Study On Process Simulation And Energy Analysis Of A Catalytic Cracking Unit

With the increasing tension of energy situation in China,petrochemical industry,as the pillar industry of the national economy,is a major energy consumer.Catalytic cracking is an important secondary processing process,and its energy consumption accounts for about onethird of the energy consumption of the industry,but there is still a gap between the energy utilization efficiency and the advanced level.Therefore,energy saving and consumption reduction of catalytic cracking units play a vital role in improving the economic efficiency of the oil refining industry and have great significance for the oil industry.It is also an effective mean to alleviate the energy shortage in China.This paper will take this as the theme to carry out research.The research object of this paper is the catalytic cracking unit of a refinery.Firstly,Aspen Plus process simulation software was used to simulate the fractionation system and absorptionstabilization system of the unit,and the accuracy of the simulation results was analyzed.Secondly,the process accounting of the reaction regeneration system is carried out,including material balance,heat balance and other necessary process accounting.In addition,the accounting also includes pumps,heat exchangers and air-cooling equipment of the whole device.Based on the results of calculation and simulation,the energy balance and exergy balance are obtained by using the three-link energy structure model,and the scientific energy consumption of the device is analyzed to realize the tapping of the energy-saving potential of the device.The results show that the conversion efficiency of energy conversion link is higher,and the proportion of smoke exhaust loss and heat dissipation loss is higher.The energy-saving potential of this part lies mainly in reducing smoke exhaust loss and heat dissipation loss.The total energy consumption level of energy technology utilization link is relatively high.The energy-saving work in this part can start with reducing equipment and process damage.The recovery efficiency of energy recovery part is high,but there is energy saving potential in low temperature heat recovery and temperature matching of heat exchanger.According to the analysis results of energy consumption in catalytic cracking unit,some feasible measures for energy saving and consumption reduction are put forward in this paper.NS-1 high efficiency nozzle,catalyst magnetic separation technology,dry gas atomization technology and power consumption optimization of pump set to reduce total energy consumption.The loss of the fractionation tower was analyzed in the energy utilization section,and the proportion of the reflux of the main fractionation tower was adjusted by Aspen Plus software.The energy-saving measures of low-temperature heat recovery system(heat exchange water system)and slurry circulation system reform are put forward in the energy recovery link.The energy-saving measures to reduce the smoke exhaust temperature are put forward in the energy conversion and transmission links,and the smoke exhaust temperature is analyzed by A.G.Okkes equation.