Synthesis gas A mixture of hydrogen

As an example of the application of a fixed-bed tubular reactor, consider the production of methanol. Synthesis gas (a mixture of hydrogen, carbon monoxide, and carbon dioxide) is reacted over a copper-based cat dyst. The main reactions are... 

Methane. The largest use of methane is for synthesis gas, a mixture of hydrogen and carbon monoxide. Synthesis gas, in turn, is the primary feed for the production of ammonia (qv) and methanol (qv). Synthesis gas is produced by steam reforming of methane over a nickel catalyst. 

Methanol [67-56-1] (methyl alcohol), CH OH, is a colorless Hquid at ambient temperatures with a mild, characteristic alcohol odor. Originally called wood alcohol siace it was obtained from the destmctive distillation of wood, today commercial methanol is sometimes referred to as synthetic methanol because it is produced from synthesis gas, a mixture of hydrogen and carbon oxides, generated by a variety of sources. 

When methanol is made from natural gas, the gas reacts with steam to produce synthesis gas, a mixture of hydrogen and carbon monoxide. This then reacts with a catalytic substance at high temperatures and pressures to produce methanol. The process is similar when methanol is produced by the gasification of biomass. The production of methanol from biomass or coal can cost almost twice as much as production from natural gas. 

The key to the efficient and clean manufacture of hydrogen from coal is to gasify the coal first, to produce a synthesis gas—a mixture of hydrogen and CO—and then to further process the CO with water to produce additional hydrogen and C02. 

Although abundant supplies of methane exist, it can also be produced synthetically. For example, the reaction between steam and hot coal results in the formation of synthesis gas, a mixture of hydrogen and carbon monoxide. When this mixture is passed over a catalyst containing nickel metal, methane is formed. A very similar process, called the Sabatier process, uses a mixture of hydrogen and carbon dioxide, rather than carhon monoxide, also resulting in the formation... 

Frans Fischer (1877-1947) and Hans Tropsch (1889-1935) discovered the reaction that carries their names around 1923 at the Kaiser Wilhelm Coal Research Institute in Miilheim, Germany. This process converts synthesis gas, a mixture of hydrogen and carbon monoxide, into a complex set of hydrocarbons that can be refined using petroleum processing technology. 

The conversion of the gaseous products of gasification processes to synthesis gas, a mixture of hydrogen (Hj) and carbon monoxide (CO), in a ratio appropriate to the application, needs additional steps, after purification. The product gases—carbon monoxide, carbon dioxide, hydrogen, methane, and nitrogen—can be used as fuels or as raw materials for chemical or fertilizer manufacture. 

Reformer. This unit chemically converts hydrocarbon or alcohol to synthesis gas (a mixture of hydrogen and carbon monoxide). The two most practical oxidants are steam and air. If air is used, the reformer is referred to as a partial oxidation (POX) reformer if steam is used, a steam reformer (SR), and if a mix of air and steam is used, an autothermal reformer (ATR). The choice of reformer type depends on a number of factors. Typically, POX reformers are smaller, cheaper, respond faster, and are suitable for a wide range of fuels. Steam reformers enable a higher system efficiency. ATRs and catalytic POX reformers (CPOX) share some of the advantages of each type ... 

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