sulfuric acid: Contact Process

In the contact process, purified sulfur dioxide and air are mixed, heated to about 450℃, and passed over a catalyst; the sulfur dioxide is oxidized to sulfur trioxide. The catalyst is usually platinum on a silica or asbestos carrier or vanadium pentoxide on a silica carrier. The sulfur trioxide is cooled and passed through two towers. In the first tower it is washed with oleum (fuming sulfuric acid, 100% sulfuric acid with sulfur trioxide dissolved in it). In the second tower it is washed with 97% sulfuric acid; 98% sulfuric acid is usually produced in this tower. Waste gases are usually discharged into the atmosphere. Acid of any desired concentration may be produced by mixing or diluting the products of this process.

Sections in this article:

• Introduction
• History of Sulfuric Acid
• Uses of Sulfuric Acid
• Contact Process
• Lean Chamber Process
• Production of Sulfuric Acid
• Dilute Sulfuric Acid
• Concentrated Sulfuric Acid

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