Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

KN-4remain out of the sight of researchers. However, it is now clear that some multiple steadystates do occur for chemical reactions with small heat of reaction (e.g., methyl acetatesynthesis), with large heat of reaction (e.g., ethylene glycol synthesis), and with intermediateheat of reaction (e.g., MTBE synthesis). In contrast to the approach specified above, thetechnique of the study of reaction-mass transfer systems which was developed in Russia isbased on qualitative methods of thermodynamic-topological analysis with the use of theconcept of the process weak model. This allows one to analyze simultaneously a full set ofprocess steady states, providing the selection of the most effective variants of the processorganization.Energy management has received surprisingly little systematic study on aspectsspecifically for catalytic distillation, although traditional methods for distillation, heat andpower integration are useful. There are two directions of energy efficiency enhancement. Oneof the two is connected with the decrease of driving force. The use of thermally-coupledcolumns, based on the model of thermodynamically reversible distillation, is an example thatcan give a reduction in energy capacity up to 30-40%. Recently, a first industrial catalyticdivided wall column was developed and tested by joint efforts of Sulzer and BASF, whichwas used for obtaining pure methanol in methyl acetate hydrolysis in the production ofpolyvinyl alcohol. The integration of a catalytic distillation unit with a rectification column ina single shell made it possible to abruptly reduce the total number of apparatuses and, as aconsequence of a decrease in the residence time of flows in an apparatus, to minimize thereverse reaction of methyl acetate formation and to obtain pure product methanol in additionto energy and metal saving.Another direction of catalytic distillation enhancement has an aim to increase kineticcoefficients because lowering driving force tends to increase dimensions of column andreactor or to decrease conversion degree of reagents. Physicochemical intensification ofprocesses, based on a synergism arising at a molecular level (Marangoni effect, diffusionhydrodynamicRayleigh instability, chemical turbulence) and characterizing the transitionfrom macrotechnology to microtechnology, was found effective, with catalytic distillationbeing most promising between different hybrid processes.At present, there is a continuing demand for conceptual design methods developing forcatalytic distillation with the aim of prompt advancement of new products, made by newtechnology, to a market.This work was financially supported by the RFBR project 08-03-00745.22