Lurgi process

Hydrogen is supplied by injected steam and the necessary heat is supplied by the combustion of a portion of the product char. The revolving grate, located at the bottom of the gasifier, supports the bed of coal, removes the ash, and allows steam and oxygen (or air) to be introduced. 

The Lurgi product gas has a high methane content relative to the products from non-pressurized gasifiers. With oxygen injection, the gas has a heat content of ca. 450 Btu/ft (16.8 MJ/m). 

The crude gas which leaves the gasifier contains tar, oil, phenols, ammonia, coal fines, and ash particles. The steam is first quenched to remove the tar and oil, and, prior to methanation, part of 

Slagging fixed bed (Grand Forks Energy Research Center) 

Source Braunslein, H.M. et al.. Environmental health and control aspects of coal conversion An information overview. 

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Benfield process Removal of carbon dioxide from fuel gases, such as those obtained by gasifying coal in the Lurgi process, by countercurrent scrubbing of the gases by hot potassium carbonate solution. 

If air (or oxygen) and steam are both passed through a high-temperature bed of coal or coke these reactions can be balanced, thus controlling the bed temperature and the fusion of the ash. In the higher pressure Lurgi process the gas obtained is high in methane, formed in reactions such as... 

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. 

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). 

In the Godrej-Lurgi process, olefins are produced by dehydration of fatty alcohols on alumina in a continuous vapor-phase process. The reaction is carried out in a specially designed isothermal multitube reactor at a temperature of approximately 300°C and a pressure of 5—10 kPa (0.05—0.10 atm). As the reaction is endothermic, temperature is maintained by circulating externally heated molten salt solution around the reactor tubes. The reaction is sensitive to temperature fluctuations and gradients, hence the need to maintain an isothermal reaction regime. 

Coal-Based Partial Oxidation Processes Two commercially establislied processes utilising coal feeds are the Lurgi process (32) and the Koppers-Tot2ek process (33) the process schemes are shown ia Figures 6 and 7, respectively. 

The original hot carbonate process developed by the U.S. Bureau of Mines was found to be corrosive to carbon steel (55). Various additives have been used in order to improve the mass transfer rate as well as to inhibit corrosion. Vetrocoke, Carsol, Catacarb, Benfteld, and Lurgi processes are all activated carbonate processes. Improvements in additives and optimization of operation have made activated carbonate processes competitive with activated MDEA and nonaqueous solvent based systems. Typical energy requirements are given in Table 9. 

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. 

P. F. H. Rudolph, "The Lurgi Process—The Route to SNG From Coal," Fourth Synthetic Pipeline Gas Symposium, Chicago, IU., 1972. 

Figure 1. Lurgi process for producing SNG from coal...

Mainly C,0-C14 alcohols are needed for the production of surfactants. Therefore the gas phase process, which gives products of high quality, is the most employed technique. Increasingly the hydrogenation of the free acids according to the Lurgi process with suspended catalyst is carried out. 

The reaction is exothermal at temperatures of 220 to 280 °C and pressures of 5 to 10 MPa. Methanol is then converted to synthetic transportation fuels (gasoline, diesel) by the MtSynfuels (trademark by Lurgi) process (see Fig. 7.4). 

In this energy chain, coal is gasified to generate synthesis gas. The H2 CO ratio required for an optimum efficiency is adjusted via the CO shift reaction of a part of the carbon monoxide (CO) contained in the synthesis gas. The remaining synthesis gas is converted to liquid hydrocarbons via Fischer-Tropsch synthesis or via methanol synthesis with a downstream MtSynfuels (trademark by Lurgi) process (see beginning of Section 7.3.4). The liquid hydrocarbon yield amounts to about 0.40 MJ per MJ of hard coal, which is of the same order of magnitude as in the case of BTL ( 0.40 MJ/MJ) to calculate the thermal process efficiency, the electricity export must also be taken into account (see Table 7.12). 

The Lurgi-Ruhrgas process is a direct retorting operation which has been proposed for use on the Alberta oil sands. It is the view of the Authority that the next step in the further development of the Lurgi process is to carry out a test run on... 

The feed stocks include naphtha, natural gas liquids, propane and butane. The cost of SNG gas from these plants is as high as 5 to 6 per Mcf. The investment cost is very low for this type of SNG plant and is on the order of 522 per million Btu per day of capacity at a 50% load factor. This can be compared with the investment cost of high-Btu pipeline-gas-from-coal plants which is now on the order of 12,444 per million Btu per day of capacity based on the Lurgi process and 90% load factor. There are two other SNG plants in the planning or construction stage. 

In the Lurgi process a cooled tube reactor is applied. The catalyst particles are located in the tubes and cooling takes place by boiling water. The most important difference between the two reactor types is the temperature profile. In the Lurgi reactor it is much flatter than in a quench reactor. 

Substitute natural gas-coal gasification (Lurgi process with advanced methanation) 14.5 18 21.5 15... 

The BASF Lurgi process, industrialized since 1968 and employing NHnethylpyiTOlidQiie as solvent, is also One of the most widespread technologies today. It is similar in principle to the other techniques, but is difierent in its practical implementation, as shown by Fig. 3X The process takes place as If the first extraction/regeneration stq> was actually divided into three parts ... 

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