Problems with dry desulfurization agents
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I saw an explanation of the principle of dry desulfurization provided by a certain design institute: \"Sodium-based powder is sprayed into the flue; under the influence of high-temperature flue gas, this powder is activated and undergoes thermal decomposition. The flue gas comes into full contact with the activated sodium-based powder, resulting in a chemical reaction that allows SO2 and other acidic substances in the flue gas to be absorbed and purified.\" The main chemical reactions that take place are: 2NaHCO3→Na2CO3+ H2O+CO2; SO2+Na2CO3→Na2SO3+2CO2; 2 Na2SO3+O2→2 Na2SO4. The desulfurized and dried powdered particles adhere to the fabric bags along with the airflow, where they undergo further desulfurization and purification. The efficiency of sodium-based dry flue gas desulfurization is greater than 90%, with almost no increase in the operating resistance of the flue gas system. ” I found information on NaHCO3 and Na2CO3, which states that Na2CO3 is more reactive with acids than NaHCO3. So why is NaHCO3 used instead of Na2CO3?
Could an expert give us an introduction? Thank you. .
Studies have shown that at the moment sodium bicarbonate decomposes into sodium carbonate, sodium carbonate with high desulfurization reaction activity is generated, which makes the desulfurization process more efficient than using pure sodium carbonate.
Dry acid removal process using baking soda: Baking soda (sodium bicarbonate, NaHCO3) is non-toxic and harmless; it is primarily used as a leavening agent in the food industry, as a source of carbon dioxide in sodas and frozen drinks, and as a preservative for butter. Specially processed soda ash for flue gas desulfurization can be used as an adsorbent for flue gas desulfurization. It removes acidic pollutants from flue gas through chemical adsorption; simultaneously, it can also remove certain inorganic and organic trace substances through physical adsorption. In this process, finely ground sodium bicarbonate powder with a certain particle size is directly sprayed into high-temperature flue gas. At these high temperatures, sodium bicarbonate decomposes to form sodium carbonate Na2CO3, H2O, and CO2. Due to the \"popcorn\" effect that occurs during decomposition, the surface area of the particles increases by more than 4 times, resulting in highly porous and active particles. These particles react rapidly with various acidic gases such as SO2 and HCl present in the flue gas, enabling a removal efficiency of 95–99%.
The soda ash decarboxylation reaction is a gas-solid reaction, and the rate of such reactions depends on 1) the adsorption of gases by the solid (also known as diffusion control), and 2) the reaction of the decarboxylating agent with acidic gases such as SO2/HCL/HF (kinetic control). At temperatures above 140 degrees, the reaction between sodium carbonate and acidic gases occurs almost instantly; therefore, the reaction rate depends on the adsorption of acidic gases by the deacidifying agent, and as such the reaction rate is diffusion-controlled. At high temperatures, baking soda decomposes to produce sodium carbonate Na2CO3, H2O, and CO2. Due to the \"popcorn\" effect that occurs during this decomposition, the surface area of the particles increases by more than 4 times, resulting in highly porous and active particles (which accelerates the rates of adsorption and diffusion). As a result, these particles react rapidly with various acidic gases such as SO2 and HCl present in flue gas
This process is new to me; is baking soda easier to obtain?
This post was last edited by huijun1003 on 2020-3-5 at 13:06. For more information on the soda ash decarboxylation technique, please visit: https://www.airepe.cn/news/673026/
For more information on the soda ash decarboxylation technology, please visit https://www.airepe.cn/news/673026/
For more information on the soda ash decarboxylation technology, please visit https://www.airepe.cn/news/673026/