Measures Of Saving Energies To Inrease Benefits In ARGG Unit

Now the energy consumption of fluid catalytic cracking (FCC) units in China is above 30% of that of the whole petroleum refining industry. Therefore, it is important to reduce the energy consumption of FCC units by taking efficient measures.As for the 1.0Mt/a ARGG unit of Daqing Refining and Chemical Company, which adopts the dual-riser called FDFCC technology,this thesis analyzed the main reasons for the high energy consumptions according to the industrial operating data. There were six main reasons: high stripping steam consumption, low utilization ratio of waste heat, low recovery power, bad atomization efficiency ,high coke yield,restrictions to long period running.This thesis also discussed the effect of gasoline riser on the total energy consumption. As the reaction temperature of gasoline riser increased, the energy consumption increased. The energy consumption would increase by 55.55 MJ/t, if the reaction temperature of gasoline riser increased by 10 oC.In order to reduce the high energy consumptions , a series of technical modifications were made by hard work, these methods are the innovations of gas turbine, stripping steam section, feeding nozzles, waste heat boiler, gasoline refining, and low temperature heat utilization combined with the 0.35Mt/a gas fractionation unit and 3.5Mt/a atmospheric and vacuum unit, and a lot of changes to the unreasonable uses of technologies and processes.The energy consumption of the ARGG unit reduced from 4396.55MJ/t to 3134.17MJ/t, decreased by 1262.38MJ/t.After taking more propylene production project, the handling capacity of the ARGG unit increased from 130 t/h to 135 t/h, the energy consumption decreased by 263.72MJ/t, the yields of liquid products, liquefied petroleum gas and propylene increased by 4.7%, 2.95% and 1.75%, respectively, the yield of coke decreased by 0.2%, and the annual economic returns increased by 100 million RMB or more.