Published February 2010
Benzine content reducing possibilities studies in gasoline reforming
A.J.HuseynovaTo improve the automobile gasolines environmental performance the possibilities of reducing the benzine content in the base components of commercial gasoline and in gasoline reforming which is the main supplier of highly toxic aromatic hydrocarbons including benzine (up to 5 - 8 % by wt.) have been studied. According to analysis of operating conditions and flow rates in the reforming process in Oil Refinery named after Heydar Aliyev, it can be shown that at temperatures 500 – 508 oC the benzine content is 5,1 - 6,1 % and the motor octane number of gasoline reforming (MON) is 84,0 - 85,6. For decreasing the content of aromatic hydrocarbons, process reforming must operate at lowering temperatures that will lead to decrease the octane number of gasoline. In these connections among the various technologies, they are allowing by chemical and physical methods to lower the content of benzine to level 0,5 - 1,0 % by wt. One of such methods is the selection of straight-run gasoline I.B.P. - 90 oC, containing background of benzine, and further hydroisomerization this fraction on industrial catalysts of hydroprocessing at t = 200 - 400 oC and p = 2–3 MPa and thus the octane number of hydroisomerization process will increase with 10 numbers. For the further decrease of gasoline reforming benzine content benzine fraction with I.B.P- 83oC is selected, which is exposed to alkylation process of light olefins on zeolite catalysts with high acidity at t = 200 – 400 oC and p = 3,5 MPa, and thus the benzine content is reduced to 50 - 70 % after alkylation process. The high octane number products non-aromatic components-alkylate and hydroisomerizate products are added into the commercial gasoline composition. On the basis of suggested studies that give us the approximate composition of commercial gasoline including gasoline catalytic cracking-50 %, hydroisomerizate light straight-run gasoline -8,0 %, alkylate from alkylation process of gasoline reforming benzine fraction -7,0 %, and also heavy fraction of gasoline reforming 83 оС–F.B.P -35 %. In this case the octane number of produced gasoline from this mixture is 83 MON and the benzine content volume decreases to 0,5 %.
