What are the disadvantages

1、 The technical characteristics of MgO 2113 desulfurization process 1. Mature technology. Magnesium oxide desulfurization technology is a kind of desulfurization technology with maturity next to calcium method. Magnesium oxide desulfurization technology has a lot of application achievements all over the world, among which more than 100 projects have been applied in Japan, 95% of power stations in Taiwan use magnesium oxide method, in addition, it has been applied in the United States, Germany and other places, and at present, it has been applied in some parts of China. 2. Sufficient raw materials. The reserves of MgO in our country are very considerable. At present, the proven reserves of MgO are about 16 billion tons, accounting for about 80% of the world. Its resources are mainly in Liaoning Province. Magnesium oxide can be used as desulfurizer in power plant. 3. High desulfurization efficiency. Magnesium oxide is much more active than calcium based desulfurizer in chemical reaction, and the molecular weight of magnesium oxide is smaller than that of calcium carbonate and calcium oxide. Therefore, the desulfurization efficiency of MgO is higher than that of calcium method under the same conditions. In general, the desulfurization efficiency of MgO is over 95-98%, while that of limestone / gypsum is only about 90-95%. 4. Less investment cost because magnesium oxide has its own unique advantages as desulfurization, so the structure design of the absorption tower, the size of circulating slurry, the overall scale of the system and the power of the equipment can be correspondingly smaller, so that the investment cost of the whole desulfurization system can be reduced by more than 20%. 5. Low operating cost. The main factors that determine the operation cost of desulfurization system are the consumption cost of desulfurizer and water, electricity and steam. The price of magnesium oxide is higher than that of calcium oxide, but the consumption of removing the same SO2 and magnesium oxide is 40% of that of calcium carbonate; in terms of power consumption such as water, electricity and steam, the liquid gas ratio is a very important factor, which is directly related to the desulfurization efficiency and operation cost of the whole system. For limestone gypsum system, the liquid gas ratio is generally more than 15L / m3, while the MgO is less than 5L / m3, so the MgO desulfurization process can save a lot of costs. At the same time, the sale of byproducts of MgO process can offset a large part of the cost. 6. Reliable operation. The biggest advantage of magnesium desulfurization over calcium desulfurization is that the system will not have the problem of equipment scaling and blocking, which can ensure the safe and effective operation of the whole desulfurization system. At the same time, the pH value of magnesium desulfurization is controlled between 6.0 and 6.5. Under this condition, the problem of equipment corrosion has also been solved to a certain extent. In general, the safety performance of magnesium desulfurization in practical engineering has a very strong guarantee. 7. The comprehensive benefit is high. Because the reaction products of magnesium desulfurization are magnesium sulfite and magnesium sulfate, the comprehensive utilization value is very high. On the one hand, we can carry out forced oxidation to generate magnesium sulfate completely, and then concentrate and purify to generate magnesium sulfate heptahydrate for sale, on the other hand, we can directly calcine to generate sulfur dioxide gas with high purity to produce sulfuric acid. 8. The by-products have a bright future. We know that sulfuric acid is called the "mother of chemical industry", and sulfur dioxide is the raw material for sulfuric acid production. China is a country with a relative lack of sulfur resources. The annual import of sulfur exceeds 5 million tons, equivalent to 7.5 million tons of sulfur dioxide. In addition, magnesium sulfate is widely used in many aspects, such as food, chemical industry, medicine, agriculture, etc., and the market demand is also large. Magnesium desulfurization makes full use of existing resources and promotes the development of circular economy. 9. In the wet desulfurization process without secondary pollution, secondary pollution is inevitable. For magnesium oxide desulfurization technology, the follow-up treatment is more perfect, SO2 is regenerated, and the problem of secondary pollution is solved. 2、 The reaction mechanism of magnesium oxide desulfurization is similar to that of calcium oxide, which is that the basic oxide reacts with water to form hydroxides, then neutralizes with sulphurous acid solution formed by dissolving sulfur dioxide in water. The magnesium sulfite and magnesium sulfate produced by magnesium oxide reacts with each other to recycle SO2, or oxidize all of them forcibly Magnesium sulfate heptahydrate is prepared by converting it into sulfate. The main chemical reactions in the desulfurization process are MgO + H2O = Mg (OH) 2mg (OH) 2 + SO2 = MgSO3 + h2omgso3 + H2O + SO2 = Mg (hso3) 2mgso3 + 1 / 2O2 = MgSO4. The main reactions in the regeneration stage are MgSO3 Process introduction of MgO + so2mgso4 → MgO + so3mg (hso3) 2 → MgO + H2O + 2so2so2 + 1 / 2O2 → so3so3 + H2O → H2SO4. MgSO3 + 1 / 2O2 → mgso4mgso4 + 7H2O → mgso4.7h2o3, MgO2 desulfurization process is a promising desulfurization technology in the commercial wet desulfurization process The process is more mature, less investment, simple structure, good safety performance, and can reduce secondary pollution, desulfurizer recycling, reduce the cost of desulfurizing, can bring certain economic benefits. Compared with calcium desulfurization, it avoids a series of problems existing in simple wet process, such as pipeline blockage, low smoke temperature, water entrainment in flue gas and secondary water pollution, etc.; at the same time, compared with the relatively complete limestone / gypsum method, it covers a small area, has low operating cost, greatly reduces the investment and greatly improves the comprehensive economic benefits. The whole process of magnesium process can be divided into two kinds: sulfuric acid production by-product and magnesium sulfate production by heptahydrate. The following are the descriptions of the process: (1) the flue gas temperature of sulfuric acid production from the boiler is mostly above 140 ℃, which contains a lot of carbon dioxide, dust and sulfur dioxide, as well as hydrofluoric acid and hydrogen