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 process for the multi-stage catalytic methanization of a carbon monoxide-containing and hydrogen-containing feed gas at high pressure and temperature is carried out in three stages. In the first stage the feed gas is premethanized at a temperature of from 400.degree. to 500.degree. C.; in a second stage the premethanized gas is converted and in a third stage the converted gas is finally methanized at a temperature of from 300.degree. to 380.degree. C. Apparatus for carrying out this process preferably comprises a single elongated pressure reactor which is divided into three reaction zones each of which contains a reaction catalyst formed into a fluidized bed. The feed gas preferably flows upwards through the reactor firstly through the first fluidized bed, then through the second fluidized bed and finally through the third fluidized bed after which the product gas is withdrawn from the top of the reactor. The reactions takes place isothermally and for this purpose each of the zones is preferably provided with an independent cooling system.
摘要:
An outer enclosed pressure container is formed of a simple steel material. An inner enclosed container is positioned within the pressure container such that there is an intermediate space therebetween. Catalyst layers are provided within the inner container. A gas containing a reducing component and water vapor are introduced into the inner container and are therein reacted by means of the catalyst to perform a desired reducing reaction. At least part of the water vapor is alone introduced into the intermediate space to thereby pressurize the intermediate space to substantially the same pressure as occurs within the inner container. The water vapor in the intermediate space operates to protect the wall of the pressure container from the temperatures occurring due to the catalytic reaction within the inner container. The water vapor is removed from the intermediate space and is at least partially added to the gas containing a reducing component before the introduction thereof into the inner container.
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:
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:
In methanizing CO and H.sub.2 containing charge gases, the charge gas is passed upwardly through a vertically extending fluidized bed reactor flowing, in turn, through a fluidized bed zone, a dust bed zone and a separation zone. From the separation zone, the gas is conveyed out of the reactor to a point of use. Coolant tubes are positioned in the reactor passing vertically through the fluidized bed zone, the dust bed zone and the separation zone for removing the heat generated in the reaction. An evaporable coolant, preferably water, is circulated through the coolant tubes. In a separate steam drum, the vapor pressure of the coolant is set for maintaining constant the temperature of the vaporizing coolant.
摘要:
Small, pourable particles of comminuted coal for coking purposes are gravity-discharged into a stream of hot gas flowing upwardly in a flight stream tube, in a direction inclined and generally opposite to the gas flow direction. Just prior to entry into the gas stream the particles are fluidized so that, on being entrained by the gas stream, they will become uniformly distributed throughout the cross-section of the same. A method and an apparatus are disclosed.
摘要:
A method of catalytic conversion of feed gases, particularly of a low-sulphur gas mixture rich in carbon monoxide and hydrogen, into a product gas mixture containing methane and/or higher hydrocarbons under high pressure includes the step of removing heat of reaction from the catalytic conversion from a reaction zone by feeding both water and steam to form a cooling medium through a pipe coil in the reaction zone. This forms superheated steam in the pipe coil and the superheated steam is then converted into another form of energy, for example in a turbo-generator. Preferably the reaction zone is a fluidized bed. The apparatus for carrying out this method comprises a reactor, which is preferably a fluidized bed reactor and in this reactor the piping system forming the superheater is disposed in the lower part of the reaction zone. The superheater is connected to a feedwater line and to a steam inlet line and a steam turbine is connected to a steam output line leading from the superheater.
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 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.