modelling process considering both mass transfer and chemical reaction

1
MODELLING AND SIMULATION OF OPERATION FOR THE
TAME SYNTHESIS BY CATALYTIC DISTILLATION.
1Plesu V., 1Bumbac G., 1Ciornei I. C.,
2Ivanescu I., 3Popescu D. C. 1University
Politehnica of Bucharest, Centre for Technology
Transfer in the Process Industries, 1, Polizu
Street, Building A, Room A056, Sector 1,
RO-011061, Bucharest, Romania, Phone/fax
40-21-2125125, email cttip_at_chim.upb.ro
2National Oil Corporation PETROM S.A., 109
Calea Victoriei, RO-010069 Bucharest, P.O. BOX
22-109, Romania, Phone [phone],
Fax [phone], email i.ivanescu_at_petrom.ro
3National Oil Corporation PETROM S.A., INCERP
Ploiesti Subsidiary, 291A, Republicii Blvd.,
RO-100072 Ploiesti, Romania, Phone
40-244-198738, fax [phone],
popescu_at_serv.incerp.ro
In the case of TAME synthesis, the reaction takes
place on the surface and/or in the pores of the
catalyst grains (cationic exchange resin
Amberlyst). The reactive zone contained Sulzer
Katapak structured packing. The non-reactive zone
was Sulzer Mellapak structured packing.
Stefan-Maxwell theory equations used
The column feed characteristics, the main
reactions, kinetic and thermodynamic data,
process flowsheet and geometric characteristics
were given in 2. Physical and thermodynamic
properties and constants are rigorously computed
using HYSYS thermodynamic packages UNIQUAC for
the liquid phase and Peng-Robinson for the vapor
phase. These are imported on-line using Windows
COM architecture, using HYSYS as an ActiveX
server.
Generally, the commercial process simulators have
scarce means for the simulation of catalytic
distillation columns.
OBJECTIVES

• modelling process considering both mass transfer
  and chemical reaction
• kinetics mass transfer kinetics is represented
  with Stefan-Maxwell model.
• model implemented in MATLAB.
• properties are calculated in HYSYS and
  transferred on-line in MATLAB

Composition, temperature, pressure
MATLAB ActiveX client Mathematical libraries
HYSYS ActiveX server Thermodynamic packages

• Possible Benefits from Multifunctional Reactor
  Concepts in
• Reactive-Distillation systems
• - increase of productivity from process
  intensification
• - increase of selectivity of reactions and/or
  separations
• - reduction of by-products and waste materials
• - more efficient (in situ) use of energy and
  inherent safety
• improved environmental compatibility (e.g. by
  avoidance of hazardous
• solvents etc.)

Physical and thermodynamic properties
The mathematical model equations and variables
were grouped to form three band diagonal
Jacobian. Solution was obtained with advanced
numeric al procedures implemented in MATLAB.
CATALYTIC DISTILLATION COLUMN PHYSICAL
MODEL (CELLS SUPERSTRUCTURE) 1
Solving this highly non-linear system of
equations using conventional numerical methods
such as Newton-Raphson is a difficult task due to
the impossibility to generate a suitable initial
solution. In this work Newton homotopy
continuation was used to solve the mathematical
model of the non-equilibrium catalytic
distillation column.
Results
CELL MATHEMATICAL MODEL
Methanol profile
TAME profile
Temperature profile
2M1B profile
References
Reactions at S-L interface

• Higler, A., Taylor, R. and Krishna, R.,
  Nonequilibrium modelling of reactive
  distillation Multiple steady states in MTBE
  synthesis, Chem. Eng. Sci., 1999, 54, 1389-1395

• G. Bumbac, V. Plesu, V. Bologa, I. Muja, C.D.
  Popescu Catalytic distillation modelling and
  simulation using HYSYS.Process? environment -
  PRES 2002-15th International Congress of Chemical
  and Process Engineering, CHISA 2002, Prague, pg.
  267, P5.82,