Heavy Water Plant at Talcher employs the ammonia-hydrogen exchange process (Bithermal). The plant is located at a distance of 150 Kms. from Bhubaneshwar. The work on this plant in October 1972 and it was commissioned in March 1985.

Process Description :

Synthesis gas (a mixture of one part of nitrogen and three parts of hydrogen)

The pressure of the synthesis gas is first raised by 10-15 Kg/cm². to take care of pressure drop in the transfer section. The gas is passed through a purification unit to remove impurities like O₂, CO, CO₂, Oil and water vapour, and to saturate it with ammonia by washing with liquid ammonia and ammonical solution of potassium amide. The purified saturated gas is then passed through the transfer column operating at -30 deg. C., where deuterium in the gas is transferred to a counter current streams of liquid ammonia obtained from the enrichment section and containing potassium amide catalyst. The depleted synthesis gas from the transfer column is sent back to the fertilizer plant