Process Design Of Mto Circulating Fluidized Bed For Producing 300000 Tons Of Olefins Per Year

Low carbon olefin is not only an important basic raw material of basic organic chemical industry,but also the cornerstone of modern chemical industry.At present,low carbon olefin mainly comes from petroleum-based raw material route,but for our fossil energy structure of"relatively more coal,less oil and poor gas",using coal-based methanol as raw material to produce low carbon olefin has extremely important strategic significance,which can not only alleviate the problem of our demand for olefin,but also reduce the continuous consumption of petroleum resources.In this paper,based on the research results of coal-based methanol to olefin for many years,the design of 300,000 tons of olefin per year methanol to olefin circulating fluidized bed process was carried out.Based on the research data of methanol to olefin in the laboratory,a complete process of methanol to olefin was established.The process mainly consists of three parts:methanol pretreatment,olefin reaction and product separation.Based on the experimental data of methanol to olefin kinetics in the research group,a six component lumped kinetic model of methanol to olefin was constructed using virtual aggregation method,laying the kinetic foundation for the work of this paper.A mathematical model of a circulating turbulent fluidized bed reactor for methanol to olefin process was established by combining the lumped kinetic model and the two-phase reactor model.On the basis of MATLAB software,the mathematical model of the reactor was numerically solved and optimized by using the fourth-order Runge-Kutta method,and the diameter of the circulating fluidized bed reactor was 8.2 m and the height was 10 m.The regenerator bed is 4 m in diameter and 10 m in height.The total mass yield of olefin in the designed reactor is 44%and the annual yield of olefin is 327,000 tons,which meets the process design objectives.Aspen Plus simulation software was used to simulate the key separation equipment,and the process design and calculation of C₂separation column,C₁separation column,ethylene rectifying column,C₃separation column,propylene rectifying column and C₄separation column were completed.The process design of the horizontal three-phase separator was completed by the half-full method.The diameter of the separator cylinder,the separation length and the length-diameter ratio of the separator were determined to be 0.7 m,2.34 m and 3.3,respectively.