Fundamental Study of Ammonia-sulfur Dioxide Reactions to Form Solid Particles. Final Report PDF Download

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 122

Get Book Here

Book Description
The effects of reaction residence time, presence of inert particles and moisture content on the SO2 removal and the product particle size distributions have been determined. Results indicated that both gas phase and particle phase reach equilibria in a very short time. The presence of inert particles increases the SO2 removal efficiency slightly, with a greater increase in removal efficiency at higher surface areas. Moisture content is the most important parameter affecting SO2 removal. Increasing the moisture content from 1.6% to 6.4% by volume results in a 30% increase of the SO2 removal at a reaction temperature of 51°C. The products at near anhydrous conditions were concluded to be NH3SO2, (NH3)2SO2 and (NH4)2S2O5. While the products at humid conditions could be either the 1:1 sulfites, NH4HSO3 and (NH4)2S2O5, or the 2:1 sulfites, (NH4)2SO3 and (NH4)2SO3 -H2O, or a mixture of the 1:1 and 2:1 sulfite. Those sulfite particles could subsequently oxidize to form the more stable sulfate particles. A gas-to-particle formation model has been developed to simulate the NH3-SO2 system in the presence and absence of seed aerosols at trace water conditions. This model accounts for simultaneous nucleation, coagulation, condensation and chemical reaction. The applicability of utilizing ammonia injection to a flue gas system has been discussed in terms of two possible removal schemes. One utilizes ammonia injection alone and the other is in conjunction with the injection of Ca(OH)2 slurry in a spray dryer system. Both schemes have the potential of achieving over 90% SO2 removal from power plants burning high-sulfur coals.