Design And Optimization Of Etnanol Separate Heat Pump Distillation System

Ethanol is an important chemical raw material widely used in the defense industry,medical and health,organic synthesis,food industry,industrial and agricultural production and other fields.With the continuous promotion of energy substitution strategies,the demand for ethanol has increased year by year.Distillation is an essential part of the ethanol production process,which has the problems of large energy consumption,low thermal efficiency,and high operating costs.Heat pump distillation is an efficient and energy-saving technology.But due to the azeotropic properties of ethanol-water solution system,MVR heat pump distilltion technology for ethanol-water lacks theoretical guidance and practical application.In this paper,based on the characteristics of ethanol-water solution,two process steps of ethanol separate MVR heat pump distilation system are developed.Through simulation optimization,thermodynamic analysis and process flow design of the system with the processing capacity of 100 kg/h,it aims to provide guidance for the practical production application of ethanol separate MVR heat pump distillation technology.Based on the phase balance diagram of the ethanol-water solution system,direct compression type and external working type of ethanol separate MVR heat pump distillation systems are developed,and the energy consumption characteristics of the system are analyzed through the temperature-enthalpy(T-H)diagram.In order to study the operating characteristics of the ethanol separate MVR heat pump rectification system,the system simulation process is established using Aspen Plus software,and the sensitivity analysis of the system is carried out using the sequential quadratic programming algorithm.The relationship between the main parameters such as system reflux ratio,feed position and the energy-saving characteristics of the system was studied.It is found that the optimal reflux ratio is 4.5-4.8,and the optimal feed plate position is the 15 th tray.The thermodynamic model of the ethanol separate MVR heat pump rectification system is established.The direct compression type and the external working type of ethanol separate MVR heat pump distillation system are evaluated and analyzed in terms of thermodynamic performance,energy consumption and operating economy.The results show that the direct compression ethanol separate MVR heat pump distillation system can save energy consumption by 64.36%,save operating costs by 75.77%,and has better performance than the external working type.Combined with the above optimization and analysis results,the design calculation of the ethanol separate MVR heat pump distillation system with the processing capacity of 100 kg/h is carried out.It is verified that the ethanol separate MVR heat pump distillation system developed in this paper can save energy consumption by more than 60% and operating cost by more than 70%,and is suitable for energy-saving transformation in ethanol distillation production process.