METHOD FOR TREATING SCR CATALYSTS HAVING ACCUMULATED IRON COMPOUNDS

The present disclosure relates to methods for treating deactivated SCR catalysts having an increased SO/SOconversion rate as a result of the accumulation of one or more iron compounds. The methods are characterized in that the catalysts are treated with an aqueous solution of an acidic reactive salt or hydrogen fluoride, with the addition of at least one antioxidant. 1. A method of regenerating an SCR catalyst having an accumulation of one or more iron compounds , the method comprising:treating an SCR catalyst having an accumulation of one or more iron compounds with a substantially aqueous solution comprising: an acidic reactive salt or hydrogen fluoride;and at least one antioxidant; andremoving at least a portion of the one or more iron compounds accumulated on the SCR catalyst.2. The method of claim 1 , wherein the substantially aqueous solution comprises an acidic reactive salt and at least one antioxidant.3. The method of claim 2 , wherein the acidic reactive salt is an ammonium-based acidic reactive salt.4. The method of claim 2 , wherein the acidic reactive salt is an ammonium salt selected from the group consisting of ammonium chloride claim 2 , ammonium fluoride claim 2 , ammonium nitrate claim 2 , ammonium sulfate claim 2 , and mixtures of any thereof.5. The method of claim 4 , wherein the acidic reactive salt is ammonium chloride or ammonium sulfate.6. The method of claim 2 , wherein the concentration of the acidic reactive salt ranges from about 0.1 wt % to about 10.0 wt %.7. The method of claim 1 , wherein the substantially aqueous solution comprises hydrogen fluoride in a concentration ranging from about 0.05 wt % to about 0.2 wt %.8. The method of claim 1 , wherein the substantially aqueous solution has a pH ranging from about 2.0 to about 5.0.9. The method of claim 1 , wherein the at least one antioxidant comprises ascorbic acid or derivatives thereof.10. The method of claim 9 , wherein the concentration of ascorbic acid or derivative thereof in the ...

METHODS FOR REMOVING IRON MATERIAL FROM A SUBSTRATE

Methods of removing iron from a catalytic converter having an accumulation of one or more iron compounds and regenerating a catalytic converter are provided. A catalytic converter having an accumulation of one or more iron compounds embedded or deposited thereon can be treated with a substantially aqueous alkaline solution in which the substantially aqueous alkaline solution includes an antioxidant. 1. A method of removing iron from a catalytic converter having an accumulation of one or more iron compounds , comprising:(i) treating the catalytic converter with a substantially aqueous alkaline solution, said aqueous alkaline solution comprises an antioxidant; and(ii) removing at least a portion of the one or more iron compounds accumulated on the catalytic converter.2. The method of claim 1 , wherein the antioxidant comprises substituted phenols claim 1 , hydroquinones claim 1 , catechols claim 1 , aliphatic mercapto compounds claim 1 , araliphatic mercapto compounds claim 1 , aromatic mercapto compounds claim 1 , dithiocarbonates claim 1 , hydroxycarboxylic acids claim 1 , enediols claim 1 , phosphites claim 1 , phosphonates claim 1 , or combinations thereof.3. The method of claim 1 , wherein the antioxidant is selected from the group consisting of ascorbic acid claim 1 , mineral ascorbate salts claim 1 , ammonium ascorbate claim 1 , and combinations thereof.4. The method of claim 1 , wherein the antioxidant comprises sodium ascorbate.5. The method of claim 1 , wherein the aqueous alkaline solution has a pH from 7 to 14.6. The method of claim 1 , wherein the aqueous alkaline solution has a pH from 8 to 14.7. The method of claim 1 , wherein the aqueous alkaline solution comprises from 0.05 to 5.00 wt. % of said antioxidant.8. The method of claim 1 , wherein the aqueous alkaline solution comprises from 0.1 to 2.0 wt. % of said antioxidant.9. The method of claim 1 , wherein the aqueous alkaline solution comprises from 0.1 to 1.0 wt. % of said antioxidant.10. The method ...

Packaging tape adhesive composition and packaging tape comprising it

A packaging tape adhesive composition for cardboard box sealing tapes, comprising: a linear tetrablock copolymer S-I-S-I', obtainable by full sequential polymerization of predominantly styrene and of predominantly isoprene respectively, having an apparent molecular weight in the range of from 205,000 to 225,000, and wherein both predominantly poly(styrene) blocks have an apparent molecular weight of from 10,000 to 12,000, wherein the intermediate S-I diblock copolymer has an apparent molecular weight in the range of from 130,000 to 185,000, wherein the intermediate S-I-S triblock copolymer has an apparent molecular weight in the range of from 145,000 to 195,000, wherein the poly(styrene) content is in the range of from 14 to 16 wt%, at least one tackifying resin in an amount of from 50 to 150 parts by weight per 100 parts by weight of block copolymers.

Pluggage removal method for scr catalysts and systems

The present disclosure relates to methods for treating an SCR catalyst or components of an SCR system having a decreased NOx potential efficiency as a result of particulate pluggage in the system or in one or more channels in the SCR catalyst which renders at least a portion of the catalytic active areas inaccessible for the flue gas. The methods include removal of the particulates and plug(s) using a blasting stream of a pressurized carrier gas having a particulate blasting medium directed at the SCR catalyst or component of an SCR system.

Methods for removing iron material from a catalytic converter using an aqueous alkaline solution and an antioxidant

Methods of removing iron from a catalytic converter having an accumulation of one or more iron compounds and regenerating a catalytic converter are provided. A catalytic converter having an accumulation of one or more iron compounds embedded or deposited thereon can be treated with a substantially aqueous alkaline solution in which the substantially aqueous alkaline solution includes an antioxidant.

Methods for removing ferrous material from a catalytic converter using an alkaline aqueous solution and an antioxidant

Un método para retirar hierro de un convertidor catalítico que tiene una acumulación de uno o más compuestos férreos, que comprende: (i) tratar el convertidor catalítico con una solución acuosa alcalina, dicha solución acuosa alcalina comprende un antioxidante, en donde el antioxidante comprende fenoles sustituidos, hidroquinonas, catecoles, mercaptocompuestos alifáticos, mercaptocompuestos aralifáticos, mercaptocompuestos aromáticos, ditiocarbonatos, ácidos hidroxicarboxílicos, enodioles, fosfitos, fosfonatos o combinaciones de los mismos, y se selecciona preferiblemente del grupo que consiste en ácido ascórbico, sales minerales de ascorbato, ascorbato amónico y combinaciones de los mismos, y en donde la solución acuosa alcalina comprende de 0,05 a 5,00% en peso de dicho antioxidante, y es preferiblemente de 0,1 a 2,0% en peso de dicho antioxidante, y más preferiblemente de 0,1 a 2,0% en peso de dicho antioxidante, y aún más preferiblemente de 0,1 a 1,0% en peso de dicho antioxidante, y en donde las especies químicas empleadas para conferir alcalinidad a la solución acuosa alcalina incluyen bases inorgánicas seleccionadas de hidróxidos de metales alcalinos e hidróxidos de metales alcalinotérreos; y (ii) retirar al menos una porción de los uno o más compuestos férreos acumulados sobre el convertidor catalítico. A method for removing iron from a catalytic converter having an accumulation of one or more ferrous compounds, comprising: (i) treating the catalytic converter with an alkaline aqueous solution, said alkaline aqueous solution comprises an antioxidant, wherein the antioxidant comprises phenols substituted, hydroquinones, catechols, aliphatic mercapto compounds, araliphatic mercapto compounds, aromatic mercapto compounds, dithiocarbonates, hydroxycarboxylic acids, enodiols, phosphites, phosphonates or combinations thereof, and is preferably selected from the group consisting of ascorbic acid, ascorbate mineral salts, ascorbate salts, ascorbate and combinations ...

Methods for removing iron material from a substrate

Methods of removing iron from a catalytic converter having an accumulation of one or more iron compounds and regenerating a catalytic converter are provided. A catalytic converter having an accumulation of one or more iron compounds embedded or deposited thereon can be treated with a substantially aqueous alkaline solution in which the substantially aqueous alkaline solution includes an antioxidant.

Packaging tape adhesive composition and packaging tape comprising it

A packaging tape adhesive composition for cardboard box sealing tapes, comprising: - a linear tetrablock copolymer S-I-S-I', obtainable by full sequential polymerization of predominantly styrene and of predominantly isoprene respectively, having an apparent molecular weight in the range of from 205,000 to 225,000, and wherein both predominantly poly(styrene) blocks have an apparent molecular weight of from 10,000 to 12,000, wherein the intermediate S-I diblock copolymer has an apparent molecular weight in the range of from 130,000 to 185,000, wherein the intermediate S-I-S triblock copolymer has an apparent molecular weight in the range of from 145,000 to 195,000, and wherein the poly(styrene) content is in the range of from 14 to 16 wt%, and - at least one tackifying resin in an amount of from 50 to 150 parts by weight per 100 parts by weight of block copolymers; packaging tape for cardboard sealing derived from said packaging tape adhesive composition; the linear tetrablock copolymer for the preparation of said packaging tape adhesive composition; and a process for the manufacture of pellets comprising said packaging tape adhesive composition.

Packaging tape adhesive composition and packaging tape comprising it

Method for treating scr catalysts having accumulated iron compounds

The present disclosure relates to methods for treating deactivated SCR catalysts having an increased SO2/SO3 conversion rate as a result of the accumulation of one or more iron compounds. The methods are characterized in that the catalysts are treated with an aqueous solution of an acidic reactive salt or hydrogen fluoride, with the addition of at least one antioxidant,