Polyols are typically produced using batch processes and KOH as the dominant homogeneous catalyst. In this case, the main reaction is an ionic polymerization reaction, and products with narrow molecular weight distributions (MWDs) are typically obtained. As observed in living polymerization systems, polyols of varying molecular weights serve as starting points for manufacture of polyols of high...

In the paper the optimization of the control loops of the variable frequency induction motor drive for the feed screw of a flame reactor has been carried out to obtain required dynamic characteristics of the electric drive for known parameters of the plant. Simulation studies of basic control loops (current, flux-linkage and speed) are performed and dynamic parameters of control quality are pre...

In this contribution we apply the approach of passivity proposed by Ydstie [M. Ruszkowski, V. Garcia-Osorio, and B.E. Ydstie. AIChE Journal, 2005] for physico-chemical processes. The originality of this work lies in the fact we consider a thermodynamically nonlinear consistent model for a continuous stirred tank reactor to built the appropriate Lyapunov function for stabilization purpose. Indee...

Temperature control of processes that involve the heating and cooling of a closed batch reactor can be a real problem for conventional proportional-integral-derivative (PID) based loop controllers. This paper describes the application of a new industrial advanced process controller. This controller is designed to handle integrating type processes with long dead times and long time constants. Th...

A multivariable nonlinear control strategy which accounts for unmeasured state variables and input constraints is developed for the free-radical polymerization of methyl methacrylate in a continuous stirred tank reactor. Monomer concentration and reactor temperature are controlled using a technique which combines nonlinear input–output decoupling and linear model predictive control. Input const...

A CSTR is an Continuously Stirred Tank Reactor with the main function of agitation and to achieve constant composition. It has an important role in chemical process plants. A CSTR has an higher degree of nonlinearity when compared with other chemical reactors, this is mainly due to the temperature variations that occur because of uncertainity in feed. Hence, temperature control is a strenuous t...

Two types of airlift fermenters, conventional (UT-ALF) and modified (CDT-ALF) were investigated to evaluate their performance with respect to baker’s yeast growth. The riser tube of conventional external loop airlift fermenter is replaced by a converging-diverging tube. The new reactor is called modified airlift reactor. The results were compared for the two types of airlift fermenter (UT-ALF a...

A nonlinear controller synthesis scheme is presented that retains the original spirit and characteristics of conventional (linear) model predictive control (MPC) while extending its capabilities to nonlinear systems. The scheme employs a Volterra model-a simple and convenient nonlinear extension of the linear convolution model employed by conventional MPC-and gives rise to a controller composed...