Abstract: A process for the removal of organic impurities and dissolved salts from hydrazine hydrate and aqueous solutions thereof by distillation of the hydrazine hydrate under reduced pressure, passing the hydrazine hydrate vapor through an adsorbent, and condensing the vapor.

Abstract: In the purification of thionyl chloride by addition of sulphur and distillation in the presence of a catalyst, the improvement which comprises effecting the distillation in the presence of an aluminum compound as the catalyst. Advantageously the aluminum compound is aluminum chloride, the sulphur is added in about 2.5 to 7% by weight based on thionyl chloride, the aluminum chloride is in admixture with sulphur monochloride in about 0.01 to 5% by weight calculated as aluminum and based on thionyl chloride, and prior to distillation the mixture of crude thionyl chloride, sulphur and aluminum chloride is heated to between about 50.degree. and 60.degree. C. for about 10 to 60 minutes. The resulting thionyl chloride is of extremely high purity.

Abstract: In the removal of water from a gas by contact with sulfuric acid, the improvement which comprises supplying the sulfuric acid in finely divided form having a surface of about 10.sup.4 to 10.sup.7 m.sup.2 /h at a concentration of about 95 to 99% and a temperature of about 35.degree. to 80.degree. C and with a contact time of about 0.2 to 2 seconds, whereby the residual moisture content of the gas is reduced to about 30 to 250 mg of H.sub.2 O/Nm.sup.3. Preferably the sulfuric acid is sprayed through a constriction into a vessel through which the gas is passed. The large sulfuric acid surface area permits high levels of dehydration to be achieved with far less sulfuric acid than heretofore believed possible and with small vessels and minimal contact times. Contact may be effected serially in several stages with the spent acids combined, brought up to initial concentration and recirculated.