XHY-8006 Desulfurization Enhancer
The concept of sulfur removal agent addition
Sulfur Dioxide (SO2) Deactivator, also known as a sulfur dioxide catalyst, primarily consists of high molecular weight catalysts with strong reactivity towards SO2. These are formulated as the main raw material, processed through atomization, activation, or atomization modification. After being reinforced and modified with advanced technology, they are thoroughly mixed with other inorganic high molecular weight materials to form a catalyst for desulfurization of flue gas, characterized by stable structure and properties.
During the desulfurization process, the reaction rate between limestone and SO2 is limited by the dissolution rate of CaCO2. CaCO3 exists in water as fine particles, and on the surface of these microspheres, a double-membrane effect exists, hindering the dissolution of CaCO3 in water. Therefore, solving the dissolution problem of CaCO3 in water will significantly improve the entire desulfurization process. Desulfurization enhancers are mainly active agents and catalysts for the surface substances of the CaCO3 area, designed to weaken and eliminate the double-membrane effect, alter the wetting of the solid-liquid interface, enhance the mass transfer efficiency at the interface, and promote the absorption of SO2. At the same time, they penetrate into the micro-pores and cracks遍布 on the surface of the CaCO3 microspheres, allowing the mass transfer of sulfur in the liquid to smoothly enter through these micro-pores and cracks, effectively increasing the mass transfer area, strengthening the solubility of limestone, and thereby greatly accelerating the reaction rate between limestone and SO2.
Working Principle
The lime is mixed into a slurry of a specific concentration, then a certain amount of desulfurization additive is added, and the mixture is agitated uniformly. The lime slurry is pumped into the desulfurization reactor tower, where it is atomized into fine mist droplets that come into contact with flue gas from the boiler. The SO is absorbed by the lime slurry, and the purified gas is then discharged from the flue.
Product Features
3.1 Increase desulfurization efficiency without the need for equipment expansion or modification, easily meeting ultra-low emission requirements. Enhance the transfer rate of SO gas and strengthen the absorption of SO to improve desulfurization efficiency. At the gas-liquid interface, the catalyst can combine with the large amount of H+ ions produced by the dissolution of SO2, transferring H+ ions from the liquid film to the bulk liquid phase. The pH value of the slurry will not drop too quickly due to the dissolution of SO2, and at the same time, the gas-phase resistance is reduced, promoting the absorption of SO2.
3.2 Energy-saving and Consumption Reduction
Sulfur concentration is within the design range, allowing for the shutdown of part of the absorption tower slurry circulation pump. This reduces the required liquid-gas ratio for the system, lowering the electricity consumption of the desulfurization process and effectively cutting down on desulfurization operation and maintenance costs. Additionally, it saves energy consumption in the pulp-making system ball mill, improves the utilization rate of coarse-grained lime (mesh), and achieves a desulfurization efficiency similar to that of limestone with a particle size of (325 mesh), significantly reducing energy consumption.
3.3 Enhance the flexibility of coal-fired adjustment and desulfurization operations, as well as backup, and reduce coal costs.
Due to the limited solubility of SO2 and the slow dissolution rate of solid CACO3, the addition of a desulfurization enhancer provides alkaline genes, enhances the mass transfer factor of the liquid membrane, and not only promotes the dissolution of Caco and increases its dissociation rate, reducing the resistance in the liquid phase. The pH value of the slurry will not drop too quickly due to the dissolution of SO2. When using desulfurization enhancers, the desulfurization system can operate at a lower pH without altering the existing operating method. This allows the main boiler to adapt to high-sulfur coal without changing the original operation, adjusts the flexibility and stability of the desulfurization system, and reduces the coal cost for the power plant.
3.4 Reduce Limestone Consumption
Increase the utilization rate of the desulfurizing agent to reduce its consumption. The catalyst enhances the solubility of limestone in the liquid phase, strengthens the solubility of limestone, and at the solid-liquid interface, it provides an acidic environment favorable for the dissolution of AC○3, reducing the resistance in the liquid phase and promoting the dissolution of limestone. After adding the desulfurization enhancer, the CACO3 content in the FGD gypsum plume decreases sharply, with experiments proving a reduction of 3%-5%, thereby improving the utilization rate of limestone.
3.5 Enhance the dispersibility of limestone, reduce shutdown accidents caused by equipment scaling
The active ingredients in the catalyst enhance the surface activity of limestone, improve its dispersibility, reduce its settling velocity, and minimize scaling and blockage in equipment.
3.6 Increase oxidation efficiency, reduce the content of sulfite, and enhance the value of FGD by-products.
Desulphurization enhancer can reduce the surface tension of limestone slurry, thereby decreasing the critical crystal nucleus radius, enhancing the oxidation of HSO3, facilitating the precipitation of gypsum from CASO and CASO, and maintaining CAO4 in an unsaturated state. This prevents the formation of chemical scale deposits, ensuring long-term equipment operation without scale buildup.
Desulfurization enhancer effectiveness
Using limestone as the absorbent, a test on the influence of liquid-gas ratio (L/G) on desulfurization efficiency was conducted under conditions of adding an appropriate concentration of desulfurization enhancer and without adding the enhancer. When the L/G ratio is the same, the net increase in desulfurization efficiency after adding desulfurization additives decreases as the desulfurization rate (L/G) increases, indicating that the desulfurization enhancer is most effective at L/G ≤ 5 L/m³. At this L/G, the desulfurization efficiency is approximately 10 percentage points or higher, with a relative increase of 18% in desulfurization efficiency and 26% or more in gas phase efficiency. When L/G ≥ 5 Lm, the desulfurization efficiency increases with L/G but decreases, still maintaining over 5 percentage points, with a relative increase of over 7% in desulfurization efficiency and over 12% in gas phase efficiency. When the desulfurization efficiency is the same, the effect of adding desulfurization enhancer is more pronounced when looking at the required L/G changes to achieve the same desulfurization efficiency. Calculations show that to achieve the same desulfurization efficiency, L/G1 is only 60%-73% of L/G2, and the larger the L/G, the more significant the decrease. Desulfurization enhancers can effectively reduce the operating costs of the system. Overall analysis indicates that adding desulfurization enhancers can increase desulfurization efficiency by about 30-50 percentage points for flue gases with varying SO2 concentrations at different inlet ports, which is quite beneficial for flue gases with higher concentrations.
4.1 The addition of desulfurization enhancer achieves ultra-low SO2 emission requirements.
Many old factories are installing new desulfurization towers to meet ultra-low emission requirements. Desulfurization modifications account for over 70% of the total ultra-low cost. Later operation and maintenance of spare parts incur high expenses. By now adding desulfurization enhancers, the efficiency of the desulfurization tower can be improved by 5-8%. Without altering the desulfurization tower, the outlet emissions can meet ultra-low emission requirements, significantly reducing secondary investment.
4.2 Effects of Desulfurization Enhancer on Slurry pH Value
To investigate the effect of desulfurization enhancer on pH value, the pH values at the inlet and outlet of the desulfurization tower were measured over time during the process. It can be observed that adding an appropriate concentration of desulfurization enhancer can lower the peak pH value and mitigate pH fluctuations, thereby acting as a buffer for pH, which accelerates the overall mass transfer reaction rate, benefiting the enhancement of desulfurization efficiency and the utilization of limestone.
4.3 Effect of desulfurization enhancer on the sedimentation of particles in the slurry
A solution of a certain concentration is prepared, stirred thoroughly, and then allowed to settle naturally. The settling velocity is observed, and the experimental results show that the addition of a desulfurization enhancer significantly slows down the settling velocity. Without the enhancer, the mixture clearly separates into a clear liquid layer and a slurry layer after 3 hours of settling, similar to the condition after 30 hours. However, with the enhancer, it separates into three layers after 5 hours of settling, with the clear liquid layer accounting for 50% of the total volume, the dilute layer 87.0%, and the concentrated slurry layer 8.0%. At this point, the dilute slurry layer and the concentrated slurry layer contain approximately 1/3 and 2/3 limestone, respectively. After 30 hours of settling, the dilute slurry layer and the concentrated slurry layer account for 85% and 10% of the total volume, with the limestone content being about 1/6 and 5/6, respectively. It is evident that the addition of the desulfurization enhancer greatly reduces the settling velocity of the limestone.
4.4 Influence of Desulfurization Enhancer on Slurry Viscosity
The test results before and after adding desulfurization enhancer indicate that, whether it is slaked lime slurry or limestone slurry, adding the λ desulfurization enhancer slightly reduces the viscosity in both cases, demonstrating that the desulfurization enhancer has a viscosity-reducing effect on the slurry.
4.5 Additional Functions of Adding Desulfurization Enhancer
Antifouling and anticorrosion, by adding a certain amount of desulfurization enhancer, has a certain effect of reducing scaling and corrosion rates, and can improve the performance of the scaling layer, making it easy to rinse with water. It can significantly reduce the concentration of S2O in the circulating tank surface, thereby greatly improving the working environment. Without the desulfurization enhancer, the S2O concentration is 50-80 ppm, while after adding the desulfurization enhancer, the S2O concentration drops to 10-3 ppm. From the reduction perspective, the desulfurization enhancer has the effect of accelerating the overall reaction rate.
5. Switch coal sources, optimize resource utilization, and reduce coal burning costs.
For instance, using our desulfurization additive at a power plant in 2016 with a total installed capacity of 4 x 600,000 kW, the economic benefits brought to the plant are as follows:
Firstly, a price survey for coal with different sulfur contents revealed that, with a reference coal price based on a low calorific value of 5500 Kcal, an increase of 1% in sulfur content results in a price reduction of over 30 RMB per ton. Under normal circumstances, a 60 million KW unit consumes approximately 5,500 tons of coal daily, while four such units would consume around 22,000 tons daily.
After using desulfurization additives, the desulfurization efficiency can be increased by 30-70% or more. Based on practical experience and theoretical conversion, the effect is to raise the upper limit of the designed fuel sulfur content from 1% to over 2%. In the actual usage process, considering the equipment's inherent anti-corrosion ability, it is entirely feasible to increase the actual coal type sulfur content from 1% to 1.3% (if the equipment has good bearing capacity, the upper limit can be raised to 1.5% or more; coal with 13% sulfur can be mixed with 70% coal having 1% sulfur and 30% coal with 2% sulfur).
Next, save the electrical consumption of the pulp circulation pump, and reduce equipment wear and tear.
In the actual operation of desulfurization, the slurry circulation pump
In the 24/7 operation of continuously pumping and transferring limestone slurry, the desulfurization tower of the power plant requires all four slurry circulation pumps (with one pump rated at 1400KW) to be running. Under this scenario, by adding a certain amount of desulfurization additive while ensuring compliance with emissions standards, the operating costs can be reduced by shutting down one slurry circulation pump, as shown in the following table of electricity cost savings:

6. Premium Operational Efficiency