CHAPTER I

BACKGROUND OF CUMENE

1.1 INTRODUCTION

Cumene is the common name for isopropylbenzene or i-propylbenzene. It’s IUPAC name

known as (1-methylethyl)benzene. Cumene is an organic compound that is based on an

aromatic hydrocarbon with an aliphatic substitution and its molecular formula is C9H12.

Likewise the structural formula for cumene is as shown in the figure 1.1.

Figure 1.1 Structural formula of Cumene

Refrence: Streitwieser, A; Heathcock, C.H. (1992). "30". Introduction to Organic Chemistry. Kosower, E.M. (4th ed.). New York: MacMillan. p. 1018

1.2 PROPERTIES OF CUMENE

Physically cumene is a colourless liquid in alkyl aromatic family with sharp and gasoline-

like odor. It is flammable and soluble in nonpolar solvents such as alcohol, carbon

tetrachloride, benzene, ether, and many other organic solvents but insoluble in water.

Below are the main properties of Cumene,

Table 1.1 Properties of Cumene

Properties Value

Molecular weight 120.19

Boiling Point, C 152.39

Freezing point, C

Density, g/cm3

Viscosity, mPa.s

-96.03

0.8450

0.612

Thermal conductivity, w/m.k

Flash point, C

Critical temperature, C

Heat of vapourisation at bp, J/g

Heat of vapourisation at 25C, J/g

0.124

44

351.4

312

367

Heat capacity, J/mol.K

Heat of combustion at 25C, J/g

197

43,370

Refrences: (HSDB, 1991; Merck, 1989; U.S. EPA, 1994a)

1.3 ROUTES TO MANUFACTURE CUMENE

Although cumene is a naturally occurring substance present in coal tar and petroleum,

most industrial cumene is synthesized from benzene and propylene. Cumene is produced

by reacting propylene and benzene over an acid catalyst. Cumene may be used to increase

the octane in gasoline, but its primary use is as a feedstock for manufacturing phenol and

acetone.

The reactions for cumene production from benzene and propylene are:

C3H6 + C6H6 C6H5 - C3H7 (1.1)

Propylene Benzene Cumene

1.4 USAGE OF CUMENE

Cumene have quiet amount of usage. Below are the usage of cumene:

1. Cumene is used for the production of phenol and its co-product acetone. The

cumene oxidation process for phenol synthesis has been growing in popularity

since the 1960’s and is prominent today. The first step of this process is the

formation of cumene hydroperoxide. The hydroperoxide is then selectively

cleaved to phenol and acetone. Phenol in its various formaldehyde resins to bond

construction materials like plywood and composition board for the bisphenol A

employed in making epoxy resins and polycarbonate and for caprolactum, the

starting material for nylon-6. Minor amounts are used for alkylphenols and

pharmacuticals.

2. Methylstyrene is produced in controlled quantities from the cleavage of cumene

hydroperoxide, or it can be made directly by the dehydrogenation of cumene.

3. Cumene in minor amounts is used as a thinner for paints, enamels and lacquers

and to produce acetophenone, the chemical intermediate dicumylperoxide and

diiso propyl benzene.

4. Cumene is also used as a solvent for fats and raisins.

phenol

methylstyrene

thinner

solvents

Usage of Cumene

Refrence: DeWitt & Co World Petrochemical Conference, 24-25 March 2010

1.5 CONCLUSION

Cumene is also known as isopropylbenzene. Physically cumene is a colourless liquid,

flammable and insoluble in water. Cumene is produced by reacting propylene and

benzene over an acid catalyst. It is widely used for the production of phenol, then for the

production of methylstyrene and also in making thinner.