53results about How to "Wide active temperature range" patented technology

The invention discloses a multi-complex-metal-oxides catalyst and the preparation method. The catalyst carrier is multi-complex-metal-oxides solid alkali or surface solid alkali or the precursors of the solid alkali or surface solid alkali. The multi-complex-metal-oxides is complex oxides by combining two or more than two selections from alumina, titania, zirconium dioxide and ceria with one or more than one selections from magnesia, calcium oxide, baryta, potassium oxide and sodium oxide. Active ingredient is composed of cobalt oxides or /and nickel oxide and molybdenum trioxide or/and tungsten trioxide. The additive added to carriers or active components is the oxide of at least one of the following elements: cerium, lanthanum, zinc, zirconium, nickel or manganese. The invention has the advantages of high activity, high activity at low-temperature, high activity stability and wide temperature range of activity; high intensity, high intensity stability and high anti-hydration and anti-pulverization ability, wide water/gas ratio adaptability and wide range for impurity content. The catalyst of the invention is applied to the promotion of dirty water gas shift reaction.

The invention relates to a catalyst for removing nitrogen oxide through selective catalytic reduction for an automobile diesel engine adopting Ce2O3 and V2O5 double active compositions. The catalyst adopts scordierite honeycomb ceramics as a framework material, the Ce2O3 and the V2O5 as main active compositions, WO3 or MoO3 as an auxiliary catalyst composition, and TiO2 as a coating substrate, wherein the mass fraction of the main active compositions, namely the Ce2O3 and the V2O5, to the auxiliary catalyst composition WO3 or MoO3 to the coating substrate TiO2 is 1-3:6:12:85-93. The specific process comprises the following steps: preparing a TiO2 precursor solution; coating a TiO2 coating; coating an auxiliary catalyst; determining the loading of active compositions of oxides; and coating the main active compositions, namely the Ce2O3 and the V2O5. The catalyst replaces the V2O5 with high toxicity with the Ce2O3 with low toxicity, and reduces the environmental hazards of the catalyst, and the replaced catalyst has wider active temperature range, particularly greatly improves the low-temperature activity, and is particularly suitable for the traffic conditions of urban highways of China.

The invention discloses a flue gas denitrification catalyst with a wide activity temperature interval as well as a preparation method thereof. The flue gas denitrification catalyst comprises 65%-99.8% of carrier TiO2, 0.1%-10% of active component V2O5, 0.1%-10% of active component WO3 and 0.1%-15% of valence-variation metallic oxide. According to the invention, a ball mill is adopted for enabling the VWTiO2 catalyst and the valence-variation metal element oxide to be fully mixed mechanically, simplifies the technological process, reduces the energy consumption, and prevents the environment pollution; the prepared flue gas denitrification catalyst has a wide activity temperature interval and high capability of NOx removing activity and SO2 and H2O toxication resistance.

The invention is catalyst purifying method for tails discharged by fuel-lean car engine. The invention provides a method which applies to fuel-lean car engine, reduces NOx in tails efficiently in wide temperature range, and oxidizes HC and CO. The method includes following steps: sprays carbinol or alcohol into discharging pipe, and makes it blend with the engine tails; the mixed gas is transmitted to front grade catalyzing reaction bed which is loaded with transition metal oxide catalyst and the back grade catalyzing reaction bed which is loaded with laden noble metal catalyst, realizes the purification of NOx, HC and CO with high efficiency, and finally discharges normal gas. The invention can spread the range of NOx reduction active temperature.

The invention discloses a preparation technology of a catalyst used for high temperature catalytic decomposition of N2O. The preparation technology comprises the following steps: dissolving magnesium nitrate, cobalt nitrate, lanthanum nitrate, cerium nitrate, nickel nitrate and zirconium nitrate in water to form a mixed nitrate solution; adding ammonia water and aluminum hydroxide, and carrying out compacting, dehydrating, drying and baking to obtain a powder material; and uniformly rolling the powder material, desalinized water and a bonding agent, drying the rolled materials to obtain a granulation material, compacting the granulation material to form a porous cylinder, and calcining the porous cylinder to obtain the catalyst. The preparation technology has the following advantages: a co-precipitation method is selected, an active component reacts with a carrier substance precursor and a precipitating agent to realize co-precipitation, and the active component interacts with the carrier, so the active component is well and stably dispersed; and the active component and the carrier precipitate are commonly calcined at a high temperature of 1000-1300 DEG C, so the active component of the catalyst has good heat tolerance and difficulty loses, thereby the catalyst has the advantages of high efficiency, good stability and long service life.

The invention belongs to the field of flue gas denitration, and specifically provides a gamma-Fe2O3 nanoparticle modified nf-MnO2/ATP low-temperature denitration catalyst. Directed at the disadvantages of low carrier strength, poor SO2 resistance and complicated preparation method for a conventional flue gas denitration catalyst, the invention provides the gamma-Fe2O3 nanoparticle modified nf-MnO2/ATP low-temperature denitration catalyst and a preparation method thereof. The preparation method comprises the following steps: with attapulgite clay with large specific surface area and high adsorption performance as a carrier and a reducing agent, allowing the attapulgite clay to react with KMnO4 under a hydrothermal condition so as to prepare a nanoflower-like MnO2-coated attapulgite clay (nf-MnO2-ATP) catalyst, preparing high-performance gamma-Fe2O3 nanoparticles under a low-temperature hydrothermal condition at the same time, and subjecting nf-MnO2/ATP to surface modification with the high-performance gamma-Fe2O3 nanoparticles so as to prepare the gamma-Fe2O3/nf-MnO2-ATP denitration catalyst. Thus, N2 selectivity and SO2 resistance of nf-MnO2-ATP are improved. Meanwhile, the preparation method provided by the invention has mild preparation conditions and simple preparation process, and is a safe and highly-efficient preparation method for a low-temperature denitration catalyst.

The invention discloses a CO selective methanation monolithic catalyst and a preparation method thereof, in particular relates to a CO selective methanation monolithic catalyst using nanometer cerium-zirconium composite oxide as a carrier and a preparation method thereof. The catalyst comprises an active ingredient Ru, a porous material matrix and the nanometer cerium-zirconium composite oxide carrier, wherein the mol ratio of Ce to Zr is 1-36:6; the coating quantity of the nanometer cerium-zirconium composite oxide is 6-30 wt % of that of the porous material matrix; the content of Ru is 0.2-2 wt % of that of the catalyst; and the particle diameter of the nanometer cerium-zirconium composite oxide carrier is 5-20nm. The CO selective methanation monolithic catalyst has good activity and high strength, has high selectivity in the whole reaction temperature area, greatly prevents the unnecessary consumption of hydrogen in reformed gas, and has simple preparation technology and relativelylow cost.

The invention discloses a multifunctional environment catalytic material for tail gas purification and a preparation method thereof, and belongs to the field of environment-friendly catalytic materials and air pollution treatment. The material is prepared by taking cerium-manganese-copper composite oxide as a catalytic active component, molybdenum-zirconium composite oxide as a cocatalyst and titanium dioxide as a carrier and adopting a step-by-step in-situ growth method. The catalyst is environment-friendly, not only can efficiently catalyze and remove nitric oxide, mercury, dioxin and carbonmonoxide at the same time, but also is wide in active temperature interval and low in SO2 oxidation efficiency. The denitration efficiency and the dioxin removal efficiency within the temperature of350-500 DEG C are both greater than 95%, and the mercury removal efficiency and the carbon monoxide removal efficiency are both greater than 99%. The product can be widely applied to the fields of industrial tail gas purification of gas power plants, gas power generation plants, waste incineration, high-speed diesel engines and the like.

The invention belongs to the field of flue gas denitrification, in particular to a kelp-shaped Mn-Fe double-metal oxide loaded CeO2 low-temperature flue gas denitrification catalyst, provides a preparation method of the kelp-shaped Mn-Fe double-metal oxide loaded CeO2 low-temperature flue gas denitrification catalyst, and aims to solve the problems that an existing loaded denitrification catalystis low in selectivity and efficiency, poor in specificity, nonuniform and bad in stability, active components are not easily fixed on catalyst carriers, active windows of the catalyst are narrow in actual use of flue gas pipelines and easily poisoned by SO2 and the like. A wrinkled kelp-shaped Mn-Fe double-metal oxide is prepared by a hot water-calcination method and serves as a carrier, the Mn-Fedouble-metal oxide can also serve as a low-temperature active component, CeO2 particles are loaded on the oxide to improve sulfur resistance, and the catalyst is an environmental-friendly NH3-SCR denitrification catalyst with a great application prospect.

The invention discloses a denitrifying honeycomb heat accumulator and a preparation method thereof. The denitrifying honeycomb heat accumulator comprises a honeycomb heat accumulator and a loaded mixture, wherein the honeycomb heat accumulator comprises inorganic powder; and the loaded mixture, which is loaded to the honeycomb heat accumulator, comprises a denitrifying catalyst and an additive; the additive comprises carbide slag. The denitrifying honeycomb heat accumulator has the functions of denitrification and heat accumulation without independently arranging the heat accumulator and the denitration catalyst, so that the arranging space can be lowered and the cost is lowered. By means of the heat-accumulating effect of the heat accumulator, the heat accumulator is arranged as required, so that the catalyst in the heat accumulator is stabilized in the optimum temperature range for denitration reaction, and therefore, the denitration efficiency is high and the emission-reducing effect is obvious.

The invention discloses a production process urea solution for vehicles. The production process comprises the following steps: S1, cooling raw urine in a raw urine tank to a temperature of 85-90 DEG C, and carrying out centrifugal impurity removal on the cooled raw urine to obtain pure raw urine; S2, introducing pure raw urine into a urine cooling crystallizer, keeping a temperature in the urinecooling crystallizer at 20-60 DEG C, and allowing urea crystal suspension liquid to be formed under the action of a stirrer in the urine cooling crystallizer; and S3, carrying out centrifugal separation on the urea crystal suspension liquid prepared in the step S2 to obtain urea crystals and a urea solution containing a small amount of urea. According to the invention, urine is used as a raw material; and compared with granular urea, the retention time of urea in the urine in a production system is shortened, and the contents of biuret, metal ions and the like are reduced, so product quality can be improved.

The invention discloses a multifunctional catalyst, and a preparation method and application thereof. A mixture of zirconium hydrogen phosphate and titanium trioxide is taken as a carrier, a cerium-manganese-iron composite oxide is taken as a catalytic active component, and strontium oxide is taken as a cocatalyst. Based on the mass of the carrier, the mass percentage of the active component is 2-4%, and the mass percentage of the cocatalyst is 0.5-1%. The preparation method comprises the following steps: uniformly stirring the active component, a cocatalyst precursor solution and the catalystcarrier, performing aging, and then carrying out extrusion molding, drying, and roasting. The catalyst is environmentally friendly, can remove NOx in diesel engine tail gas and synergistically catalyze and remove CO and HC at a low temperature, and has a wide active temperature interval and low SO2 oxidation efficiency. The denitration efficiency of the catalyst is higher than 95% and reaches upto 100% in a temperature range of 150-350 DEG C, and the oxidation efficiency of CO and HC is higher than 90% and reaches up to 98.7% and 97.6%, respectively. The catalyst is high in cost performanceand particularly applicable to the field of low-speed diesel engine tail gas purification.

The invention discloses a wide-temperature vanadium-free denitration catalyst preparation method, which comprises: 1, dissolving a chromium-containing precursor, an iron-containing precursor and a copper-containing precursor in deionized water, and stirring in a water bath at a temperature of 20-30 DEG C for 30-60 min to obtain a mixed solution; step 2, adding a pretreated HY molecular sieve into the mixed solution obtained in the step 1, and heating in a water bath to 70-80 DEG C under a stirring condition to obtain a viscous mixture; and step 3, sequentially carrying out ultrasonic oscillation, room-temperature aging, drying, roasting and cooling treatment on the obtained viscous mixture to obtain the catalyst, the mass ratio of the HY molecular sieve to the Fe precursor is (1.33-2.67): 1. The prepared wide-temperature vanadium-free denitration catalyst is wide in active temperature range, low in activation temperature and high in denitration efficiency, the composite desulfurization catalyst can be arranged in equipment behind a dust remover and a desulfurization tower, the service mechanical life of the catalyst is prolonged, and the denitration efficiency can reach 95% or above within the range of 200-360 DEG C under the sulfur-free working condition.