Systems for treating wastewater containing organic nitrogen compounds are disclosed. The systems include a wet air oxidation unit having an oxidation zone, a catalytic zone, and a metal-based catalyst. Methods of treating wastewater containing organic nitrogen compounds are also disclosed. The methods include contacting the wastewater with an oxidant to produce a mixed liquor, contacting the mixed liquor with a metal-based catalyst to catalyze ammonia and produce a gas containing nitrogen and a liquid effluent containing nitrogen. Methods of retrofitting a wet air oxidation unit including providing a metal-based catalyst are also disclosed. Methods of facilitating treatment of wastewater in a wet air oxidation unit including providing a metal-based catalyst are also disclosed.

Systems for treating wastewater containing organic nitrogen compounds are disclosed. The systems include a wet air oxidation unit having an oxidation zone, a catalytic zone, and a metal-based catalyst. Methods of treating wastewater containing organic nitrogen compounds are also disclosed. The methods include contacting the wastewater with an oxidant to produce a mixed liquor, contacting the mixed liquor with a metal-based catalyst to catalyze ammonia and produce a gas containing nitrogen and a liquid effluent containing nitrogen. Methods of retrofitting a wet air oxidation unit including providing a metal-based catalyst are also disclosed. Methods of facilitating treatment of wastewater in a wet air oxidation unit including providing a metal-based catalyst are also disclosed.

A method for ambient-temperature synthesis of a catalyst for water electrolysis by dissolving an amount of an Fe.sup.2+ source and optionally an amount of a salt of another divalent cation in deionized water at ambient temperature to form a solution, placing nickel (Ni) foam into the solution, whereby the Ni foam serves as a substrate and/or a Ni source for growth of the catalyst, leaving the Ni foam in the solution at ambient temperature for a time duration in a range of from about 0.5 hour to about 4 hours to provide a treated foam, during which time duration, the catalyst is grown on the substrate, and removing the treated foam from the solution after the time duration, wherein the treated foam comprises the catalyst grown thereon.

Methods of heating a reactor system by providing electrical energy are described. A reactor system comprising at least one reactor tube having a catalyst disposed therein and comprises at least one electrically conductive surface is heated by providing electrical energy to the at least one electrically conductive surface on the reactor tube and adjusting a current level of the electrical energy provided to the at least one electrically conductive surface to control the temperature of the reactor tube and the catalyst disposed therein. The reactor tube may be electrically isolated from other electrically conductive components of the reactor system.

Methods of heating a reactor system by providing electrical energy are described. A reactor system comprising at least one reactor tube having a catalyst disposed therein and comprises at least one electrically conductive surface is heated by providing electrical energy to the at least one electrically conductive surface on the reactor tube and adjusting a current level of the electrical energy provided to the at least one electrically conductive surface to control the temperature of the reactor tube and the catalyst disposed therein. The reactor tube may be electrically isolated from other electrically conductive components of the reactor system.

The invention relates to a method of regenerating the catalytic activity of a spent catalyst comprising nickel on a refractory oxide support, said method comprising the steps of contacting the spent catalyst with a nitric acid solution, heat-treating the spent catalyst, calcining and reducing the catalyst.

The invention relates to a method of regenerating the catalytic activity of a spent catalyst comprising nickel on a refractory oxide support, said method comprising the steps of contacting the spent catalyst with a nitric acid solution, heat-treating the spent catalyst, calcining and reducing the catalyst.

A catalyst has a carrier and a hydrogenation active metal component supported on the carrier. The hydrogenation active metal component contains at least one Group VIB metal component and at least one Group VIII metal component, and the carrier is composed of phosphorus-containing alumina. When the hydrogenation catalyst is measured using a hydrogen temperature programmed reduction method (H.sub.2-TPR), the ratio of the peak height of the low-temperature reduction peak, P.sub.low-temp peak, at a temperature of 300-500° C. to the peak height of the high-temperature reduction peak, P.sub.hi-temp peak, at a temperature of 650-850° C., i.e. S=P.sub.low-temp peak/P.sub.hi-temp peak, is 0.5-2.0; preferably 0.7-1.9, and more preferably 0.8-1.8. The hydrogenation catalyst shows excellent heteroatom removal effect and excellent stability when used in hydrotreatment.

A catalyst has a carrier and a hydrogenation active metal component supported on the carrier. The hydrogenation active metal component contains at least one Group VIB metal component and at least one Group VIII metal component, and the carrier is composed of phosphorus-containing alumina. When the hydrogenation catalyst is measured using a hydrogen temperature programmed reduction method (H.sub.2-TPR), the ratio of the peak height of the low-temperature reduction peak, P.sub.low-temp peak, at a temperature of 300-500° C. to the peak height of the high-temperature reduction peak, P.sub.hi-temp peak, at a temperature of 650-850° C., i.e. S=P.sub.low-temp peak/P.sub.hi-temp peak, is 0.5-2.0; preferably 0.7-1.9, and more preferably 0.8-1.8. The hydrogenation catalyst shows excellent heteroatom removal effect and excellent stability when used in hydrotreatment.

A catalyst structure for synthesis gas production of a synthesis gas that contains carbon monoxide and hydrogen, the catalyst structure being provided with a carrier that has a porous structure, while being configured from a zeolite type compound; first catalyst particles that contain one or more iron group elements which are selected from the group consisting of nickel (Ni), iron (Fe) and cobalt (Co); and second catalyst particles that contain one or more platinum group elements which are selected from the group consisting of platinum (Pt), palladium (Pd), rhodium (Rh) and ruthenium (Ru). The catalyst structure for synthesis gas production has passages in communication with each other within the carrier. The first catalyst particles are present at least in the passages of the carrier; and the second catalyst particles are present at least either inside the carrier or on the outer surface of the carrier.