Some embodiments are directed to a new methodology aimed at preparing highly N-doped mesoporous carbon macroscopic composites, and their use as highly efficient heterogeneous metal-free catalysts in a number of industrially relevant catalytic transformations.

A catalyst for selectively oxidizing hydrogen sulfide to element sulfur, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to sulfur are disclosed. The catalyst for selectively oxidizing hydrogen sulfide to element sulfur is prepared by: 10-34% of iron trioxide and 60-84% of anatase titanium dioxide, and the balance being are auxiliary agents. Also a catalyst for burning tail-gas is prepared by: 48-78% of iron trioxide and 18-48% of anatase titanium dioxide, and the balance being auxiliary agents. The catalyst of the present invention has high selectivity and high sulfur recovery rate. An isothermal reactor and an adiabatic reactor of the present invention are connected in series and are filled with the above two catalysts for reactions, thus reducing total sulfur in the vented gas while having a high sulfur yield and conversion rate.

The present invention is related to a catalyst supported for the selective oxidation of sulphur compounds of the tail gas from the Claus process or streams with an equivalent composition to elemental sulphur or sulphur dioxide (SO.sub.2). It is also the object of the present invention, a process for the preparation of a catalyst of this type, as well as the process of selective oxidation of sulphur compounds to elemental sulphur using the catalyst of the invention, as well as the process of catalytic incineration of the tail gas from the Claus process using the catalyst of the present invention.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S- containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.

The invention relates to an installation and a method for treating hydrogen sulphide. In particular, the invention relates to an installation and a method comprising at least one system for oxidizing hydrogen sulfide to sulfur (S) and water (H.sub.2O) with a solid reagent and at least one oxidizing system with an agent for oxidizing the solid reagent present in the reduced state, wherein the system of oxidizing the hydrogen sulfide to sulfur and the system for oxidizing the solid reagent, are so arranged that the hydrogen sulfide is not brought into contact with the agent oxidizing the solid reagent.

Installation and method for treating a flow comprising hydrogen sulfide The invention relates to an installation and a method for treating hydrogen sulphide. In particular, the invention relates to an installation and a method comprising at least one system for oxidizing hydrogen sulfide to sulfur (S) and water (H.sub.2O) with a solid reagent and at least one oxidizing system with an agent for oxidizing the solid reagent present in the reduced state, wherein the system of oxidizing the hydrogen sulfide to sulfur and the system for oxidizing the solid reagent, are so arranged that the hydrogen sulfide is not brought into contact with the agent oxidizing the solid reagent.

A method and system for abating the emissions of at least sulfur dioxide present in a tail gas emitted from sulfur recovery units are provided. The invention is characterized by the provision of at least two adsorber units in a parallel arrangement. While one adsorber is in an adsorption mode, it receives a gas contaminated w/ sulfur dioxide and adsorbs and removes the sulfur dioxide out of the gas. The other adsorber is in regeneration mode, and receives an acid gas stream comprising hydrogen sulfide as well as an oxygen-containing gas to regenerate the spent adsorbent material and produce an off-gas comprising hydrogen sulfide and sulfur dioxide. This off-gas is then recycled back to the sulfur recovery unit.

Some embodiments are directed to a new methodology aimed at preparing highly N-doped mesoporous carbon macroscopic composites, and their use as highly efficient heterogeneous metal-free catalysts in a number of industrially relevant catalytic transformations.