558results about How to "Improve sulfur resistance" patented technology

The present invention provides a catalyst comprising metallic Pt and / or Pd supported on a binder-free zeolite for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock, wherein the amount of metallic Pt and / or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total weight of the catalyst, and the binder-free zeolite is selected from the group consisting of mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The present invention also provides a process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock using said catalyst.

The invention relates to a catalyst of selective reduction of nitrogen oxide by ammonia, which mainly solves the existing problems that the commonly used NH3-SCR catalyst system is toxic to environment and human body, the anti-SO2 poisoning ability of the catalyst system is poor in the reference and the catalyst system can not adapt to the conditions of high space velocity. The invention adopts cheap and non-toxic raw materials to prepare a Fe-Ti oxide catalyst with high activity, selectivity, stability and anti-S2 poisoning ability by the simple and practicable co-precipitation method, which can better solve the existing technical problems. If the catalyst is loaded on honeycomb ceramics after being made into pulp, the catalyst is hopeful to be put into practical application of flue gas denitrification of coal-fired power plants.

A catalytic hydrodealkylation / reforming process which comprises contacting a heavy hydrocarbon feedstream under catalytic hydrodealkylation / reforming conditions with a composition comprising borosilicate molecular sieves having a pore size greater than about 5.0 Angstroms and a Constraint Index smaller than about 1.0; further containing a hydrogenation / dehydrogenation component; wherein at least a portion of the heavy hydrocarbon feedstream is converted to a product comprising benzene, toluene, xylenes and ethylbenzene.

The invention discloses a low-temperature sulfur-resistant denitration catalyst and a preparing method of the low-temperature sulfur-resistant denitration catalyst. The low-temperature sulfur-resistant denitration catalyst is formed by mixing, by weight, 15%-100% of active sites and 0-85% of carbon-based carriers; the active sites are formed by mixing one or two of the first active sites and the second active sites; the first active sites are composed of Mn(0.1-0.8)Ce(0.2-0.9)Ox or Mn(0.1-0.8)Mg(0.2-0.9)Ox dispersed into a 3A molecular sieve, and the value of the x is determined according to the content and the oxidation valence state of metallic elements in the chemical formula; the second active sites are composed of Mn (0.1-0.8)Mg(0.2-0.9) or Mn (0.1-0.8)Ce (0.2-0.9)Ox with the surface coated with a TiO2 or SiO2 protecting layer. According to the method, one or more of the first active sites and the second active site are mixed with carbon-based carriers to obtain the low-temperature sulfur-resistant denitration catalyst. As surface dewatering is performed on the catalyst, water molecules contained in flue gas are attached in an open-framework structure of the catalyst to form capillary condensation very difficultly or form vitriol or sulphurous acid ammonium salt with NH3 and SO2 or SO3 to cause deactivation of the catalyst.

The invention discloses a low-temperature denitration catalyst MnOx-CeO2-TiO2-Al2O3, and a preparation method and an application thereof. The low-temperature denitration catalyst MnOx-CeO2-TiO2-Al2O3 is composed of carriers and active components, wherein the carriers are TiO2 and Al2O3 and the active components are MnOx and CeO2. The molar ratio of Ce:Ti:Al:Mn in the low-temperature denitration catalyst MnOx-CeO2-TiO2-Al2O3 is 0.2-0.4:1:1:0.4-1.2. The preparation method is that: the low-temperature denitration catalyst MnOx-CeO2-TiO2-Al2O3 is prepared by taking titanium sulfate, aluminium nitrate, manganous nitrate and cerium nitrate as precursors and employing a coprecipitation method. The preparation cost is low, and the low-temperature denitration catalyst MnOx-CeO2-TiO2-Al2O3 has better denitration effect in a flue gas at a temperature of 150-300 DEG C.

The present invention relates to a method for selective hydrogenation through cracking of a C5-C9 distillate. According to the method, the catalyst comprises an alumina carrier having a macroporous structure and metal active components comprising nickel and tungsten and supported on the carrier, the nickel oxide content is 12-22 wt% based on the total weight of the catalyst, the tungsten oxide is 1.5-8 wt% based on the total weight of the catalyst, and the hydrogenation reaction process conditions are that the reaction inlet temperature is 40-55 DEG C, the reaction pressure is 2.0-3.5 MPa, the hydrogen oil volume ratio is 60-150, and the liquid volume space velocity is 3.0-5.5 h<-1>. According to the present invention, the catalyst has characteristics of good glue capacity, strong arsenic resistance, strong sulfur resistance, strong coking inhibition and low temperature activity; and the method provides strong adaptability for the cracking gasoline raw materials having different arsenic contents and different sulfur contents.

The invention discloses application of a metal oxide modified CePO4 catalyst to collaborative denitration and demercuration. The application includes introducing medium-high temperature flue gas containing elemental mercury and nitrogen oxide into a catalyst loaded catalytic apparatus. Specifically, the main component of the catalyst is cerium phosphate, and the modification component is at least one of cobalt, manganese, copper, iron, vanadium, cerium, molybdenum and tin metal oxides. The temperature of the medium-high temperature flue gas is 250-420DEG C. According to the application of the metal oxide modified CePO4 catalyst to collaborative denitration and demercuration, the oxidation efficiency to null valence mercury in high temperature flue gas is high, the NO is the flue gas can promote and enhance the catalytic efficiency of the catalyst, and the practicability is strong. In addition, the catalyst has good medium-high temperature SCR activity and anti-sulfur and waterproof performance.

The invention discloses a catalyst based on a modified molecular sieve and hydrotalcite derived oxides and applied to a diesel engine. The catalyst adopts the Co modified ZSM-5 molecular sieve as a main catalyst, a CeO2-ZrO2 solid solution as a cocatalyst, adopts multi-metal modified hydrotalcite derived composite oxides and gamma-Al2O3 as coating base materials and adopts cordierite honeycomb ceramic as a catalyst support. A preparation technology comprises steps as follows: determination of the use quantity of the raw materials of the catalyst; preparation of the Co modified ZSM-5 molecular sieve and the multi-metal modified hydrotalcite derived composite oxides; preparation and coating of coating slurry. The catalyst can efficiently catalyze adsorption-reductive purification reaction of NOx in exhaust gas. By means of the synergistic effect of four metallic oxides, NOx adsorption performance and heat stability of the hydrotalcite derived oxides are improved. Meanwhile, a precious metal main catalyst is replaced with the Co modified ZSM-5 molecular sieve, so that the cost of the raw materials is reduced, and sulfur resistance and heat stability of the catalyst are improved.

The invention discloses a low-temperature sulphur-resisting denitration catalyst and preparation method thereof. The catalyst is formed by mixing the following components in weight percent: 1-15% of active site and 85-99% of a carbon-base carrier, wherein the active site is formed by mixing one or several of Ag2O, K2O, BaO, SnO2, Bi2O3 or PbO improved vanadium-base alloy oxides. The preparation method comprises the steps of mixing the active site and the carbon-base carrier to prepare the low-temperature sulphur-resisting denitration catalyst. Since the surface hydrophobic treatment is performed on the catalyst prepared by the invention, the situation that water molecules in the flue gas adhere to an open-framework structure of the catalyst to form capillary condensation or form sulfuric acid or ammonium sulfite with adsorbed NH3 and SO2 or SO3 to inactivate the catalyst is avoided.

The invention relates to a composite oxide iron-based molecular sieve SCR catalyst and a preparation method thereof. The composite oxide iron-based molecular sieve SCR catalyst is characterized in that the preparation method comprises the following steps: uniformly mixing copper oxide, iron oxide and co-catalyst metal oxide materials with molecular sieves by using a high energy ball milling method; adding an active component guiding-in agent and a surface dispersant to carry out impregnation; and ball-milling, drying, grinding and calcining to obtain the composite oxide iron-based molecular sieve SCR catalyst. The composite oxide iron-based molecular sieve SCR catalyst is used for catalytically purifying NOx in motor vehicle exhaust. The preparation process of the catalyst is simplified, the high energy ball milling method is adopted, the active component guiding-in agent and the surface dispersant are added so that metal active components are uniformly distributed in molecular sieve holes and on surfaces of the molecular sieve holes, during calcining, the metal oxide has abundant valence states, and the NOx conversion efficiency is high; and by the added co-catalyst metallic compound, sulfur resistance is improved, meanwhile, the co-catalyst metallic compound can also serve as an active component, NO-to-NO2 conversion is strengthened, the activity of the SCR catalyst is improved remarkably, and the actual application value is high.

The invention discloses a low-dimensional nano-structured iron vanadate denitration catalyst which is characterized in that the iron vanadate has a nano-rod or nano-wire or nano-sheet structure. The catalyst is prepared by using meta-vanadate, nitric acid, iron salt and ammonia water with a molar ratio of 1.0:10.0:0.5-1.0:0.1-4.0:0.0-4.0. The invention also discloses a preparation method and an application of the low-dimensional nano-structured iron vanadate denitration catalyst. According to the invention, advantages of a vanadium-based catalyst, an iron-based catalyst, and the low-dimensional nano structure are combined. Excellent activity, selectivity, thermal stability, and SO2 intoxication resistance are provided. The catalyst can be used in removing of nitrogen oxides in various flue gases.

The invention discloses a preparation method of a low-temperature NH3-SCR sulfur-resistant denitration catalyst. The preparation method is characterized in that titanium tetrachloride, titanium(IV) isopropoxide, isopropyl titanate and butyl titanate are used as the titanium sources of the sulfur-resistant denitration catalyst, and a chemical vapor deposition method or aqueous phase method to precipitate a TiO2 sulfur-resistant layer on the surface of a Cu-SAPO-34 catalyst or wrap the surface of the Cu-SAPO-34 catalyst with the TiO2 sulfur-resistant layer so as to form a TiO2 / Cu-SAPO-34 compound catalyst. The prepared catalyst keeps the low-temperature high-activity feature of the Cu-SAPO-34 catalyst and adopts the TiO2 sulfur-resistant layer to evidently enhance of the sulfur resistance. At 300-500 DEG C, SO2 (100-500ppm) is fed into a reaction system, and the conversion rate of NOx in the NH3-SCR reaction is above 80%. Compared with a common catalyst, the compound catalyst is wider in temperature operation window, excellent in low-temperature activity and high in sulfur resistance.