Study on Emission Control for Precursors Causing Acid Rain in Chongqing, China Sulfur Fixating Using Bio-briquette Technology

摘要

Air pollution and aicd precipitation in China, especially in southwestern China, are directly related to coal utilization. Since coal with a high sulfur content is burned in combustion equipment, such as medium or small boilers and domestic stoves, the impact of pollution on both vegetation and people's health has become serious in Chongqing city. A part of our study on controlling acid rain in Chongqing area is described in this paper. The experimental results showed that the effectiveness of sulfur fixation by Ca-based materials is in the order of Ca(OH)_2 >CaO>CaCO_3. The optimum temperature for sulfur fixation was 800degC because CaSO_4 was a stable final product. Further, bio-briquettes were made of raw coal, biomass and slaked lime simply by compression. The bio-briquette gave a significant reduction in SO_2 emission, compared to the raw coal. The measurements overall indicated that the sulfur fixation effectiveness of bio-briquette is better than that of raw coal with a reduced emission to about 85-90%. The influences of combustion conditions on sulfur fixation were also discussed in the paper. The results of this study will play an important role in reducing SO_2 emmission and mitigating acid precipitation in Chongqing area.