| This paper introduces the technology of catalytic cracking at home and abroad, the quality of the gasoline and its development; It analyses the characters of the ARGG unit and the quality of the gasoline; It points out the main problem on the quality of the gasoline is over olefin content. After we have known the productive technology of the clean gasoline at home and abroad, we defined the technical scheme and technological route of how to reduce the olefin content in the gasoline in the ARGG unit, according to the reality of the gasoline. After we carried out a lot of research (looking up some documents, making some technology investigation and research, designing the schemes, doing some middle-sized experiments, doing some industrial experiments, etc.) and the commercial application in the unit, we reduced the ARGG gasoline's olefin content to below 35v%. So the quality of the gasoline can meet the new national standard (GB17930-1999).At present, there are four ways of reducing the olefin content in the gasoline. Firstly, we add some co-catalysts or some new catalyst in order to reduce the olefin content in the gasoline in the present unit directly; Secondly we adopt some excellent technologies that can reduce the olefin content (such as MOD, MIP, FDFCC and so on ) to revamp the present unit properly; Thirdly, we can reduce the olefin content by adding some straight run gasoline to the catalytic gasoline; Fourthly, we can blend the catalytic gasoline with the high octane value gasoline containing low olefin, which can be produced by the etherification of the light gasoline, hydrogenation, iso-merization, reformation of the FCC gasoline and MTBE, etc. After researching the four ways carefully, and considered some elements such as the technology, investment,cost, the structure of the unit, the characters of the quality of the gasoline, we defined two ways to carry out the research work of how to reduce the olefin content in the gasoline produced by the ARGG unit. One way is use of some co-catalyst and catalyst, the other is to revamp the present unit by carrying out MGD process.Having done some middle-sized experiment on the LAP co-catalyst and some commercial test in the ARGG unit, we find that LAP co-catalyst have some functions of selective cracking, hydro-transfering and aromatization. added some LAP co-catalyst at a 5% additive share in total catalyst inventory, the olefin content in the gasoline can be reduced by 5 percentage points. But the LAP co-catalyst itself is unstable and deactivate easily, the cetane number of the diesei oil is reduced. So LAP isn't suitable for the industrial unit.The research on the activity of the catalyst proves that improving the active of the catalyst is beneficial to reducing the olefin content in the gasoline, the result of the MGD industrial experiment is: the activity of the catalyst in the system is raised from 64.6 to 71.1, the olefin content in the gasoline can be reduced from 41.2% to 37.6%. compared Rag-8 catalyst with Rag-6, we find Rag-8 is better than Rag-6 at reducing the olefin content. When the reaction temperature is 515℃ and the rag-8 is 25% in the system , the olefin content in the gasoline can be reduced from 39.2% to 38.7%.We inspected effect on olefin content of the varies of the main technological parameters (the reaction temperature, catalyst to oil ratio, the weight space velocity, the proportion recycle of the naphtha, etc.) in the middle-sized unit and ARGG industrial unit. It shows that: When the reaction temperature is reduced, the olefin content is reduced too. In the research of the industrial experiment, the olefin content in the gasoline can be reduced from 42.9%to 39.8% when the reaction temperature isreduced from 520℃ to 510℃.Improving the catalyst to oil ratio is beneficial to reducing the oiefin content in the gasoline. In the research of the industrial experiment, the oiefin content in the gasoline can be reduced form 42.6%to 37.1% when the catalyst to oil ratio is risen from 8.57 to 9.46.Improving the weigh...
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