Improvements in or relating to the preliminary treatment or purification of illuminating or coal gas or coke oven gases intended for the recovery of hydrogen by partial liquefaction

摘要

195,598. Soc. l'Air Liquide, Soc. Anon. pour l'Etude et l'Exploitation des ProcÚdÚs G. Claude. March 30, 1922, [Convention date]. Separating gaseous mixtures by liquefaction.-In a preliminary purification of coal or coke-oven gases prior to partial liquefaction, the gases, after having been dried and freed from sulphur compounds, benzol and carbon-dioxide, are passed through a heat exchanger E which they enter by a pipe A, and travel in counter current to the hydrogen, nitrogen, carbon monoxide and methane previously separated from the gases; the hydrogen circulates from pipe B to pipe C and the remaining gases from pipe D to pipe X. As the gases descend they are cooled, but the more condensible constituents are prevented from solidifying by mixture with the liquefied and less easily condensible constituents. The liquid mixture so obtained comprising all the easily condensible gases and a little methane is drawn off through a cock R, and reheated by passage through a coil S. If the proportion of methane is high, liquids less rich in methane may be drawn off through a cook R1 at a higher level. The apparatus may be modified to collect the condensates fractionally by arranging draw off cocks at suitable heights. A small quantity of alcohol may be added to the gases and the alcoholic liquid containing all the water in the gases removed by collectors in the upper part of the heat exchanger. Specifications 174,327 and 175,605 are referred to.