The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

In an exhaust gas purification system provided with a denitration catalyst layer, a reducing agent oxidation catalyst layer is installed together; a reducing agent and air are supplied into the reducing agent oxidation catalyst layer at the time of catalyst regeneration of the denitration catalyst layer; a high-temperature oxidation reaction gas is produced by a reaction heat generated by an oxidation reaction of the reducing agent and the air in this reducing agent oxidation catalyst layer; and this high-temperature oxidation reaction gas is introduced into the denitration catalyst layer to heat the denitration catalyst, thereby recovering a denitration performance of the catalyst.

In an exhaust gas purification system provided with a denitration catalyst layer, a reducing agent oxidation catalyst layer is installed together; a reducing agent and air are supplied into the reducing agent oxidation catalyst layer at the time of catalyst regeneration of the denitration catalyst layer; a high-temperature oxidation reaction gas is produced by a reaction heat generated by an oxidation reaction of the reducing agent and the air in this reducing agent oxidation catalyst layer; and this high-temperature oxidation reaction gas is introduced into the denitration catalyst layer to heat the denitration catalyst, thereby recovering a denitration performance of the catalyst.

Methods and systems for re-dispersing platinum on catalysts used in continuous catalyst regeneration reformer systems are disclosed. Some aspects of the disclosure provide, for example, methods of evaluating the platinum re-dispersion of a reforming catalyst in a small-scale reactor for use in a continuous catalyst regeneration reformer system and methods of improving the activity and selectivity of reforming catalysts for use in a continuous catalyst regeneration reformer system by selection of appropriate reaction parameters in a small-scale reactor for use in a continuous catalyst regeneration reformer system.

Methods and systems for re-dispersing platinum on catalysts used in continuous catalyst regeneration reformer systems are disclosed. Some aspects of the disclosure provide, for example, methods of evaluating the platinum re-dispersion of a reforming catalyst in a small-scale reactor for use in a continuous catalyst regeneration reformer system and methods of improving the activity and selectivity of reforming catalysts for use in a continuous catalyst regeneration reformer system by selection of appropriate reaction parameters in a small-scale reactor for use in a continuous catalyst regeneration reformer system.

Apparatuses and methods are provided for regenerating catalyst particles. In one embodiment, a method for regenerating catalyst particles includes passing the catalyst particles through a halogenation zone and a drying zone. The method feeds drying gas to the drying zone and passes a first portion of the drying gas from the drying zone to the halogenation zone. The method includes removing a second portion of the drying gas from the drying zone and injecting a halogen gas into the second portion of the drying gas. Further, the method includes delivering the halogen gas and the second portion of the drying gas to the halogenation zone. In the method, substantially all of the drying gas fed to the drying zone enters the halogenation zone.

Disclosed is a method of making and using a titania supported palladium catalyst for the single step synthesis of 2-ethylhexanal from a feed of n-butyraldehyde. This titania supported palladium catalyst demonstrates high n-butyraldehyde conversion but also produces 2-ethylhexanal in an appreciable yield with maintained activity between runs. This method provides a single step synthesis of 2-ethylhexanal from n-butyraldehyde with a catalyst that can be regenerated that provides cleaner downstream separations relative to the traditional caustic route.

Disclosed is a method for separating a chlorine-containing species from an aqueous solution of the chlorine-containing species in a catalytic hydrocarbon conversion process that includes the step of oxidizing a spent chloride-containing hydrocarbon conversion catalyst, the spent hydrocarbon conversion catalyst including a hydrocarbon residue formed thereon. The oxidizing forms a flue gas including chlorine-containing species, water, and oxides of carbon. The method further includes contacting the flue gas with a water scrubbing stream to dissolve at least a portion of the chlorine-containing species in the water scrubbing stream to form an aqueous acid solution and contacting the aqueous acid solution with a hygroscopic liquid to generate dehydrated hydrogen chloride gas. Still further, the method includes contacting the dehydrated hydrogen chloride gas with additional spent chloride-containing hydrocarbon conversion catalyst to sorb chlorine onto the additional spent chloride-containing hydrocarbon conversion catalyst.

Disclosed is a method for separating a chlorine-containing species from an aqueous solution of the chlorine-containing species in a catalytic hydrocarbon conversion process that includes the step of oxidizing a spent chloride-containing hydrocarbon conversion catalyst, the spent hydrocarbon conversion catalyst including a hydrocarbon residue formed thereon. The oxidizing forms a flue gas including chlorine-containing species, water, and oxides of carbon. The method further includes contacting the flue gas with a water scrubbing stream to dissolve at least a portion of the chlorine-containing species in the water scrubbing stream to form an aqueous acid solution and contacting the aqueous acid solution with a hygroscopic liquid to generate dehydrated hydrogen chloride gas. Still further, the method includes contacting the dehydrated hydrogen chloride gas with additional spent chloride-containing hydrocarbon conversion catalyst to sorb chlorine onto the additional spent chloride-containing hydrocarbon conversion catalyst.

The present invention provides a catalyst for producing a hydrocarbon from a syngas, including one of a cobalt metal and a combination of a cobalt metal and cobalt oxides; zirconium oxides; and a noble metal; supported by a catalyst support mainly composed of silica, wherein a content of impurities in the catalyst is less than or equal to 0.15 mass %; a producing method and regenerating method thereof; and a producing method of the hydrocarbon by using the catalyst.