caa a22 4500 378927949 CHVBK 20180305123622.0 cr unu---uuuuu 161128e20040623xx s 000 0 eng 10.2202/1542-6580.1152 doi (NATIONALLICENCE)gruyter-10.2202/1542-6580.1152 Modeling, Simulation and Optimal Control of Ethylene Polymerization in Non-Isothermal, High-Pressure Tubular Reactors [Elektronische Daten] [Fred Z Yao, Ali Lohi, Simant R. Upreti, Ramdhane Dhib] Low-density polyethylene (LDPE) is a very important polymer, which is usually produced through a free radical polymerization process in high-pressure tubular reactors. In this study, the mathematical model of this process is developed on the basis of a comprehensive reaction mechanism to accurately determine polymerization rate, and polymer properties under extreme temperature conditions. The model comprises of (i) the mass balances of monomer, initiator, solvent, live radicals and dead polymer chains, and (ii) the energy balances of a tubular LDPE reactor, and its jacket under steady state condition. The model considers the variations in the density and viscosity of reactants along reactor length. Computer simulation of the model is successfully carried out to accurately describe the performance of a non-isothermal, high-pressure, industrial LDPE reactor with multiple initiator injections. Based on the developed non-linear model, the optimal control of the industrial reactor is carried out using genetic algorithms to maximize monomer conversion using jacket temperature as a control function of reactor length. The application of optimal control leads to significant improvements in the final monomer conversion, and capacity utilization of the reactor. ©2011 Walter de Gruyter GmbH & Co. KG, Berlin/Boston process systems engineering nationallicence kinetics nationallicence polyethylene nationallicence tubular reactor nationallicence optimal control nationallicence genetic algorithms nationallicence Yao Fred Z. Ryerson University, zyao@ryerson.ca aut Lohi Ali Ryerson University, alohi@ryerson.ca aut Upreti Simant R. Ryerson University, supreti@ryerson.ca aut Dhib Ramdhane Ryerson University, rdhib@ryerson.ca aut International Journal of Chemical Reactor Engineering De Gruyter 2/1(2004-06-23) 2:1 2004 2 ijcre https://doi.org/10.2202/1542-6580.1152 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.2202/1542-6580.1152 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yao Fred Z. Ryerson University, zyao@ryerson.ca aut NATIONALLICENCE 700 1- Lohi Ali Ryerson University, alohi@ryerson.ca aut NATIONALLICENCE 700 1- Upreti Simant R. Ryerson University, supreti@ryerson.ca aut NATIONALLICENCE 700 1- Dhib Ramdhane Ryerson University, rdhib@ryerson.ca aut NATIONALLICENCE 773 0- International Journal of Chemical Reactor Engineering De Gruyter 2/1(2004-06-23) 2:1 2004 2 ijcre CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter