Gases - Fundamentals of Industrial Chemistry: Pharmaceuticals, Polymers, and Business - page 17

CHAPTER 3

Gases

3.1 SYN GAS

Carbon monoxide and hydrogen are perhaps two of the simplest
building blocks in chemistry. Carbon monoxide can be converted to
other one-carbon molecules such as methanol, used to make hydrocarbons as
in the Fischer-Tropsch process, or used to extend molecules by addition of
one carbon as in hydroformylation of alkenes. Hydrogen has many uses. It is
used to make inorganic compounds such as ammonia or make hydrocarbons.
Hydrogen has widespread use in the reduction of unsaturated organic
compounds. Many processes rely on both carbon monoxide and hydrogen.
Examples include the production of methanol, the Fischer - Tropsch process
and hydroformylation reactions. In addition to often being used together,
they are typically coproduced.
Syn gas, or synthesis gas [1, 2], is a term for mixtures of hydrogen and
carbon monoxide. Coal was the major feedstock, but today the mixture is
mainly made by the partial oxidation of hydrocarbons. The source of the
hydrocarbon varies, but is commonly natural gas or petroleum distillates.
The composition of natural gas varies depending on its source but it is mainly
methane and can have other components such as hydrogen, ethane, propane,
butane, and nitrogen. Often the petroleum distillates used for the production
of syn gas are the heavier fractional residues left after the oil distillation in
the gasoline refining process. The partial oxidation is exothermic and in the
case of petroleum, gives a 1:1 molar yield of carbon monoxide and hydrogen.

CH 2 + 0.5 O 2 CO + H 2

The exotherm can be controlled by employing a second endothermic
reaction with steam.