘稠状液体是多硫化物或丁二烯低聚体或重质烃类；上述生成物与LPG中的丙烯、丁烯的存在及其含量无关。严格控制普通LPG来料中的丁二烯含量(摩尔分数不超过0．5％)和重烃含量(每100ml气样LPG的蒸发残留物不超过0．05ml)，且采用常温、液相吸附工艺对普通LPG进行精制，即可获得满足用户要求的车用LPG。在5000辆LPG汽车上应用获得成功。

Identification and Removal of Harmful Impurities in LPG for Vehicle

About twelve kinds of general LPG are used for driving test. It is found that uncertain quantities of powders or pieces deposited in vehicle fuel apparatus, in case of severity, plugging of evaporator or electric valve occurred, sometimes sticky liquids were formed in evaporator, and LPG with water freezing can also result in plugging of gas feeding system. The identification shows that the main composition of powder is element sulfur, the pieces are sulfide formed by metal corrosion, and the sticky liquids are polysulfide, low-molecular polymer of butadiene or heavy hydrocarbons. The identification also shows that the compounds mentioned are independent of propene and butane in LPG. LPG for vehicle that meets user requirements can be obtained by strictly controlling butadiene content (mole fraction not exceeding 0.5%) and heavy hydrocarbons content (evaporated residue of LPG not exceeding 0.05ml per 100ml of sample) in general LPG, and using atmospheric liquid-phase adsorption process to refine general LPG. About 5000 vehicles have successfully used the refined LPG.