The cold synthesis gas depleted in deuterium from the first exchange tower, before its return to Ammonia Plant, is heated by the incoming feed gas and is passed through an ammonia synthesis unit. In this unit, a portion of the synthesis gas equivalent to the amount of the ammonia cracked in the crackers is converted into liquid ammonia and fed to the top of first exchange tower.  The rest of the depleted synthesis gas equivalent to the feed gas supplied is returned to the ammonia plant.

    The power to the plant is supplied by Gujarat State Electricity Board from their 66 KV grid.  For heating of the crackers of the plant the fuel used is natural gas which is supplied by ONGC.

Some of the special features of the plant are:

1.HWP (Hazira) is the second heavy water plant in the country based on the ammonia-hydrogen exchange process which has been set up without foreign collaboration.  The basic design of isotopic exchange unit was developed in-house.

2.The plant adopts the latest technology using micro-processor based distributed digital control system for instrumentation and process control instead of the conventional pneumatic analogue system.   The system provides supervisory and monitoring functions for feed control stations.   It displays and records data acquired from the plant system and has facilities for data logging and printing alarm messages.

3.This plant comprises of two streams with some common units like synthesis unit, sub-station, inert gas unit, instrument air unit, catalyst preparation unit, cooling towers etc.

4.Completion of the project has been successfully achieved without any time overrun.