95 results about "Ammonia adsorption" patented technology

An SCR catalyst is provided in an exhaust pipe of an engine and a urea solution addition valve is provided upstream of the SCR catalyst in the exhaust pipe. An ECU calculates ammonia adsorption quantity of the SCR catalyst and controls urea solution addition quantity, which is added by the urea solution addition valve, based on the ammonia adsorption quantity. The ECU obtains temperature of the SCR catalyst or temperature information correlated with the temperature through measurement or estimation. The ECU switches an execution mode of the urea solution addition control based on the catalyst temperature or the temperature information. Thus, reducing agent addition control can be performed suitably and eventually NOx purification in a NOx catalyst (i.e., SCR catalyst) can be performed suitably.

The invention discloses a urea injection control method based on real-time ammonia storage amount management for catalytic reduction of diesel. The method comprises the following steps: an ammonia storage amount calculation model is established according to ammonia mass conservation of an SCR system, and ammonia storage amount of SCR at the current moment in actual working condition is calculated; NOx emission map, an exhaust mass flow map and an ammonia-nitrogen ratio map of an engine are calibrated on the basis of steady-state experiments, and basic urea injection amount is calculated; a target ammonia storage amount area, an ammonia adsorption time constant and an ammonia release time constant are experimentally calibrated, and modified urea injection amount is calculated; urea injection is controlled in the actual working condition on the basis of the sum of the basic urea injection amount and the modified urea injection amount, and slow urea injection and injection stopping are used for assistance under the working condition of sudden increase of exhaust temperature, so that the ammonia storage amount of the SCR at the current moment approaches the target ammonia storage amount area. NOx conversion efficiency in all working conditions of the SCR in aftertreatment of the diesel can be increased, and urea consumption and ammonia leakage are reduced.

An exhaust gas purifying system for a diesel engine has an ECU, a passage of exhaust gas, a unit having SCR catalyst, a NOx sensor placed at a downstream side of the unit, and a urea water adding valve placed at an upstream side of the unit. The SCR catalyst in the unit selectively adsorbs ammonia, and selectively purifies NOx contained in an exhaust gas emitted from the diesel engine by the adsorbed ammonia. The ECU changes the urea water adding amount, and performs abnormality diagnosis based on the detection result of the NOx sensor while changing an adding amount of the urea water. The ECU uses a first condition to indicate the presence of an excess NOx amount in the exhaust gas, and a second condition to indicate there is no error cause by the ammonia adsorption on the SCR catalyst.

The present invention relates to adsorbent for ammonia refrigeration, is especially one kind of attapulgite clay base composite adsorbent for ammonia refrigeration and its preparation and application, and belongs to the field of new chemical functional material preparing technology. The composite adsorbent for ammonia refrigeration is prepared through mixing alkali earth chloride, attapulgite clay, pore expanding agent and adhesive in certain proportion, forming in a pelletizing machine, stoving and roasting. The composite adsorbent has the advantages of stable performance, high adsorption stability, etc.

In an internal combustion engine, an NOX selective reduction catalyst (15) is arranged in an engine exhaust passage, an aqueous urea solution is fed to the NOX selective reduction catalyst (15) and the ammonia generated from the aqueous urea solution is made to be adsorbed at the NOX selective reduction catalyst (15), and the adsorbed ammonia is used to selectively reduce NOX. At the time the engine is stopped, when the ammonia adsorption amount at the NOX selective reduction catalyst (15) is smaller than a predetermined target amount of adsorption, the urea necessary for making the ammonia adsorption amount at the NOX selective reduction catalyst (15) the target amount of adsorption is fed to the NOX selective reduction catalyst (15) at the time the engine is stopped.

An SCR catalyst is provided in an exhaust pipe of an engine and a urea solution addition valve is provided upstream of the SCR catalyst in the exhaust pipe. An ECU controls urea solution addition quantity of the urea solution addition valve based on ammonia adsorption quantity to the SCR catalyst. The ECU calculates the ammonia adsorption quantity in the SCR catalyst based on time-series data of an ammonia balance between ammonia supply to the SCR catalyst accompanying the urea solution addition of the urea solution addition valve and ammonia consumption in the SCR catalyst. The ECU calculates NOx quantity introduced into the SCR catalyst or a parameter correlated with the NOx quantity and performs initialization of the ammonia adsorption quantity at timing decided based on a result of the calculation.

The invention provides a bamboo charcoal viscose fiber and a preparation method thereof. The fiber is prepared by mixing bamboo charcoal pulp with viscose and then spinning, wherein the content of the nano bamboo charcoal is 0.1-10 percent of weight of the finished product fiber; the specific indexes of the bamboo charcoal viscose finished product are that the dry fracture strength is 1.6-3.5 cN / dtex, the dry breaking elongation is 16-20 percent, the dry strength variable coefficient CV is less than or equal to 18 percent, the dry breaking elongation variable coefficient CV is less than or equal to 8 percent, the flaw is less than or equal to 4 mg / 100, the content of bamboo charcoal is 0.1-10 percent, the antibacterial ratio is greater than 99.9 percent, the ammonia adsorption rate is greater than 50 percent, and the color fastness to washing is class 4-5. The prepared fiber finished product has the characteristics of high strength, good adsorption performance, superior antibacterial effect, uniform and consistent color and strong color fixation; a high-quality bamboo charcoal viscose fiber raw material is provided for textiles.

The invention relates to a preparation method of special active carbon for ammonia adsorption. The preparation method is characterized by comprising the following steps: by taking commercial granular active carbon as raw materials, performing acidification pretreatment, then steeping and modifying through metal inorganic salt, washing, filtering, drying and preparing the active carbon material for efficiently adsorbing ammonia gas at room temperature. The operation technology has the main characteristics that the production cost is low, the operations are simple, the industrial batch production is favorably realized, the prepared active carbon has a good adsorption effect on ammonia gas, the modified samples are not easily desorbed at room temperature, and the effect of effectively removing the ammonia gas for long time can be achieved.

The invention provides preparation of a foam metal / MOF (metal-organic framework) composite and an application to ammonia adsorption, and belongs to the technical field of composites. A preparation process of the composite is mainly characterized in that foam metal is processed and serves as a support of MOFs, then the MOFs are uniformly supported by the foam metal with an in-situ crystal growth method, and finally, the foam metal / MOF composite with both macroporous structure and microporous structure is obtained. The obtained material has good adsorption and removal performance for trace ammonia in air, the preparation method of the material is simple and feasible, and the composite has potential application value in air purification and government.

The invention provides an absorption control method of ammonia inside an SCR (Silicon Controlled Rectifier) catalyst, comprising the following steps of: measuring temperature inside the SCR catalyst, actual ammonia adsorption quantity and saturated ammonia adsorption quantity at the current temperature; comparing the magnitude of the actual ammonia adsorption quantity and set ammonia adsorption quantity; if the actual ammonia adsorption quantity is more than the set ammonia adsorption quantity, increasing ammonia consumption quantity till the actual ammonia adsorption quantity is equal to the set ammonia adsorption quantity; and if the actual ammonia adsorption quantity is not more than the set ammonia adsorption quantity, increasing ammonia supplying quantity till the actual ammonia adsorption quantity is equal to the set ammonia adsorption quantity. The invention considers two conditions that the actual ammonia adsorption quantity is more than or less than the set ammonia adsorption quantity, also obtains an empirical formula of ammonia adsorption rate, approximates temperature intervals with same ammonia adsorption rate, fits an absorption function and computes the ammonia adsorption quantity through the absorption function, thereby accurately and reliably estimating the ammonia adsorption quantity; and in addition, the invention simplifies the operation content and the structure of an SCR system, enhances the stability of the SCR system, reduces the cost of the SCR system and can be actually applied.

The exhaust gas purification apparatus includes an oxidation catalyst, an ammonia adsorption portion, a selective catalytic reduction catalyst and a urea water supply device. The oxidation catalyst is provided in a passage through which exhaust gas flows. The ammonia adsorption portion is located in the passage downstream of the oxidation catalyst with respect to the flow of the exhaust gas and operable to adsorb ammonia. The selective catalytic reduction catalyst is located in the passage downstream of the ammonia adsorption portion. The urea water supply device is provided for supplying urea water to the passage upstream of the selective catalytic reduction catalyst.

An exhaust gas control apparatus includes a control device controlling a urea addition valve for adding urea from an upstream side of a NOx reduction catalyst. The control device obtains an ammonia adsorption amount distribution through the NOx reduction catalyst. When an ammonia adsorption amount in a predetermined part on a downstream side equals or exceeds a predetermined threshold, the control device controls the urea addition valve to stop the urea supply or reduce the amount thereof. The urea addition valve is controlled based on an adsorption amount distribution obtained from a model on which the catalyst is divided into cells such that an ammonia adsorption amount in a first cell positioned furthest upstream equals or exceeds a predetermined threshold close to a saturation adsorption amount and an ammonia adsorption amount in a second cell positioned downstream of the first cell reaches a predetermined target value smaller than the threshold.

An exhaust gas purifying system for a diesel engine has an ECU, a passage of exhaust gas, a unit having SCR catalyst, a NOx sensor placed at a downstream side of the unit, and a urea water adding valve placed at an upstream side of the unit. The SCR catalyst in the unit selectively adsorbs ammonia, and selectively purifies NOx contained in an exhaust gas emitted from the diesel engine by the adsorbed ammonia. The ECU changes the urea water adding amount, and performs abnormality diagnosis based on the detection result of the NOx sensor while changing an adding amount of the urea water. The ECU uses a first condition to indicate the presence of an excess NOx amount in the exhaust gas, and a second condition to indicate there is no error cause by the ammonia adsorption on the SCR catalyst.

A sorbent that is particularly effective for the efficient adsorption and subsequent desorption of ammonia is produced from a high-purity carbon material which is exposed to an oxidizing environment so as to produce an effective amount of at least one oxygen species on its exposed surfaces. The high purity carbon material may be produced by carbonizing a polymer material, and the sorbent may comprise a support having an open-cell, three dimensional, lattice-like structure.

An exhaust gas purification apparatus includes a first oxidation catalyst provided in a passage through which exhaust gas flows, a particulate matter collecting device provided downstream of the first oxidation catalyst, a selective catalytic reduction catalyst integrally formed with the particulate matter collecting device and having ammonia adsorption property, a second oxidation catalyst integrally formed with the particulate matter collecting device and oxidizing ammonia at a predetermined temperature or higher and a urea water supply device provided upstream of the selective catalytic reduction catalyst for supplying urea water. The urea water supply device supplies urea water only when a temperature of the second oxidation catalyst is below the predetermined temperature.

The invention discloses a tail gas heat exchanger used in ammonia adsorption refrigerator which can utilize the left heat of tail gas. The invention can supply stable heat to the left-heat refrigerator, while the heat exchanger uses external structure to be maintained easily. Based on the ammonia adsorption refrigerator, the invention connects a tail gas heat exchanger on a gas-liquid entrance of a left-heat generator as tubular frame steam generator, and a gas-liquid separator between the tail gas heat exchanger and the left-heat generator. The invention can be used on the ammonia adsorption refrigerator on ship or engine.

The invention discloses an ammonia adsorbent regeneration and regeneration liquid pollution-free disposal method and a device; the method comprises the following steps that: in an electrobath, using an electrode comprising Fe, Ti, Al, Pd, Cu, Zn, Sn, Cu / Zn, Cu / Pd or Ti / Pd as the cathode, using an insoluble electrode comprising Pt, Ir, Ru, Pd or Pb as the anode, using the solution containing a chloride ion compound as the electrolyte, putting ammonia adsorbent after ammonia adsorption saturation into the solution containing the chloride ion compound, and electrolyzing for 1 to 5h under the current density of 10 to 50mA / cm2. The invention carries out regeneration liquid pollution-free disposal while carrying out adsorbent regeneration, thereby reducing the regeneration cost of the ammonia absorbent, preventing secondary pollution and realizing the reuse of the regeneration liquid, and the device for implementing the ammonia adsorbent regeneration and regeneration liquid pollution-free disposal method has the advantages of simple manufacturing, convenient operation and easy automation realization; and in addition, the regeneration disposal can be fully completed in a single reaction device without other reactors.

An SCR catalyst is provided in an exhaust pipe of an engine and a urea solution addition valve is provided upstream of the SCR catalyst in the exhaust pipe. An ECU calculates ammonia adsorption quantity of the SCR catalyst and controls urea solution addition quantity, which is added by the urea solution addition valve, based on the ammonia adsorption quantity. The ECU obtains temperature of the SCR catalyst or temperature information correlated with the temperature through measurement or estimation. The ECU switches an execution mode of the urea solution addition control based on the catalyst temperature or the temperature information. Thus, reducing agent addition control can be performed suitably and eventually NOx purification in a NOx catalyst (i.e., SCR catalyst) can be performed suitably.

The invention belongs to the technical field of blood purification, and discloses a five-layer blood perfusion device and a blood perfusion method. The blood perfusion device comprises a perfusion device body, and a gel microsphere anticoagulant layer, a beta-2 microglobulin adsorption layer, a urea decomposition layer, an ammonia adsorption layer and an activated carbon adsorption layer are arranged in the perfusion device body in the direction of blood flow. The blood perfusion method comprises the steps of allowing blood to successively pass through the gel microsphere anticoagulant layer,the beta-2 microglobulin adsorption layer, the urea decomposition layer, the ammonia adsorption layer and the activated carbon adsorption layer. The five-layer blood perfusion device and the blood perfusion method have the advantages of comprehensive blood purification and good purification effect.

An NOx purification system having a selective reduction catalyst, adapted so that even when no ammonia or urea is supplied, NOx is converted to ammonia by a first catalyst including a lean NOx catalyst or a ternary catalyst at ammonia formation control and the ammonia is adsorbed by the selective reduction catalyst disposed downstream and so that by the adsorbed ammonia, there is carried out reduction purification of the NOx contained in the exhaust gas when no ammonia formation control is performed by the selective reduction catalyst. At the ammonia formation control, an ammonia adsorption target amount being a target value of ammonia adsorbed by the selective reduction catalyst is computed, and the ammonia formation control is carried out only when a cumulative value of an ammonia formation amount formed by the first catalyst at the ammonia formation control is under the ammonia adsorption target amount. Consequently, ammonia is stably supplied in just proportion to the selective reduction catalyst.

The invention discloses an ecological ceramic tile. Main raw materials of the ecological ceramic tile comprise 70 to 90 percent of gold tailings particles, 5 to 25 percent of bamboo carbon and 5 to 15 percent of purple gold clay. Aqueous solution of sodium silicate, with the weight of 2 to 4 percent of the total weight of the raw materials, is used as a bonder. A preparation method of the ecological ceramic tile comprises the following steps of: 1, placing the main raw materials into a mixer to mix the main raw materials for 5 to 15 minutes, then adding the aqueous solution of sodium silicateto mix for 60 to 120 minutes and carrying out ageing mixture for 10 to 14 hours to obtain a mixture; 2, carrying out pressure forming on the mixture under the pressure of 30 to 80MPa and then naturally drying the obtained product by 12 to 24 hours to obtain a dried formed product; and 3, sintering the dried formed product for 2 to 4 hours at the temperature of 1,000 to 1,250 DEG C to obtain the ecological ceramic tile. The ecological ceramic tile has functions of ammonia adsorption, far infrared emission and the like.

The invention belongs to the field of water environment protection, and particularly provides an ammonia-adsorption-based improved SBR biological nitrogen and phosphorus removal system and method for low-carbon-source sewage. The method is an improvement to a traditional SBR technology, and comprises the steps of (1) adding a powdery adsorbent in the system to promote ammonia adsorption of sludge and the adsorbent and to promote settling of the sludge at the same time; (2) additionally adding an anaerobic tank; and (3) changing a specific operating procedure of an original SBR. Sewage enters an SBR reaction tank after running through the anaerobic tank, and a circulating procedure of the SBR reaction tank comprises (1) water ingress, (2) oxygen deprivation, (3) sedimentation and water discharging, and (4) aeration. The most important difference between an SBR operating procedure part of the method and the traditional SBR is as follows: firstly, the front-end anaerobic tank is added, secondly, sedimentation and water discharging are conducted immediately after the oxygen deprivation procedure is carried out, and aeration is conducted on the sludge which is obtained after sedimentation and water discharging are conducted. The method is suitable for municipal sewage with a low carbon-nitrogen ratio, moreover, the nitrogen and phosphorus removal efficiency is high, the technology is simple, and energy consumption is low.

The invention discloses a preparation method of a molecular sieve supported SCR (selective catalytic reduction) catalyst. According to the prepared molecular sieve supported SCR catalyst, two catalytic activity units of the catalyst are designed. A first activity unit for promoting a catalytic oxidation reaction in the first step and a second activity unit which enhances the acidity of molecular sieve solids and improves the ammonia adsorption capability are designed through optimization of a molecular sieve supporting mode and components. Organic unification of the two catalytic activity units is effectively coordinated. The high-temperature hydrothermal durability of the molecular sieve catalyst is further enhanced while the catalytic activity of the molecular sieve catalyst is improved. After a high-temperature hydrothermal ageing test, 95% or higher of the catalytic activity of the catalyst can be maintained, conventional V2O5-WO3 / TiO2 oxide catalysts are almost completely inactivated, and the activity of an ordinary macroporous molecular sieve SCR catalyst can also be reduced by 50% or higher.

An exhaust gas control apparatus includes a control device controlling a urea addition valve for adding urea from an upstream side of a NOx reduction catalyst. The control device obtains an ammonia adsorption amount distribution through the NOx reduction catalyst. When an ammonia adsorption amount in a predetermined part on a downstream side equals or exceeds a predetermined threshold, the control device controls the urea addition valve to stop the urea supply or reduce the amount thereof. The urea addition valve is controlled based on an adsorption amount distribution obtained from a model on which the catalyst is divided into cells such that an ammonia adsorption amount in a first cell positioned furthest upstream equals or exceeds a predetermined threshold close to a saturation adsorption amount and an ammonia adsorption amount in a second cell positioned downstream of the first cell reaches a predetermined target value smaller than the threshold.

The invention relates to a metal organic framework / halide composite ammonia adsorbent and a preparation method thereof, and belongs to the technical field of new energy materials. The metal organic framework / halide compound ammonia adsorbent is prepared from a preferred metal organic framework and a preferred halide through a solution permeation recrystallization method, and the preferred metal organic framework suspension concentration and the preferred halide solution concentration are adopted; the halide is uniformly adsorbed on the surface of the metal organic framework and in a pore structure, and in the ammonia adsorption / desorption process, the metal organic framework / halide compound ammonia adsorbent captures ammonia at the same time to generate physical-chemical coupling adsorption so as to realize efficient heat storage and refrigeration performance. The metal organic framework / halide compound ammonia adsorbent can effectively solve the problems that a traditional graphite-based compound ammonia adsorbent is low in dipping salt proportion and adsorption capacity, poor in heat and mass transfer capacity in a stacking state and the like, and the metal organic framework / halide compound ammonia adsorbent is applied to an adsorption type refrigeration and heat storage system for the first time; and the performances of high halide impregnation amount, ammonia adsorption amount, heat and mass transfer and the like can be realized.

A wastewater stream including ammonia and water is fed to at least one packed column including packing material having a surface of solid magnesium phosphate or solid magnesium ammonium phosphate or both. Each of the packed columns is capable of cycling between an ammonia absorption operation and an ammonia regeneration operation. The magnesium phosphate compound reacts with the water and ammonia to form a magnesium ammonium phosphate compound. In one embodiment, this system provides for the regeneration of the magnesium ammonium phosphate compound for further use as an ammonia sorber. In another embodiment, the magnesium ammonium phosphate compound is used as fertilizer. Additionally, the ammonia capture and recovery system may be used in conjunction with other unit operations in an overall wastewater treatment system.

The invention discloses application of a composite adsorption material to an adsorption refrigeration system, a combined cold-electricity system or a combined cold-heat-electricity system. The composite adsorption material comprises 60 to 70 parts of a chloride salt, 30 to 40 parts of expanded graphite and 1 to 6 parts of nanocarbon particles. An application method comprises the following concrete steps: filling an adsorption bed with the composite adsorption material and allowing the density of the composite adsorption material on the adsorption bed to be 300 to 600 Kg / m<3>; and adjusting the temperature of the adsorption bed and the temperature of a condensation / evaporation terminal for adsorption and desorption of ammonia, wherein adsorption and desorption separately last for 1 to 2 h. Compared with conventional chloride salt-expanded graphite adsorbents, the nanocarbon / expanded graphite-chloride salt composite adsorption material provided by the invention is obviously improved in ammonia adsorption rate and ammonia desorption rate; and when the nanocarbon / expanded graphite-chloride salt composite adsorption material is applied to an adsorption refrigeration system employing a chloride salt-ammonia working substance pair and a combined cold-electricity system and a combined cold-heat-electricity system based on adsorption refrigeration, adsorption refrigeration efficiency of the systems is improved, and the composite adsorption material has substantial application value in the field of adsorption refrigeration.

The invention relates to an ammonia release adsorption device in the hydration reaction process of coal ash-based filling paste. The device comprises a curing chamber I for placing the coal ash-basedfilling paste, a gas collecting hood with a unique outlet for air and gas is arranged above the curing chamber I, and the outlet is connected with a gas inlet of an ammonia adsorption tower II througha pipeline with a sucking pump and a gas flowmeter. Absorption liquid is arranged in the ammonia gas adsorption tower II and located below the gas inlet, a hollowed-out filler supporting plate, an absorption liquid collecting and redistributing device, a filler pressing device and an absorption liquid distributor are sequentially arranged above the gas inlet, and a tail gas exhaust port is formedin the top of the ammonia gas adsorption tower II; and the absorption liquid distributor is connected with absorption liquid at the bottom of the ammonia gas adsorption tower II through a return pipewith a return pump. The invention further provides an adsorption method based on the adsorption device and an ammonia release detection method, and the total release amount and the release rule of ammonia gas in the hydration reaction process of the denitrified fly ash-based filling paste can be accurately mastered.

In an internal combustion engine, an NOX selective reduction catalyst (15) is arranged in an engine exhaust passage, an aqueous urea solution is fed to the NOX selective reduction catalyst (15) and the ammonia generated from the aqueous urea solution is made to be adsorbed at the NOX selective reduction catalyst (15), and the adsorbed ammonia is used to selectively reduce NOX. At the time the engine is stopped, when the ammonia adsorption amount at the NOX selective reduction catalyst (15) is smaller than a predetermined target amount of adsorption, the urea necessary for making the ammonia adsorption amount at the NOX selective reduction catalyst (15) the target amount of adsorption is fed to the NOX selective reduction catalyst (15) at the time the engine is stopped.

An ammonia adsorption product is described which may be used for fresh caught fish and bait. The product may comprise functionalized tectosilicate compound and a buffer. High concentrations of ammonia produced by fish waste can be lethal, even though oxygen availability is rich enough to keep fish breathing. The product is a user-friendly, sustainable, affordable product which is able to extend the life of the fish by safely removing ammonia by an ion-exchange mechanism. This product can convert toxic ammonia into ammonium and uptake ammonium by releasing sodium ions in the water.