稻壳炭提取SiO_2及制备活性炭联产工艺

Poly-generation of activated carbon and silica from rice husk charcoal

为了利用气化发电的固体产物稻壳炭,通过单因素试验,研究了稻壳炭同时提取二氧化硅及制备活性炭工艺技术,得出优化的工艺条件:质量分数20%的K2CO3溶液与稻壳炭原料的液固比为15mL/g,煮溶温度100℃,煮溶时间3.5h;稻壳炭的炭化温度是450℃,活化温度850℃,活化时间2h;SiO2的陈化温度为3℃、陈化时间3h。此条件下制备的稻壳基活性炭得率39.34%、碘吸附值978.35mg/g、亚甲基兰吸附值12mL/0.1g;二氧化硅得率25.77%、白度89.91%。试验表明该工艺制备出的稻壳基活性炭及二氧化硅产品的质量均达到了国家标准的要求,同时为稻壳炭的高效、无公害及资源化利用提供了一条可循的途径。

In order to effectively utilize the solid product of gasification electricity generation, the optimum reaction conditions of the poly-generation technology for production of activated carbon and silica extraction from the rice husk charcoal were optimized by single-factor experiment. The results showed that the optimal conditions were as follows： the liquid-solid ratio of K2CO3 solution（mass fraction of 20%） to rice husk charcoal was 15：1（mL/g）, and the mixture was melted at 100℃ for 3.5 h; The carbonization temperature and activation temperature for rice husk activated carbon was 450℃ and 850℃, respectively, and activation time was 2 h. The aging temperature and aging time for silica was 3℃ and 3h respectively. Under these conditions, the yield of activated carbon was 39.34%, the iodine adsorption value was 978.35 mg/g, and the methylene blue adsorption value was 12 mL/0.1 g. The yield of SiO2 was 25.77% and its whiteness was 89.91%. The experiment indicated that the quality of rice husk activated carbon and silica product prepared in this process both reached to the national standards. The research can provide a practical way for the high efficiency, pollution-free and resource utilization of rice husk charcoal.