The Experimental Studies On Desulfurization Characteristic Of Limestone And Compound Sulfur Sorbent

Nowadays, wet flue gas desulphurization in which the primary sulfur sorbents are limestone and gypsum is the most widely used method in the world. But the initial investment in the system construction, operation and maintenance expenses are so high that to some extent, the application of FGD can not be widely used in thermal power plants in our country. Therefore, in order to reduce the FGD system investment as well as the expenses of both operation and maintenance and increase the proportion of applying FGD in thermal power plants in our country, the appropriate sulfur sorbents with low price and high efficiency should be adopted.This paper provides an idea that using fly ash discharged from power plants as sulfur sorbent for desulfurization, which comes after the comparison of the advantages and shortcomings of the sulfur sorbents both in domestic and abroad FGD system. This method can not only economize large expenses of sulfur sorbents and simplify desulfurization devices, but also solve the pollution of fly ash discharging. The primary investigation as follows:(1) Three kinds of typical fly ash samples are applied in this experiment. The contents of each matter of the fly ash, coal types, burning modes and types of dust catchers are identified ahead.(2) The granularity distributing regulations of each kind of fly ash, the relationship between the pH values of the fly ash sample slurry and the granularities and concentrations of fly ash samples and hydration time are identified by filtrating experiment and hydration experiment respectively. This work is the foundation of investigating the effects of the granularities of the fly ash samples on the desulfurization efficiency of the fly ash sample slurry.(3) Firstly, the desulfurization efficiency of CaCO₃ and Ca(OH)₂ are researched in order to make sure the efficiency of the desulfurization with this experiment setup. Secondly, the desulfurization regulations with different proportions and concentrations of compound sulfur sorbents (CaCO₃ and fly ash) are studied. Finally, the desulfurization regulations with different granularities and fly ash samples and concentrations of fly ash sample slurry are investigated. The essential parameters are provided for the industrial application of fly ash in FGD via the above investigations.