The present invention aims to provide a regeneration method capable of sufficiently restoring the catalytic performance of a solid catalyst used in a dehydration reaction of lactic acid and derivatives thereof. The present invention relates to a method for regenerating a solid catalyst used in a dehydration reaction of lactic acid and derivatives of lactic acid, the method including a contacting step of bringing a solid catalyst containing a component that forms a molten salt in the presence of steam into contact with oxygen and steam under pressure.

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.

A method and apparatus (1) for treating a filter (2) for filtering particulate matter from exhaust gas and a treated filter (2) are described. A reservoir (3) containing a dry powder (4) is provided. A vacuum generator (6) establishes a primary gas flow through a porous structure of the filter (2) by applying a pressure reduction to an outlet face of the filter (2). A spray device (7) receives the dry powder (4) from a transport device (8) and sprays the dry powder (4) towards the inlet face of the filter (2). A controller (9) is configured to control operation of at least the vacuum generator (6) and the spray device (7). The dry powder (4) comprises or consists of a metal compound for forming by thermal decomposition a metal oxide.

A method for separation of at least one catalyst or adsorbent from a homogeneous mixture of catalysts or adsorbents, used in a method for treatment of gas or hydrocarbon feedstock, in which the grains of catalysts or adsorbents are separated according to a sorting threshold corresponding to a content of the constituent element that is sought and defined by the user.

The present invention relates to a process for the production of a recycled catalyst comprising at least one metal M1 from group VI B, and/or at least one metal M2 from group VIII, optionally phosphorus and/or sulfur, and a support based on oxide(s). The process comprises the recycling of at least a part of the metal or metals of a source catalyst comprising the metal M1 and/or the metal M2 common with the recycled catalyst to be produced, with: an extraction by an extraction solution of the metal M1 and/or of the metal M2 from said source catalyst, in order to obtain a solution of extracted metal/metals, thenan impregnation of the support with an impregnation solution resulting from said solution of extracted metal/metals, in order to obtain an impregnated substrate, said extracted metal(s) remaining in the liquid phase from the extraction until the impregnation.

The invention relates to catalytically producing formic acid and regenerating the catalyst used in the process. A vanadyl ion, vandate ion, or polyoxometallate ion, which is used as the catalyst, of the general formula [PMo.sub.xV.sub.yO.sub.40].sup.n is brought into contact with an alpha hydroxyl aldehyde, an alpha hydroxy carboxylic acid, a carbohydrate, a glycoside, or a polymer, which contains a carbon chain and which comprises at least two OH groups bonded as substituents to the carbon chain as a substituent in a repeating manner and/or an O, N, or S atom contained in the carbon chain in a repeating manner, in a liquid solution (12) in a vessel (10) at a temperature above 70 C. and below 160 C., wherein 6x11, 1y6, 3<n<10, and x+y=12, where n, x, and y is each a whole number.

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 rejuvenating an at least partially spent hydrotreating and/or hydrocracking catalyst, said catalyst comprising a group VIII metal, a group VIB metal and an oxide support, said process comprising the following steps: a) the catalyst is regenerated, b) said regenerated catalyst is then brought into contact with an impregnation solution consisting of a mixture of water, at least one precursor of a group VIB metal, at least one precursor of a group VIII metal and at least one organic compound, the amount of organic compound introduced into the regenerated catalyst being optimized with respect to the metals already present in the regenerated catalyst and with respect to the amount of metals introduced via the impregnation solution, c) a drying step is then carried out without subsequently calcining it.

The present invention relates to a synthesis method of N-substituted maleimides using a non-homogeneous solid acid catalyst, and particularly, a synthesis method of N-substituted maleimides with high synthesis yield by using a zirconium(IV) hydrogen phosphate as a catalyst, by which, the loss of the catalyst is minimized, the separation and recovering processes of the catalyst are simplified, in case when the activity of the separated and recovered catalyst is decreased, the complete regeneration of the catalyst is possible via washing or firing, and solvents that could be used during a washing process of the catalyst are not limited.