GB835751A - Improvements in the removal of impurities from gases or vapours - Google Patents

Abstract

In a process for the removal of impurities from a gas or vapours, the gas or vapour is passed over a mixture comprising a copper compound which has been precipitated together with or on to a precipitate of one or more compounds of magnesium and/or iron and optionally cobalt and/or nickel. Suitable compounds are the hydroxides, carbonates and silicates and the weight ratio of copper to the other metals in the mixture may vary between 1 : 20 and 20 : 1, preferably lying between 1 : 2 and 2 : 1. Small amounts of compounds of the alkaline earth metals, zinc, cadmium, chromium, molybdenum, tungsten, vanadium, uranium, titanium and/or thorium, singly or in admixture with one another may be incorporated in the mixture. The purification may be carried out at any pressure or reduced pressure and at room temperature or a temperature below 0 DEG C. or at an elevated temperature. The mixture may be reduced, e.g. with hydrogen at between 80 DEG and 150 DEG C., before use as a purifying material. Impurities which can be removed are inorganic and organic sulphur compounds, oxygen, formaldehyde, acetylene and its homologues, halogens and their compounds, e.g. hydrochloric acid and vinyl chloride, hydrogen cyanide; pyridine, nitrogen di-oxide, nitric acid, carbon monoxide, metal carbonyls and ammonia. Gases or vapours which can be purified are nitrogen, carbon dioxide, ethylene, propylene or other gaseous hydrocarbons or their derivatives, hydrogen or synthesis gases or cracking gases containing hydrogen in admixture with carbon monoxide or nitrogen, and the vapours of liquid hydrocarbons such as gasoline or benzene. In described applications of the process oxygen is removed from air to obtain nitrogen, oxygen, acetylene and hydrogen sulphide are removed from ethylene or propylene, hydrogen sulphide is removed from carbon di-oxide, oxygen is removed from hydrogen, organic sulphur compounds are removed from hydrogen and thiophene is removed from benzene in the presence of hydrogen. Regeneration of exhausted purifying material may be effected by oxidation or reduction at an elevated temperature, e.g. by reduction with hydrogen at 150 DEG C., or when the material has been used to remove acetylene by passing nitrogen over the material.ALSO:In a process for the removal of impurities from a gas or vapour, the gas or vapour is passed over a mixture comprising a copper compound which has been precipitated together with or on to a precipitate of one or more compounds of magnesium and/or iron and optionally cobalt and/or nickel. Suitable compounds are the hydroxides, carbonates and silicates and the weight ratio of copper to the other metals in the mixture may vary between 1 : 20 to 20 : 1, preferably lying between 1 : 2 and 2 : 1. Small amounts of compounds of the alkaline earth metals, zinc, cadmium, chromium, molybdenum, tungsten, vanadium, uranium, titanium and thorium, singly or in admixture with one another may be incorporated in the mixture. The purification may be carried out at any pressure or reduced pressure and at room temperature or a temperature below 0 DEG C. or at an elevated temperature. The mixture may be reduced, e.g. with hydrogen at between 80 DEG and 150 DEG C., before use as a purifying material. Impurities which can be removed are inorganic and organic sulphur compounds, oxygen, formaldehyde, acetylene and its homologues, halogens and their compounds, e.g. hydrochloric acid and vinyl chloride, nitric acid, carbon monoxide, metal carbonyls, and ammonia. Gases or vapours which can be purified are nitrogen, carbon dioxide, ethylene, propylene or other gaseous hydrocarbons or their derivatives, hydrogen or synthesis gases or cracking gases containing hydrogen in admixture with carbon monoxide or nitrogen, and the vapours of liquid hydrocarbons such as gasoline or benzene. In described applications of the process oxygen is removed from air to obtain nitrogen, oxygen, acetylene and hydrogen sulphide are removed from ethylene or propylene, hydrogen sulphide is removed from carbon di-oxide, oxygen is removed from hydrogen, organic sulphur compounds are removed from hydrogen and thiophene is removed from benzene in the presence of hydrogen. Regeneration of exhausted purifying material may be effected by oxidation or reduction at an elevated temperature, e.g. by reduction with hydrogen at 150 DEG C., or when the material has been used to remove acetylene by passing nitrogen over the material.