Relationship between coal slurry particle size and carbon dioxide
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When the particle size of the coal slurry is too fine, especially below 325 mesh – which is twice the specified value – how does the carbon dioxide content in the gas change? In other words, what is the impact of particle size on the gas composition?
The mesh sizes of coal slurry, 8/14/40/200/325, are in a proportional relationship. In other words, the gas composition remains constant under fixed operating pressure, temperature, load, and coal type. The gas composition is related to atomization and slurry quality. The higher the mesh number, the finer the particles; theoretically, the finer they are, the faster the reaction rate, as this is due to a larger specific surface area for the reaction. However, the finer the coal slurry, the more difficult it is to transport it, resulting in higher pipeline resistance and greater pressure drops. As a result, the pressure reaching the burner is lower, and the particles after atomization end up being larger ； At the same time, coal particles have many fine components, which results in higher viscosity; this makes atomization more difficult and leads to larger atomized particles. The particles are large, the quality of the coal slurry is unstable, and it tends to stratify, causing significant damage to coal slurry pumps, pipelines, and especially burners. Overall, the gas composition is out of spec, with high CO2 levels. C + O2 = CO2; CO2 + C = 2CO. The amount of CO2 produced remains basically the same, but the amount of CO2 consumed decreases