1924:

Construction of the First Plant for Coke Gas Separation

In a collaborative effort with the Rombacher Hüttenwerken, an experimental plant in Oberhausen was constructed in 1921. This served to do research into the possibility of separating coke furnace gas, a by-product of coke plant operations, into its component parts methane and ethylene. Basing their work on research results and experience in water gas separation, Linde ultimately developed a process to extract pure hydrogen from coke furnace gas.

By sprinkling the hydrogen with liquid nitrogen, the final remaining admixtures such as carbon oxide, oxygen and methane are washed out. The mixture of hydrogen and nitrogen extracted by this method is, because of its unusual purity, the ideal base gas for the synthetic production of ammonia. Ammonia can then be further processed to make such products as nitric acid and fertilizers. The first plant for the extraction of a hydrogen-nitrogen mixture from coke furnace gas was ordered by a Belgian firm in 1924.

Plant for the separation of coke gas in New Orleans, USA (1954)

When coke furnace gas is separated, a by-product with an ethylene content of about 30 per cent also occurs. A special rectification process finally enabled Linde to extract pure ethylene. Ethylene is gaseous and one of the simplest hydrocarbon compounds. It can, for example, be used as a ripening hormone for fruit and vegetables. Ethylene acquired its greatest significance, however, as a raw material for the manufacture of the plastic polyethylene, from which, for example, foils are made. The first plant for the extraction of ethylene was built in 1931 for the Chemische Fabrik Holten and served for the manufacture of the anti-freeze glycol.