The unit design is based on a high pressure catalytic reforming method to produce 1000 short tons per stream day of anhydrous liquid ammonia from primary raw materials comprising natural gas (chiefly methane), steam and air. Included, as an integral part of the design, are items of equipment with sufficient steam generating capacity to satisfy the process and equipment requirements of the plant. This is accomplished with an auxiliary gas fired boiler and waste heat exchangers that utilize a common steam separator drum and steam superheater system. The water treating and boiler feed water systems are common to the auxiliary boiler and waste heat steam exchangers.
The production of the liquid anhydrous ammonia is accomplisehd in the following processing steps:
1. Raw Synthesis Gas Preparations
a. Desulfurization (by absorption)
b. Reforming (primary)
c. Secondary Reforming plus Nitrogen Addition
d. Carbon Monoxide (CO) Shift and Carbon Dioxide (CO2)
2. Synthesis Gas Purification
a. Carbon Dioxide (CO2) removal by absorption.
b. Conversion of CO and trace amounts of CO2 (total oxides) by Methanation.
3. Liquid Ammonia Synthesis (Production)
a. Compression of synthesis feed gas
b. Synthesis (conversion) of synthesis gas to ammonia
c. Separation of liquid ammonia from the synthesis gas (chilling)
4. Removal of Uncondensibles (Methane and Argon)
Approximately 1.140 tons per day of carbon dioxide (CO2) plus water is released from the CO2 stripper in the purification section and vented to the atmosphere as a waste by-product of the process. Purge and flash gases from the synthesis loop and refrigeration systems are routed to the fuel gas system for use in the arch, tunnel and 103-B burners. Ammonia produced at 1,000 short tons per stream day is delivered to battery limits from the first stage, refrigerant flash drum (110-F) and from the third stage refrigerant flash drum (112-F) at a combined temperature of -2°C (28°F)
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