Pioneer of low-temperature SCR denitrification technology
Publishdate：2015-07-06 Views：49
As a major pollutant in the air of big cities, the combination of NOx and PM2.5 is one of the main causes of haze, seriously endangering people's physical health and social environment construction. Therefore, at the Fourth Session of the Tenth National People's Congress in 2011, the Outline of the Twelfth Five Year Plan for National Economic and Social Development proposed to add "reducing ammonia nitrogen and nitrogen oxides emissions by 10% respectively" as one of the main goals for economic and social development in the Twelfth Five Year Plan, based on the implementation of the 10% reduction targets for chemical oxygen demand and sulfur dioxide emissions during the Tenth Five Year Plan period.
He Hong: Pioneer of Low Temperature SCR Denitration Technology
Facing air pollution and strict emission standards, it is imperative to accelerate the research of efficient treatment technologies for nitrogen oxides. Here, Professor He Hong from the Department of Chemistry and Chemical Engineering at the School of Environment and Energy Engineering, Beijing Institute of Technology, has been committed to exploring and researching low-temperature SCR industrial denitrification technology for a long time. Starting from solving the denitrification problem in the non power industry, he takes low-temperature SCR catalytic materials as a breakthrough point, fully explores advanced technology concepts at home and abroad, and after nearly a decade of unremitting efforts, has finally developed a technology with independent intellectual property rights and a denitrification efficiency of up to 90% The engineering cost and operating cost are far lower than the low-temperature SCR industrial denitrification technology of medium and high temperature SCR catalytic denitrification technology.
Undertaking the mission: The pollution problem urgently needs to be solved
It is reported that NOx emissions in China mainly come from thermal power generation, transportation, and various industrial processes. In the past decade, with the development of China's automobile industry and the increasingly strict implementation of motor vehicle emission standards, as well as the development of three-way catalysts and diesel SCR catalytic technology, NOx emissions in the transportation industry have been controlled to a certain extent. In recent years, China has increased the control of NOx emissions from flue gas of thermal power plants and implemented a policy of compensating for denitrification electricity prices for power enterprises, greatly promoting the process of denitrification in the power industry.
However, the control of NOx emissions in non electric industries (including self owned power plants) has encountered significant difficulties, as the emission temperatures of industrial furnace equipment (such as industrial boilers, glass ceramic furnaces, cement furnaces, metallurgical sintering furnaces, coking and petrochemical system cracking equipment, etc.) and process gases related to nitric acid production and use in non electric industries are mostly below 300 ℃, The working temperature of SCR denitrification catalysts currently used in the power industry is between 300 ℃ and 400 ℃. Therefore, it is difficult to directly use medium to high temperature (300 ℃~400 ℃) SCR catalytic processes to control NOx emissions in non power industries.
At present, the mainstream technologies for NOx emission control in industry are Selective Non catalytic Reduction (SNCR) and Selective Catalytic Reduction (SCR). The former has low NOx purification efficiency and is difficult to meet strict emission standards. Therefore, SCR is the main engineering technology to achieve the goals of the Air Pollution Prevention and Control Action Plan. The production technology and denitrification engineering technology of SCR denitrification catalysts in China are basically from foreign countries. Although the technology abroad is relatively mature, due to the significant difference in energy structure between China and the West, coal energy accounts for about 70% of the total energy consumption. The treatment of high sulfur and high ash flue gas is difficult to solve solely by relying on foreign technology. This problem is more prominent in the denitrification field of non power industries. If the denitrification problem in non power industries cannot be solved, So by 2017, it will be difficult to achieve the goal of reducing the emission intensity of major pollutants in China by 30%.
As early as ten years ago, Professor He Hong realized the particularity of controlling smoke pollutant emissions due to the different industrial energy structures in China. Since 2003, he has taken this as his mission and started researching and developing low-temperature and high sulfur flue gas denitrification technology, hoping to solve this problem someday.
Painstaking determination: overcoming obstacles and finally achieving breakthroughs
According to Professor He Hong, currently, the catalyst system used for denitrification in electric boilers is V2O5-WO3 (or MoO3)/TiO2, and the operating temperature of this series of catalysts is between 300 ℃ and 400 ℃. For a long time, the academic community has also been trying to study non vanadium based SCR catalysts. However, due to the 50 year history of research on SCR catalysts, and the current industrial use of vanadium based SCR catalysts, Professor He Hong and others have realized that reducing the operating temperature of V2O5-WO3 (or MoO3)/TiO2 catalysts may be a feasible direction for the development of low-temperature SCR catalysts.
Starting from adjusting the surface acidity and microstructure of the catalyst, Professor He Hong's team has developed a series of low-temperature SCR catalyst formulations and preparation processes after years of research. The working temperature range of the catalyst has been expanded to 160 ℃ to 400 ℃. Based on the basic formula of low-temperature SCR catalyst, Professor He Hong's team has conducted in-depth research on the molding formula and molding technology of honeycomb SCR catalyst.
The formation of honeycomb SCR catalysts is the core technology for producing SCR catalysts, and it is also a secret of various catalyst manufacturers. There is no mature literature or report to refer to. Therefore, Professor He Hong's team of scientific and technological personnel carefully screened each molding agent from the perspective of ceramic molding technology, studied their compatibility and mutual coordination. After experiencing countless failures, they searched for clues to success from the failures and eventually mastered the molding formula and process of low-temperature SCR catalysts, producing qualified low-temperature SCR catalyst products.
Afterwards, in order to improve and promote the industrial application of low-temperature SCR catalysts, Professor He Hong's team further developed low-temperature SCR industrial denitrification engineering technology. Starting from the denitrification experiment of a 10 ton industrial coal-fired boiler, they studied the effects of temperature, wind speed, NOx content, ash content, water vapor content, and O2 content on denitrification efficiency. They also studied the design of SCR catalytic reactors, flue gas flow equalization, and reducing agent injection technology.
After mastering the engineering data, Professor He Hong's team undertook the construction of the NOx removal system for the acid pickling line of Yunnan Titanium Industry Group. The acid pickling line of Yunnan Titanium Industry Group consists of mixed acid pickling tanks, cleaning tanks, acid circulation tanks, and other equipment. During operation, it generates waste gas containing mixed acids. The acidic waste gas is introduced into the acid mist scrubber through a gas collection hood, and HF is absorbed by a mixture of 10% Na2CO3 and NaOH. The waste gas is then heated to 200 ℃ by a duct type air heater and enters the SCR reactor. NOx in the waste gas is removed by a low-temperature SCR catalyst. The denitrification efficiency of this system is as high as 90%, and its engineering and operating costs are far lower than those of medium and high temperature SCR catalytic denitrification technology.
Entering the market: Pioneer in low-temperature denitrification
Due to its wide range of applications and promising market prospects, low-temperature SCR denitrification technology quickly received high attention from the industry. In 2012, Beijing Fangxin Lihua Technology Co., Ltd. was established in Beijing, with the production technology of low-temperature SCR catalysts from Beijing Institute of Technology as the core, invested by Conbey Group and some individual investors. The company has established a low-temperature SCR catalyst production line and a low-temperature SCR catalytic engineering technology pilot experimental base, and has begun to provide low-temperature SCR catalysts to the industrial denitrification market. At present, the company is developing industrial low-temperature denitrification technology that is suitable for low-temperature SCR catalysts, aiming to become the leader of low-temperature SCR denitrification technology in China.
This year, Professor He Hong's team and Beijing Fangxin Lihua Technology Co., Ltd. undertook the NOx tail gas treatment project of Hubei Yitai Pharmaceutical Co., Ltd.'s oxidation oxalic acid production process. Hubei Yitai Pharmaceutical Co., Ltd. is located in Tianmen City, Hubei Province. The company has two oxidation oxalic acid production lines, with a total exhaust gas flow rate of 8000-1000m3/h, exhaust gas temperature of 30 ℃, and NOX concentration of 500-2000mg/Nm3. The oxidation oxalic acid production process has low NOx exhaust gas temperature, high NOx concentration, and high water vapor content, making denitrification engineering difficult, Professor He Hong led his team of technicians and engineering technicians from Beijing Fangxin Lihua Technology Co., Ltd. to carefully analyze the problems in the denitrification project, and carefully designed the low-temperature denitrification technology process and equipment. Currently, the low-temperature denitrification project has been completed and has passed the acceptance of the local environmental protection department. On October 22 this year, the Environmental Protection Supervision Center of the Ministry of Environmental Protection conducted an inspection of the denitrification project. The measured denitrification data showed that the concentrations of NO, NO2, and O2 at the inlet of the SCR denitrification reactor were 410ppm, 56ppm, and 18%, respectively. The concentrations of NO, NO2, and O2 at the outlet of the reactor were 3ppm, 0ppm, and 18%, respectively. The inlet and outlet temperatures of the reactor were 210 and 200 ℃. The NOX tail gas treatment system of the oxidation process for oxalic acid production has different denitrification activities, meeting the engineering design requirements. It is the first denitrification project in China's oxalic acid industry to use domestically produced low-temperature SCR catalyst technology.
Although Professor He Hong's team has achieved remarkable results in the research and development of low-temperature SCR catalysts, achieving efficient low-temperature SCR catalysts with operating temperatures as low as 160 ℃, they have encountered a challenge that must be overcome when using them for denitrification in coal-fired industrial boilers or other sulfur-containing flue gases. During the denitrification process, some SO2 in the sulfur-containing flue gas will be oxidized to SO3. Under the condition of water vapor, SO3 reacts with NH3 to form ammonium bisulfate (ABS). When the temperature is below 220 ℃, ammonium bisulfate will condense and accumulate on the surface of the catalyst, covering the active center and deactivating the SCR catalyst.
At present, Professor He Hong's team is collaborating with Beijing Fangxin Lihua Technology Co., Ltd. to solve the problem of low-temperature SCR catalyst application in low-temperature and high sulfur flue gas denitrification. The ongoing work includes studying the generation of ABS in the low-temperature SCR catalytic bed and the degree of damage to the SCR catalyst, studying the law of flue gas conditions ABS generation SCR catalyst failure, and studying the operating conditions and control methods of low-temperature SCR catalytic denitrification equipment Reactor design, coupling of SCR and desulfurization and dust removal equipment, and in-situ regeneration technology of low-temperature SCR catalysts. Continuing from the past and opening up the future, they will develop low-temperature and high sulfur flue gas denitrification technology suitable for controlling pollutant emissions in industrial boilers (kilns) in China, starting from catalytic materials, SCR denitrification process design, equipment and in-situ regeneration technology, in order to contribute new opportunities to solving China's air pollution problem through further progress.
He Hong is a professor and doctoral supervisor in the Department of Chemistry and Chemical Engineering at the School of Environment and Energy Engineering, Beijing Institute of Technology. Born in 1956, graduated with a bachelor's degree in Physical Chemistry from the Department of Chemistry at Lanzhou University in 1982, obtained a master's degree in Multiphase Catalysis from the Department of Chemistry and Environmental Engineering at Beijing Institute of Technology in 1988, and obtained a doctoral degree in Physical Chemistry from the School of Science at Hong Kong Baptist University in 1996.
Also serving as a member of the Catalysis Committee of the Chinese Chemical Society, a member of the Rare Earth Catalysis Professional Committee of the Chinese Rare Earth Society, a member of the Environmental Chemistry Expert Review Group of the Chemical Science Department of the Natural Science Foundation of China, a member of the National Professional Standardization Technical Committee, the Chairman of the Material Declaration Sub technical Committee of the National Environmental Standardization Technical Committee for Electrical and Electronic Products and Systems, as well as an editorial board member of the Industrial Catalysis magazine and an industry expert on the Guolian Resource Network Member of the Academic and Expert Committee of the International Energy Conservation and Environmental Protection Association.
In the past five years, Director He Hongdao's team has undertaken two "863" projects, one key project of the Natural Science Foundation, one general project of the Natural Science Foundation, two key projects of the Beijing Natural Science Foundation, and multiple other technology development projects commissioned by enterprises. So far, more than 100 articles have been published in academic journals both domestically and internationally. Selected as a cross century talent in Beijing in 2001.
As a major pollutant in the air of big cities, the combination of NOx and PM2.5 is one of the main causes of haze, seriously endangering people's physical health and social environment construction. Therefore, at the Fourth Session of the Tenth National People's Congress in 2011, the Outline of the Twelfth Five Year Plan for National Economic and Social Development proposed to add "reducing ammonia nitrogen and nitrogen oxides emissions by 10% respectively" as one of the main goals for economic and social development in the Twelfth Five Year Plan, based on the implementation of the 10% reduction targets for chemical oxygen demand and sulfur dioxide emissions during the Tenth Five Year Plan period.
He Hong: Pioneer of Low Temperature SCR Denitration Technology
Facing air pollution and strict emission standards, it is imperative to accelerate the research of efficient treatment technologies for nitrogen oxides. Here, Professor He Hong from the Department of Chemistry and Chemical Engineering at the School of Environment and Energy Engineering, Beijing Institute of Technology, has been committed to exploring and researching low-temperature SCR industrial denitrification technology for a long time. Starting from solving the denitrification problem in the non power industry, he takes low-temperature SCR catalytic materials as a breakthrough point, fully explores advanced technology concepts at home and abroad, and after nearly a decade of unremitting efforts, has finally developed a technology with independent intellectual property rights and a denitrification efficiency of up to 90% The engineering cost and operating cost are far lower than the low-temperature SCR industrial denitrification technology of medium and high temperature SCR catalytic denitrification technology.
Undertaking the mission: The pollution problem urgently needs to be solved
It is reported that NOx emissions in China mainly come from thermal power generation, transportation, and various industrial processes. In the past decade, with the development of China's automobile industry and the increasingly strict implementation of motor vehicle emission standards, as well as the development of three-way catalysts and diesel SCR catalytic technology, NOx emissions in the transportation industry have been controlled to a certain extent. In recent years, China has increased the control of NOx emissions from flue gas of thermal power plants and implemented a policy of compensating for denitrification electricity prices for power enterprises, greatly promoting the process of denitrification in the power industry.
However, the control of NOx emissions in non electric industries (including self owned power plants) has encountered significant difficulties, as the emission temperatures of industrial furnace equipment (such as industrial boilers, glass ceramic furnaces, cement furnaces, metallurgical sintering furnaces, coking and petrochemical system cracking equipment, etc.) and process gases related to nitric acid production and use in non electric industries are mostly below 300 ℃, The working temperature of SCR denitrification catalysts currently used in the power industry is between 300 ℃ and 400 ℃. Therefore, it is difficult to directly use medium to high temperature (300 ℃~400 ℃) SCR catalytic processes to control NOx emissions in non power industries.
At present, the mainstream technologies for NOx emission control in industry are Selective Non catalytic Reduction (SNCR) and Selective Catalytic Reduction (SCR). The former has low NOx purification efficiency and is difficult to meet strict emission standards. Therefore, SCR is the main engineering technology to achieve the goals of the Air Pollution Prevention and Control Action Plan. The production technology and denitrification engineering technology of SCR denitrification catalysts in China are basically from foreign countries. Although the technology abroad is relatively mature, due to the significant difference in energy structure between China and the West, coal energy accounts for about 70% of the total energy consumption. The treatment of high sulfur and high ash flue gas is difficult to solve solely by relying on foreign technology. This problem is more prominent in the denitrification field of non power industries. If the denitrification problem in non power industries cannot be solved, So by 2017, it will be difficult to achieve the goal of reducing the emission intensity of major pollutants in China by 30%.
As early as ten years ago, Professor He Hong realized the particularity of controlling smoke pollutant emissions due to the different industrial energy structures in China. Since 2003, he has taken this as his mission and started researching and developing low-temperature and high sulfur flue gas denitrification technology, hoping to solve this problem someday.
Painstaking determination: overcoming obstacles and finally achieving breakthroughs
According to Professor He Hong, currently, the catalyst system used for denitrification in electric boilers is V2O5-WO3 (or MoO3)/TiO2, and the operating temperature of this series of catalysts is between 300 ℃ and 400 ℃. For a long time, the academic community has also been trying to study non vanadium based SCR catalysts. However, due to the 50 year history of research on SCR catalysts, and the current industrial use of vanadium based SCR catalysts, Professor He Hong and others have realized that reducing the operating temperature of V2O5-WO3 (or MoO3)/TiO2 catalysts may be a feasible direction for the development of low-temperature SCR catalysts.
Starting from adjusting the surface acidity and microstructure of the catalyst, Professor He Hong's team has developed a series of low-temperature SCR catalyst formulations and preparation processes after years of research. The working temperature range of the catalyst has been expanded to 160 ℃ to 400 ℃. Based on the basic formula of low-temperature SCR catalyst, Professor He Hong's team has conducted in-depth research on the molding formula and molding technology of honeycomb SCR catalyst.
The formation of honeycomb SCR catalysts is the core technology for producing SCR catalysts, and it is also a secret of various catalyst manufacturers. There is no mature literature or report to refer to. Therefore, Professor He Hong's team of scientific and technological personnel carefully screened each molding agent from the perspective of ceramic molding technology, studied their compatibility and mutual coordination. After experiencing countless failures, they searched for clues to success from the failures and eventually mastered the molding formula and process of low-temperature SCR catalysts, producing qualified low-temperature SCR catalyst products.
Afterwards, in order to improve and promote the industrial application of low-temperature SCR catalysts, Professor He Hong's team further developed low-temperature SCR industrial denitrification engineering technology. Starting from the denitrification experiment of a 10 ton industrial coal-fired boiler, they studied the effects of temperature, wind speed, NOx content, ash content, water vapor content, and O2 content on denitrification efficiency. They also studied the design of SCR catalytic reactors, flue gas flow equalization, and reducing agent injection technology.
After mastering the engineering data, Professor He Hong's team undertook the construction of the NOx removal system for the acid pickling line of Yunnan Titanium Industry Group. The acid pickling line of Yunnan Titanium Industry Group consists of mixed acid pickling tanks, cleaning tanks, acid circulation tanks, and other equipment. During operation, it generates waste gas containing mixed acids. The acidic waste gas is introduced into the acid mist scrubber through a gas collection hood, and HF is absorbed by a mixture of 10% Na2CO3 and NaOH. The waste gas is then heated to 200 ℃ by a duct type air heater and enters the SCR reactor. NOx in the waste gas is removed by a low-temperature SCR catalyst. The denitrification efficiency of this system is as high as 90%, and its engineering and operating costs are far lower than those of medium and high temperature SCR catalytic denitrification technology.
Entering the market: Pioneer in low-temperature denitrification
Due to its wide range of applications and promising market prospects, low-temperature SCR denitrification technology quickly received high attention from the industry. In 2012, Beijing Fangxin Lihua Technology Co., Ltd. was established in Beijing, with the production technology of low-temperature SCR catalysts from Beijing Institute of Technology as the core, invested by Conbey Group and some individual investors. The company has established a low-temperature SCR catalyst production line and a low-temperature SCR catalytic engineering technology pilot experimental base, and has begun to provide low-temperature SCR catalysts to the industrial denitrification market. At present, the company is developing industrial low-temperature denitrification technology that is suitable for low-temperature SCR catalysts, aiming to become the leader of low-temperature SCR denitrification technology in China.
This year, Professor He Hong's team and Beijing Fangxin Lihua Technology Co., Ltd. undertook the NOx tail gas treatment project of Hubei Yitai Pharmaceutical Co., Ltd.'s oxidation oxalic acid production process. Hubei Yitai Pharmaceutical Co., Ltd. is located in Tianmen City, Hubei Province. The company has two oxidation oxalic acid production lines, with a total exhaust gas flow rate of 8000-1000m3/h, exhaust gas temperature of 30 ℃, and NOX concentration of 500-2000mg/Nm3. The oxidation oxalic acid production process has low NOx exhaust gas temperature, high NOx concentration, and high water vapor content, making denitrification engineering difficult, Professor He Hong led his team of technicians and engineering technicians from Beijing Fangxin Lihua Technology Co., Ltd. to carefully analyze the problems in the denitrification project, and carefully designed the low-temperature denitrification technology process and equipment. Currently, the low-temperature denitrification project has been completed and has passed the acceptance of the local environmental protection department. On October 22 this year, the Environmental Protection Supervision Center of the Ministry of Environmental Protection conducted an inspection of the denitrification project. The measured denitrification data showed that the concentrations of NO, NO2, and O2 at the inlet of the SCR denitrification reactor were 410ppm, 56ppm, and 18%, respectively. The concentrations of NO, NO2, and O2 at the outlet of the reactor were 3ppm, 0ppm, and 18%, respectively. The inlet and outlet temperatures of the reactor were 210 and 200 ℃. The NOX tail gas treatment system of the oxidation process for oxalic acid production has different denitrification activities, meeting the engineering design requirements. It is the first denitrification project in China's oxalic acid industry to use domestically produced low-temperature SCR catalyst technology.
Although Professor He Hong's team has achieved remarkable results in the research and development of low-temperature SCR catalysts, achieving efficient low-temperature SCR catalysts with operating temperatures as low as 160 ℃, they have encountered a challenge that must be overcome when using them for denitrification in coal-fired industrial boilers or other sulfur-containing flue gases. During the denitrification process, some SO2 in the sulfur-containing flue gas will be oxidized to SO3. Under the condition of water vapor, SO3 reacts with NH3 to form ammonium bisulfate (ABS). When the temperature is below 220 ℃, ammonium bisulfate will condense and accumulate on the surface of the catalyst, covering the active center and deactivating the SCR catalyst.
At present, Professor He Hong's team is collaborating with Beijing Fangxin Lihua Technology Co., Ltd. to solve the problem of low-temperature SCR catalyst application in low-temperature and high sulfur flue gas denitrification. The ongoing work includes studying the generation of ABS in the low-temperature SCR catalytic bed and the degree of damage to the SCR catalyst, studying the law of flue gas conditions ABS generation SCR catalyst failure, and studying the operating conditions and control methods of low-temperature SCR catalytic denitrification equipment Reactor design, coupling of SCR and desulfurization and dust removal equipment, and in-situ regeneration technology of low-temperature SCR catalysts. Continuing from the past and opening up the future, they will develop low-temperature and high sulfur flue gas denitrification technology suitable for controlling pollutant emissions in industrial boilers (kilns) in China, starting from catalytic materials, SCR denitrification process design, equipment and in-situ regeneration technology, in order to contribute new opportunities to solving China's air pollution problem through further progress.
He Hong is a professor and doctoral supervisor in the Department of Chemistry and Chemical Engineering at the School of Environment and Energy Engineering, Beijing Institute of Technology. Born in 1956, graduated with a bachelor's degree in Physical Chemistry from the Department of Chemistry at Lanzhou University in 1982, obtained a master's degree in Multiphase Catalysis from the Department of Chemistry and Environmental Engineering at Beijing Institute of Technology in 1988, and obtained a doctoral degree in Physical Chemistry from the School of Science at Hong Kong Baptist University in 1996.
Also serving as a member of the Catalysis Committee of the Chinese Chemical Society, a member of the Rare Earth Catalysis Professional Committee of the Chinese Rare Earth Society, a member of the Environmental Chemistry Expert Review Group of the Chemical Science Department of the Natural Science Foundation of China, a member of the National Professional Standardization Technical Committee, the Chairman of the Material Declaration Sub technical Committee of the National Environmental Standardization Technical Committee for Electrical and Electronic Products and Systems, as well as an editorial board member of the Industrial Catalysis magazine and an industry expert on the Guolian Resource Network Member of the Academic and Expert Committee of the International Energy Conservation and Environmental Protection Association.
In the past five years, Director He Hongdao's team has undertaken two "863" projects, one key project of the Natural Science Foundation, one general project of the Natural Science Foundation, two key projects of the Beijing Natural Science Foundation, and multiple other technology development projects commissioned by enterprises. So far, more than 100 articles have been published in academic journals both domestically and internationally. Selected as a cross century talent in Beijing in 2001.
