Numerical Simulation Of Carbonylation Reactor For Syngas To Ethylene Glycol

The reactor for the production of dimethyl oxalate from carbon monoxide and methyl nitrite is one of the most important equipments in the glycol industry.The article is mainly about the numerical simulation and analysis of tubular and radial flow carbonylation reactor,The process optimization is carried out.The design law of radial flow reactor is studied.And a design of radial carbonylation reactor with annual output of 100kt dimethyl oxalate is given.COMSOL Multiphysics is used to simulate the tubular reactor.The effects of process conditions on the reaction are investigated.The results show that the increase of inlet temperature and cooling medium temperature helps to improve the conversion rate of methyl nitrite and the yield of dimethyl oxalate.But this increase has a negative impact on the hot spot temperature.A proper increase of space speed will increase bed pressure drop and reduce the conversion rate of the reactant.But it can increase the total output and is conducive to reduce the hot spot temperature.Reaction tube with smaller diameter has stronger temperature control ability and can maintain the reaction more safe and efficient.A cold model is simulated to study the cross flow and cross heat transfer.The simulation results are in conformity with experimental data.On this basis,a two-dimensional model of the radial quasi-isothermal reactor is simulated.The influence of the diameter and arrangement of the heat exchange tube on the bed temperature and pressure distribution is studied.The results show that there is a negative correlation between heat transfer capacity and the value of tube pitch/diameter in the tube layout area.The bed with higher inlet temperature and slower inlet speed has the thinner inlet insulation layer.The single-row heat exchange tube has limited ability to control the temperature of the gap position.And the double-row arrangement of heat exchange tube can make the bed temperature distribution more uniform.The hot spot temperature of the smaller heat exchange tube is lower,but when the tube center distance/tube diameter is small,the hot spot temperature has little difference.The radial position of hot spot moves backward when the temperature of cooling medium decreases The double-row heat exchange tube has certain tolerance to the temperature fluctuation at the inlet of the bed.A design scheme of 100kt per year radial carbonylation reactor is proposed.The bed has lower pressure drop and higher catalyst yield,it is possible to achieve large scale.