Nam Present

22
Matou q, M., T. Tag awa and S. Go to.  J. Chem. Eng. Jpn. 27 (1994): 302-306 Combine Process for Production of MTBE from tert -Butyl Alcohol and Methanol

Transcript of Nam Present

Page 1: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 1/22

Matouq, M., T. Tagawa and S. Goto.

 J. Chem. Eng. Jpn. 27 (1994): 302-306

Combine Process for Production of MTBE

from tert -Butyl Alcohol and Methanol

Page 2: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 2/22

Page 3: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 3/22

A+B

C+D

R eaction

Separation

Combined Process Concept

C

D

(Animation)

Page 4: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 4/22

R eactive Distillation

RD is a simultaneous implementation of reaction and

separation in a column. Both homogeneous and heterogeneous

can be applied. First Patents in 1920s

The main advantages of RD over the sequential processes of 

reaction and distillation;

1) Simplification of reactants-products separation.

2) Achievement of higher yields for reversible reactions

(equilibrium limited reactions) using solid catalysts.

Page 5: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 5/22

Reactive Section

Temperature Indicator 

Voltage and CurrentMonitor 

Stripping 

Section

Pump

Feed

Vents

Distillate

Bottom 

Product

Multi-timer 

Heating Mantle

A + B C + D

Page 6: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 6/22

What is oxygenate?

Oxygenates are used as octane booster to promotemore complete combustion of gasoline and to reduce

carbon monoxide (CO) and volatile organic compounds

(VOC¶s) emitted from the exhaust pipes.

Examples of oxygenate are alcohols, e.g. methanol

and ethanol, and their derivative alkyl ethers, e.g. MTBE,

ETBE, TAME, TAEE

MeOH + IB = MTBE

MTBE Synthesis-Commercial Process

Page 7: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 7/22

Iso-Butene (IB) CH2=C-CH3

CH3

Methanol (MeOH) CH3-OH

O-CH3

Methyl tert-Butyl Ether (MTBE) CH3-C-CH3

CH3

+

Page 8: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 8/22

MeOH + TBA = MTBE + H2O

Synthesis of MTBE from TBA

tert -Butyl alcohol (TBA), which is a major by-product of 

 propylene oxide production from isobutene and propylene,

can be employed instead of IB as a reactant due to theshortage of IB .

However, the following side-reactions can be occurred.

TBA = IB + H2O

MeOH + IB = MTBE

Page 9: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 9/22

CH3

tert-ButylAlcohol(TBA) CH3-C- OH

CH3

Methanol (MeOH)

CH3-OH +

O-CH3

Methyl tert-Butyl Ether (MTBE) CH3-C-CH3

CH3

+ H2O

Page 10: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 10/22

Drawbacks of RD such as

1) can¶t separate azeotropic mixtures

2) significant energy consumption3) require large difference volatility

To overcome this  drawback , pervaporation unit  was 

applied.

What is pervaporation (PV)?

One of the membrane process.

The name is from permeate + vapor

Page 11: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 11/22

The transport mechanism of pervaopration process

1) sorption of liquid into the membrane at the feed side

2) transport (permeate) through the membrane

3) desorption into the vapor  phrase at the permeate side

www.p2pays.org

Page 12: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 12/22

Membrane - A material that allows selective permeation of certain molecules. Main classify; organic and

inorganic membrane.

Permeate - The part of the fluid stream that passes through

the membrane.

R etentate - The part of the fluid stream that does not pass

through the membrane.

Advantages of Pervaporation

It enables the separation of a liquid mixture withclose boiling points, azeotropic mixtures, isomers,

and mixtures consisting of heat-sensitive

compounds by partly vaporizing it through a dense

membrane.

Ter minologies of  membr ane pr ocessTer minologies of  membr ane pr ocess

Page 13: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 13/22

Feed

Treated Effluent

PervaporationModule

Vacuum

Pump

Condenser

Condensate

Schematic of a typical pervaporation system. 

Pervaporation is one of the membrane separation process. It can be applied as a membrane reactor.

So now we change the present topic to 

membr ane reactor 

Page 14: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 14/22

ConceptIntegrating reaction and separation by membrane

in one single unit

Membrane reactors are categorized into two types:

inert membrane reactor (IMR) and catalytic membrane

reactors (CMR)IMR, the catalytically active material does not form

a part of the membrane

Membrane R eactor

Page 15: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 15/22

Basic Functions of Membrane R eactors

I) Extractor-removal of reaction product

II) Distributor-addition of reactant

Page 16: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 16/22

I) Extractor

 

A+B

Sweep gas

Impermeable wall

D D D

D DSweep gas

Sweep gas, D

Sweep gas, D

DC

R emoval of reaction pr oduct therefore

shif t react ion equilibr i um

Page 17: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 17/22

Page 18: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 18/22

Membrane reactor applications

 I n extract or mod e

1) Pervaporation membrane reactor

MeO

H + TBA MTBE + H2O

Synthesis of MTBE from TBA

By product, water, was removed from ether production

 by pervaporation

Page 19: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 19/22

Distillation and

Pervaporation Simple

Combined Process

Page 20: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 20/22

Reactant A

Reactant B

Product

II) Distributor

Controlled addition of a reactant.

Limitation of side reactions.

Page 21: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 21/22

Page 22: Nam Present

8/9/2019 Nam Present

http://slidepdf.com/reader/full/nam-present 22/22