Study On The Transalkylation Process Of Heavy Aromatics In Cumene Device

Phenol is an important organic chemical raw materials.The main production process is the cumene method,which based on benzene and propylene as raw materials by the alkylation process.The preparation of phenol by cumene produces many heavy aromatics.Heavy aromatics were used as a fuel in traditional process,resulting in waste of resources.In this article,the gas-solid heterogeneous catalytic transalkylation reaction was occurred in the fixed bed reactor,which using heavy aromatics as raw materials,and FTH-2 as catalyst.Cumene which produced in the transalkylation reaction were used as a raw material of the process of phenol by cumene.The reaction conditions,thermodynamic analysis,the intrinsic kinetics of the process,simulating the process of heavy aromatics transalkylation,the design and selection of the main equipment are the main research contents in this article.By means of single factor experiment,the effects of three factors of the B/DIPB molar ratio(6:1 to 16:1),reaction temperature(185 to 255?)and space velocity(1 to 9 h-1)on the conversion of DIPB and on the selectivity of IPB were studied.The appropriate conditions were determined by the experimental results and analysis as follows:B/DIPB molar ratio of 10,reaction temperature of 215? and reaction space velocity of 5 h-1.The conversion rate of DIPB and the selectivity of IPB were respectively about 96%and about 98%.By means of single factor experiment,the effects of three factors of the B/TIPB molar ratio(12:1 to 20:1),reaction temperature(240 to 360?)and space velocity(1 to 9 h-1)on the conversion of TIPB and on the selectivity of IPB and DIPB were studied.The appropriate conditions were determined by the experimental results and analysis as follows:B/TIPB molar ratio of 18,reaction temperature of 280? and reaction space velocity of 5 h-1.The conversion rate of TIPB was about 75%,the selectivity of IPB and DIPB were respectively about 64%and about 31%.The main contents of thermodynamic study of B and heavy aromatics mixture of the transalkylation reaction include calculating the correlation equilibrium parameters of series reaction by Benson group contribution method,and building the network structure of the reactions.The intrinsic kinetic analysis was carried out on the transalkylation reaction of B and heavy aromatics mixture by intrinsic kinetics research method.Excluded internal and external effects and combined with the variable airspeed experiment to determine the main reaction for the reaction(1).The kinetic experiments were carried out under the conditions of B/TIPB(mol)of 12-22,temperature of 200-310?,space velocity of 5 h-1.The kinetic model is established and the parameters are estimated.The parameters of the kinetic model are optimized and tested by MATLAB programming.The intrinsic kinetic equation of the transalkylation reaction of B with heavy aromatics is determined as follow:(?)The process of heavy aromatics transalkylation unit was simulated by Aspen plus,the equipment,such as the reactor,heat exchanger,mixer and pump,were designed and selected by the material balance and heat balance.Among them,EDR was also used for detailed accounting in the heat exchanger design.Finally,the PID chart and PFD chart of the heavy aromatics transalkylation unit were drew.