Purification by Fractional Liquefaction or Evaporation

If liquid air is available, the hydrogen in the methane prepared above is best removed by fractional distillation. The following is an outline of the method (see Fig. 52) — 

This process can be repeated if a very pure gas is required. In each operation about one-third of the original gas is lost. The purity of the 

The methods of fractional liquefaction and distillation have very many similar and important applications in the chemistry of gases. 

The reactions discussed below are based on the reduction of the group—  

Such reactions comprise practically all those in which hydrogen is linked to carbon to produce of necessity hydroxy compounds, which are of industrial importance, e.g., the manufacture of methanol and higher alcohols from carbon monoxide and hydrogen in presence of catalysts, such as zinc-chromium oxides. 

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