| Fuel ethanol gasoline is very important energy source as a renewable energy add to gasoline. It can use directly without any changes on the original gasoline engine. It also very useful and has development prospects. In this paper, the process of fuel ethanol production distillation was designed. Determine the processing plan of three differential pressure of the three column named crude tower (C31101), the first distillation column (C31102), the second distillation column (C31103). At the beginning of this paper, the process plan and production requirements of distilltion is obtained, by the Aspen Plus simulation,the operating parameters can obtained. Then translate the steady state simulation to Aspen Dynamic simulation, the control plan was designed. Finally, the energy conservation scheme the process scheme of three differential pressure was designed, the main conclusions are as follows:The main material fuel ethanol distillation section are ethanol (EtOH) and water (H2O), through the literature, EtOH-H2O vapor liquid equilibrium data was got. There are three thermodynamic methods named NRTL,Wilson and UNIQUAC. Then the experimental data were used to regress the binary interaction parameters by Data Regression model in Aspen Plus. By comparing the deviation of experimental data and calculated data of the three thermodynamic methods, NRTL model was proved to be more suitable for this system.Ethanol and water can form azeotrope, and when closer to the azeotropic point,the reflux ratio is huge, the greater the energy consumption is higher. Connect the energy of the molecular sieve and C31103, though calculateion, when C31103 top produced mass fraction of EtOH is 90%-92%,the energy consumption is minimum. Though calculation,100000 tons/year fuel ethanol production, the top distillation of C31101 is 14644 kg/h, lateral distillation is 62240 kg/h.The sensitivity analysis function is used to determine the C31101 operating condition:feed position is the 5th plate, lateral position is the 14th plate, no reflux, on the basis of this, puts forward the ratio control scheme of distillation rate and side distillation rate of C31101 column, determine the sensitive plate is the 15th plate, analysis the dynamic response of the feed rate and feed composition disturbances, the results show that the scheme can control the operating stability and ensure feed quality and fraction of C31102 and C31103 stability.For the simulating of C31102 and C31103 tcolumn, the operating conditions were determined firstly:C31102 feeding position is the 43th plate, the t distillate quantity is 4550 kg/h, reflux ratio is 2.2. C31103 feeding position is the 58th plate, the distillate quantity is 10321 kg/h, reflux ratio of C31103 IS1.57, on the basis of this, reflux rate control and reflux ratio control are put forward, determine the sensitive plate of both column are the 64th plate, analysis the dynamic response of the feed rate and feed composition disturbances, the results show that the reflux ratio control scheme can ensure stable operation better, it can ensure the product quality. But the energy consumption may be higher.Higher energy consumption in distillation devote to three different pressure of three columns process, though analysis, feed heating can save operating costs by 29.3%, on the basis it and using differential pressure distillation, it can save 54.8% operation cost. Though campare with the original process, it can save energy comsumption of 36.52%.Though process design and process control scheme, energy saving technology and stable production process. is obtained. |
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