Issues related to the utilization of flue gas desulfurization by-products
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Currently, the dominant technology for desulfurizing industrial flue gases is the wet method, and calcium-based desulfurizers are used in this approach. Although calcium-based desulfurizers are inexpensive, the utilization rate of their product, calcium sulfate, is low. Lacks market competitiveness. Is it possible to design a new process that uses sulfur dioxide in flue gas as a raw material to produce a product with market value?
Calcium sulfate slag is mainly used in the construction materials market, but its utilization rate is low; it is mostly stored there, as there are yet no better ways to make use of it!
Ammonia-based desulfurization is also used; the by-product is ammonium sulfate, which can be used as a fertilizer. Another process involves using activated carbon to adsorb sulfur dioxide from flue gas, and then producing sulfuric acid after desorption; however, the cost of this method is too high for power plants in China, so it is hardly used there.
About ten years ago, wet flue gas desulfurization was quite popular. The by-product calcium sulfate is mainly used in the construction materials market, but its utilization rate is low, primarily due to its high water content. Therefore, the vast majority is stored, causing another form of pollution
An integrated process combining the sodium method with oxidants for desulfurization and denitration can be used to produce fertilizers
Ammonia-based desulfurization, and the use of sulfuric acid as fertilizer can solve this problem
The cost of ammonia-based desulfurization is also high. We can sell sulfuric acid AN here, but the cost is too high
Could we first use a strong oxidant to oxidize sulfur dioxide to sulfur trioxide, and then add water to absorb it and produce sulfuric acid?
This technology already exists; the absorbed sulfur dioxide can be separated to produce sulfuric acid. It is believed that this process will replace the lime-gypsum method, especially with the introduction of a carbon tax. Lime-gypsum carbon removal is 0.69 times that of SO2 absorption. (Wt).
It is necessary to determine what process is responsible for the generation of sulfur dioxide-containing flue gas. The low-concentration sulfur dioxide flue gas from evaporation kilns can be absorbed using wet zinc oxidation; the desulfurization agent utilizes zinc sulfate, which is a by-product, in zinc electrolysis