What is the desulfurization catalyst?

Abstract: Desulfurization catalyst can also be called desulfurization synergist, which refers to the catalyst used in desulfurization process. Most desulfurization catalysts are prepared with γ -alumina as carrier and cobalt, molybdenum and nickel as active components. Desulfurization catalyst can improve the gas-liquid mass transfer rate of sulfur dioxide, strengthen the absorption of sulfur dioxide and improve the desulfurization rate. Let's take a look at the desulfurization catalyst. 1. What is a desulfurization catalyst?

Desulfurization catalyst, also known as desulfurization synergist and desulfurization additive. A novel catalytic oxidation flue gas desulfurization additive with stable structure and performance, which takes polymer as the main raw material, undergoes physical and chemical treatment, activation or physical and chemical modification, and is strengthened and modified by high technology, and then fully mixed with other inorganic polymer materials. Most of its main components are polymer catalysts, which have strong reactivity with SO2. The flue gas desulfurization additive has good stability and completely meets the requirements of desulfurization process.

Most thermal power plants in China use limestone wet desulfurization. With the continuous improvement of the national sulfur dioxide emission standard for desulfurization units in thermal power plants, the existing equipment and technology can no longer meet the relevant requirements. Adding desulfurization catalyst in the desulfurization process can greatly improve the desulfurization efficiency and make the emission concentration obviously lower than the national standard.

Second, the advantages of desulfurization catalyst

1, improving desulfurization efficiency, without equipment expansion and transformation.

Improve the gas-liquid mass transfer rate of sulfur dioxide, strengthen the absorption of sulfur dioxide, and improve the desulfurization rate. At the gas-liquid interface, the catalyst can combine a large number of H+ ions generated by SO2 dissolution, so that the H+ ions can be transferred from the liquid membrane to the main body of the liquid phase, and the pH of the slurry will not drop too fast due to SO2 dissolution, at the same time, the gas phase resistance will be reduced, which will promote SO2 absorption.

2. Energy saving and consumption reduction (provincial auxiliary power consumption)

On the premise that the sulfur dioxide concentration at the inlet of the desulfurization unit is within the design value, some slurry circulating pumps in the absorption tower can be stopped at first, so as to relatively reduce the liquid-gas ratio required by the system and reduce the auxiliary power rate of the desulfurization system, thus effectively reducing the desulfurization operation cost and the desulfurization maintenance and repair cost; Secondly, it can save the energy consumption of the ball mill in the pulping system, effectively improve the utilization rate of coarse limestone (250 mesh), and the desulfurization efficiency is basically the same as that of limestone (325 mesh).

3. Reduce the amount of limestone.

Improve the utilization rate of desulfurizer, thus reducing its dosage. Catalyst can improve the solubility of limestone in liquid phase and strengthen the dissolution of limestone. At the solid-liquid interface, the catalyst can provide an acidic environment conducive to the dissolution of CaCO3, reduce the liquid resistance and promote the dissolution of limestone.

4, improve the flexibility of coal regulation and desulfurization operation and standby.

Because the solubility of SO2 and the dissolution of solid CaCO3 are limited, the addition of desulfurization catalyst provides basic groups, which enhances the mass transfer coefficient of liquid film, not only promotes the dissolution of CaCO3, improves its dissociation rate, but also reduces the liquid resistance, and the pH value of slurry will not drop too fast due to the dissolution of SO2. When the desulfurization catalyst is used, the desulfurization system can operate at a lower pH value, which increases the flexibility and stability of the main engine coal-burning adjustment and desulfurization system operation.

5. Increase the dispersity of limestone and reduce equipment scaling.

The active components in the catalyst can improve the surface activity of limestone, increase the dispersibility of limestone, reduce its sedimentation rate and reduce the scaling and blockage of equipment.

6, improve the oxidation efficiency, reduce the sulfite content, improve the dehydration efficiency of vacuum belt conveyor.

Catalyst can reduce the surface tension of limestone slurry, reduce the critical crystal nucleus radius, and strengthen the oxidation of HSO3-, which makes CaSO4 and CaSO3 easy to precipitate gypsum, and CaSO4 is in unsaturated state, which hinders the formation of chemical hard scale. Ensure long-term operation of equipment and prevent scaling.

7. Reduce system resistance and energy consumption.

Stopping the slurry circulating pump in some absorption towers can relatively reduce the liquid-gas ratio required by the system, and also reduce the system resistance and energy consumption.