Adaptive Control of a Non isothermal Fixed Bed Reactor

Abstract

Fixed bed reactors are extensively used in chemical and process industries. Tight newlinetemperature control can play a crucial role in determining the performance of such newlinedevices and has therefore been a subject of many investigations over the past few newlinedecades. These studies addressed fluid-packed particle heat transfer, the transient newlineresponse of fixed bed reactor, and various useful parameters under the unsteady state newlineincluding effective axial and radial thermal conductivities, wall to fluid heat transfer newlinecoefficient and overall heat transfer coefficient. newlineProcess control systems inevitably include adjustable controller settings that newlinefacilitate process operation over a wide range of conditions. Typically, controller newlinesettings are tuned after the control system has been installed using time-consuming, newlinetrial-and-error procedures. If process conditions change significantly, then the newlinecontroller must be retuned to obtain satisfactory control. Recently, there has been broad newlineinterest in adaptive control systems that automatically adjust the controller settings to newlinecompensate for unanticipated changes in the process or the environment. Adaptive newlinecontrol schemes provide systematic, flexible approaches for dealing with uncertainties, newlinenonlinearities, and time-varying process parameters. newlineA semi-analytical approximate solution has been obtained for a fixed bed reactor newlinemodel having strong nonlinearity. A hydrolysis endothermic reaction of ethyl acetate in newlinepresence of porous catalyst, Amberlyst-15, has been considered for the study. Classical newlineAdomian Decomposition Method (ADM) is not found to be very successful to acquire newlinean approximate solution for longer period of time. Therefore, a Multistage Adomian newlineDecomposition Method (MADM) has been applied for solving the nonlinear distributed newlineparameter model of the fixed bed reactor and the reliable solution has been obtained. newlineTo demonstrate the reliability, a comparison between MADM and Method of Lines newline(MOL) has been shown. Further, it has been demonstrated that accuracy of the solution newlinecan be