Denitrification catalyst is one of the essential components in the denitrification process of industrial flue gas treatment, and its use can improve denitrification efficiency and achieve ultra-low emissions. However, catalysts need to be replaced periodically during use as operating time increases, due to dust clogging, sintering, alkali metal poisoning, loss of active components, etc. So, what are the common deactivation causes of denitrification catalyst deactivation? 1) Physical factors. Decrease in catalyst activity due to changes in the physical properties of the catalyst itself or physical changes in the catalyst surface structure; mainly includes three types: high temperature sintering, pore blockage, and substrate abrasion. 2) Chemical factors. The chemical activity of the active component is destroyed or inhibited after the catalyst absorbs and adsorbs the chemical components in the flue gas, which leads to the reduction of denitrification catalyst activity; mainly including: alkali metal (Na) poisoning, alkaline earth metal (Ca) poisoning, arsenic (As) poisoning, SO3 poisoning, phosphorus (P) poisoning, and the effect of water vapor (H2O). 01 Sintering After long-term operation of SCR denitrification catalysts under high temperature conditions, TiO2 undergoes phase transition from anatase to rutile; at the same time, the active component V2O5 agglomerates to form large particles resulting in reduced dispersion. The specific surface area and activity of the catalyst will be reduced as a result. 02 Clogging 1) Surface coverage - the fly ash in the flue gas covers the surface of the catalyst monomer causing blockage (fly ash deposition). 2) Pore blockage - the internal pores of the catalyst are blocked, resulting in catalyst deactivation (ammonium salt deposition). 03 Abrasion The intensity of catalyst abrasion is related to the airflow velocity, fly ash characteristics, impact angle and the catalyst itself characteristics. 1) Impact of the catalyst by external forces during installation or replacement. 2) Excessive flue gas flow velocity (> 8 m/s) during operation. 3) Excessive dust concentration (> 45 g/Nm3). 04 Alkali metal poisoning (Na, K) Alkali metals can react directly with the active component of the catalyst, making the catalyst surface less acidic and reducing the reducibility of the active component, resulting in the loss of catalyst activity. 05 Alkaline earth metal poisoning (Ca) The free CaO in the fly ash reacts with the SO3 adsorbed on the catalyst surface to form CaSO4, which scales on the catalyst surface and prevents the diffusion of the reacting material to the catalyst surface and to the catalyst interior. 06 Arsenic poisoning (As) Arsenic (As) poisoning is caused by the presence of gaseous As2O3 in the flue gas. As2O3 is dispersed into the catalyst and solidified in the active and inactive regions, so that the diffusion of the reactant gas within the catalyst is restricted and the microscopic capillary pore ch...

Dust bag is the whole dust removal system plays an extremely important role, but dust bag as a loss of goods also has different degrees of advantages and disadvantages, such as although you can achieve more than 99.99% of dust removal efficiency, but may face accelerated consumption of dust bag due to working conditions, then the dust bag and what are the advantages and disadvantages? Advantages of dust filter bags     1. High dust removal efficiency, generally up to 99.99% and above. Exhaust dust concentration is low, generally lower than 50mg/m3, or even up to 10mg/m3 below.     2. Strong adaptability to dust, can capture high specific resistance dust and dust with high SiOZ + AID3 content, low sulfur, high ash coal dust, not sensitive to the physical and chemical properties of dust.     3. The inlet dust concentration is within a wide range of variation, which has less influence on dust removal efficiency and resistance.     4. Simpler structure, smaller land area, lower primary investment, can do online rotation of maintenance and bag change in separate chambers. With dry and semi-dry desulfurization system, it has certain desulfurization effect.     5. The service life of dust bag can reach 30000 hours. Disadvantages of dust filter bags Dust bag filter media is sensitive to the nature of the soot, such as temperature, humidity, acid dew point, oxygen content, etc., although there are already temperature-resistant 170-190 ℃ dust bag, but must be equipped with temperature reduction measures. The following network to PPs dust bag as an example of the relationship between flue gas oxygen content, flue gas temperature, service life. It shows that in the case of ensuring the service life of the dust bag, the higher the oxygen content of the flue gas, the lower the temperature of the dust bag used, because every 10'C increase, the chemical reaction into a double increase. That is to say the original life of 4 years, if the temperature increases by 100C, its life will only be 2 years due to the higher cost of dust bag, so the operation and maintenance costs are higher. Equipment system pressure loss is large, generally at 1500-2000 Pa. Improper combustion control in boiler operation directly affects the service life of dust collector dust bag. At the initial stage of using dust bag, the main role of dust removal mechanism is inertial collision, diffusion and retention, in addition, electrostatic force and gravity also have a role. During this period, the dust removal efficiency is slightly lower than the normal use period. However, the dust layer (usually called the filter cake layer) that accompanies the dust deep on the surface of the filter media, and the baghouse in normal use into the filter media interior, so that the fiber space is gradually reduced and eventually formed to attach to the period is mainly dependent on this initial layer and the dust layer that gradually builds up afterwards to ...

Recently, Yuanchen Technology successfully won the tender for supplying SCR denitrification catalyst for 100,000 tons/year CO2 capture project of Xinjiang Huayi Jinlong Thermal Power Co. After the project is completed and put into operation, it will provide another application case to promote the scale development of CCUS in Xinjiang, which is of great significance to build the "artificial carbon cycle" model and will effectively help to achieve the carbon peaking and carbon neutrality goals. It is understood that CCUS technology is currently being promoted in China, and CCUS adds "utilization" to carbon dioxide capture and storage (CCS), a concept that has gained widespread recognition as CCS technology develops and its understanding deepens. The project provides technical support and accumulates practical experience for cogeneration companies to achieve near-zero emissions in the true sense, and is of great significance to the implementation of carbon peaking and carbon neutral goals. As a national high-tech enterprise, Yuanchen Technology has been deeply engaged in the environmental protection field since its establishment. Especially in recent years, through continuous technological innovation and product iteration, the business field has gradually covered from traditional power industry to many industries such as steel, cement, waste incineration, glass, etc. On the other hand, through industry chain extension and layout of new tracks, the company has gradually formed a green industrial ecology from product design, R&D, production, sales and comprehensive services. The winning bid is a successful attempt of the company to keep pace with the times, grasp the opportunity and ride on the momentum, and is also a strong proof of the company's full commitment to fight the hard battle of reform and development, which fully reflects the high recognition of the market parties to the company's independent research and development catalyst and technical service level. In the future, Yuanchen Technology will continue to strengthen the attributes of science and innovation, adhere to the innovation drive, achieve innovation and research, use the capital power to accelerate the research and development of functional high-end new materials and dual carbon business areas and other zero-carbon and carbon-negative emerging industries and technology research, further broaden the market, enhance the influence and competitiveness of enterprises, and contribute to the realization of "3060" in China To contribute to the goal of "3060" carbon neutral, and to welcome the 20th Party Congress with practical actions and excellent achievements!

As individual, business and society become more aware of environmental protection, the denitrification of biomass boilers will be implemented according to the ultra-low emission requirements. Biomass boiler is a new type of boiler using biomass energy as fuel, which has lower sulfur dioxide and nitrogen oxide content in the flue gas emission from the boiler and does not produce waste residue. Therefore, compared with coal-fired boilers, they are more energy-efficient and environmentally friendly. However, with the improvement of national environmental standards for boiler flue gas, coupled with the promotion and implementation of ultra-low emission of boiler flue gas. Biomass boiler denitrification catalyst will be widely used. The boiler fuel type of biomass, low calorific value and poor feeding uniformity cause drastic temperature changes in the combustion zone, large fluctuations in the initial NOx emission concentration at the boiler outlet, low flue gas temperature, high alkali metal and fly ash content, and its outlet tail gas temperature is similar to the tail gas temperature in the waste incineration industry, which is also around 130~150℃. The main denitrification catalysts are characterized by ① large differences in furnace chamber temperature, ② high hydrogen content in biomass, ④ low and fluctuating sulfur dioxide and nitrogen oxide concentrations, which are hazardous to SCR catalysts due to the high mass fraction of alkali metals in the soot and the presence of sparks in the dust at high temperatures. The current SNCR denitrification technology can meet the standard of 200mg/Nm3 NOx content in the export tail gas, now the biomass boiler emission standards according to the thermal power industry emission standards, requiring NOx emissions at 100 mg/Nm3 or even lower to 50 mg/Nm3, so the biomass boiler upgrading and retrofitting additional desulfurization and SCR denitrification device has become imperative Biomass boiler tail gas denitrification process comparison The current denitrification process is mainly to transform the boiler, take the gas from the coal economizer outlet at 200~240℃, and enter the SCR denitrification system after dry desulfurization and dust removal.

The boiler dust bag dust collector has the phenomenon of paste bag, resulting in high running resistance of pulse bag dust collector, and running resistance is an important performance index of dust collector. A high-performance, well-running pulse bag filter not only has high dust removal efficiency, but also the running resistance should be kept below 1500Pa. If the dust adhering to the filter bag cannot be effectively removed when cleaning the pulse bag type dust collector, the dust will gradually accumulate on the outer surface of the filter bag and block the bag, which not only makes the filter bag easy to break, but also increases the running resistance of the dust collector and increases the running load of the dust fan, resulting in increased operating costs. Installing differential pressure detection alarm device on the dust collector can easily monitor its operating resistance. If the operating resistance of pulse bag filter is found to be higher than the control range, troubleshooting should be done from the following aspects: A Short cleaning time, cleaning cycle is too long, the dust on the filter bag can not be cleared, dust collector into the filter state, will make the operating resistance quickly rise. For pulse bag filter, the time used for dust cleaning process (i.e. pulse valve blowing time) is the dust cleaning time, adjustable within 0.05~0.5s. The time between two dust cleaning is the dust cleaning cycle, generally 0-30min. B When the pulse bag filter processing high temperature, high humidity gas, if the operation of the gas temperature is lower than the dew point, water vapor will condense dew, so that the filter bag moisture, a large amount of dust adhered to the surface of the filter bag, blocking the pores of the filter bag, and blowing compressed air can not be removed, resulting in the filter bag paste bag. The cleaning function of the dust collector fails, the resistance is too large, and the operation condition deteriorates. To prevent the pulse bag filter from gluing bags, it is necessary to keep the processing gas temperature higher than its dew point 25~35℃. C Pulse bag filter usually works under negative pressure, if the equipment leaks, it will suck in a lot of outside air and rainwater, making the filter bag damp and slatted, increasing the running resistance. Therefore, the dust collector should be sealed strictly, and the air leakage rate should be less than 3%. D Pulse bag filter generally use compressed air for blowing dust, compressed air contains more oil, water, impurities, such as not purified directly into the filter bag, it will make the filter bag dirty and damp leading to condensation. If the dust collector is dealing with high temperature, high humidity gas, once sprayed into the cold compressed air, hot and cold rendezvous such as reaching the dew point temperature will produce dew on the surface of the filter bag, adhesion of a large amount of dust caused by slating.

Denitrification catalyst refers to the catalyst on the SCR (selective catalytic reduction) denitrification system of power plants, which is the substance that induces the chemical reaction between the reducing agent and the nitrogen oxides in the flue gas selectively at a certain temperature in the SCR reaction. As an important part of the flue gas treatment process, it is now widely used in various fields such as power and non-power industries, and has achieved good results. The commonly used denitrification catalysts in the market nowadays are V2O5-WO3(MoO3)/TiO2 series. Different combustion raw materials and different flue gas compositions have led to the creation of catalysts with different compositions. Characteristics of glass kiln flue gas Larger content of alkali metals and larger amount of dust. Domestic glass production lines mainly use rock tar, heavy oil, natural gas and furnace gas as fuels, which have small dust particle size and strong adhesion, and high NOx concentration in flue gas, mostly above 2000mg/m3; in addition, during the dynamic fire change of the kiln, SO2, NOx and dust concentration will change drastically, which increases the difficulty of flue gas denitrification. Characteristics of biomass power generation flue gas Biomass has high hydrogen content and high water content in the flue gas, with water content up to 15%-30%, and the soot contains high mass fraction of alkali metals, up to 8% or more. Furthermore, the SO2 and NOx concentrations are low and fluctuating, and the SO2 and NOx mass concentrations fluctuate from 100-250 mg/m3 when burning pure biomass. Glass kiln and biomass power flue gas denitrification processing difficulties Mainly, the alkali metal content is high and viscous, especially the working condition where the fuel is petroleum tar. Alkali metal ions Na+, K+, Mg2+, Ga2+, etc. are widely present in the flue gas, which easily bond chemically with the structure of V2O5, opening the V-OH bond, occupying the surface acidic sites and active sites, generating compounds that do not have catalytic ability, weakening the adsorption and activation of the reductant NH3 while inhibiting the ability to oxidize NO to surface NO2, thus leading to catalyst Several SCR reaction paths on the catalyst are inhibited and severe catalyst deactivation occurs. Alkali metal resistant SCR denitrification catalysts In response to the above industry flue gas characteristics and emission reduction difficulties, Yuanchen Technology has developed a matching alkali metal resistant SCR denitrification catalyst, which can remove NOx from the above flue gas with high efficiency and good resistance to alkali metal poisoning. Commonly used cellular denitrification catalysts have 20, 22 and 25 pores. Anhui Yuanchen Environmental Technology Co., Ltd (hereinafter referred to as "Yuanchen Technology") is a high-tech enterprise integrating R&D, production and sales of dust removal bags and denitrification catalysts. Over the past 15 y...