Disclosed is a method for improving the stability of a catalyst in recycling HFC-23. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a metal oxide, wherein the metal oxide is selected from at least one metal oxide of K, Na, Fe, Co, Cu, Ni, Zn or Ti, and has an addition amount of 0.1-5 wt %. The present invention has advantages such as a good catalyst stability, a long life, and a low content of by-product CFC-12.

Catalyst systems are provided for reforming of hydrocarbons, along with methods for using such catalyst systems. The catalyst systems can be deposited or otherwise coated on a surface or structure, such as a monolith, to achieve improved activity and/or structural stability. The metal oxide support layer can correspond to a thermally stable metal oxide support layer, such as a metal oxide support layer that is thermally phase stable at temperatures of 800° C. to 1600° C. The catalyst systems can be beneficial for use in cyclical reaction environments, such as reverse flow reactors or other types of reactors that are operated using flows in opposing directions and different times within a reaction cycle.

Systems and methods are provided for using size-reversing materials in vessels where direct heating is used to at least partially provide heat for reforming reactions under cyclic reforming conditions. An example of a size-reversing material is the combination of NiO and Al.sub.2O.sub.3. It has been discovered that size-reversing materials can undergo a phase transition that can assist with re-dispersion of metal at elevated temperatures. This can assist with maintaining catalytic activity for reforming over longer time periods in the presence of cyclic reforming conditions.

The present invention provides a process of catalytic depolymerization of polystyrene involving a spherical catalyst, an apparatus for carrying out the depolymerization, recovering the aromatic rich liquid product and recycling the catalyst without any decrease in the catalytic performance. Further, the present invention provides that the aromatic rich liquid product includes styrene, xylene, benzene, ethyl benzene, with styrene content greater than 65%. Additionally, the catalyst involved in the depolymerization process is a spherical catalyst that is easily recovered from coke/char formed during the process and is recycled and reused without any decrease in the catalytic performance.

The present invention provides a process of catalytic depolymerization of polystyrene involving a spherical catalyst, an apparatus for carrying out the depolymerization, recovering the aromatic rich liquid product and recycling the catalyst without any decrease in the catalytic performance. Further, the present invention provides that the aromatic rich liquid product includes styrene, xylene, benzene, ethyl benzene, with styrene content greater than 65%. Additionally, the catalyst involved in the depolymerization process is a spherical catalyst that is easily recovered from coke/char formed during the process and is recycled and reused without any decrease in the catalytic performance.

A method for regenerating a deactivated denitration catalyst includes steps of preparing a washing fluid including a water-contained liquid and entrained carbon dioxide bubbles, and subjecting the deactivated denitration catalyst to a treatment with the washing fluid. An apparatus for regenerating the deactivated denitration catalyst is also provided.

The invention concerns a method for rejuvenating an at least partially used catalyst originating from a hydroprocessing and/or hydrocracking process, the at least partially used catalyst being derived from a fresh catalyst comprising at least one group VIII metal (in particular, Co), at least one group VIB metal (in particular, Mo), an oxide support, and optionally phosphorus, the method comprising the steps: a) regenerating the at least partially used catalyst in a gas stream containing oxygen at a temperature between 300° C. and 550° C. so as to obtain a regenerated catalyst, b) then placing the regenerated catalyst in contact with phosphoric acid and an organic acid, each having acidity constant pKa greater than 1.5, c) performing a drying step at a temperature less than 200° C. without subsequently calcining it, so as to obtain a rejuvenated catalyst.

The invention relates to a process for the rejuvenation of an at least partially spent catalyst resulting from a hydrotreating process, said at least partially spent catalyst resulting from a fresh catalyst comprising a metal from group VIII, a metal from group VIb, an oxide support, and optionally phosphorus, said at least partially spent catalyst additionally comprising carbon in a content of between 2% and 20% by weight, with respect to the total weight of the at least partially spent catalyst, and sulfur in a content of between 1% and 8% by weight, with respect to the total weight of the at least partially spent catalyst, said process comprising the following stages: a) said spent catalyst is brought into contact with an impregnation solution containing a compound comprising a metal from group VIb, b) a drying stage is carried out at a temperature of less than 200° C.

The invention relates to a process for the rejuvenation of an at least partially spent catalyst resulting from a hydrotreating process, said at least partially spent catalyst resulting from a fresh catalyst comprising a metal from group VIII, a metal from group VIb, an oxide support, and optionally phosphorus, said at least partially spent catalyst additionally comprising carbon in a content of between 2% and 20% by weight, with respect to the total weight of the at least partially spent catalyst, and sulfur in a content of between 1% and 8% by weight, with respect to the total weight of the at least partially spent catalyst, said process comprising the following stages: a) said spent catalyst is brought into contact with an impregnation solution containing a compound comprising a metal from group VIb, b) a drying stage is carried out at a temperature of less than 200° C.

The present disclosure relates to a low temperature method for the production of pure hydrogen using a methane rich stream as raw material, and to perform in-situ catalyst regeneration. The process involves the decomposition of methane into COx-free hydrogen in an electrochemical/chemical membrane/chemical reactor or chemical fluidised reactor. As the methane decomposition reaction progresses, carbon structures (whiskers) are accumulated at the catalyst surface leading eventually to its deactivation. The catalyst regeneration is achieved using a small fraction of the produced hydrogen to react with carbon formed at the catalyst surface provoking the carbon detachment, thus regenerating the catalyst. This is achieved either by chemical/electrochemical methanation of carbon at the catalyst interface with hydrogen/protons or by rising the temperature of the catalyst, ideally keeping the reactor temperature constant. A single compact device is described, enabling the hydrogen production, hydrogen purification and catalyst regeneration.