摘要:
A method for removing mercury in a combustion exhaust gas includes injecting ammonia or urea as a reducing agent into a combustion exhaust gas containing nitrogen oxides, sulfur dioxide, metallic mercury, and hydrogen halides, and then introducing the combustion exhaust gas to a denitration apparatus filled with a denitration catalyst to cause a denitration reaction and oxidize the metallic mercury to produce mercury halide; and introducing the combustion exhaust gas through an air preheater and an electric dust collector to a wet desulfurization apparatus, thereby removing sulfur dioxides and the mercury halide, wherein the ammonia concentration of the combustion exhaust gas at an exit of the denitration apparatus is maintained at 5 ppm or higher, and the mercury halide is adsorbed or precipitated onto combustion ash and collected by the electric dust collector to discharge the mercury halide out of a system.
摘要:
A method for removing mercury in a combustion exhaust gas includes injecting ammonia or urea as a reducing agent into a combustion exhaust gas containing nitrogen oxides, sulfur dioxide, metallic mercury, and hydrogen halides, and then introducing the combustion exhaust gas to a denitration apparatus filled with a denitration catalyst to cause a denitration reaction and oxidize the metallic mercury to produce mercury halide; and introducing the combustion exhaust gas through an air preheater and an electric dust collector to a wet desulfurization apparatus, thereby removing sulfur dioxides and the mercury halide, wherein the ammonia concentration of the combustion exhaust gas at an exit of the denitration apparatus is maintained at 5 ppm or higher, and the mercury halide is adsorbed or precipitated onto combustion ash and collected by the electric dust collector to discharge the mercury halide out of a system.
摘要:
Provided is a method for cleaning a used denitration catalyst, which prevents release of mercury to the atmosphere by collecting and removing mercury which would have been released to the atmosphere in the process of cleaning the used denitration catalyst. The method comprises immersing the used denitration catalyst mainly composed of titanium oxide and having been used in exhaust gas containing mercury in a cleaning liquid, and stirring the cleaning liquid to dissolve and remove catalyst poisons including the mercury from the used denitration catalyst, wherein a waste gas generated in the step of stirring the cleaning liquid is conducted to a flue having a mercury removal device so as to remove the mercury, and then vented to the atmosphere.
摘要:
Provided is a method for cleaning a used denitration catalyst, which prevents release of mercury to the atmosphere by collecting and removing mercury which would have been released to the atmosphere in the process of cleaning the used denitration catalyst. The method comprises immersing the used denitration catalyst mainly composed of titanium oxide and having been used in exhaust gas containing mercury in a cleaning liquid, and stirring the cleaning liquid to dissolve and remove catalyst poisons including the mercury from the used denitration catalyst, wherein a waste gas generated in the step of stirring the cleaning liquid is conducted to a flue having a mercury removal device so as to remove the mercury, and then vented to the atmosphere.
摘要:
To overcome the problem of a conventional catalyst and to provide an exhaust gas purifying catalyst that meets the requirement concerning Hg oxidation activity and SO2 oxidation activity; i.e., an exhaust gas purifying catalyst which specifically reduces percent SO2 oxidation, while maintaining percent Hg oxidation at a high level.The invention provides an exhaust gas purifying catalyst which comprises a composition containing oxides of (i) titanium (Ti), (ii) molybdenum (Mo) and/or tungsten (W), (iii) vanadium (V), and (iv) phosphorus (P), wherein the catalyst contains Ti, Mo and/or W, and V in atomic proportions of 85 to 97.5:2 to 10: 0.5 to 10, and has an atomic ratio of P/(sum of V and Mo and/or W) of 0.5 to 1.5, and an exhaust gas purifying method comprising exposing an exhaust gas containing a nitrogen oxide (NOX) and metallic mercury (Hg) to the catalyst in the presence of ammonia as a reducing agent, to thereby perform reduction of NOX contained in the exhaust gas and oxidation of metallic mercury (Hg) contained in the exhaust gas.
摘要:
An exhaust gas purification catalyst is provided which contains titanium oxide as a main component and an oxide of one element or two or more elements selected from the group consisting of tungsten (W), molybdenum (Mo), and vanadium (V) as an active component, wherein the exhaust gas purification catalyst contains phosphoric acid or a water soluble phosphoric acid compound so that the atomic ratio of phosphorus (P) to a catalytically active component represented by the following formula is more than 0 and 1.0 or less;P/catalytically active component (atomic ratio)=number of moles of P/(number of moles of W+number of moles of Mo+number of moles of V).
摘要翻译:提供一种废气净化催化剂,其包含氧化钛作为主要成分,并且选自钨(W),钼(Mo)和钒(V)作为活性的一种或两种以上的元素的氧化物 其中所述废气净化催化剂含有磷酸或水溶性磷酸化合物,使得磷(P)与由下式表示的催化活性成分的原子比大于0和1.0以下; P /催化活性成分(原子比)= P /摩尔数(W的摩尔数+ Mo的摩尔数+ V的摩尔数)。
摘要:
A catalyst mainly containing silicon oxide and vanadium oxide and having an Si/V atomic ratio within the range from 99.5/0.5 to 85/15 is obtained by gelatinizing a liquid mixture of a colloidal silica and a vanadium compound in advance, then mixing the thus-obtained slurry by heating, and finally drying and/or firing the resulting mixture. As a catalyst for oxidizing mercury metal, this catalyst is brought into contact with an exhaust gas containing mercury metal, thereby oxidizing mercury metal.
摘要:
An exhaust gas purification catalyst is made as a composition comprising titanium oxide (TiO2), aluminum sulfate (Al2(SO4)3), an oxide of vanadium (V), and an oxide of molybdenum (Mo) and/or tungsten (W), wherein on titanium oxide having sulfate ions and aluminum ions adsorbed thereon obtained by making contact with aluminum sulfate at more than 1 wt % and not more than 6 wt % relative to titanium oxide in the presence of water, an oxo acid salt of vanadium or a vanadyl salt and an oxo acid or an oxo acid salt of molybdenum and/or tungsten are supported in a proportion of more than 0 atom % and not more than 3 atom %, respectively. By this, the degradation of catalyst performance can be suppressed even with exhaust gas containing potassium compounds at a high concentration in combustion ash.
摘要:
The invention realizes a catalyst which is hardly deteriorated even when volatile catalyst-poisoning compounds such as P and As are accumulated and which can reduce the rate of oxidation of SO2 to a level as low as a fraction of that of the catalyst in the prior art, and provides an exhaust gas purification catalyst which can maintain a high activity and a low rate of oxidation of SO2 for a long time even with any diversified coal, a method of producing the same, and an exhaust gas purification method using the same. Disclosed is an exhaust gas purification catalyst having a composition comprising oxides of titanium (Ti), molybdenum (Mo) and/or tungsten (W), vanadium (V) and bismuth (Bi), wherein the atomic ratio of Ti:(Mo and/or W):V is 75 to 98.9:1 to 0.1 to 10 and the atomic ratio of Bi/(Mo and/or W) is 0.1 to 0.8.
摘要:
A metal substrate for flue gas-denitration catalyst that, like SUS304, can be used without corroding is provided by improving the corrosion resistance of SUS430 substrate that is inexpensive and can easily be supplied stably. A method for producing the metal substrate for flue gas-denitration catalyst, wherein the method comprising the steps of: lath-processing a band-shaped steel plate made of ferrite stainless steel into a band-shaped metal lath; (1) degreasing process oil adhering to the metal lath; (2) passing the metal lath through a solution containing phosphoric acid and surfactant to load the solution; (3) draining off the excess solution; and (4) drying and heating the solution-loaded metal lath to react the phosphoric acid with the substrate, in which respective steps are carried out sequentially to form a film of phosphate compound on a surface of the substrate.