ADVANCED CONTROL OF A COMPLEX CHEMICAL PROCESS

Three phase catalytic hydrogenation reactors are important reactors with complex behavior due to the interaction among gas, solid and liquid phases with the kinetic, mass and heat transfer mechanisms. A nonlinear distributed parameter model was developed based on mass and energy conservation principles. It consists of balance equations for the gas and liquid phases, so that a system of partial differential equations is generated. Because detailed nonlinear mathematical models are not suitable for use in controller design, a simple linear mathematical model of the process, which describes its most important properties, was determined. Both developed mathematical models were validated using plant data. The control strategies proposed in this paper are a multivariable Smith Predictor PID controller and multivariable Smith Predictor structure in which the primary controllers are derived based on Internal Model Control. Set-point tracking and disturbance rejection tests are presented for both methods based on scenarios implemented in Matlab/SIMULINK.

[1]  Finn Andrew Tobiesen,et al.  Experimental validation of a rigorous desorber model for CO2 post-combustion capture , 2008 .

[2]  Min-Sen Chiu,et al.  Decoupling internal model control for multivariable systems with multiple time delays , 2002 .

[3]  Roxana Both,et al.  Dynamic modeling and validation of 2-ethyl-hexenal hydrogenation process , 2013, Comput. Chem. Eng..

[4]  J. Afonso,et al.  Hydrogenation of 2-ethyl-hexen-2-al on Ni/Al2O3 catalysts , 2004 .

[5]  Rubens Maciel Filho,et al.  Evaluation of control algorithms for three-phase hydrogenation catalytic reactor , 2008 .

[6]  L. Bolle,et al.  Comparison of hydrodynamic parameters for countercurrent and cocurrent flow through packed beds , 1997 .

[7]  Yu Zhang,et al.  Decoupling Smith Predictor Design for Multivariable Systems with Multiple Time Delays , 2000 .

[8]  E. Bristol.  On a new measure of interaction for multivariable process control , 1966 .

[9]  Don W. Green,et al.  Perry's Chemical Engineers' Handbook , 2007 .

[10]  B. Davis,et al.  Kinetics of the catalytic hydrogenation of 2‐Ethyl‐2‐Hexenal , 1983 .

[11]  Qing-Guo Wang,et al.  PID Control for Multivariable Processes , 2008 .

[12]  Xin Qi,et al.  A new control method for MIMO first order time delay non-square systems , 2011 .

[13]  Thomas J. McAvoy,et al.  Some results on dynamic interaction analysis of complex control systems , 1983 .

[14]  Christophe Boyer,et al.  Modelling of the hydrodynamics of the cocurrent gas–liquid trickle flow through a trickle-bed reactor , 1999 .

[15]  Timothy W. Simpson,et al.  Metamodels for Computer-based Engineering Design: Survey and recommendations , 2001, Engineering with Computers.

[16]  G. Smedler.  Kinetic analysis of the liquid phase hydrogenation of 2‐ethyl‐hexenal in the presence of supported Ni, Pd and Ni‐S catalysts , 1989 .

[17]  A. Burghardt,et al.  Hydrodynamics and mass transfer in a three-phase fixed-bed reactor with cocurrent gas—liquid downflow , 1995 .

[18]  Ana-Maria Cormos,et al.  Dynamic modeling and validation of absorber and desorber columns for post-combustion CO2 capture , 2011, Comput. Chem. Eng..

[19]  G. Smedler,et al.  Kinetics of Adsorption and Reaction for the consecutive Hydrogenation of 2- Ethylhexenal on a Ni/SiO2 Catalyst , 1987 .

[20]  Robin De Keyser,et al.  A simplified control method for multivariable stable nonsquare systems with multiple time delays , 2011, 2011 19th Mediterranean Conference on Control & Automation (MED).

[21]  Paul Serban Agachi,et al.  Optimal Process Control and Operation of an Industrial Heat Integrated Fluid Catalytic Cracking Plant Using Model Predictive Control , 2010 .

[22]  Ian Postlethwaite,et al.  Multivariable Feedback Control: Analysis and Design , 1996 .

[23]  H. M. Kvamsdal,et al.  Dynamic modeling and simulation of a CO2 absorber column for post-combustion CO2 capture , 2009 .

[24]  H. Yeung,et al.  Dynamic modelling and analysis of post-combustion CO2 chemical absorption process for coal-fired power plants , 2010 .

[25]  EXPERIMENTAL ANALYSIS AND EVALUATION OF THE MASS TRANSFER PROCESS IN A TRICKLE-BED REACTOR , 2003 .

[26]  W. Cai,et al.  A practical loop pairing criterion for multivariable processes , 2005 .

[27]  D. Luss.  Optimum volume ratios for residence time in stirred tank reactor sequences , 1965 .