Catalysis for the valorization of exhaust carbon: from CO2 to chemicals, materials, and fuels. technological use of CO2.

http://egon.cheme.cmu.edu/Papers/BatchReviewMendezGrossmann.pdf

State-of-the-art review of optimization methods for short-term scheduling of batch processes

Modelling reactive distillation

Natural emulsifiers - Biosurfactants, phospholipids, biopolymers, and colloidal particles: Molecular and physicochemical basis of functional performance.

Acid catalysts in industrial hydrocarbon chemistry.

Conceptual design of distillation systems

Kinetically controlled reactive distillation is a bridge between the two limiting cases of nonreactive and equilibrium reactive distillation. In this paper, we study the influence of heterogeneous catalysis on the transition from the nonreactive to the equilibrium reactive limits for the esterification of acetic acid with methanol. A Langmuir−Hinshelwood/Hougen−Watson rate model was developed to represent the reaction kinetics. Since reactive distillation is carried out at the boiling temperature of the liquid, the pressure of the system plays an important role in determining the product composition. Higher operating pressures imply higher temperatures and faster rates of reaction but could also lower equilibrium conversions (for exothermic systems) and trigger unwanted side reactions. To study the importance of side reactions and the effect of pressure on product selectivity, we also include the reaction kinetics for methanol dehydration. Isothermal batch kinetic experiments were performed using a hetero...

Measurement of Residue Curve Maps and Heterogeneous Kinetics in Methyl Acetate Synthesis

A class of models is derived for studying the effects of chemical kinetics on residue curve maps for reactive distillation. Activity-based rate and phase equilibrium expressions provide an accurate and thermodynamically consistent description of composition changes in nonideal, reacting vapor-liquid mixtures. For certain strategies of operation, which dictate the rate of product removal, the model equations are nonautonomous, leading to unusual dynamic behavior. However, for a certain special product removal policy, the effects of kinetics can be described by a single parameter, the Damkohler number, which measures the rate of reaction relative to product removal. For small values of the Damkohler number, the nonreactive simple distillation residue curve map is recovered and the singular points are the pure components and azeotropes in the nonreactive mixture. A bifurcation analysis shows the deformation and, in some cases, the disappearance of these singular points as the Damkohler number is increased until the equilibrium reactive residue curve map is recovered at large values. This bifurcation analysis reveals the limitations of the equilibrium analysis. A model problem for the reactive distillation of methyl tertbutyl ether from isobutene and methanol is solved.

Effect of kinetics on residue curve maps for reactive distillation

The product compositions in single-feed distillation columns can be specified only in certain regions of the composition space, which depend only on the pressure, feed, and vapor-liquid equilibrium for the mixture. In nonideal mixtures, even without azeotropes, the regions may allow unusual product distributions. For example, the distillate in a direct split is composed primarily of the lightest component. Intuition and experience with relatively ideal mixtures suggest that the next most plentiful component is the intermediate boiler. In nonideal mixtures, however, with or without azeotropes, the next most plentiful component may be the highest-boiling species with only trace amounts of the intermediate boiler. For azeotropic mixtures, distillation boundaries may give rise to additional restrictions on the product compositions. The authors describe how simple distillation boundaries deform into continuous distillation boundaries and, in a limited number of cases, how the simple distillation boundaries can be crossed in continuous columns for certain ranges of the design variables. Unfortunately, such designs may be quite sensitive to model uncertainties or to disturbances in the parameters.

Feasibility of separations for distillation of nonideal ternary mixtures

A global algorithm for implementing the Gibbs tangent plane stability test in multicomponent, multiphase liquid mixtures is described. The algorithm is self-starting and significantly improves the reliability and robustness of multiphase equilibrium calculations. The main improvement is a result of a new approach for locating the stationary points of the tangent plane distance function. This relies on the geometric properties of the tangent plane distance function but is independent of the specific fluid model. For ternary mixtures, it is shown that stationary points in the tangent plane distance function satisfy a global topological constraint Nmax + Nmin − Nsad = 1 where Nmax is the number of maxima, Nmin is the number of minima, and Nsad is the number of saddles. This provides a global consistency check on the numerical results that is independent of the specific model or parameters used to describe the mixture. The method has been implemented and tested on a variety of problems with three and four com...

Michael F. Malone

Papers

Conceptual design of distillation systems

Measurement of Residue Curve Maps and Heterogeneous Kinetics in Methyl Acetate Synthesis

Effect of kinetics on residue curve maps for reactive distillation

Feasibility of separations for distillation of nonideal ternary mixtures

Global Stability Analysis and Calculation of Liquid−Liquid Equilibrium in Multicomponent Mixtures†