Nitric Acid Scrubber

Explanation

  • Nitric acid is one of the most common mineral acids in the chemical Industry. It is produced by a high temperature oxidation of ammonia with oxygen catalyzed by a platinum/rhodium contact.
  •  This results in a nitric acid/water mixture with a strength of up to almost 68 wt% nitric acid.  The majority of nitric acid is used for the production of fertilizers.
  • Other processes such as the production of explosives, pigments, rocket fuels or polyurethanes require higher concentrated nitric acid. 

Features

These plants are built with highly corrosion resistant components made of borosilicate glass 3.3 and glass-lined steel manufactured by De Dietrich Process Systems.  Process designs are always optimized for the utilities available at your site.  Optimization and adaptation of these processes according to your feed stream and your quality specification of the product can be tested at our experimental facility.

Mechanism

The system nitric acid / water (HNO3/H2O) displays a maximum azeotrope at about 68 wt% and a boiling temperature of 120°C at ambient pressure. In order to manufacture high-concentrated nitric acid, it is necessary to overcome the azeotrope point by using high-concentrated sulfuric acid.

Rectification processes are used for the pre-concentration of nitric acid (HNO3) from below 55 wt%, where water is distilled to the head section and nitric acid to the bottom, up to 67 wt%. These columns are operated with minimum reflux ratio for energy saving reasons so either tray columns or glass packaging columns (DURAPACK) are used.

Low energy consumption is achieved by:

  • Indirect heating of the high-concentrated nitric acid by employing a horizontal evaporator.
  • Supplementary and indirect heating performed by intermediate heaters and energy integration.
  • Optimized inflow conditions due to preliminary mixing of the feed flows.

Applications

Despite these complexities, there are several applications that use wet scrubbers for NOx abatement. These include nitric acid manufacturing, metal finishing operations, and other types of chemical processing.