摘要:
The invention relates to a process for the manufacture of a catalyst for the reduction of nitrogen oxides in exhaust gases. The catalyst contains a metal oxide. The catalyst is preferably used for catalytic reduction with ammonia. The process comprises screening a natural goethite iron ore to the required grain size and then treating the ore with sulfuric acid. Subsequently, the goethite iron ore is heated to a temperature which approximately equals the temperature at which it will be used in the catalytic reaction.
摘要:
In a process for the manufacture of catalyst moldings a natural raw material containing Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3 or another such catalyst component such as TiO.sub.2, NbO.sub.2, WO.sub.3, V.sub.2 O.sub.5 or MoO.sub.3 is screened to a grain size equal to or less than approximately 0.25 mm. This screened base mixture is thoroughly blended, and then preferably a concentrated sulphuric acid is added. This mixture of material is then pressed into a molding in a hydraulic press with a pressure of approximately 500 bar to produce the molding.
摘要翻译:在制造催化剂模制品的方法中,将含有Fe 2 O 3,Cr 2 O 3或另一种这样的催化剂组分如TiO 2,NbO 2,WO 3,V 2 O 5或MoO 3的天然原料筛分至等于或小于约0.25mm的晶粒度。 将该筛分的基础混合物充分混合,然后优选加入浓硫酸。 然后将该材料混合物压制成压力为约500巴的液压机中的模塑制品以产生模制品。
摘要:
A catalyst for use with ammonia for the selective reduction of nitrogen oxides in waste gases. The catalyst comprises a mixture of substances which has high activity and selectivity with regard to nitrogen oxide conversion and high sorption capabilities with regard to ammonia, but low oxidation capabilities with regard to sulfur dioxide, ammonia, or similar substances. The invention also provides a process for the manufacture and use of such catalysts.
摘要:
A structure made from catalyst for use in the separation of nitrogen oxides from combustion exhaust gases which contain dust. The catalytic structure has plates with spaces therebetween to carry a flow of the exhaust gas therethrough. The catalyst is constructed of individual ceramic plates. The abrasion or wear resistance of the plates is chosen such that the dust in the exhaust gases flowing through the spaces abrades the plate surface at a rate which is at least equivalent to the deactivation of the catalyst surface by action of the nitrogen oxides, which constantly provides a fresh catalyst surface for reaction with the nitrogen oxides. The movement of the exhaust gas through the catalytic structure carries the dust and abraded material along with it and out of the structure.
摘要:
A catalyst for use in a process for the removal of nitrogen oxides from exhaust gases contaminated with dust in which the process uses ammonia. The catalyst is made of a material which is easily disposable. Furthermore, the catalyst should be completely used up in the catalysis. The catalyst comprises individual ceramic bricks with a porous surface, and passages therethrough for the flow of the exhaust gases. The bricks exhibit a resistance to abrasion which is designed so that the dust of the exhaust gas which flows through the passages erodes the catalyst surface, thereby reactivating the catalyst. The exhaust gas carries the dust and the eroded material along with it.
摘要:
In a process for cleaning a waste gas containing various pollutants, the exhaust gas with the pollutants is introduced directly into a reduction reactor. In the reactor, the pollutants are reduced by ammonia. The catalyst used is iron oxide material or a mixed oxide material of iron oxide and chromium oxide, or a mixture of the mixture material of the mixed oxide material and the iron oxide material.
摘要:
A process for the removal of nitrogen oxides and soot from exhaust gases from machines and combustion installations burning heavy fuel oil by means of free-passage catalysts at increased temperatures with the addition of ammonia into the exhaust gas stream ahead of the catalysts. To make the process mre effective, the soot adhering to the catalyst surfaces is removed by burning it off and/or by friction resulting from the admixture of sand, ash or similar abrasive mixtures into the exhaust gas stream ahead of the catalysts.
摘要:
The invention relates to catalyst plates for reducing nitrogen oxide in exhaust gases. These plates are molded of granular Fe.sub.2 O.sub.3 catalyst material and a binder. To achieve high activity and strength in the plates, these are molded of a combination of a first mixture comprised of Fe.sub.2 O.sub.3 catalyst material and phosphoric acid as binder, and a second, separately-produced mixture comprised of Fe.sub.2 O.sub.3 catalyst material and sulphuric acid as binder. The plates can also be a molding having layers, which layers have alternate layers of the first and second mixtures.
摘要翻译:本发明涉及用于还原废气中的氮氧化物的催化剂板。 这些板由粒状Fe 2 O 3催化剂材料和粘合剂成型。 为了在板中实现高活性和强度,它们由由Fe 2 O 3催化剂材料和磷酸组成的第一混合物作为粘合剂的组合以及由Fe 2 O 3催化剂材料和硫酸作为粘合剂组成的第二个单独制备的混合物组合。 板也可以是具有层的模制品,这些层具有第一和第二混合物的交替层。
摘要:
This invention relates to a process for the manufacture of catalysts for the reduction of nitrogen oxides in exhaust gases or for chemical air cleaning processes, in which catalyst moldings are produced from iron oxide or mixtures of iron oxide and chromium oxide and/or manganese oxide, which are reduced to grain sizes less than 2 mm, with the use of inorganic binders and sulfuric acid, and with the possible addition of activating additives.In accordance with the invention:(a) either the mixture of the solid primary material is reacted with sulfuric acid, a mixture of sulfuric acid and phosphoric acid or a sulfuric acid or mixture of sulfuric acid and phosphoric acid containing sulfate, hydrogen sulfate, phosphate or hydrogen phosphate of ammonium, aluminum, iron, vanadium, manganese, molybdenum, chromium, copper and/or cobalt, and moldings are formed from this mixture, or the mixture of the solid primary material is formed into moldings after the addition of fluid and/or phosphoric acid and/or phosphates, and these moldings are treated with sulfuric acid or a sulfuric acid containing sulfate or hydrogen sulfate of ammonium, aluminum, iron, vanadium, manganese, molybdenum, chromium, copper, and(b) then, on the moldings obtained in Step (a), a drying treatment is performed at 110.degree. C. to 250.degree. C., followed by a tempering treatment at 250.degree. C. to 600.degree. C.The catalysts manufactured using the process described by the invention have a low sensitivity to moisture and good activity.
摘要:
This invention relates to a process for the manufacture of catalysts for the reduction of oxides of nitrogen from exhaust gases and in chemical air cleaning processes in which a catalytically active material containing iron ores, chromium ores and/or zeolite is placed in contact with a carrier means having a series of openings; e.g., wire mesh, expanded or perforated metal or any type of grid-like structure to form a catalytic member. The carrier means is etched with an acid etchant before forming the catalytic member or, instead, the catalytic member is etched with an acid etchant. The catalytic member is bonded by a thermal treatment; e.g., drying, tempering and/or fixing. This invention also relates to catalytic members or products produced by the process. This invention proposes the use of pressure bonding to obtain a catalytic member product which has significantly improved catalytic activity, greater mechanical strength and higher resistance to chipping.