循环流化床烟气脱硫塔进口流场模拟及优化

为了改进循环流化床脱硫塔因下部装有的弯管加文丘里管式入口结构所造成的底部区域不均匀气流场,采用RNGκ-ε湍流模型对脱硫塔的气流场进行了模拟计算,讨论了这种进口结构对脱硫塔流场的影响机理,并对该进口结构进行了优化.结果表明:RNGκ-ε模型对于该流场具有较好的模拟效果,在弯管和文丘里管综合作用下,脱硫塔内中下部的气流场分布不均,而返料口对脱硫塔的气流场影响很小.通过对比3种入口结构的优化方式,发现采用改进导流叶片的方式优化效果较好,可成功均布脱硫塔气流场,造成的床层压损也很小.     

Preparation of activated carbon with low ash content and high specific surface area from coal in the presence of KOH

An activated carbon with ash content less than ]0% and specific surface area more than 1600 m^2/g was prepared from cool and the effect of K-containing compounds in preparation of cool-based activated carbon was investigated in detail in this paper. KOH was used in co-carbonization with coal, changes in graphitic crystallites in chars derived from carbonization of coal with and without KOH were analyzed by X-ray diffraction (XRD) technique, activation rates of chars with different contents of K-containing compounds were deduced, and resulting activated carbons were characterized by nitrogen adsorption isotherms at 77 K and iodine numbers. The results showed that the addition of KOH to the coal before carbonization can realize the intensive removal of inorganic matters from chars under mild conditions, especially the efficient removal of dispersive quartz, an extremely difficult separated mineral component in other processes else. Apart from this, KOH demonstrates a favorable effect in control over cool carbonization with the goal to form nongraphitizable isotropic carbon precursor, which is a necessary prerequisite for the formation and development of micro pores. However, the K-containing compounds such as K2CO3 and K20 remaining in chars after carbonization catalyze the reaction between carbon and steam in activation, which leads to the formation of macro pores. In the end an innovative method, in which KOH is added to coal before carbonization and K-containing compounds are removed by acid washing after carbonization, was proposed for the synthesis of quality coal-based activated carbon.     

高炉渣作为可回收材料的综合利用探讨

文章主要介绍了高炉渣目前阶段的各种综合利用技术，分析了我国高炉渣综合利用中还存在的问题，探讨了高炉渣利用的未来的发展趋势。     

火灾逃生面具中挥发性物质含量检测方法的研究

采用高温热辐射试验、高温热裂解试验、热失重试验研究测试了火灾逃生面具中挥发性有机物的种类及含量;通过模拟实际的作业环境,利用气相色谱质谱连用仪、快速热裂解试验仪等对实验结果进行分析,指出了三种测试方法的优缺点,建议采用热失重测试方法。     

循环流化床技术在烟气脱硫中的应用

阐述了循环流化床烟气脱硫工艺的机理,指出反应器的应用、水分的加入和脱硫剂物料的循环是该脱硫工艺的主要特点;综述了国外几种循环流态化脱硫工艺如CFB、RCFB、GSA、NID的流程和特点;介绍了循环流态化脱硫工艺在我国的发展和应用情况,提出应深入研究脱硫塔内气—固运动规律,解决压力降问题,开发高品位脱硫剂,拓宽脱硫副产物的利用途径。     

活性炭硝酸表面改性对催化剂分散度的影响

无论是活性炭作为催化剂载体还是在活性炭本身的催化制备过程中,催化剂在活性炭或活性炭前体上的高度分散都是至关重要的。通过X射线能谱(EDX)和扫描电子显微镜(SEM)技术直接观察、研究了活性炭表面经硝酸氧化改性对硝酸铜在煤基活性炭中分散度的影响。此外,将经硝酸表面改性的商品活性炭采用浸渍法负载上硝酸铜催化剂,再经水蒸气二次活化制备了一种新的活性炭。结果表明,硝酸处理造成活性炭吸附性能的下降,并且硝酸处理的强度越高,活性炭吸附性能的下降程度越大。然而,对硝酸处理的活性炭经简单的水洗可恢复其吸附性能。研究结果还表明,活性炭经硝酸氧化提高了炭表面含氧官能团的数量,使催化剂在活性炭的内外表面均能均匀分布,提高了催化剂的分散度和抗烧结能力。活性炭经硝酸改性后再负载硝酸铜进行二次活化制备高性能活性炭,可使硝酸铜的催化性能得到进一步的提升。     

活性炭的表面性质及表面改性研究进展

活性炭表面的不饱和电子云和炭结构中存在的杂原子影响了其应用范围,为了满足应用需求,必须对其表面进行改性;介绍了活性炭表面改性的方法,包括对活性炭外观、形状的改变,采用碳沉积技术对孔结构的改形,针对不同应用条件对活性炭表面极性的改性等。     

溶液酸度对磁性活性炭吸附性能和磁性能的影响

以太西无烟煤为原料、Fe3O4为添加剂制备煤基磁性活性炭,用不同浓度的盐酸溶液浸泡,测定酸液浸泡前后活性炭的碘值和亚甲蓝值,采用X射线衍射仪和振动样品磁强计分别测定、表征活性炭中含铁化合物的组成和磁性能.结果表明,溶液酸度对磁性活性炭的吸附性能和磁性能均有影响,当溶液酸浓度达到1mol/L时,磁性活性炭浸泡后的碘值提高了7.9%、达732.49mg/g,比磁化系数从259×10-7 m3/kg降低到7.16×10-7 m3/kg,但仍能采用磁场分选回收;当溶液酸浓度达到2mol/L时,磁性活性炭完全失磁.     

煤基活性炭孔径分布的调控

提出并研究了一种煤基活性炭孔径分布的调控方法及调控机理.将煤样与不同质量的KOH混合后炭化,分别对炭化料进行酸洗,以控制其中的钾含量,然后对酸洗料进行蒸汽活化,制成活性炭.通过对所制活性炭进行氮气吸附实验、扫描电镜及能谱分析和吸附能力表征实验后发现:改变KOH加入量和采用质量浓度为5%的盐酸对炭化料进行酸洗,能够改变炭化料中的钾含量;随着KOH含量的提高,活性炭的口发附能力逐渐增强,平均孔径从2.379 nm逐渐增大到2.636nm,同时孔径分布由以微孔为主逐渐向以中孔为主转移,其中孔含量由30.9%提高到46.1%.