Sulfuric acid also known as oil of vitriol, battery acid, and king of chemicals produced using contact process used in the manufacture of fertilizers, explosives, dyes, petroleum products, lead-acid batteries
Sulfuric acid king of chemicals industrial production using contact process
SULFURIC ACID KING OF
Published by www.worldofchemicals.com
Sulfuric acid molecular formula written as H2SO4, with
other names includes oil of vitriol, battery acid, and
king of chemicals. Sulfuric acid composed of
hydrogen, oxygen, and sulfur and available forms
include dilute sulfuric acid, concentrated sulfuric acid.
Sulfuric acid is formed naturally by the oxidation of
sulfide minerals, such as iron sulfide. On earth,
sulfuric acid does not exist in a natural form. But on
the planet Venus, there are lakes of the sulfuric acid
exist. The sulfuric acid from lakes will evaporate to
form clouds, leading to sulfuric acid rain on the
Sulfuric acid is the largest volume industrial chemical
produced in the world i.e., 200 million tons per year.
93-98 per cent (concentrated) sulfuric acid is used in
the manufacture of
fertilizers, explosives, dyes, petroleum
products, domestic acidic drain cleaner, lead-acid
batteries, mineral processing, fertilizer
manufacturing, oil refining, wastewater
processing, and chemical synthesis.
International commerce of sulfuric acid, lists sulfuric
acid under Table II of the convention as a chemical
frequently used in the illicit manufacture of narcotic
drugs or psychotropic substances.
Sulfuric acid Lab and industrial
In laboratories or industries if you spill a drop of
sulfuric acid on your hand, it will burn tissue
instantly. It also causes skin dehydration. Other
severe effects of sulphuric acid are fumes cause
blindness, and damage the lungs if inhaled. Even
dilute sulfuric acid is dangerous.
While handling sulfuric acid following
precautionary steps need to be follow
Always wear thick gloves
Wear a lab coat or apron
Never handle it on an open bench
Never pour it / through out from the bottle
Precautions Cont ……
Never pipette out with mouth
Always use a thick glass pipette with a rubber bulb
Sulfuric acid is often stored in concentrated form
Sulfuric acid has following properties
Sulphuric acid is a powerful protonating agent.
Sulphuric acid is also a powerful dehydrating agent and is
used to remove a molecule of water from many organic
Dilute sulphuric acid is a strong dibasic acid forming two
series of salts.
Sulfuric acid reacts with most bases to give the
It can oxidize non-active tin and copper metals
Sulfuric acid production
The production of sulfuric acid has come to be accepted
throughout the world as a reliable barometer of industrial
activity. Its universal use has made it indispensable, in the
widest sense of the world, in chemical and process industries.
Sulfuric acid is a strong acid i.e. is in aqueous solution it’s
largely changed to hydrogen ions and sulfate ions. Each
molecule gives 2 hydrogen ions and thus sulfuric acid is
The preparation by burning sulfur with saltpeter was first
described by Valentinus in the fifteenth century. Later its
preparation by distilling niter with green vitriol was mentioned
by Persian alchemist Abu-Bekr-Ahhases, who died in
940.The weathering of iron pyrites was usually the source of
green vitriol. Sulfuric acid has been an important item of
commerce for at least 250 years and has been known and
used since the Middle Ages.
Sulfuric acid production process
n the eighteenth and nineteenth centuries, it was
essentially and entirely produced by chamber
process, in which oxides of nitrogen (as nitrosyl
compounds) were used as homogeneous catalysts for
the oxidation of sulfur dioxide. The product made by
this process was of rather low concentration not high
enough for many commercial uses.
In 1746, Roebuck of Birmingham, England produced
successfully on commercial scale by burning sulfur
and potassium nitrate in ladle suspended in a large
glass partially filled with water.
Sulfuric acid production process
The contact process was first discovered in 1831 by
Phillips, an Englishman whose patent included the essential
features of the modern contact process namely the passing
of the mixture SO2 over a catalyst followed by absorption of
SO3 in 98 to 99 per cent H2SO4.
Later it was demonstrated that excess of oxygen in the
gaseous mixture for contact process was advantageous. The
contact process has been improved in all details and at the
current scenario is one of the low cost industries and is
almost wholly automatic continuous process for the
manufacture of sulfuric acid.
Primary impetus for the development of the contact process
came from a need for high strength acid and oleum to make
synthetic dyes and organic chemicals. The contact process
employing platinum catalysts began to be used on large scale
for this purpose late in the nineteenth century. Its
development accelerated during the World War I to provide
the concentrated mixtures of sulfuric and nitric acid for the
production of explosives.
Sulfuric Acid Production – Using
The contact process is the current method of producing
sulfuric acid in the high concentrations needed for industrial
processes. Platinum was formerly employed as a catalyst for
the reaction, but as it is susceptible to poisoning by arsenic
impurities in the sulfur feedstock, vanadium oxide (V2O5) is
The sulfur dioxide is obtained by burning sulfur or by roasting
sulphide ores in air. Purification of air and SO2 is necessary to
avoid catalyst poisoning. The sulfur dioxide, mixed with an
excess of air, is purified and dried then passed through a
series of converters where the catalyst is stored on shelves in
a way which exposes the maximum possible surface area to
the reacting gases.
Contact Process Cont ….
The oxidation is exothermic and operating
temperature is maintained without external heating by
using heat exchangers.
After passing through the converters the gases are
cooled and passed into an absorption tower where the
sulfur trioxide dissolves in concentrated sulfuric acid.
The product leaving the absorption tower is normally
100 per cent sulfuric acid. Some of it is diluted with
water, cooled, and reirculated through the absorption
tower. By controlling the dilution the contact process
can be adapted to produce fuming sulfuric acid.
Double Contact Double
Another significant change in the contact
process occurred in 1963, when Bayer AG
announced the first large scale use of Double
Contact Double Absorption process and
granted several patents.
In this process the product
gases SO2 and SO3are passed through
absorption towers twice to achieve further
absorption and conversion of SO2 to SO3and
production of higher grade sulfuric acid.
Double Contact Double
Absorption process Cont …..
SO2 rich gases enter the catalytic converter, are converted to
SO3, achieving the first stage of conversion. The exit gases
from this stage contain both SO2and SO3 which are passed
through intermediate absorption towers where sulfuric acid is
trickled down packed columns and SO3reacts with water
increasing the sulfuric acid concentration. Unreactive
SO2 comes out of the absorption tower.
This stream of gas containing SO2, after necessary cooling is
passed through the catalytic converter bed column again
achieving up to 99.8 per cent conversion of SO2 to SO3 and
these gases are again passed through the final absorption
column thus resulting high conversion of SO2but also
enabling production of higher concentration of sulfuric acid