摘要:
A catalyst layer is formed on the metallic surface of a structure constructing a reactor by diffusing a developable metal into the structure by the pack cementation method and developing the diffused metal. The catalyst layer is metallurgically combined with the structure, so that it has excellent mechanical strength and heat conductivity. Thus, by using the structure having the catalyst layer as a heat exchanger type methanation reactor it is possible to obtain a methanation reactor enabling an extremely enhanced rate of reaction to be obtained with superior operability and at great savings.
摘要:
Fuel cell with improved and stabilized electrode performance having at least one gas diffusion electrode, where the gas diffusion electrode comprises an electronconductive, gas-permeable substrate and an electrode catalyst uniformly distributed on the substrate, the electrode catalyst comprising colonies each consisting of not more than 20 primary particles of noble metal each having a size of 10-30 A and being uniformly distributed and deposited on carrier powder.
摘要:
A catalyst compositions for reducing nitrogen oxide comprising, as its chief ingredient, an intimate mixture ofA. titanium (Ti) as component A, withB. at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), iron (Fe), vanadium (V), nickel (Ni), cobalt (Co), copper (Cu), chromium (Cr), and uranium (U), as component B,in the form of their oxides, and a process for reducing nitrogen oxides to nitrogen, which comprises contacting a gaseous mixture containing nitrogen oxides and molecular oxygen and a reducing gas with aforesaid catalyst compositions at an elevated temperature.
摘要:
A catalyst composition for reducing nitrogen oxides, which is characterized in that the same contains, as its chief ingredient,A. tin (Sn) as the component A, andB. at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), and iron (Fe), as the component (B).in the form of their oxides, and a process for reducing nitrogen oxides to nitrogen, which comprises contacting a gaseous mixture containing nitrogen oxides and molecular oxygen and a reducing gas with aforesaid catalyst composition at elevated temperatures.
摘要:
A waste gas containing sulfur oxides is contacted with an adsorbent comprising an intimate mixture of an iron oxide and/or a copper oxide and a titanium oxide at a temperature of 250.degree.-500.degree. C. The sulfur oxides thus adsorbed are desorbed with a reducing gas and recovered as sulfur material.The efficiency of the adsorbent is not reduced even after many repetitions of the adsorption-desorption cycle. Since the adsorbent exhibits a high resistance to sulfuric acid mist (SO.sub.3) contained in the waste gas.
摘要:
An ammonia gas to be determined, and an oxidative gas containing nitrogen oxides in moles more than those of the ammonia are brought into contact with an analytical catalyst capable of forming nitrogen and water from ammonia and nitrogen oxides.Concentrations of nitrogen oxides of the gas before and after the contact with the analytical catalyst are determined, and an ammonia concentration of the gas is determined by converting the difference between the concentrations of nitrogen oxides to the ammonia concentration by calculation.
摘要:
A fuel cell provided with an electrolyte retaining plate made of electrical insulating long fibers such as lithium aluminate long fibers which have preferably a length of 100 to 400 .mu.m and a diameter of 1 to 4 .mu.m, are interlocked each other and have vacant spaces for filling an electrolyte can be constructed and operated safely without damaging the electrolyte retaining plate for a long period of time.
摘要:
A coal or petroleum combustion flue gas containing sulfur oxides and dust is treated by contacting the flue gas with a sulfur dioxide-oxidizing catalyst, thereby converting sulfur dioxide to sulfur trioxide, allowing the resulting sulfur trioxide to react with components of dust, absorbing the trioxide into the dust as a sulfate, and removing the dust. Catalytic oxidation of sulfur dioxide can be efficiently carried out at a low temperature and sulfur oxides can be efficiently removed from the flue gas.
摘要:
There is provided a method for converting sulfur dioxide in an exhaust gas to sulfur, which comprises the reduction step of reducing sulfur dioxide in an exhaust gas containing water vapor to hydrogen sulfide in the presence of carbon, a part of the exhaust gas is caused to bypass the reduction step and the remainder of the exhaust gas is fed to the reduction step to convert sulfur dioxide in the exhaust gas to hydrogen sulfide; the gas from the reduction step is mixed with the exhaust gas bypassing the reduction step while controlling the amount of the bypassing exhaust gas so that the ratio of hydrogen sulfide to sulfur dioxide in the mixed gas is maintained at 2; the mixed gas is fed to the Claus reaction step; and the Claus reaction step of reacting hydrogen sulfide formed at the reduction step with sulfur dioxide to convert hydrogen sulfide to sulfur.
摘要:
A process for treating an exhaust gas containing nitrogen oxides, oxygen and ammonia gas with a catalyst consisting essentially of titanium oxide, copper oxide in an amount of 0.02 to 0.3 mole and molybdenum oxide or tungsten oxide in an amount of 0.01 to 0.5 mole per one mole of the titanium oxide. Because the catalyst exhibits good properties for decomposition of ammonia as well as for decomposition of nitrogen oxides it is possible to avoid secondary pollution due to unreacted ammonia.