Analysis of regeneration technology of denitration catalyst.
Analysis of regeneration technology of denitration catalyst. There are two processes for the regeneration treatment after the denitration catalyst is deactivated, one is on-site regeneration, and the other is industrial regeneration.
On-site regeneration can simply remove surface sediments and attached materials by physical and chemical methods, and then load a certain amount of chemically active substances. But the dangers brought by on-site regeneration: Deactivated catalyst contains arsenic, vanadium, molybdenum, tungsten and other heavy metals. Wastewater and waste residues containing heavy metals will be generated during the on-site regeneration and cleaning process. In addition, there are no harmless treatment equipment and systems on site. It is easy to cause secondary pollution to the surrounding environment and water quality of the power plant, which causes greater health risks to the power plant staff.
Factory regeneration is an organic combination of physical and chemical methods, which can completely remove the catalyst surface and micropore plugs. More importantly, the chemical poisons arsenic, phosphorus and alkali metals are also effectively removed. Factory regeneration can strictly control the drying and calcining environment, which is critical to the effectiveness of the loading process of chemically active substances. The real factory regeneration process is a complex physical and chemical process, and it is also a tailor-made regeneration scheme for each customer, which can restore the catalyst's chemical performance to 100%. The industrial regeneration is equipped with sewage treatment facilities, which can discharge the wastewater generated during the regeneration process to the standard discharge.
On August 19, 2014, the Ministry of Environmental Protection of the People's Republic of China rejected the on-site regeneration in the "Guidelines for the Examination of the Operating License for Hazardous Wastes from Waste Flue Gas Denitration Catalysts" and encouraged the plant to regenerate. Therefore, plant regeneration is the mainstream technology in the denitration catalyst regeneration industry. The denitration catalyst regeneration technology has nearly 20 years of application experience abroad. The technology is mature and has a large number of successful applications. The domestic regeneration business has just started, with only a few applications.
At present, foreign denitration catalyst regeneration companies mainly include Germany's Ebinger (Ebinger), Steag (Steig), the United States Coalogix (Koje), and so on. Binger (Ebinger) is the originator of catalyst plant regeneration technology. Steag's self-developed technology, part of which is derived from Ebinger, is the largest catalyst regeneration manufacturer in the world. Coalogix technology is derived from Ebinger and Stiger, and is the second largest recycling manufacturer after Stiger.
The denitration catalyst regeneration methods of various companies basically include the following steps: ① vacuum cleaning or compressed air blowing ash; ② cleaning solution soaking or spraying; ③ ultrasonic cleaning; ④ re-impregnation of active components; ⑤ calcination.
Three, concluding remarks
The denitration catalyst regeneration project conforms to the national environmental protection policy, which can save a lot of resources for the country and avoid secondary pollution to the environment. It is a project that the country explicitly encourages development. From the market perspective, the regeneration of denitration catalysts is in line with the current development trend and has a good domestic market. At present, domestic enterprises are also actively introducing advanced foreign technology, and the regeneration of denitration catalysts is bound to usher in great development.