Study On Chemical Process Energy Integration Based On Aspen Tech And Stochastic Methods

Energy integration is one of the whole process system synthesis problems which targets appropriate energy utilization; it maximizes the heat exchanges between streams and minimizes the hot and cold utilities required in the processes. Energy integration deals with the supply and demand relations, by adjusting process structure, operation parameters.Pinch Analysis technology for energy integration has seen widespread applications throughout the process industries, however it targets the energy cost minimization rather than total cost function minimization (including investment cost and utility cost). In this case , this paper presents a study on energy integration of chemical process, which is based onincorporated applications of Stochastic Methods--Genetic Algorithm (GA) and PatternSearch (PS), and the widely applied commercial industrial software- AspenPlus.Firstly, stream data can be generated automatically via the interface between AspenPlus and AspenPinch, and Heating and cooling curves can be drawn by AspenPinch, via which ways of debottlenecking for energy integration can be better guided.Secondly, Gain mathematical fitting equations of main distillation column parameters (such as the operation pressure, reflux ration, temperature at the top of the column, etc.) using sensitivity analysis of ApenPlus. Then Appropriate Cost Function of chemical process can be easily embedded in GA or PS which helps target the cost function minimization in chemical process. An example of petrochemical plant energy integration is presented, which showed the validity of this method.Besides, this paper offers two strategies for realizing energy integration of chemical processes which, are both based on the Consistancy Unit Energy Consumption: Raising column operation pressure so that consequently raises the temperature of condensers and reboilers; Using the condenser as a mid-reboiler for another column.