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.     

两条煤制油与石油路线的技术环境和经济分析

中国液体燃料的生产严重依赖石油,为了缓解石油高度对外依存带来的风险,中国正在积极探索石油的替代路线。在中国“富煤贫油”的情况下,煤制油有望成为缓解石油供应安全风险的重要替代途径。利用生命周期评价的方法(from cradle to gate)从能耗、碳排放和经济性三个角度对煤直接液化(direct coal liquefaction,DCL)和煤间接液化(indirect coal liquefaction,ICL)进行分析,并与传统炼油(oil refining,OR)路线进行对比。结果表明:DCL和ICL路线的生命周期能耗分别是OR路线生命周期能耗的2.4倍和2.8倍,碳排放分别是OR路线碳排放的8倍和10倍。当油价低于45美元/桶时,无论是DCL还是ICL均难以与OR路线竞争;当油价在35美元/桶~65美元/桶,煤价在低于400元/t时,ICL有较好的竞争力;而当油价高于75美元/桶时,即使煤价高达700元/t,DCL仍具较好的竞争力。     

关于我国煤矸石发电存在的问题的调查

论述了我国煤矸石综合利用电厂的基本情况，分析了煤矸石电厂在并网及生产经营过程中存在的问题，并提出了解决问题的相关建议。     

链条炉改烧型煤的探讨

探讨了链条锅炉中燃烧工业型煤时遇到的一些问题 ,分析了其产生的原因 ,提出了解决的途径。     

活性炭纤维布担载纳米TiO2的三种方法

TiO2光催化剂与多孔炭材料的复合，可以将吸附性能与光催化降解性能有机地结合在一起。以活性炭纤维布(ACFC)为载体，采用TiO2粉体分散液直接浸涂法、中频交流磁控溅射法及溶胶-凝胶法进行了担载实验，用SEM对三种担载方法得到的样品进行形貌观察，结果表明溶胶-凝胶法比较适合于ACFC上担载TiO2。而且，通过控制提拉速度、浸涂次数、热处理条件，可以得到形貌完整、结合强度较好的复合体，该复合体的XRD衍射结果表明，ACFC表面担载的TiO2为锐钛矿，在紫外-可见光漫反射光谱中，于350—400nm区间有明显的吸收边，表明此复合体具有光催化活性。     

石墨化CVI泡沫炭的结构和性能

本文采用化学气相渗透技术(CVI)对泡沫炭进行复合处理,利用SEM、XRD等分析手段对石墨化样品进行了分析.研究结果表明,CVI热解炭在泡沫基体的沉积方式是:小颗粒积聚生长成为大颗粒·大颗粒不断接合,经石墨化处理后形成更加规则的结构.石墨化CVI泡沫炭相比原生石墨泡沫炭的电学和力学性能有很大提高,在350*C、2MPa压力条件下制备的石墨化CVI泡沫炭的电导率可以提高近0.9倍;在350"C、1MPa压力条件下制备的石墨化CVI泡沫炭的压缩强度增大近3.5倍.因此,CVI处理可以有效改善石墨泡沫炭的基体结构,提高石墨泡沫炭性能.     

还原参数对铁基催化剂F—T合成性能的影响

在浆态床反应器中详细考察了还原参数对工业铁基催化剂在F—T合成反应中的影响。研究结果表明：提高还原气体中CO／H2的比值有助于提高烯烃的选择性;提高还原气体的空速可以提高催化剂的活性,但是烯烃的选择性有所降低;升高还原温度在一定程度上可以提高催化剂的活性,但是温度过高容易造成催化剂积炭活性下降,适宜的还原温度范围为210～260℃。     

Removal of Volatile Organic Compounds by Adsorption and Photocatalytic Oxydation

Based on the study of equilibrium adsorption on viscose rayon-based activated carbon fiber （ACF） by gravimetric method, mounting of TiO2 on PAN-based activated carbon cloth （ACC） and their photocatalytic activity as well as adsorption performance for benzene were investigated. The crystallinity of TiO2 and pore structure were characterized by XRD and N2 adsorption. The results show that crystallinity of TiO2 and pore structure could be postulated by heat treatment condition. Both crystallinity of TiO2 and pore structure of hybrid have effects on photocatalytic performance of TiO2-mounted ACC. It would be more attractive and prospective for the combination of TiO2 photocatalytic activity and adsorption ability of porous materials.     

测量煤浆灰分的试验研究

介绍了清华大学工程物理系研制的煤浆灰分检测装置,并在淮北选煤厂对影响煤浆灰分测量的因素进行了试验研究,这对于改进、完善和定型该装置,以及开发配套的浮选控制系统具有非常重要的意义。     

以煤沥青为粘结剂制备柱状活性炭的工艺参数优化

传统煤焦油基制备柱状活性炭粘结剂存在成本高、污染严重、质量不稳定等诸多问题,文章将煤沥青和膨化淀粉复配为新型粘结剂,以无烟煤为原料制备柱状活性炭。采取正交试验设计实验方案,研究活化温度、炭化温度、活化时间、炭化时间与水蒸气通量对柱状活性炭强度、碘吸附值、亚甲基蓝吸附值以及收率的影响,并利用热重分析仪考察了粘结剂的热性能。结果表明:制备柱状活性炭的最佳工艺参数为:活化温度850℃,炭化温度600℃,活化时间300 min,炭化时间60 min,水蒸气通量0.2 mL/min,其碘吸附值达到1241.1 mg/g,亚甲基蓝吸附值高达159.5 mg/g,强度为75.2%,收率38.9%,说明新型粘结剂可制备出符合要求的净化用柱状活性炭。