Carbon monoxide synthesis gas

Fischer-Tropsch reaction The catalytic reaction of hydrogen and carbon monoxide (synthesis gas ) to produce high-molecular weight hydrocarbons. 

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. 

A two-step-reaction sequence describes the methanol synthesis. In the first step, steam reforming, a packed bed reactor (reformer) converts methane into a mixture of hydrogen and carbon monoxide (synthesis gas), according to Equation 3.5.1. Then, in the second step, a second packed-bed reactor (converter) converts the synthesis gas into methanol, as shown by Equation 3.5.2. 

Direct oxidation of methane (natural gas) with tonnage oxygen of about 95 per cent purity is assuming increasing importance in connection with the production of hydrogen-carbon monoxide synthesis gas, raw material for the American modified Fischer-Tropsch synthesis of liquid fuels and chemicals. ... 

Synthesis gas or shortly syngas is a term used for a mixture of hydrogen and carbon monoxide. Synthesis gas is an important building block for a number of petrochemicals as well as an important feedstock for liquid fuels via the Fischer Tropsch route or as reducing gas for iron ore reduction (Fig. 1). 

The Fischer-Tropsch process was developed by F. Fischer and H. Tropsch in 1921 to produce clean alternative fuel from coal, natural gas, and low-grade refinery products for use in automobile and diesel engines. The process entails the synthesis of hydrocarbons and other aliphatic compounds, such as alcohols, from a mixture of hydrogen and carbon monoxide (synthesis gas, or syngas). The following equation illustrates the chemical reactions involved in the process ... 

Hydrogen/carbon monoxide synthesis gas production by either steam gas reforming or by partial oxidation of hydrocarbons. Steam reforming of... 

Full reviews of the early work are given by Robert Anderson and H. H. Storch. The synthesis of Itydrocarbons from hydrogen and carbon monoxide synthesis gas by Fischer, Tropsch, and their associates became known as the Fischer-Tropsch process. This has been used and developed extensively since 1955 by Sasol, in South Africa, where it is still known as the Synthol process. 

Among many methods, MSR is the main process used for producing a mixture of hydrogen and carbon monoxide (synthesis gas) and, currently, it contributes about 50% of the world s hydrogen production (Armor, 1999 Scholz,1993). 

These operations carry energy penalties, and the heat of combustion released when burning the methane, hydrogen, or carbon monoxide produced is less than the energy that would have been released had the coal been burned directly. To produce heavier liquids, the equimolar mixture of hydrogen and carbon monoxide (water gas, also known as synthesis... 

The recent interest in chemical production is based on a higher return expected for chemical [uoducts versus fuels. For example, biomass gasification can be used to produce a synthesis gas of hydrogen and carbon monoxide. This gas can be used in catalytic synthesis of a range of chemicals, from methanol and formaldehyde to higher hydrocarbons, in the same way that synthesis gas derived from natural gas can be used. However, by breaking down the biomass to the basic building blocks all product differentiation relative to fossil fuels is lost. 

Preparation. The reagent is most readily prepared from a Co (I I) salt, preferably the carbonate, but also the acetate. It has been prepared in ether or in benzene solution by the reaction of Raney cobalt with carbon monoxide at 150° under a pressure of 3,200 p.s.i. It has been prepared also from cobalt (II) carbonate and synthesis gas (I H -I CO), and by the decomposition of HCo(CO)4 ... 

It may be noted that catalyst poisons which owe their toxic properties to the presence of a multiple bond, in general lose this toxicity if they pass into saturated derivatives during hydrogenation. Thus, in the purification of ammonia synthesis gases in which the hydrogen contains small concentrations of carbon monoxide, the gas is sometimes, before its passage to the main catalyst chamber, passed through a precatalyst by means of which the traces of carbon monoxide are converted into nontoxic... 

Town or coal gas is that supplied from the local gas works and consists chiefly of a mixture of hydrocarbons, hydrogen, and carbon monoxide. Natural gas consists of a mixture of hydrocarbons, but natural gas from the North Sea is chiefly methane and therefore, in addition to its use as a fuel, may be employed as a starting material in the synthesis of other chemicals, for example, ammonia, acetylene, and alcohols. 

The chemical processes being used in the twenty-first century favor the indirect Fischer-Tropsch method of coal liquefaction. In this process, coal is initially subjected to very high heat to create a charred substance that can be combined with carbon dioxide and steam to produce a synthesis gas composed of hydrogen and carbon monoxide. The gas is then chemically subjected to a metallic catalyst, which transforms it into a synthetic crude oil. The resultant synthetic oil can then be refined into the desired fuel. 

In a plant of this type, synthesis gas was produced by the steam reforming of naphtha or natural gas at a pressure of 10-20 bar followed by shift conversion and removal of carbon dioxide and carbon monoxide. This gas was then compressed to a pressure of 300-350 bar using multistage reciprocating compressors. It was... 

In some instances, it is preferable to use copper scrubbing to remove the last traces of carbon monoxide in the ammonia synthesis gas. This process usually is carried out at pressures in the range of 1000 to 1500 psi, which are intermediate pressures of the high pressure ammonia synthesis feed compressors. The copper liquor is circulated countercurrent to the synthesis gas, picking up the carbon monoxide as a copper ammonium carbonate-carbon monoxide complex and producing a relatively carbon monoxide-free gas. Methane and argon, however, are not removed they pass on with the hydrogen to the ammonia synthesis units. 

An example of such recychng in a parallel reaction system is in the Oxo process for the production of C4 alcohols. Propylene and synthesis gas (a mixture of carbon monoxide and hydrogen) are first reacted to ra- and isobutyraldehydes using a cobalt-based catalyst. Two parallel reactions occur ... 

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... 

Synthetic oil is feasible and can be produced from coal or natural gas via synthesis gas (a mixture of carbon monoxide and hydrogen obtained from incomplete combustion of coal or natural gas). However, these are themselves nonrenewable resources. Coal conversion was used in Germany during World War II by hydrogenation or. 

A mixture of the two reactants carbon monoxide and hydrogen is called synthesis gas and IS prepared by several processes The most widely used route to synthesis gas employs methane (from natural gas) and gives a 3 1 hydrogen to carbon monoxide ratio... 

Fischer-Tropsch Process. The Hterature on the hydrogenation of carbon monoxide dates back to 1902 when the synthesis of methane from synthesis gas over a nickel catalyst was reported (17). In 1923, F. Fischer and H. Tropsch reported the formation of a mixture of organic compounds they called synthol by reaction of synthesis gas over alkalized iron turnings at 10—15 MPa (99—150 atm) and 400—450°C (18). This mixture contained mostly oxygenated compounds, but also contained a small amount of alkanes and alkenes. Further study of the reaction at 0.7 MPa (6.9 atm) revealed that low pressure favored olefinic and paraffinic hydrocarbons and minimized oxygenates, but at this pressure the reaction rate was very low. Because of their pioneering work on catalytic hydrocarbon synthesis, this class of reactions became known as the Fischer-Tropsch (FT) synthesis. 

Oxo Synthesis. Ad of the synthesis gas reactions discussed to this point are heterogeneous catalytic reactions. The oxo process (qv) is an example of an industriady important class of reactions cataly2ed by homogeneous metal complexes. In the oxo reaction, carbon monoxide and hydrogen add to an olefin to produce an aldehyde with one more carbon atom than the original olefin, eg, for propjiene ... 

The mixture of carbon monoxide and hydrogen is enriched with hydrogen from the water gas catalytic (Bosch) process, ie, water gas shift reaction, and passed over a cobalt—thoria catalyst to form straight-chain, ie, linear, paraffins, olefins, and alcohols in what is known as the Fisher-Tropsch synthesis. 

Any of the medium heat-value gases that consist of carbon monoxide and hydrogen (often called synthesis gas) can be converted to high heat-value gas by methanation (22), a low temperature catalytic process that combines carbon monoxide and hydrogen to form methane and water. 

Synthesis Gas Chemicals. Hydrocarbons are used to generate synthesis gas, a mixture of carbon monoxide and hydrogen, for conversion to other chemicals. The primary chemical made from synthesis gas is methanol, though acetic acid and acetic anhydride are also made by this route. Carbon monoxide (qv) is produced by partial oxidation of hydrocarbons or by the catalytic steam reforming of natural gas. About 96% of synthesis gas is made by steam reforming, followed by the water gas shift reaction to give the desired H2 /CO ratio. 

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