Boiler ammonia-based desulfurization process flow
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The ammonia-based desulfurization process for boilers uses ammonia water as the desulfurization absorbent, which comes into contact with the flue gas entering the reaction tower. In this process, SO2 in the flue gas reacts with ammonia water to form sulfurous acid, which is then oxidized by air to produce sulfuric acid solution. Through crystallization in a storage tank, dehydration using a centrifuge, and filtration, the chemical fertilizer sulfuric acid is obtained. Operating costs for ammonia-based desulfurization: Taking a boiler that uses 75 tons of coal with a sulfur content of 2.5% as an example, the operating costs are calculated briefly. Annual operating costs of the equipment: Item, Quantity, Price (10,000 yuan), Remarks. Ammonia usage: 2,009 tons – 314.53; cost: 1,700 yuan/ton. Water usage: 10,500 tons – 2.47; cost: 2.35 yuan/ton. Electricity usage: 630,000 kWh – 20.48; cost: 0.325 yuan/kWh. Labor costs: 3 workers – 3.9; cost: 26,000 yuan per worker per year. Price of ammonium sulfate: 7,799.6 tons + 546; cost: 700 yuan/ton. Total: – +204.62. In fact, the amount of pollution fees that can be saved due to reduced SO2 emissions is also significant, but this has not been taken into account here. If operated properly, ammonia-based desulfurization can bring economic benefits to enterprises, at least allowing them to recoup their investment costs in the short term. Practical application of ammonia-based desulfurization: There is an existing ammonia plant near a power plant, and the coal used in that power plant has a high sulfur content. High-sulfur coal is cheaper, but it causes more severe SO2 pollution. While using the limestone method increases equipment costs significantly, the ammonia method allows for the production of more sulfuric acid, resulting in better economic benefits. ) For example, a 350MW power plant in Dakota State, USA, switched to the ammonia method in 1996 because it used high-sulfur coal. There is another larger power plant with a desulfurization efficiency of 95%, which produces 100,000 tons of sulfuric acid per year. Therefore, under certain conditions, using the ammonia method for desulfurization is profitable. Advantages of ammonia-based desulfurization: It has a very high desulfurization efficiency, exceeding 95%. (Since ammonia reacts with SO2 much more rapidly than limestone (or lime) does, and moreover the ammonia method does not require an absorbent recycling system, the system is smaller, simpler, and more reliable than the limestone-gypsum method; its capital cost is lower, and it requires less space. The common scaling and clogging problems associated with the use of limestone as a desulfurization agent do not occur in this process. The products after desulfurization are (NH4)2SO3 and (NH4)2SO4 (in small amounts), along with a portion of (NH4)HSO3 solution; these substances serve as absorbents for NOx. Therefore, the ammonia method also has a denitration function. It has a certain dust removal function: Ammonia-based desulfurization does not generate any industrial wastewater, and aside from ammonia sulfate used in fertilizers, there is basically no waste residue produced, which prevents secondary pollution and saves a great deal of storage space ； Fertilizers can also be produced, which brings certain economic benefits. Since the absorbed sulfur and nitrogen compounds are harmful gases, and the ammonia solution used to absorb sulfur is also industrial waste, it is possible to achieve the goal of using waste to treat other waste. In the desulfurization chemical reaction, the amount of ammonia used is much less than that of lime in the limestone method, thereby reducing transportation costs and saving expenses. It features high reliability – with an availability of over 99%, as downtime due to failures is extremely rare. Longer lifespan – can be used normally for 25 years under proper maintenance conditions. Advantages of Kyle’s ammonia-based desulfurization method: In addition to all the advantages mentioned above, Kyle’s ammonia-based desulfurization method also stands out in the following aspects: ammonia-based desulfurization based on automatic control. Automatically monitored ammonia-based desulfurization takes advantage of the company’s instrumentation capabilities to monitor residual ammonia, exhaust gas composition, and desulfurization processes. Design emergency protection measures for ammonia leakage incidents. '
Are there any companies in the country that have successful implementations?
It would be good to have a flowchart.
Thank you; it would be better if there were a process flow diagram.
Upload a flowchart, LZ
Ammonia-based desulfurization has been successfully applied in China, with excellent results – the desulfurization efficiency can reach over 95%, satisfying all environmental standards. It also produces ammonium sulfate as a by-product, which is in line with the principles of a circular economy. Many domestic fertilizer companies that operate their own power plants have adopted this method, and some large power plants are also starting to use it. For power plants, the source of ammonia is an issue that deserves consideration.
Our plant uses ammonia for desulfurization, but the problem is that there is severe ash accumulation in the desulfurization tower, and crystallization occurs in the ammonia injection pipes! I can’t do anything other than not knowing if anyone has any good ideas?
Reply to 1# oydw: Our current performance is poor; we are unable to obtain the desired product. Even if a small amount is available, it’s of poor quality. Please recommend companies that use this product successfully so that we can go and investigate them.
Replying to floor 9: The reasons for your poor performance can be analyzed, but it’s not possible to analyze your specific situation. If you think I can be trusted, I’ll communicate with you. I hope it can be helpful.
In chemical enterprises, ammonia-based desulfurization is a very suitable method. Especially chemical thermal power plants that use ammonia or liquid ammonia. Once the principle of the ammonia method is understood, it is simpler than the processes and techniques used in many other positions.
Electricity consumption: 630,000 kWh –20.48, at 0.325 yuan/kWh. Labor costs: 3 people, –3.9, 26,000 yuan per person per year. ---------------------------- These two figures are definitely fake. First, with 630,000 kWh of electricity consumption, and assuming 300 days per year meaning 7,200 hours, the electricity usage would be 87.5 kWh per hour. Just use common sense to think about it – I can’t believe that a 75-ton ammonia-based desulfurization unit would not require a power output of 300 KW. Although I haven’t worked with such systems before, judging from the sodium-alkali method (used for producing sodium sulfite) in desulfurization, the power requirement for the ammonia method is certainly not lower than that of the sodium-alkali method. 0.32 yuan per kilowatt-hour for electricity is way too low; it should be at least 0.5 yuan or more. Here, the cost is over 1 yuan per kilowatt-hour. Second: three people for the work? This is absolutely impossible; the packaging process using the ammonia method requires at least 2 people per shift, for a total of 6 people. There are also those who need to monitor the instruments per shift, as well as those responsible for equipment maintenance ； At least 3 people are needed per shift, which means a minimum of 9 people per year. At 26,000 per year, the total salary cost would be 234,000 yuan per year. Thirdly, the escape of ammonia isn’t taken into account; the calculations are based on a 100% reaction rate.