Coal processing: coal-based ammonia plant operation

Journal Article · Sun Aug 01 04:00:00 EDT 1976 · Chem. Eng. Prog.; (United States)

OSTI ID:7336574

Partridge, L J

Near the end of 1974, a 1100 short ton/day coal-based ammonia plant based on the Koppers-Totzek low pressure, high temperature, coal gasification process was brought on stream at the AE and CI Modderfontein plant near Johannesburg, South Africa. The plant feedstock is a semi-bituminous coal containing about 14 percent ash, 36 percent volatiles, and 1 percent sulfur. Oxygen for the gasifiers is supplied from a single-stream air separation unit. Coal dust, produced in two large ring and ball mills, is gasified in six gasifiers. The gas is compressed and desulfurized by washing with methanol at -36/sup 0/F at a pressure of about 30 atmospheres. Desulfurized gas containing about 58 percent CO is reacted with steam over conventional iron high temperature shift catalyst to produce hydrogen. Carbon dioxide is removed from the gas by washing with methanol at -72/sup 0/F at a pressure of about 51 atmospheres. Final gas purification to remove residual carbon monoxide, argon, and methane is by washing with liquid nitrogen at -310/sup 0/F. Ammonia synthesis is at about 220 atmospheres in a conventional synthesis loop with ammonia refrigeration. Among the problems encountered during startup were valve and joint failures, a dust bunker explosion, and erosion from ash particles impinging on boiler tubes.

• Research Organization: AE and CI, Modderfontein, South Africa
• OSTI ID: 7336574
• Journal Information: Chem. Eng. Prog.; (United States), Journal Name: Chem. Eng. Prog.; (United States) Vol. 72:8; ISSN CEPRA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
010500 -- Coal
Lignite
& Peat-- Products & By-Products
090320 -- Inorganic Hydrogen Compound Fuels-- Preparation-- (1976-1989)
10 SYNTHETIC FUELS
AMMONIA
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COAL GASIFICATION
CONTROL
CONTROL SYSTEMS
DESULFURIZATION
DIAGRAMS
DUSTS
ELECTROSTATIC PRECIPITATORS
EQUIPMENT
EROSION
EXPLOSIONS
FLOWSHEETS
FUEL FEEDING SYSTEMS
FUEL SYSTEMS
GASIFICATION
HYDRIDES
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KOPPERS-TOTZEK PROCESS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL EQUIPMENT
RECTISOL PROCESS
SYNTHESIS
TOXICITY