The Study On Distilling Apparatus Of Cyclohexane, Cyclohexanol And Cyclohexanone In Enery-saving Revamping

Cyclohexanol and cyclohexanone are very important law materials in chemical industry,which are widely applied to the production and processing of fibre, synthetic rubber,industrial paint, medication as well as pesticide. Aboult 1 Mt cyclohexanones are producedper annum all over the world, mainly used in producing adipic acid, which can be furtherlyused to manufacture nylon 6 and nylon 66.At present, most of production of the cyclohexanol and cyclohexanone adopts thecyclohexane oxidation technology. The oxide mixture of cyclohexane in the practical process,including the cyclohexane, cyclohexanol and cyclohexanone as the main components, isdehydrated by dehydrating tower and then purified to some extent to reduce its impurity ofcyclohexane, cyclohexanol and cyclohexanone by distilling apparatus of cyclohexane,cyclohexanol and cyclohexanone (hereafter refers to as the alcohol ketone distillingapparatus). Thereafter cyclohexane is as raw material again to prepare cyclohexanol andcyclohexanone, while the recovered cyclohexanol and cyclohexanone are further treated byother following processes as the raw material for the next reaction. Therefore the alcoholketone distilling apparatu is a very important unit not only for it is used to treat with materialin producing adipic acid but aslo to separate product.The energy consumption of distillation is comparative high. Liaoyang Petrochemical NylonCompary introduces a new double-effect distillation system in order to reduce the energy cost.However, a series of problems such as tray jam-up, heat exchanger coking after running thedouble-effect device occur which greatly affect the normal production and obviously deviatethe original intention of the plant. Therefore it is necessary to do this research, to discover thereason of coking, restore the stable production, and simultaneously reduce the energyconsumption.In the present work, a detailed simulation about both design status and actual productionhave been carried out by using ASPEN PLUS software. Based on these results, a series ofrevamping projects are proposed for resolving these problems. By checking the load of mainequipment (rectification tower and heat exchanger), an optimization project is selected whichcan not only successly solve the existent problems, but also reduce the energy cost from 13.6t/h to 10.8 t/h, and brings many benefits to the company.Those factors affecting the energy consumption of double effect distillation process such asreflux ratio, operating pressure, material distribution, purity of anterior tower detached andothers are studied based on the simulation and analyzing of actual data. Besides of solvingabove actual problems based on our results, the principle of saving enery is set forth and thealcohol ketone distilling apparatus process is redesigned.