INVESTIGADORES
DIAZ Maria Soledad
artículos
Título:
Reactive distillation processes used as unique operation or finishing stage: A comparison
Autor/es:
JUAN P. ARCHENTI; MARIA SOLEDAD DIAZ; PATRICIA HOCH
Revista:
COMPUTER AIDED CHEMICAL ENGINEERING
Editorial:
ELSEVIER B. V.
Referencias:
Lugar: Oxford; Año: 2012 vol. 30 p. 732 - 736
ISSN:
1570-7946
Resumen:
Reactive distillation has been receiving growing attention as an example of process intensification. It combines the advantages of reaction and separation, obtaining a process which is both cost effective and energy efficient, without some of the drawbacks of reaction and distillation alone. MTBE is a fuel additive, produced commercially by conventional and non-conventional processes. The distinction between both kinds of processes resides on the fact of including or not reactive distillation as a unit operation. The Phillips and the Hüls processes are the most relevant among the conventional processes (Myers, 1986) while the UOP and ABB Lummus processes are the most important among the non-conventional ones (Fahad and El-Harthi, 2008). The main objective of this work is modeling and designing a reactive distillation unit with rigorous hydraulic constraints, determining the configuration at the same time. The RD unit is modeled using an equilibrium model (Taylor and Krishna, 2000) based on first principles (mass and energy balances and phase equilibrium relationships). Two different process schemes are proposed: one in which the reactive distillation unit represents the only reactive operation within the process and one in which reactive distillation is used as a finishing process, after a fixed bed adiabatic reactor stage. In both schemes, the reactive stages are modeled as trays with catalyst bags (Jones Jr., 1985). Two different optimization targets are evaluated: maximizing MTBE product purity and maximizing isobutylene global conversion to MTBE. The unit is sized according to rigorous hydraulic considerations (Stichlmair and Fair, 1998), while the number of reactive and non-reactive trays is estimated within an MINLP problem. Cost estimations are provided. Results for process variables are summarized in table 1 for industrial size designs. Results show that lumping reaction and separation unit operations reduces the cost for the process equipment and also the energy consumption, still obtaining a similar process performance since product purity and reactant conversion are very similar to those of conventional processes. References Fahad S. Al-Harthi (2008), ?Modelling and Simulation of a Ractive Distillation Unit for the Production of MTBE?, Master?s Thesis, King Saud University, Kingdom of Saudi Arabia. Jones Jr E.M. (1985), US Patent 4536373. Meyers R. A. (1986). ?Handbook of Chemical Production Processes?, McGraw-Hill. Stichlmair J.G., Fair J.R. (1998). ?Distillation: Principles and Practices?, J. Wiley and Sons. Taylor R., Krishna R. (2000)."Modelling Reactive Distillation", Chemical Engineering Science 55, pp. 5183-5229.