Methanol Lurgi process

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 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. 

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 processes listed in Table 9.4 that are reported to be used commercially to supply synthesis gas for methanol production are the Lurgi process, the... 

As with the Commercial Solvents process, essentially all plants using this process have been replaced by new processes. In fact, in the United States only three processes are used for the manufacture of methanol. Of the total U.S. capacity, 63.3% is based on the Lurgi process 34.8% is based on the ICI process. 

Flow sheet of the Lurgi low pressure methanol synthesis process. 

The reactions are exothermal and volume-reducing, thus low temperatures and high overpressures are desirable. A catalyst is required to maximize methanol output. The specific consumption is 2300 Nm of CO and H2 per ton of methanol. A processing scheme has been proposed by Lurgi (see Fig. 7-1). Nowadays conventional synthesis reactors have a capacity of up to 3(XX) t/d of methanol. 

A side stream of gas is bypassed around the shift unit to achieve the correct Hj CO ratio for the methanol synthesis process. Methanol synthesis itself operates at about 80 bar using the Lurgi Low Pressure Methanol Process followed by a distillation step to achieve the required product quality specification. 

In order to control heat removal and therefore the catalyst temperature, multiple-tube reactors (Lurgi process) or quench reactors with several catalyst layers and introduction of cold gas (ICI process) are mainly used. Catalyst performance in modern larger reactors is 1.3-1.5 kg of methanol per liter per hour, and large-scale plants have capacities of up to 10 fra, which reflects the position of methanol as a key product of Ci chemistry. 

The following subsection briefly describes current industrial processes for methanol production with adiabatic multi-bed and isothermal single-bed reactor design. We will refer to the ICI (adiabatic multiple-bed reactor) and to the Lurgi process (isothermal single-bed reactor), which are important representatives of the different ways of producing methanol commercially nowadays. 

Excess reagent. Methanol (wood alcohol), formerly produced by the distillation of wood, is produced by the Lurgi process, CO(g) -I- 2Hx jg) CH30H(1). If equal masses of reactants are used, which one is present in excess ... 

The Lurgi process requires the use of a degummed and deacidified feedstock. The refined vegetable oil and methanol are reacted in a two-stage mixer-settier arrangement in the presence of a catalyst. The glycerine produced in the reaction, dissolved in the surplus methanol, is recovered in the rectification column. Most of the entrained methanol and glycerine are recovered from the methyl ester in the countercurrent scrubber. The methyl ester can be further purified by distillation (6). 

Supp. E., Technology of Lurgi s Low Pressure Methanol Process, Chem. Tech., 3 430, 1973. 

Cold methanol has proven to be an effective solvent for acid gas removal. Cold methanol is nonselective in terms of hydrogen sulfide and carbon dioxide. The carbon dioxide is released from solution easily by reduction in pressure. Steam heating is required to release the hydrogen sulfide. A cold methanol process is Hcensed by Lurgi as Rectisol and by the Institute Francaise du Petrole (IFP) as IFPEXOL. 

AMISOL A process for removing sulfur compounds and carbon dioxide from refinery streams by absorption in methanol containing mono- or di-ethanolamine and a proprietary additive. Developed by Lurgi, Germany, in the 1960s and first commercialized in the early 1970s. 

Hytanol A peak shaving process for making fuel gas from methanol. Offered by Lurgi. 

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