Sulphur dioxide/oxygen mixture

About 1875 Winkler (see p. 898) was working with platinised asbestos and a sulphur dioxide-oxygen mixture made in the same way as Messel s. Rudolf T. J. Knietsch (1854-1906) first showed that the gas from burnt pyrites could be used after careful purification from catalyst poisons, and his process was adopted in 1898 by the Badische Co. Simultaneously, the same process was adopted by the firm of Meister, Lucius, and Briining at Hochst, as a result of experiments of Krauss and von Berneck. 

The lamp method involves combustion of a sample of sulphone in a closed system with an atmosphere of 30% oxygen and 70% carbon dioxide214. The mixture of sulphur dioxide and sulphur trioxide formed is converted in situ to sulphate by oxidation with hydrogen... 

Type 4A sieves. The pore size is about 4 Angstroms, so that, besides water, the ethane molecules (but not butane) can be adsorbed. Other molecules removed from mixtures include carbon dioxide, hydrogen sulphide, sulphur dioxide, ammonia, methanol, ethanol, ethylene, acetylene, propylene, n-propyl alcohol, ethylene oxide and (below -30°) nitrogen, oxygen and methane. The material is supplied as beads, pellets or powder. 

Sulphur Dioxide as an Oxidising Agent.—Sulphur dioxide does not support the combustion of most substances which burn in oxygen, but many metals, e.g. sodium, potassium, magnesium and finely divided lead, when heated in a stream of the gas undergo conversion into a mixture of sulphide and oxide or sulphite, so much heat being liberated that the mass becomes incandescent in the case of the alkali metals some thiosulphate also may be formed.12... 

In 1S78, Berthelot, by submitting a mixture of sulphur dioxide or trioxide with excess of oxygen under compression to a silent electric discharge of high potential, obtained a product which he regarded as sulphur heptoxide 1... 

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