It1.
Introduction & History :-
1.1 Introduction to Cumene :-
Structure :-
Cumene is the common name for isopropylbenzene or i-propylbenzene. It’s
IUPAC name known as ( I-methylethylbenzene ).
It is produce by the alkylation of benzene with propene using an acidic
catalyst.
Cumene is an organic compound that is based on an aromatic hydrocarbon
with an aliphatic substitution and it’s molecular formula is C9H12.
It is a constituent of crude oil and refined fuels. So it is a petrochemical.
It is a flammable and colourless liquid with aromatic adour.
It is less dense than water and insoluble in water. Vapour are heavier than
air.
May be moderately toxic by inhalation, ingestion and skin absorption.
History :-
Cumene was invented by Heinrich Hock in 1944 and independently by
R.Ūdrishand P.sergeyev in 1942.
Cumeneentered into market in 1944 by hack and langwhen they proved
Cumene can be oxidized to form hydrocarbon can be decomposes in
phenol and acetone.
Cumene
Cumene was first synethesizedin large quantities during World War 2 as an
aviation gasoline.
It is obtained from petroleum directly.
2. PRESENT STATUS INCLUDING LIST OFINDUSTRIES
Industries producing Cumene as main product at
Global Level.
1. The Dow Chemical Company Exxon Mobil.
2. CorporationChina Petrochemical Development.
3. CorporationChang Chun GroupBraskem.
4. S.A.Royal Dutch Shell plcSumitomo Chemical.
5. Co.,Ltd.INEOS GroupBASF SEBorealis AG.
Industries Producing Cumene As intermiedient with
capacity.
Sr. Present status and location capacity
no
1 Herdillia chemicals ltd. 2000
TPA
Air india building
13th floor, nariman point,
Bombay 400021 (Maharashtra)
2 Si group India ltd. 1470
TPA
Ballarpur road
Opp. juinagar railway station
Turbhe thane
Navi Mumbai (Maharashtra)
3 Hindustan organic chemical industries 40000
TPA
81, maharishi karvemarg
Harchandrai house,
Mumbai (400002)
4 Global polychemllc. 10301
TPA
N-5, sector 11
Noida-201301,
Uttar Pradesh
3. Properties and application of cumene :-
Physical properties of cumene
Molecular weight :- 120.19
Melting point :- -96.90c
Boiling point :- 152.50c
Density :- 0.862 gm/cc
Flash point :- 390 c
Vapour pressure :- 4.5 mmhg at 250C
Ignition point :- 1380 c
Freezing point :- -96.030 c
Thermal conductivity :- 0.124 w.m/k
Surface tension :- 0.791 n/m
Flammable limits in air:-Lower 0.9 volume %
Upper 6.5 volume %
Toxic limit concentration in :- 200 ppm
Cumeneis insoluble in :- alcohol, ether,
carbontetrachloride .
Soluble in :- Water
Cumene is a colourless liquid.
Chemical properties of Cumene.
Cumene undergoes oxidation to give cumenehydroperoxide by
means of air or oxygen :-
C6H5CH(CH3)2+O2=C6H5(CH3)2COOH
By the catalytic action of dilute sulphuric acid,
cumenehydroperoxide is split into phenol and acetone :-
C6H5(CH3)2COOH = C6H5OH + CH3COCH3
Application of Cumene:-
Cumene is mainy used as a intermediate for production of Phenol
and Acetone.
It is used in small amount as thinner in manufacture of
paint,lacquers and enamels.
It is also used in manufacture of acetophenone and methyl
styrene.
Cumene is also used as a solvent for fats and raisins.
4 Properties of raw material for cumene
Raw materials required for production of cumene are
benzene, propane, propylene.
Benzene
molecular formula :- C6H6
molecular weight :- 78
melting point :- 5.5 0C
boiling point :- 80.1 0C
density at 25 C :- 0.876 g/ml
vapour density :- 2.77
vapour pressure :- 166 mm hg
appearance :- colourless liquid
flash point :- -11.630C
autoignition point :- 497.78 0C
specific heat capacity :- 136.0 J/kmol
viscosity :- 0.625 cP
odour :- aromatic, gasoline-like
Stability :- stable. Substance to be avoided
include strong oxidizing agent sulphuric acid , flammable .
Soluble in water, alcohol, chloroform, acetone.
Propane
Molecular formula :- C3H8
Molecular weight :- 44.10
Appearance :- colourless gas
Oder :- oderless
Density at 0 C :- 2.098 gm/mol
Melting point :- -187.7 C
Boiling point :- -42.25 C
Vapour pressure :- 853.16 kPa
Specific heat capacity :- 73.60 J/kmol
Flash point :- -104 C
Autoignition temp :- 540 C
Explosive limits :- 2.37
Soluble in water
Propylene
Molecular formula :- C3 H6
Molecular weight :- 42.08
Critical temperature :- 91.40c
Critical pressure :- 352.38 mmhg
Boiling point :- -47.660c
Melting point :- -185.22 0c
Liquid density :- 0.49 gm/cc
Gas density :- 0.0017 gm/cc
Specific volume :- 9.05 ft3/lb
Specific gravity :- 1.05
Specific heat capacity :- 15.56
5 VARIOUS PROCESSES OF CUMENE
MANUFACTRING
(1)Cumene phenol processes (hot processes).
This process converts two relatively cheap stating materials
benzene and propylene, into two more valuable ones phenol
and acetone, other reactant required are oxygen from air
and small amounts of a radial initiators.
Most o worldwide production of phenol and actone is now
based on this method in 2003; nearly 7 million tonnes of
phenol was produced by the cumene process.
(2)Cumene production by propylene alkylation of benzene
Proprietary, non-corrosive PBE-1 zeolite catalyst
Low pressure and low temperature operation
No chemical required
No acids waste streams and minimal fugitive emissions
Can be designed to process chemical and refinery grade
propylene feedstocks in addition to polymer grade propylene
6 MOST SUITABLE PROCESS IN DETAIL WITH FLOW
SHEET
cumene production by propylene alkylation of benzene
processes is generally used
justification
Product yield of 99.7 wt%
High activity and selectivity with minimal formation of by-
product impurities
Typical cumene purity is 99.5% or higher
Extremely tolerant to poisons
Proven run-lengths of up to five years
Low catalyst cost
Raw material:- propylene, propane, benzene, water,
Steam, etc.
chemical reaction:-
(a) main reaction:-
C6H6+CH3CH=CH2 =C6H5C3H7
(b) side reaction:-
C6H6+nCH3CH=CH2 =C6H6-n(C3H7)n
Flowsheet
Process Description:-
• Propylene obtained from refinery processes as a mixture of propylene and propane.
• The mixture along with benzene is compressed to 25 atms.
• Eventually the mixture enters a heat integrated exchanger to heat the pre-heat the feed mixture.
• The feed mixture enters a packed bed reactor.
• The stream distribution in the packed bed reactor corresponds to cold shot arrangement i.e., cold
propane from the distillation column in the process is added after every reactor with the product stream
so that the temperature of the stream is controlled.
• Here, propylene is the limiting reactant and therefore, presumably all propylene undergoes
conversion.
• Here, propane does not react but is a diluents or inert in the system. In that way it controls the
reaction temperature.
• The reactor units are maintained at about 250oC.
• The product vapors are cooled using the heat integrated exchanger.
• The vapors then pass to a depropanizer which separates propane from the product mixture.
• The bottom product consisting of benzene, cumene and polyalkyl benzenes enters another distillation
column which separates benzene from the mixture of cumene and polyalkyl benzene. The benzene
stream is recycled to enter the compressor.
• The bottom product from the benzene column is sent to a cumene column which produces cumene as
top product and poly alkyl benzene as bottom product.
• Therefore, the entire process technology is nothing but a simple reactor separator recycle
arrangement.
