连铸板坯三角区裂纹成因分析及改进措施

通过对铸坯的低倍检验和三角区裂纹部位的电镜扫描,分析了连铸板坯三角区裂纹的类型和成因;提出了从钢水成分、二冷配水、驱动压力、轻压下、支撑段等方面的改进措施。其结果表明,钢中硫和铸坯的支撑段是影响三角区裂纹的主要因素。具体措施的实施,使三角区裂纹的发生率和级别大幅度下降。     

硫磺回收及尾气处理工艺新型流程

针对硫磺回收及尾气处理Claus +SCOT装置存在的问题进行探讨 ,提出采用非在线加热炉并合理利用自身热源的新型简化流程。对新老流程进行了对比 ,指出了新流程设计中应考虑的问题。     

Effect of low-sulfur fuels upon NH3 and N2O emission during operation of commercial three-way catalytic converters

The use of low-sulfur fuel is known to improve the performance of the three-way catalytic converter (TWC). However, in this work we report how low-sulfur operation of commercial TWC also favors formation of N₂O and NH₃ as by products. We found that low-sulfur rich operation above 300 °C increases the production of NH₃, inhibiting the formation of N₂O characteristic of high-sulfur operation. During lean operation, the production of N₂O near the stoichiometric point is not significantly affected by the sulfur level. The large production of N₂O observed during light-off is not affected by SO₂ when the operation is lean, but under rich conditions N₂O is produced up to 575 °C. The increased production of NH₃ and N₂O in TWC as a result of the introduction of low-sulfur gasoline is an area that requires further analysis because of its implication upon public health in large urban settings.     

氯元素对燃煤烟气脱汞的影响研究进展

燃煤电厂是最主要的人为汞排放污染源,氯元素对汞的形态转化及脱除率有非常重要的影响。本文概述了燃煤电厂汞的释放特性和现有控制技术,从氯元素作为烟气组分、活性炭改性物以及燃料添加剂这3个方面详细阐述了氯对汞排放控制的影响。首先氯化氢作为烟气组分,对单质汞向氧化态汞的形态转化有促进作用,这有利于现有除尘、脱硫装置对烟气汞的脱除。含氯化合物改性活性炭吸附剂时,物理吸附和化学吸附同时存在,这能有效提高吸附剂对汞的吸附性能。氯化物作为燃煤添加剂也能有效促进烟气汞的氧化和脱除,其中氯元素在湿法脱硫废水中富集,如何把其利用到烟气汞的脱除对开发高效脱汞技术有重要的意义。同时,比较了以上3种氯添加方案的优缺点。最后指出,深入研究氯元素对汞作用机理是今后的研究方向。     

煤有机硫赋存形态模拟与微生物脱硫研究进展

分析了煤的有机质结构和煤中有机硫赋存形态的复杂多样性，依据煤化学结构模型的预示以及煤化程度加深对芳核缩合程度增加的基本规律，探讨了模型化合物选择的理论依据及其规律性，归纳了微生物降解煤中有机硫的三种典型机理，综述了DBT，NTH，BTH和BMS等模型化合物及其部分衍生物微生物脱硫的研究进展，提出了运用多模型化合物选育降解煤中有机硫的微生物、多菌群复合培养和单一菌株广谱脱硫性能研究的新理念，展望了微生物脱硫技术的工业可行性．     

不同密度级高硫煤质量分布状况

以北宿、洛阳等两地高硫煤为样品按照国标（GB／T478—2001）进行了浮沉试验,并对两煤样进行了不同密度级煤的质量（灰分、比磁化率、硫分）状况的测定;结果表明随着密度级的增加,煤的灰分和比磁化率均逐渐增大,而硫分在各密度级的分布同煤种有关,缺乏普遍规律可循,与低密度级相比高密度级高硫煤的煤质普遍较差。     

The effects of pressure and temperature on the catalytic oxidation of hydrogen sulfide in natural gas and regeneration of the catalyst to recover the sulfur produced

The influence of pressure up to 5600 kPa and temperature up to 175 °C on the oxidation of low concentrations of H₂S in natural gas was studied in a fixed bed reactor over an activated carbon catalyst. Operation of this system at 5600 kPa provides higher catalyst activity (virtually 100% H₂S conversion) over a longer period of time and with lower selectivity to SO₂ than when operated at atmospheric pressure. The desorption of sulfur from a loaded catalyst occurs first from the macropores (> 100 nm) of the catalyst which contain a substantial portion of the sulfur load and then from the micropores (< 100 nm). This study also indicated that the sulfur recovery process is both rapid and effective at 327°C.     

褐煤在甲烷气氛下热解特性及硫析出规律研究

利用热天平研究了龙口褐煤在甲烷气氛下的热解失重特性．研究表明,在低于400℃时,甲烷对褐煤没有促进热解的作用．在400℃～750℃范围内,甲烷促进了煤的热解．750℃以后煤在甲烷气氛下热解的TG曲线上升,出现增重．在固定床上进行了褐煤在天然气气氛下的热解实验,分析了热解气体中碳氢组分和硫的析出规律,发现煤热解气相产物中CH4（甲烷）、C2（乙烷和乙烯）、C3（丙烷和丙烯）和C4H10（丁烷）都是在350℃开始析出,到550℃达到最大值,750℃时已基本全部析出．在天然气气氛下,硫的析出量一直较在氮气气氛下多,说明甲烷能促进煤中硫向气相中迁移．     

磁氧分析仪在克劳斯硫磺回收中的应用

结合超级克劳斯硫磺回收技术的流程特点和过程氧含量分析的具体要求,从磁力机械式氧分析仪的选用、工作原理、采样预处理系统结构以及应用中的注意事项等方面,着重介绍磁力机械式氧分析仪在硫磺回收中的应用。