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101.
102.
Xiaofang Zhang Li Dong Juwei Zhang Yajun Tian Guangwen Xu 《Journal of Analytical and Applied Pyrolysis》2011,91(1):241-250
Simulating the conditions of pyrolytic topping in a fluidized bed reactor integrated into a CFB boiler, the study was devoted to the reaction fundamentals of coal pyrolysis in terms of the production characteristics of pyrolysis oil in fluidized bed reactors, including pyrolysis oil yield, required reaction time and the chemical species presented in the pyrolysis oil. The results demonstrated that the maximal pyrolysis oil yield occurred on conditions of 873 K, with a reaction time of 3 min and in a reaction atmosphere gas simulating the composition of pyrolysis gas. Adding H2 and CO2 into the reaction atmosphere decreased the pyrolysis oil yield, while the oil yield increased with increasing the CO and CH4 contents in the atmosphere. TG-FTIR analysis was conducted to reveal the effects of reaction atmosphere on the chemical species present in the pyrolysis oil. The results clarified that the pyrolysis oil yield reached its maximum when the simulated pyrolysis gas was the reaction atmosphere, but there were slightly fewer volatile matters in the pyrolysis oil than the oil generated in the N2 atmosphere. All of these results are expected not only to reveal the composition characteristics of the pyrolysis oil from different conditions of the coal topping process but also to optimize the pyrolysis conditions in terms of maximizing the light pyrolysis oil yield and quality. 相似文献
103.
Coal is a non renewable fossil fuel, used mainly as a source of electrical energy and in the production of coke. It is subjected to thermal treatment, pyrolysis, which produces coke as a main product, in addition to a condensed liquid by-product, called tar. Tar is a complex mixture of organic compounds which contains different chemical classes, presenting aromatic and sulphur heterocyclic compounds. In general, identification of these compounds requires steps of isolation and fractionation, mainly due to co-elution of these compounds with polyaromatic hydrocarbons (PAH). The objective of this work is to characterize the sulphur compounds present in the coal tar obtained via pyrolysis, using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detector (GC×GC/TOFMS). Coal samples from the State of Paraná, Brazil were subjected to laboratorial scale pyrolysis. Several experimental conditions were tested, such as sample weight (5, 10 and 15g), heating ramp (10, 25 and 100°C/min) and final temperature (500, 700 and 900°C). Samples were analyzed by one dimensional gas chromatography (1D-GC) coupled to a quadrupole mass spectrometry detector (GC/qMS) and two-dimensional gas chromatography with time-of-flight mass spectrometry detector (GC×GC/TOFMS). The higher amount of sulphur compounds was obtained at a final temperature of 700°C and a heating ramp of 100°C/min. The main classes observed in the color plot were thiophenes, benzothiophenes and alkylated dibenzothiophenes. GC×GC/TOFMS allowed the identification of the greater number of compounds and the separation of several sulphur compounds from one another. Moreover, separation of sulphur compounds from polyaromatic hydrocarbons and phenols was achieved, which was not possible by 1D-GC. Comparing GC×GC/TOFMS and 1D-GC (SIM mode) also showed that 1D-GC, one of the most employed quantification tools for sulphur compounds, can be misleading for detection, identification and quantification, as the number of isomers of sulphur compounds found was greater than theoretically possible. 相似文献
104.
曹瑛 《华北科技学院学报》2003,5(3):76-78
针对煤炭企业生产过程具有特殊性和复杂性,开发了成本管理信息系统,为解决其中入库验收信息处理问题的难点,在正常的入库验收业务流程系统外,增加一个待验不经过正式验收而直接入库的数据处理系统,从而解决了实际业务数据与计算机即时传输数据控制成本难以合拍的问题,做到了成本的真正即时反馈和控制,提高了管理决策的准确性。 相似文献
105.
杨建武 《科技情报开发与经济》2005,15(4):277-278
介绍了雁崖矿和晋华宫矿大倾角煤层的开采情况及经验,总结了大倾角煤层开采的设备防滑措施,针对大倾角煤层开采中存在的问题,提出了相关的建议。 相似文献
106.
本文采用顺序等离子体光谱技术测定煤飞灰中主要成份(Ca、Mg、Fe、Al、Si、Na、K、Ti)及微量成份(Cu、Sc、V、Ni、Be、Mn)。用扫描光谱法研究了分析线的选择和光谱背景的扣除。试样用密封罐混酸溶解。测定煤飞灰标准样品NBS1633a的结果与标准值一致。方法用于测定新制备的煤飞灰标准参考物。 相似文献
107.
刘启荣 《科技情报开发与经济》2004,14(1):172-173
采用理论联系实践的方法对沁水煤田9#煤的薄煤层回采工艺进行了初步的研究与探讨,包括破煤、装煤、运煤、采场支护、采空区处理等。 相似文献
108.
Review of proton conductors for hydrogen separation 总被引:1,自引:0,他引:1
There is a global push to develop a range of hydrogen technologies for timely adoption of the hydrogen economy. This is critical in view of the depleting oil reserves and looming transport fuel shortage, global warming, and increasing pollution. Molecular hydrogen (H2) can be generated by a number of renewable and fossil-fuel-based resources. However, given the high cost of H2 generation by renewable energy at this stage, fossil or carbon fuels are likely to meet the short- to medium-term demand for hydrogen. In view of this, effective technologies are required for the separation of H2 from a gas feed (by-products of coal or bio-mass gasification plants, or gases from fossil fuel partial oxidation or reforming) consisting mainly of H2 and CO2 with small quantities of other gases such as CH4, CO, H2O, and traces of sulphur compounds. Several technologies are under development for hydrogen separation. One such technology is based on ion transport membranes, which conduct protons or both protons and electrons. Although these materials have been considered for other applications, such as gas sensors, fuel cells and water electrolysis, the interest in their use as gas separation membranes has developed only recently. In this paper, various classes of proton-conducting materials have been reviewed with specific emphasis on their potential use as H2 separation membranes in the industrial processes of coal gasification, natural gas reforming, methanol reforming and the water–gas shift (WGS) reaction. Key material requirements for their use in these applications have been discussed. 相似文献
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