PEP Review IX-3-1
Synthesis Gas from Natural Gas or Coal
Published: May 1974
Synthesis gas mixtures of hydrogen and carbon monoxide are versatile intermediates for the production of numerous large volume organic chemicals. Over the past several decades, natural gas has replaced coal as the source of synthesis gas in the United States.
Synthesis gas is widely used for the production of methanol, and it has been proposed for the large scale production of synthetic natural gas (SNG). Numerous other alcohols, aldehydes, olefins, and hydrocarbons are also possible by Fischer-Tropsch synthesis from carbon monoxide and hydrogen. In Sasolburg, South Africa, synthetic gasoline has been produced on a commercial scale from synthesis gas. Also, there exist processes for the manufacture of ethylene and ethylene glycol from synthesis gas.
The economics of synthesis gas from coal by existing technology is greatly influenced by the scale of operation and the ratio of hydrogen to carbon monoxide in the gas. This ratio depends on the intended application of the synthesis gas. For example, the production of synthetic natural gas (methane) requires 3 mols of hydrogen per mol of carbon monoxide. For ethylene, the ratio is 2 to 1 and for ethylene glycol it is 1.5 to 1.