Reactive distillation is the combination of separation and reaction ina single vessel. Today Reactive Distillation is discussed as a part of the broader area of reaction and separation, which comprises of many combination of chemical reaction with separation methods including distillation, stripping, absorption, extraction, crystallization and membrane separation.
Reactive Distillation is a unit operation in witch chemical reaction and distillation separation are carried out simultaneously with a fractional distillation apparatus. Conversion can be increased far beyond chemical equilibrium conversion due to the continuous removal of reaction products from the reactive zone. This may lead to enormous reduction of capital and investment costs and may be important for suitable development due to lower consumption of resources. Enhancement in conversion, selectivity, energy utilization, reductions in equipment cost are some of the objectives simultaneously fulfill by reactive distillation. It has become an attractive technology not only for reaction engineers but also for separation technologists. Because of the advance in reaction engineering, catalysis, modeling and simulation, reactive distillation has been able to advantageously accommodate several reactions under its umbrella. New applications are being explored with an increasing rate. Reactive distillation has started looking beyond the classic of esterification, etherification reaction. It can be successfully used for both fine and bulk chemicals.
[...] The results of the batch reactive distillation shows that the considerable amount of reaction equilibrium was shifted to obtain better conversion of Lactic acid. The best conversion of more than 95.15 %was obtained with reactant mole ratio 1.5 the increased conversions are obtained by continuous removal of the water formed during the reaction through the separating column connected with a condenser and collector. The increase in concentration of the solution with addition of catalyst or without addition of catalyst increases the volume of water collected. [...]
[...] If reactive distillation is applied to exothermic reaction, the reaction heat can be used for the vaporization of liquid. This leads to savings of costs by the reduction of reboiler duties. Improved conversions of reactant approaching 100%. This increase in conversion gives a benefit in reduced recycle costs. Improved Selectivity: Removing one of the products from the reaction mixture or maintaining a low concentration of one of the reagent can lead to reduction of the rates of side reactions and hence improved selectivity for the desired products. [...]
[...] CH3CHOHCOOH + C2H5CH2CH2CHOH ( CH3CHOHCOOC4H+H20 For the above reaction the law of mass action is given by [CH3CHOHCOOC4H]+[H20] K = CH3CHOHCOOH + C2H5CH2CH2CHOH The important limitation of reactive distillation is that the volatilities of the components should be favorable. Water can be removed simultaneously during the course of reaction so that reaction is shifted in the forward direction and conversion of butyl lactate can be enhanced CHEMICALS AND MATERIALS USED Lactic acid n-Butanol of 99% Purity (Merk) Dry cation exchange resin Amberlite IR-120 purchased from LUBA chemicals Pvt Ltd, used as solid catalyst. [...]
[...] LITERARURE REVIEW 2.0 Reactive Distillation of Lactic acid: J.L.Choi & W.H.Hong [1999] reported that batch distillation of lactic acid with the simulation reactions was studied. Lactic acid was reacted with methanol, and methyl lactate was produced by the esterification reaction. The volatile methyl lactate was distilled simultaneously with the hydrolysis reaction into lactic acid. To recover pure lactic acid through two reactions and distillation, batch distillation system consisted of two condensers, feed vessel, and reboiler was studied. For both reactions of esterification and hydrolysis, the acidic cation exchange resin was used as a solid catalyst. [...]
[...] EFFECT OF TEMP 1:1 MOLE RATIO WITHOUT CATALST IN SIMPLE DISTILLATION Reactive Distillation of Lactic acid with Butanol The experiments were carried out by using butanol (moleratio 1.5 ) as reactive entrainer and observed the variation of FLA, TLA and PLA contents in the residue samples with various time intervals. Fig ( 4.3 to 4.14 ) shows the above said variations. Using butanol, it is evident from fig that the PLA formation in the residue started at same time of 80 min as in case of simple distillation but the water removal rate is rapid than the case of simple distillation By the time the poly lactic acid started forming 60% of initial water has been removed. [...]
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