Integrated technology of dry flue gas desulfurization and denitrification

2017-10-9 16:16:50

Dry flue gas desulfurization and denitrification integrated technology includes four aspects: solid absorption / regeneration method, gas / solid catalytic simultaneous desulfurization and denitrification technology, absorbent injection method and high-energy electronic activated oxidation method.

(1) solid adsorption / regeneration method

Carbonaceous material adsorption method

According to the different adsorption materials can be divided into activated carbon adsorption method and activated coke adsorption method two, activated carbon adsorption process of desulfurization and denitrification process is divided into two parts: adsorption tower and regeneration tower. The activated coke adsorption method has only one adsorption tower, the tower is divided into two layers, the upper denitration, the lower desulfurization, active coke in the tower up and down, the flue gas flows through the tower. The main advantage of this method is that there are some advantages of this method:

(80%) high desulfurization rate (98%) and low temperature (100~200 C) higher denitrification rate (2%);

No heating is needed before the flue gas is discharged;

Do not use water, there is no two pollution;

Fourth, the adsorbent has a wide range of sources, and there is no poisoning problem;

Remove SO2 which is difficult to remove by wet method;

The removal of pollutants in the exhaust gas can be HF, HCl, arsenic, mercury, is the depth of processing technology;

With dust removal function, outlet dust concentration is less than 10mg/m3;

The Recyclable products, such as: high purity sulfur, sulfuric acid, liquid SO2, chemical fertilizer etc.;

To lower construction cost, operation cost, small occupying area.

Desulfurization and denitrification technology of activated carbon fiber

The technology is to make the activated carbon fiber about 20 m in diameter, which greatly increases the adsorption area, and improves the adsorption and catalytic capacity. The desulfurization and denitrification rate of this technology can reach 90%.

In recent years, people have to combine the activated carbon adsorption and microwave technology, put forward by catalytic reduction of desulfurization and denitration technology of microwave technology, the use of activated carbon as carrier of nitrogen oxides, can induce can realize the desulfurization and denitrification rate reached above 90% by microwave.

No * so method denitration technology of activated alumina adsorption desulfurization, adsorbent of the method is using r- alumina as carrier, with the solution of alkali or alkali component of salt spray carrier, then the adsorbent soaked in heating, drying, removing residual moisture made. After the adsorbent is saturated and regenerated, the regeneration process is to send the adsorbent saturated to the heater, heated at about 600 DEG C to make NOx release, and then send the NOx back to the burner of the boiler. In the combustor, the concentration of NOx reaches a stable state, and a chemical equilibrium is formed, thus inhibiting the formation of nox. A high concentration of SO2 and H2S mixed gas can be produced by adding reducing gas into the regenerator, and sulfur recovery can be carried out by Claus method.

CuO adsorption desulfurization and denitrification process using cuo/al2o3 or cuo/sio2 as adsorbent for desulfurization and denitrification, the whole reaction is divided into two steps:

1) in the adsorber: in the temperature range of 300 to 450 DEG C, the adsorbent and the reaction of sulfur dioxide, generating CuSO4; because the CuO and CuSO4 generated a high catalytic activity for NH3 reduction of nitrogen oxides, combined with SCR method for denitrification.

2) in the regenerator: adsorbent absorption saturation generated after CuSO4 is sent to the regenerator regeneration, regeneration process of CuSO4 reduction by H2 or CH4, sulfur dioxide regenerated by Claus device for recovering acid; reduction by copper or Cu2S in adsorbent processor used in flue gas or air oxidation CuO generated CuO again for the absorption reduction process. The process can achieve more than 90% SO2 removal rate and 75% - 80% nitrogen oxide removal rate.

One step dry scrubbing of pahlman process can remove more than 99% of the sulfur oxides in the flue gas, and can selectively or simultaneously remove 99% of the nitrogen oxides. The exhaust gas completely meets the environmental standards. Because it uses inorganic compounds as absorbent, so its by-product is Recyclable nitrate and sulfate, this process applies to natural gas or coal fueled power plants, is still in the experimental stage, has not been found in industrial applications.