The Process Optimization Of Gasoline Hydrotreating Unit After The Upgrade Of China ?

PetroChina LanZhou Petrochemical Company's 1.8 Mt / a FCC Gasoline hydrodesulfurization unit has been retrofitted to produce motor gasoline components that meets the requirements of the entire factory for the national standard of grade V gasoline.In order to know whether the unit after upgrade meets the contract signed by PetroChina Lan Zhou Petrochemical Company with AXENS company in all kinds of technical parameters,product quality,energy consumption and production capacity,we accomplished the unit calibration.According to the calibration results,the unit circulating water single consumption was 3.12 t/t.It was 1.46t/t above the design value of 1.66t/t,which had a large optimized space.In addition,the light gasoline(LCN)extraction rate was 26.31%,which was 4.69% shorter than the design value of 31%.The difference between the 95% of the light gasoline(LCN)distillation range and the 5% of heavy gasoline(HCN)distillation range was 13.5 deg.C,and it was 30 deg.C lower than the design value.It's sure that LCN and HCN cutting effect is not the best which it can be optimized.Two stages of hydrogenation unit desulphurization rates were 84.06% and 92.91% respectively,their deolefination rates were 19.80% and 24.08% respectively.Obviously,there was a big difference.And two reactor inlet temperatures' difference was 13.38 deg.C.Two reactor outlet temperatures' difference was 11.62 deg.C.if we can make these differences become smaller,the reactor operation can be optimized.These optimizations are designed to reduce energy consumption and to reduce octane number loss.On the basis of the above analysis,through the adjustment of the process for six months,we finally cut the single consumption of circulating water to 2.18 t/t,raise the light gasoline(LCN)extraction rate to 30.06%,reduce two reactor inlet temperatures' difference and outlet temperatures' difference to respectively 4.20 deg.C and 1.19 deg.C.Two stages of hydrogenation unit desulfurization rate are 89.09% and 89.98% respectively,and their deolefination rate are 21.30% and 22.65% respectively.Through this a series of adjustment,the octane number loss of mixing gasoline products has been gradually reduced from 2.7 units to 1.7 units.Finally we are able to produce the high octane number gasoline products and create benefits for the company.