Technical characteristics of Magnesium Oxide light powder desulphurization process

1, mature technology

Magnesium oxide desulfurization technology is a kind of desulfurization technology whose maturity is second only to calcium method. Magnesium oxide desulfurization technology has a lot of application achievements all over the world. Among them, more than 100 projects have been applied in Japan, 95% of Taiwan's power plants are using magnesium oxide method, and it has been applied in the United States, Germany and other places, and now in China. Some regions already have applied achievements.

2. Sufficient raw materials.

Magnesium oxide reserves in China are considerable. At present, the proven reserves of magnesium oxide 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 desulfurization system.

3, high desulfurization efficiency.

Magnesium oxide is much more active than calcium-based desulfurizer in chemical reaction, and its molecular weight is smaller than that of calcium carbonate and calcium oxide. Therefore, the desulfurization efficiency of Magnesium Oxide is higher than that of calcium method under other conditions. Generally, the desulfurization efficiency of magnesium oxide can reach 95-98%, while the desulfurization efficiency of limestone/gypsum method can only reach 90-95%.

4, less investment cost

Magnesium oxide as desulfurization has its own unique advantages, so the structure design of absorption tower, the size of circulating slurry, the overall scale of the system and the power of the equipment can be relatively small, so that the investment cost of the whole desulfurization system can be reduced by more than 20%.

5. Low operating cost

The main factors determining 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 magnesium oxide is 40% of calcium carbonate. The liquid-gas ratio is a very important factor in power consumption, such as water, electricity and steam, which directly affects the desulfurization efficiency of the whole system and the operation cost of the system. For the limestone gypsum system, the liquid-gas ratio is generally above 15L/m3, while the magnesium oxide is below 5L/m3, so the magnesium oxide desulfurization process can save a large part of the cost. At the same time, the sale of by-products of Magnesium Oxide can offset a large part of the cost.

Light burning powder

6. Reliable operation

The greatest advantage of magnesium desulfurization over calcium desulfurization is that the system will not cause fouling and blockage of equipment, and 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 corrosion problem of equipment has also been solved to a certain extent. In general, magnesium desulphurization has a very strong guarantee in the actual engineering safety performance.

7. High comprehensive efficiency.

Because the reaction products of magnesium desulphurization are sub Magnesium Sulfate and Magnesium Sulfate, the comprehensive utilization value is very high. On the one hand, all magnesium sulfate can be produced by forced oxidation, and then concentrated and purified to produce magnesium sulfate heptahydrate for sale. On the other hand, sulfur dioxide gas with high purity can be directly calcined to produce sulfuric acid.

8, the by-product utilization prospect is broad.

We know that sulfuric acid is known as "the mother of chemical industry", and sulphur dioxide is the raw material for producing sulphuric acid. China is a country with relatively scarce sulphur resources. The annual import of sulphur exceeds 5 million tons, equivalent to 7.5 million tons of sulphur dioxide. In addition, magnesium sulfate is widely used in food, chemical industry, medicine, agriculture and many other fields, and the market demand is also relatively large. Desulphurization by magnesium has made full use of existing resources and promoted the development of circular economy.

9. No two pollution.

There are inevitably two pollution problems in the common wet desulphurization process. For magnesium oxide desulfurization technology, the follow-up treatment is more perfect, SO2 is regenerated to solve the problem of secondary pollution.

The reaction mechanism of magnesium oxide desulfurization is similar to that of calcium oxide desulfurization. Both of them are alkaline oxides reacting with water to form hydroxides, and then reacting with sulfite solution formed by sulfur dioxide dissolving in water to neutralize acid and alkali. Magnesium sulfite and magnesium sulfate produced by magnesium oxide reaction are recovered after SO2 is recovered. It can be reused or forced to oxidize to seven water Magnesium Sulfate. The main chemical reactions occurring during desulfurization are MgO+H2O=Mg(OH)2Mg(OH)2Mg(OH)2Mg(OH)2+SO2=MgSO3+MgSO3+H2O+SO2=Mg(HSO3)2MgSO3+1/2O2=MgSO3+MgSO3+1/1/2O2=MgSO4 magnesium oxide during the regeneration stage of MgSO4 magnesium oxide. The main reactions occurring during the regeneration stage of MgSO3_MgSO3_MgO+SO2 Mg Mg Mg MgO+SO2 MgSO4 MgO+SO3MgMgMgMgO+SO3MgMgMgMgMgMgMgO(HSO(HSO)2)2 MgO+H2OH2SO4 when forcing by-products Oxidation of MgSO4 and 7H2O sold at MgSO3 + 1/2O2 + MgSO4MgSO4 + 7H2O to MgSO4. 7H2O

Brief introduction of the process flow of magnesium oxide desulfurization process. Magnesium oxide desulfurization technology is a promising desulfurization technology in the commercial operation of wet desulfurization process. The process is mature, less investment, simple structure, good safety performance, and can reduce secondary pollution, recycle desulfurizer and reduce the cost of desulfurization. It can bring some economic benefits. Compared with calcium desulfurization, it avoids a series of problems existing in simple wet process, such as pipeline blockage, low flue temperature, flue gas carrying water and secondary water pollution, etc. At the same time, compared with the more complete limestone/gypsum method, it occupies a small area, has a low operating cost, greatly reduces investment, and achieves a very good comprehensive economic benefit. Great improvement.