Metales

Journal of Loss Prevention in the Process Industries 13 (2000) 527–545
www.elsevier.com/locate/jlp

Review

Removal of Volatile Organic Compounds from polluted air
Faisal I. Khan *, Aloke Kr. Ghoshal
Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani-333 031, Rajasthan, India

Abstract
Volatile Organic Compounds (VOCs) are among the most common airpollutants emitted from chemical, petrochemical, and
allied industries. VOCs are one of the main sources of photochemical reaction in the atmosphere leading to various environmental
hazards; on the other hand, these VOCs have good commercial value. Growing environmental awareness has put up stringent
regulations to control the VOCs emissions. In such circumstances, it becomes mandatory for eachVOCs emitting industry or facility
to opt for proper VOCs control measures. There are many techniques available to control VOCs emission (destruction based and
recovery based) with many advantages and limitations. Therefore, deciding on a particular technique becomes a difficult task. This
article illustrates various available options for VOCs control. It further details the merits, demerits andapplicability of each option.
The authors hope that this article will help in critically analysing the requirements and accordingly decide on the appropriate strategy
to control VOCs. © 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Adsorption; Bio-filtration; Membrane; Oxidation; RFR; Volatile Organic Compounds (VOCs)

1. Introduction
Volatile Organic Compounds (VOCs) include mostsolvent thinners, degreasers, cleaners, lubricants, and
liquid fuels. A brief list of some common VOCs are
presented in Table 1, which includes methane, ethane,
tetrachloroethane, methyl chloride, and various chlorohydrocarbons and perfluorocarbons. VOCs are the
common air pollutants emitted by the chemical and
petrochemical industries. Emissions of VOCs originate
from breathing and loadinglosses from storage tanks,
venting of process vessels, leaks from piping and equipment, wastewater streams and heat exchange systems.
Control of VOCs emission is a major concern of the
industries’ commitment towards the environment.
From an environmental point of view, it is necessary
to limit and control vapour emissions because they affect
the change of climate, the growth and decay ofplants,
and the health of human beings and all animals. For
example, according to a report of the National Academy
of Sciences, the release of chlorofluoromethanes and
chlorine-containing compounds into the atmosphere
increases the absorption and emission of infrared radi-

* Corresponding author. Fax: +91-01596-44183.
E-mail address: khan@bits-pilani.ac.in (F.I. Khan).

Table 1
Some of thecommon VOCs
Serial Number

Volatile Organic Compounds

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

Acetaldehyde
Acetone
Benzene
Carbon tetrachloride
Ethyl acetate
Ethylene glycol
Formaldehyde
Heptane
Hexane
Isopropyl alcohol
Methyl ethyl ketone
Methyl chloride
Monomethyl ether
Naphthalene
Styrene
Toluene
Xylene

ation. If the heat loss from the earth isretarded, the
earth’s temperature and climate are affected. Studies on
carcinogenicity of certain classes of hydrocarbons indicate that some cancers appear to be caused by exposure
to aromatic hydrocarbons found in soot and tars. Hydrocarbons in combination with NOx, in the presence of sun-

0950-4230/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved.
PII: S 0 9 5 0 - 4 23 0 ( 0 0 ) 0 0 0 0 7 - 3

528

F.I. Khan, A. Kr. Ghoshal / Journal of Loss Prevention in the Process Industries 13 (2000) 527–545

light, undergo photochemical oxidation, producing a
photochemical smog that is environmentally hazardous.
1.1. Regulation to control VOCs emission
Regulations on controlling organic vapour pollutants
in air have been issued world-wide. In the ambient air...