Abstract: A catalyst having decreased activity is subjected to a contact treatment with a reducing gas containing carbon monoxide and/or hydrogen. Also, the catalyst can be effectively activated by being treated by contacting with an oxidizing gas after having been treated by contacting with the reducing gas. As the catalyst for production of chlorine, a ruthenium catalyst, particularly a catalyst containing ruthenium oxide is suitably activated.

Abstract: A catalyst having decreased activity is subjected to a contact treatment with a reducing gas containing carbon monoxide and/or hydrogen. Also, the catalyst can be effectively activated by being treated by contacting with an oxidizing gas after having been treated by contacting with the reducing gas. As the catalyst for production of chlorine, a ruthenium catalyst, particularly a catalyst containing ruthenium oxide is suitably activated.

Abstract: There are disclosed a process for producing a ruthenium oxide-supported material, characterized in that a ruthenium compound is supported on a titania carrier in which silica is supported on titania, and the obtained material is then calcined under an atmosphere of an oxidizing gas; and a process for producing chlorine by oxidizing hydrogen chloride with oxygen in the presence of the ruthenium oxide-supported material produced by the above-described process.

Abstract: Disclosed is a process for producing chlorine, which makes it possible to successfully continue an oxidation reaction, even if sulfur component-containing hydrogen chloride is used. This process comprises a step of feeding sulfur component-containing hydrogen chloride and oxygen into a reaction tube 1 comprising a catalyst packed bed 10, to thereby oxidize the hydrogen chloride to produce chlorine, wherein the catalyst packed bed 10 includes an alumina-mixed catalyst packed bed 20 formed of a mixture of a catalyst 3 with alumina (or a diluent 4), and wherein the BET specific surface area of the alumina is from 10 to 500 m2/g. Preferably, the alumina is ?-alumina and/or ?-alumina.

Abstract: There is disclosed a process for producing chlorine by feeding hydrogen chloride and oxygen into catalyst beds which are formed in the reaction tubes of a fixed-bed multitubular reactor and which contain catalysts for use in oxidation of hydrochloric acid, and this process is characterized in that the catalyst beds in one reaction zone in the fixed-bed multitubular reactor are catalyst beds formed by packing catalysts of a plurality of production lots; and in that the catalysts of the plurality of production lots satisfy the following condition (I): Condition (I): a value of A/B is smaller than 1.20 (with the proviso that A and B are values of three significant figures, having a relationship of A?B), wherein the pore volume of a catalyst of one production lot optionally selected from the plurality of production lots is A [ml/g], and the pore volume of another one production lot is B [ml/g].

Abstract: A method for producing chlorine by oxidizing hydrogen chloride with oxygen in the presence of a catalyst, wherein the catalyst satisfies the following conditions (i) and (ii): (i) the BET specific surface area is from 1 to 250 m2/g; and (ii) the value of H/D, wherein H is the half width of the peak of a pore distribution curve as determined by a mercury intrusion method; and D is the average pore diameter, is from 0.6 to 1.5.

Abstract: The present invention provides a process for producing supported ruthenium, which comprises recovering a ruthenium compound from supported ruthenium used as a catalyst in production of chlorine by oxidation of hydrogen chloride with oxygen, and supporting the ruthenium compound on a carrier; and a process for producing chlorine, which comprises producing a supported ruthenium catalyst by the process mentioned above and oxidizing hydrogen chloride with oxygen in the presence of the supported ruthenium.

Abstract: A catalyst having decreased activity is subjected to a contact treatment with a reducing gas containing carbon monoxide and/or hydrogen. Also, the catalyst can be effectively activated by being treated by contacting with an oxidizing gas after having been treated by contacting with the reducing gas. As the catalyst for production of chlorine, a ruthenium catalyst, particularly a catalyst containing ruthenium oxide is suitably activated.

Abstract: There are disclosed a process for producing a ruthenium oxide-supported material, characterized in that a ruthenium compound is supported on a titania carrier in which silica is supported on titania, and the obtained material is then calcined under an atmosphere of an oxidizing gas; and a process for producing chlorine by oxidizing hydrogen chloride with oxygen in the presence of the ruthenium oxide-supported material produced by the above-described process.

Abstract: An object of the present invention is to provide a process for recovering ruthenium at a sufficient recovery rate from a solid in which a ruthenium compound is supported on a carrier. The present invention relates to a process for recovering ruthenium, comprising the following steps (1) to (3): (1) bringing a solid in which a ruthenium compound is supported on a carrier, into contact with a reducing gas, to thereby reduce the ruthenium compound; (2) cooling the solid obtained in the step (1) to 250° C. or lower under an atmosphere of a non-oxidizing gas; and (3) mixing the solid obtained in the step (2) with an oxidizing solution, to thereby dissolve ruthenium in the solution.

Abstract: The present invention provides a process for producing supported ruthenium oxide comprising a step of supporting a ruthenium compound on a carrier and then calcining it in an oxygen-containing gas atmosphere, wherein the ruthenium compound has a total of each content of sodium, calcium, magnesium, iron, silicon, aluminum, copper and zinc of 500 weight ppm or less based on the amount of ruthenium.

Abstract: The present invention provides a process for producing supported ruthenium, which comprises recovering a ruthenium compound from supported ruthenium used as a catalyst in production of chlorine by oxidation of hydrogen chloride with oxygen, and supporting the ruthenium compound on a carrier; and a process for producing chlorine, which comprises producing a supported ruthenium catalyst by the process mentioned above and oxidizing hydrogen chloride with oxygen in the presence of the supported ruthenium.

Abstract: A process for producing chlorine by oxidizing hydrogen chloride with oxygen. The process uses various supported ruthenium catalysts or a catalyst system containing (A) an active component of a catalyst and (B) a compound having thermal conductivity of a solid phase measured by at least one point within a range from 200 to 500° C. of not less than 4 W/m. ° C. Specifically, in the drafted Abstract, we proposed to delete the detailed description of various supported ruthenium catalysts which is present on pages 12 and 13 of the specification and in Claim 1.

Abstract: A process for producing chlorine by oxidizing hydrogen chloride with oxygen. The process uses various supported ruthenium catalysts or a catalyst system containing (A) an active component of a catalyst and (B) a compound having thermal conductivity of a solid phase measured by at least one point within a range from 200 to 500° C. of not less than 4 W/m. ° C.

Abstract: The present invention is to provide a process for producing chlorine by oxidizing hydrogen chloride with oxygen, wherein said process uses one catalyst selected from the following catalysts (1) to (9):