ABSTRACT
Large-scale methyl alcohol processes based on hydrogen-carbon oxide mixtures were introduced in the 1920s. Conventional methyl alcohol technology has been modified by the development of a two step or combined reforming process. The hydrocarbon feedstock, desulphurized by passing over activated carbon or hot zinc oxide at 400°C, is mixed with process steam at 2 bar before entering a tubular reformer. The tubes, packed with a promoted nickel catalyst, are heated from the outside. The ratio of hydrogen and carbon is adjusted to give a stoichiometric ratio of 2:1 by purging excess hydrogen or adding carbon dioxide. The product gas is scrubbed with water, desulphurized and adjusted to the optimum ratio of hydrogen and carbon monoxide before being fed directly into the methyl alcohol synthesis loop. Methyl alcohol is one of the world’s major chemicals, its most important outlet being in the manufacture of formaldehyde which accounts for around a third of total demand.
