Abstract: An electrolytic bath is divided into an anodic chamber and a cathodic chamber by a cation-exchange membrane. A base alkaline solution of high impurity concentration is supplied into the anodic chamber from a tank of a base material as well as a circulating anolyte overflowed from the anodic chamber is supplied and circulated from an anode circulating tank, and NaOH solution of low impurity concentration is supplied and circulated into the cathodic chamber through a tank of a refined solution. The concentration of the circulating anolyte is detected, and based on this detected value the supplying amount of the base NaOH solution is controlled and electrolysis is performed. Thus, the concentration of NaOH solution in the anodic chamber is kept stable, and the refined NaOH solution of low impurity concentration can be obtained in the cathodic chamber.

Abstract: An electrolytic bath is divided into an anodic chamber and a cathodic chamber by a cation-exchange membrane. A base alkaline solution of high impurity concentration is supplied into the anodic chamber from a tank of a base material as well as a circulating anolyte overflowed from the anodic chamber is supplied and circulated from an anode circulating tank, and NaOH solution of low impurity concentration is supplied and circulated into the cathodic chamber through a tank of a refined solution. The concentration of the circulating anolyte is detected, and based on this detected value the supplying amount of the base NaOH solution is controlled and electrolysis is performed. Thus, the concentration of NaOH solution in the anodic chamber is kept stable, and the refined NaOH solution of low impurity concentration can be obtained in the cathodic chamber.

Abstract: Epoxidized C6-C12 cyclohydrocarbon compounds, for example, epoxidized C6-C12 cycloalkanes, cycloalkenes and/or cycloalkadienes are converted to cycloalkanols, cycloalkanones and cycloalkanes by hydrogenating the epoxidized C6-C12 cyclohydrocarbon compounds with hydrogen under a pressure of 0.1 to 5.4 MPa at a temperature of 100 to 280° C. in the presence of a catalyst containing at least one platinum group metal, for example, Pd or Ru.

Abstract: A dehydration catalyst useful for producing a monoalkylether of dihydric phenolic compound by a dehydration reaction of a dihydric phenolic compound with a lower alkyl alcohol with a high conversion at a high selectivity, comprises at least one inorganic substance of the empirical formula (I):Al.sub.a P.sub.b Ti.sub.c Si.sub.d X.sub.e O.sub.f (I)wherein X represents a member selected from the group consisting of (1) an antimony and/or a bismuth atom, and (2) a sulfur atom, a, b, c, d, e and f respectively represent the numbers of Al, P, Ti, Si, X and 0 atoms, the atomic ratio a:b is 1:1.0 to 1.9, the atomic ratio a:c is 1:0.05 to 0.5, the atomic ratio a:d is 1:0.05 to 0.2, the atomic ratio a:e is 1:0.01 to 0.3 when X represents antimony and/or bismuth atom and 1:0.004 to 0.015 when X represents a sulfur atom, and the atomic ratio a:f is 1:4.1 to 8.4.

Abstract: A monoalkylether of a dihydric phenol compound is produced at a high conversion and selectivity by catalytically dehydration reacting a dihydric phenol compound with a lower monohydric alcohol in the presence of a catalyst comprising at least one inorganic substance of the empirical formula (I):Al.sub.a P.sub.b Ti.sub.c Si.sub.d X.sub.e O.sub.f (I):wherein X is an alkali metal (Group Ia) atom, alkaline earth metal (Group IIa) atom or a metal atom of Group VIII of the Periodic Table, a, b, c, d, e and f are the numbers of Al, P, Ti, Si, X and O atoms respectively, and provided that a =1, b =1.0 to 1.9, c =0 05 to 0.5, d=0.05 to 0.2, e=0 to 0.9 and f=4.2 to 8.1, and collecting the resultant reaction product from the reaction system.