Design And Analysis Of Internally Heat Integrated Reactive Distillation Processes

Process intensification is the long term goal of domestic and foreignchemical industry field, which is aimed at integrating different processes indesign to reduce utility consumption and capital investment, as well asachieving environmental and safety benefits. Internally heat integrateddistillation and reactive distillation are representative examples of suchdesign technology and have attracted people's attention in recent years. Anovel scheme combining both internally heat integrated distillation andreactive distillation, termed the internally heat integrated reactivedistillation column (HIRDC), is proposed in this thesis. The major purposeof this study is to explore the potential advantage of the HIRDC in thechemical and petrochemical process industries.The internally heat integrated reactive distillation column is dividedinto a high pressure section and a low pressure section and the ascendingvapor flow from the low pressure section is pressurized by a compressorand entered into the high pressure section. In order to achieve the heat integration between the high pressure section and the low pressure section,the temperature difference must be kept by the pressure difference betweenthe high pressure section and the low pressure section. With the rectifyingzone and the stripping zone situated in the high pressure section and in thelow pressure section respectively, three configurations of HIRDC aredesigned, depending on the reaction zone located in the high pressuresection (H HIRDC), in both the high and low pressure sections(M HIRDC), or in the low pressure section (L HIRDC). A systematicmethod is proposed for the synthesis and design of the HIRDC to minimizethe total annual cost (TAC).In terms of three hypothetical quaternary reactive distillation systemsof different construction the feasibility of the HIRDC is evaluatedsystematically with respect to reaction thermal effect (i.e., exothermic orendothermic reaction), relative volatilities between components, andchemical equilibrium constants. Simulation results obtained demonstratethat the internally heat integrated reactive distillation can provide positiveenergy savings and better economic figures than its conventionalcounterpart, if the reaction zone can be properly placed in the high pressuresection or in both high and low pressure sections. The most TACreduction from the implementation of internal heat integration can beobtained for the reactive distillation column with the reaction zone locatedat column top.