Azeo Extra Mole Reac Distillation

7/31/2019 Azeo Extra Mole Reac Distillation

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Azeotropic distillation

Add substance that forms minimum boiling

azeotrope with one or both components.

Take azeotrope off top and separate bydecanting or by solvent extraction

May get binary or ternary azeotrope, either

homogeneous or heterogeneous


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Extractive distillation

Add non-volatile substance/entrainer that

modifies relative volatility of the other

components.

May reverse volatilities

However, leads to higher T in reboiler Must separate entrainer by decanting,

distillation or solvent extraction


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Extractive distillation - examples

Max boiling Azeotropes

Nitric acid/water or hydrochloric acid/water

extract water using sulphuric acid

Close Boilers

Toluene/methylcyclohexane add phenol to

dissolve toluene. Gives mch overhead distill

phenol/toluene


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Extractive distillation - examples

Reverse volatilities

Paraffins/aromatics add glycol to dissolve

aromatics recover glycol with water wash

Propene/propane in presence of nitrogen use

acrylonitrile to reverse the volatilities of propane

and propene. Propene dissolves in acrylonitrile

separate by flash followed by distillation


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Molecular DistillationFor those classes of chemical compounds

which decompose, polymerize, react or

are destroyed by conventional lowpressure distillation, efficient commercial

high vacuum distillation equipment is

available for those compounds


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By centrifugal force, the materialspreads in a film across the

heated disc which intimately faces

a large condensing surface.

The lighter compound evaporates

and condenses in a fraction of a

second. The heavier residue

which has not evaporatedslides off the outer edge of the disc


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NO HEAT DEGRADATION:Low pressure and a thermal residence timeof less than one second protects against decomposition.

HIGHER PRODUCT QUALITY:This process can remove objectionable

colors, odors, and excess reactants, adding value to product.

VALUABLE BY-PRODUCTS:Materials removed from product remainintact. These waste materials become potential marketable products.

LOW PROCESS COST: can be processed small or large volumes at lowcosts because stills use less energy, are very efficient and economical inoperation.

PROCESS SMALL OR LARGE VOLUMES: throughput ranging from

ounces to 2,000 pounds per hour


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Food Processing IndustriesProvide a method for refining edible oils that result in decolorized,deodorized, pure oil, separating valuable products such as vitamins,

sterols, fatty acids, and antioxidants. The centrifugal moleculardistillation process provides a gentle method for purifying and fractioningessential oils. Odors, colors, and flavors can be separated withoutdanger of hydrolysis, air oxidation or decomposition. Monoglycerides oremulsifiers can be more highly concentrated than with traditionalseparation techniques.

Cosmetic IndustriesThis type of distillation equipment is ideal for use in recovering lanolinfrom wool grease, the crude soft wax obtained from the hair of thesheep. Fragrance derived from fatty acids are also isolated through thissystem.

Pharmaceutical IndustriesGovernment requirements concerning enrichment of food with vitamins

have caused increased interest in centrifugal molecular distillation ofnatural vitamins A and E. Natural vitamins K-1 and K-2 are beingdistilled to replace synthetic K-3 and -4. Synthetic vitamin E also hasbeen distilled by Myers molecular distillation equipment. Stills are usedin a variety of purification and separation processes for many drugs,including tranquilizers.


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Paint and Varnish IndustryThe drying properties and firm hardness of polymerized oils such ascastor and linseed can be altered by distilling off low molecularweight compounds.

Epoxy Resin ManufacturesManufacturers of liquid epoxy resins have discovered that this

distillation technique results in desirable color reduction, loweredviscosity, and increased shelf life by removing the catalyst typicallyused in the formulation.

Tall Oil ProductionTall oil producers have benefited from Myers centrifugal moleculardistillation in two ways. First, the distillation reduces the problem of

tall oil pitch disposal. Secondly, the remaining fatty acids can berecovered in profitable quantities to be reused for emulsifiers,flotation agents, plasticizers, disinfectants, soaps, and cleaningagents.


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Silicon Producers

Myers molecular stills are ideal for the removal of either low orhigh molecular weight polymers from a mixture of polymers.

Wax ProducersCrude paraffin, beeswax carnauba, and certain microcrystallineand high melting point waxes are purified by the Myerscentrifugal molecular distillation system.

Basic ResearchMolecular distillation has been proven successful in separatingvarious isotopes, as well as many other research application.The Myers still is an effective tool for separating components ofhigh molecular weight and for concentrating components forquantitative or qualitative analysis. Surfactant ProducersSugar esters and poly-oxyalkylins glycol have been routinelypurified by Myers molecular distillation. Crude fatty acids andwax derivatives of fatty acids have been distilled in maximumpurity concentrations without thermal damage.


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Plastic IndustryThis method benefits plastics manufacturers. Plasticizers such asdi-octyl phthalate and di-octyl sebacate are purified with the Myersstills to remove excess reactants of estererification, moisture ofcondensation, objectionable color, odor, and traces of catalyst.

Mineral Oil Production

High temperature lubricating oils and greases are commonlydistilled from the C/35 - C/100 fractions of petroleum bottoms. Lubeoils purified by Myers molecular distillation are more stable andprotected from decomposition. Resins and bitumin are separated bythe method as well.

Oil Reclamation

With the rising cost of oils and fluids, recovery of these materials bythe Myers molecular distillation process is highly practical,profitable, and environmentally compatible by reducing disposablewaste.


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INTRODUCTION

Reactive distillation is a process where thechemical reactoris also the still.

Separation of the product from the reactionmixture does not need a separate distillationstep, which saves energy (for heating) andmaterials.

This technique is especially useful forequilibrium-limited reactions such asesterification and esterhydrolysis reactions.
http://en.wikipedia.org/wiki/Reactorhttp://en.wikipedia.org/wiki/Stillhttp://en.wikipedia.org/wiki/Distillationhttp://en.wikipedia.org/wiki/Esterificationhttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Esterificationhttp://en.wikipedia.org/wiki/Distillationhttp://en.wikipedia.org/wiki/Stillhttp://en.wikipedia.org/wiki/Reactor


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Reactive distillation can be used with a

wide variety of chemistries, including the

following:Acetylation

Aldol condensation

Alkylation

Amination

Dehydration

Esterification

Etherification

Hydrolysis

Isomerization

Oligomerization
http://en.wikipedia.org/wiki/Acetylationhttp://en.wikipedia.org/wiki/Aldol_condensationhttp://en.wikipedia.org/wiki/Alkylationhttp://en.wikipedia.org/wiki/Aminationhttp://en.wikipedia.org/wiki/Dehydrationhttp://en.wikipedia.org/wiki/Esterificationhttp://en.wikipedia.org/wiki/Etherhttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Isomerhttp://en.wikipedia.org/wiki/Oligomerizationhttp://en.wikipedia.org/wiki/Oligomerizationhttp://en.wikipedia.org/wiki/Isomerhttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Etherhttp://en.wikipedia.org/wiki/Esterificationhttp://en.wikipedia.org/wiki/Dehydrationhttp://en.wikipedia.org/wiki/Aminationhttp://en.wikipedia.org/wiki/Alkylationhttp://en.wikipedia.org/wiki/Aldol_condensationhttp://en.wikipedia.org/wiki/Acetylation


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PROBLEM STATEMENT

To study a proposed method of production of

methyl acetate. The acetic acid is to be reacted

with methanol in a catalyst filled semi batch

reactor.

To simulate the reaction and see if reactive

distillation is a better option than without.


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HAc

MeOH

MeAc

H2O

STRIPPING

COLUMN

CONDENSER

REBOILER

DISTILLATION

COLUMN

EXTRACTIVE

REACTIVE

RECYCLE

SIMPLIFIED FLOWDIAGRAM OF PRODUCTION OF METHYL ACETATE

MeOH

HAc


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CHAc

CMeAc

CMeOH

CH2O

T I M E

M

O

L

E

S

Y

X

300


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n-butyl acetate

C4H9OH + CH3COOH CH3COOC4H9 + H2O

Market price (India): Rs.54/kg

Global demand: 600,000 tpa (growth: 2-3%pa)

Indian producers: Laxmi Organics, VAM

Organics, RK Chemicals, Sterling Solvents etc.

International producers: BASF, Celanese, DOW,

Eastman Chemicals etc.


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Literature survey and process

selection Conventional process

homogeneously catalyzed (H2SO4)

problems of corrosion effluent treatment (tin octoate)

vapor phase

Heterogeneous catalysis Catalyst selection

ion-exchange resin

zeolites HPAs

Reactive distillation


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Reaction & Distillation ProcessBA

AA

Reactor

Condensor

Reboiler

Waste

Stream

Product

Stream

Dis

tillation

Co

lumn

Mixer / Heater

Reflux

Drum

Product Cooler

Recycle

Stream


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Reactive Distillation Column

ProcessCondensor

Reboiler

Effluent

Stream

Product

Stream

RD

Column

Decanter

Product Cooler

HAc

BuOH


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ADVANTAGES:

Increased speed and improved efficiency.

Lower costs reduced equipment use, energy

use and handling.

Less waste and fewer byproducts.

Improved product quality reducing opportunity

for degradation because of less heat exposure.


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DIFFICULTIES:

The performance of the reactive column is not

optimal when equated to a chemical reactoranda distillation column seperately.

It is not feasible to use a reactive distillationcolumn when the optimum process parameters(temp,pressure etc) differ too much.


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Thank you!

Azeo Extra Mole Reac Distillation

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