Advantages of flue gas ammonia recovery desulfuriz

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Advantages of power plant flue gas ammonia recovery desulfurization technology

1) complete recycling - turning waste into treasure and harm into benefit

ammonia recovery desulfurization technology converts all recovered sulfur dioxide and ammonia into fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, etc. or when sulfur users purchase equipment, acid, liquefied sulfur dioxide and other chemicals (generally by-product ammonium sulfate, but also by-product other products according to the local conditions of the power station) do not produce secondary pollution. It is a real technology that recycles all pollutants

2) the desulfurization cost decreases with the increase of sulfur content of coal - high sulfur coal can be used for power generation, and the desulfurization cost is low

because ammonia recovery desulfurization is a recovery method, and by-products with high added value can increase the value of ammonia, the operation cost of ammonia recovery desulfurization is small (generally below 450 yuan/ton SO2, 0.01 yuan/kwh), and decreases with the increase of sulfur removal. Therefore, the power plant uses low-cost high sulfur coal, which not only greatly reduces the power generation cost, but also reduces the desulfurization cost, killing two birds with one stone

3) small resistance of the device - convenient for boiler system configuration and saving operation power consumption

using the high activity of ammonia desulfurization, the liquid gas ratio is only 1 ~ 1.5l/m3 (the liquid gas ratio of conventional wet desulfurization technology requires l/m3), the resistance of desulfurization tower is about 850pa, and the total resistance of desulfurization island including flue is about 1000Pa when there is no heating device; When equipped with steam heater, the total design resistance of desulfurization island is only about 1250pa. Therefore, ammonia desulfurization devices can take advantage of the potential of the original boiler induced draft fan, and most of them do not need a new booster fan; Even if the original fan has no potential, the fan can be properly transformed or the fan with small head can be added. The system resistance is more than 50% less than that of conventional desulfurization technology. In addition, the substantial decrease of the liquid gas ratio has reduced the power consumption of the circulating pump by nearly 70%

4) process energy saving optimization - high energy efficiency, low equipment cost

generally, wet desulfurization requires the flue gas to be cooled to ℃, and reheated after desulfurization to rise above 70 ℃. The reheating mode is mostly GGH heat exchanger. Due to the small temperature difference and low heat transfer speed, GGH has a large volume, which requires both land occupation and high investment. The ammonia recovery method utilizes the process characteristics, uses the high-temperature flue gas heat entering the desulfurization island for the concentration of by-products, and uses steam as the heat source for the reheat of flue gas, so that the heat transfer area can be greatly reduced due to the high temperature difference of heat transfer, the land occupation of reheater can be reduced by more than 60%, the equipment cost can be saved by more than 75%, and the resistance can be reduced by more than 60%, saving the power consumption of desulfurization booster fan or original boiler induced draft fan, The total power consumption of desulfurization Island accounts for less than 1% of the power generation capacity

5) the desulfurization device is reliable - easy and efficient to operate

ammonia method is a gas-liquid two-phase reaction, with strong reactant activity and large chemical reaction rate. The desulfurizer and desulfurization products are soluble substances, and the desulfurization solution in the device is a clear solution without scale and wear. Therefore, the ammonia method is easier to realize PLC, DCS and other automatic control, and the operation control is simple and easy; The desulfurization efficiency can be stabilized above 90% (it can be stabilized above 95% when there are special requirements). Secondly, the ammonia method adopts advanced heavy-duty anti-corrosion technology, selects reliable materials and equipment, and there is no problem of the above electro-hydraulic servo control. In addition, it adopts high-precision load sensor to measure the force, so that the reliability of the device is as high as 98.5%, the amount of daily maintenance is small, and the annual maintenance cost of the device only needs% of the total investment

6) the device is equipped with less equipment - the land occupation is small, which is conducive to the general layout

the ammonia recovery desulfurization device does not need the raw material pretreatment process, and the production process of desulfurization by-products is relatively simple. The total configuration of the device is about 30 sets of equipment; And the treatment capacity is small (only 2.1 tons of ammonium sulfate are produced per ton of sulfur dioxide absorbed), so the equipment selection does not need to be too large. The land occupation of desulfurization equipment is related to the scale of boiler, and the land occupation of 75t/h-1000t/h boiler is about 150m2-500m2; Desulfurization liquid treatment, i.e. the land occupation of ammonium sulfate process is related to the sulfur content of the boiler, but the correlation coefficient is small. The whole ammonium sulfate process normally occupies an area of 500m2. Compared with the conventional desulfurization technology called autoclave technology, the land occupation is saved by more than 50%

7) both desulfurization and denitration - control the emission of NOx in advance to meet the higher requirements of environmental protection

the absorbent of ammonia desulfurization is ammonia, which also absorbs NOx. In addition, ammonium sulfite produced in the desulfurization process also reduces NOx, so ammonia desulfurization can also achieve the purpose of denitration. Generally, the denitration efficiency of ammonia recovery desulfurization technology is more than 60%, which can be nearly 90% after strengthening. It is conducive to the power plant to control the emission of NOx, adapt to the higher requirements of environmental protection, and avoid secondary investment


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