Feedstocks methanol synthesis

Liquid Fuels via Methanol Synthesis and Conversion. Methanol is produced catalyticaHy from synthesis gas. By-products such as ethers, formates, and higher hydrocarbons are formed in side reactions and are found in the cmde methanol product. Whereas for many years methanol was produced from coal, after World War II low cost natural gas and light petroleum fractions replaced coal as the feedstock. 

Of the indirect liquefaction procedures, methanol synthesis is the most straightforward and well developed [Eq. (6)]. Most methanol plants use natural gas (methane) as the feedstock and obtain the synthesis gas by the steam reforming of methane in a reaction that is the reverse of the methanation reaction in Eq. (5). However, the synthesis gas can also be obtained by coal gasification, and this has been and is practiced. In one modern low-pressure procedure developed by Imperial Chemical Industries (ICI), the synthesis gas is compressed to a pressure of from 5 to 10 MPa and, after heating, fed to the top of a fixed bed reactor containing a copper/zinc catalyst. The reactor temperature is maintained at 250 to 270°C by injecting... 

The current primary feedstock for industrial methanol synthesis is synthesis gas a mixture of CO, C02> and hydrogen derived from the reforming of natural gas or other hydrocarbons [2], The interconversion of carbon oxides and methanol, central to methanol synthesis and steam reforming, is defined by the following three equilibrium equations ... 

Methanol synthesis plants utilizing the low-pressure process currently operate at capacities of 2 x 105 to 2 x 106 metric tons per year [15]. Such installations are composed of a synthesis gas production unit, the actual methanol synthesis reactor, and a separation and purification section. The production and purification of synthesis gas accounts for 50%-80% of the total cost of methanol production, with the remaining cost associated with the actual synthesis and purification of methanol [2, 8], Although a variety of carbonaceous feedstocks can be transformed into synthesis gas, the steam reforming of natural gas (Equation [4]) is by far the most common option, especially for large plants [2, 15-16] ... 

Methanol. Methanol is a water-soluble, low molecular weight alcohol that may be of increasing importance as a low-sulfur fuel, a chemical feedstock, and perhaps as a gasoline additive or an intermediate in gasoline production. The synthesis of methanol is accomplished by the catalytic conversion of synthesis gas containing two moles of hydrogen for each mole of carbon monoxide. Methanol synthesis is widely practiced in industry on a commercial scale. See Chapter 10 for a discussion of methanol manufacture. 

Utilizing a natural gas feedstock for methanol synthesis, the conventional steam reforming route yields "excessive hydrogen as follows ... 

The Mitsubishi Gas Chemical Low-Pressure Methanol Synthesis Process. A schematic flow diagram of the process developed by the Mitsubishi Gas Chemical Company [27] is shown in Figure 3.16. This process also uses a copper-based methanol-synthesis catalyst and is operated at temperatures of 200-280°C over a pressure range of 50-150 atm. The temperature in the catalyst bed is kept under control by using a quench-type converter design, as well as by recovering some of the reaction heat in an intermediate stage boiler. The process uses hydrocarbon feedstock. The feed is desulfurized and... 

Haldor Topsoe A/S Low Pressure Methanol Synthesis Process. Figure 3.19 shows a schematic of Haldor Topsoe A/S process [9], starting from natural gas or associated gas feedstocks using two-step reforming. The syn-... 

Today methanol has become a very important feedstock for the production of many chemicals. Use as a clean fuel has increased and methanol is used in the production of the popular oxygenated fuel additive, MTBE. It has also been postulated that methanol could be a carrier of energy for safe transportation between remote countries. Furthermore, to prevent a greenhouse effect caused by COj generated from the tremendous oxidation reactions on the earth, methanol synthesis from CO2 is regarded as one of the potential solutions to decrease CO2 by the reaction with hydrogen which is produced by electrolysis of water, for example. Due to the increasing demand for methanol, many researchers are involved in the development of more active methanol synthesis catalysts. 

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