Lurgi plants

Table VII. Comparison of the Slagging Gasifier and a Commercial Lurgi Plant...

Otfier Lurgi Plants. Lurgi gasifiers have found use in a coal-based ammonia plant at Beijing, the People s Republic of China (11). The plant has four Lurgi gasifiers and produces 1,100 t/d of ammonia from anthracite. 

The chemical complex includes the methanol plant, methyl acetate plant, and acetic anhydride plant. The methanol plant uses the Lurgi process for hydrogenation of CO over a copper-based catalyst. The plant is capable of producing 165,000 t/yr of methanol. The methyl acetate plant converts this methanol, purchased methanol, and recovered acetic acid from other Eastman processes into approximately 440,000 t/yr of methyl acetate. 

Fig. 5. Diagram of large Lurgi Spblgas carbonization plant A, coal conveyor B, movable distributor C, coal bunker D, drying zone E, connecting shafts ...

The Lurgi process has been the most commercially accepted gasification method since its commercialization in 1936, and is used in the large plants in South Africa, in modified designs in Germany, and in the United States for the Great Plains faciUty (25,49,50). 

E. Supp and A. T. Weschler, "Conversion of Ammonia Plants to Methanol Production using Lurgi s Combined Reforming Technology", HTChE 1992 SpringMeeting, New Orleans. 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

The first commercial operation of the Lurgi process was in Germany in 1936 using brown coal. The reactor was modified to stir the coal bed to permit utilization of bituminous coal. One plant was built at the Dorsten Works of Steinkohlengas AG, and the Sasol plants were built in South Africa to provide synthesis gas for Hquid fuels. 

The success of the Sasol project is attributed to the availabiUty of cheap coal and the rehabiUty of the selected components. Plants using Lurgi or Koppers-Totzek gasifiers for making chemicals are located in AustraUa, Turkey, Greece, India, and Yugoslavia, among other countries. 

A development of interest to the chemical industiy is the tubular precipitator of reinforced-plastic construction (Wanner, Gas Cleaning Plant after T1O2 Rotary Kilns, technical bulletin, Lurgi Corp., Frankfurt, Germany, 1971). Tubes made of polyvinyl chloride plastic are reinforced on the outside with polyester-fiber glass. The use of modern economical materials of construction to replace high-maintenance materials such as lead has been long awaited for corrosive applications. 

Status of Indirect Liquefaction Technology The only commercial indirect coal liquefaction plants for the production of transportation fuels are operated by SASOL in South Africa. Construction of the original plant was begun in 1950, and operations began in 1955. This plant employs both fixed-bed (Arge) and entrained-bed (Synthol) reactors. Two additional plants were later constructed with start-ups in 1980 and 1983. These latter plants employ dry-ash Lurgi Mark IV coal gasifiers and entrained-bed (Synthol) reactors for synthesis gas conversion. These plants currently produce 45 percent of South Africa s transportation fuel requirements, and, in addition, they produce more than 120 other products from coal. 

The German Lurgi Company and Linde A. G. developed the Rectisol process to use methanol to sweeten natural gas. Due to the high vapor pressure of methanol this process is usually operated at temperatures of -30 to -100°F. It has been applied to the purification of gas 1 plants and in coal gasification plants, but is not used commonlv natural gas streams. 

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