Abstract: A method for removing a perfluoroalkyl alcohol from a waste gas and recovering the perfluoroalkyl alcohol comprising the steps of bringing the waste gas into contact with an aqueous alkaline solution thereby to absorb the perfluoroalkyl alcohol into said solution and consequently obtain an aqueous alkaline solution containing an alkoxide of the perfluoroalkyl alcohol. Adding an acid to the aqueous alkaline solution containing the alkoxide of the perfluoroalkyl alcohol until the alkaline solution turns into an acidic solution with a pH value smaller than 5, thereby to turn said alkoxide into said perfluoroalkyl alcohol and subjecting the acidic solution to distillation to recover the perfluoroalkyl alcohol.

Abstract: A group of polyfluoroaldehydes represented by 3,3,3-trifluoropropanal can be formed with very good selectivity by reacting polyfluoroalkenes represented by 3,3,3-trifluoropropene with water in the presence of a source of divalent palladium. A group of polyfluoroacetals represented by 1,1-dialkoxy-3,3,3-trifluoropropane can be formed with very good selectivity by reacting the same polyfluoroalkenes with an alcohol in the presence of a source of divalent palladium.

Abstract: 1,1,1,3,3,3-hexafluoropropane-2-ol is prepared easily and efficiently by gas-liquid reaction between hydrogen gas and a hexafluoroacetone hydrate such as trihydrate, which is liquid at room temperature, using a suitable catalyst such as active carbon-palladium catalyst. Preferably the gauge pressure of hydrogen gas is 2-10 kg/cm.sup.2, and the hydrogenolysis reaction temperature is 70.degree.-100.degree. C. The life of the catalyst can be prolonged by the addition of a small quantity of sodium hydroxide. The addition of a small quantity of aluminum hydroxide is effective in suppressing the formation of fluorine ions in the reaction liquid.