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为优化高炉燃料结构和降低生产成本,从半焦的基础性能、工艺性质、喷吹效果等方面论述了中低温热解半焦作为高炉喷吹燃料的研究现状,分析了半焦替代喷吹煤粉后存在的主要问题,提出了改善半焦性能的途径和建议。现有中低温热解半焦的煤质特征和多数工艺性质满足高炉喷吹要求,但其可磨性与燃烧性能波动较大,需区别对待。随着半焦添加比例的增加,混煤的燃烧和可磨性能总体呈下降趋势。提出应通过热解过程控制、与其他燃料共热解、催化燃料等方式改善低温干馏半焦性能,增加廉价燃料在喷吹燃料中所占比例,降低高炉炼铁成本。 相似文献
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对扎赉诺尔度固体热载体干馏半焦作高炉喷吹料的可行性进行考察。结果表明:低灰褐煤制得的半焦满足高炉喷吹料的一般要求,并具有低硫、低挥发分1较高热值和较高性的特点,是一种新型高喷吹料。褐煤固体热载体干馏新技术用于钢铁企业;半焦有于高炉喷吹,煤气补充冶金燃气不足,将为企业内部能尖平衡提供一人可行的办法。 相似文献
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低阶煤低温热解半焦在模拟高炉喷吹条件下的燃烧性能 总被引:1,自引:0,他引:1
采用自制固定床热解装置在隔绝空气的条件下制备神木长焰煤热解终温分别为400℃、450℃、500℃及550℃的热解半焦,利用管式沉降炉模拟高炉喷吹条件研究神木长焰煤低温热解半焦的燃烧性能,并考察了热解终温、半焦喷吹粒径以及燃烧反应温度对半焦燃烧性能的影响。研究表明:低温热解半焦的燃烧性能优于实验所选用无烟煤的燃烧性能,半焦的燃烧性能与其燃料比之间存在负相关关系,即燃料比越高,燃烧性能越差;降低热解终温、减小半焦喷吹粒径以及提高燃烧反应温度均能改善半焦的燃烧性能,当热解终温为400℃、喷吹粒径100~200目、燃烧反应温度为1100℃时半焦的燃尽度最佳为96%。本实验半焦制备及燃烧条件与现有低温热解和高炉喷吹工艺相符,且热解半焦各项性能均符合喷吹用煤指标。 相似文献
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扎赉诺尔褐煤制取高炉喷吹料和中热值煤气研究:(I)煤气,焦油产率及性质 总被引:1,自引:1,他引:0
本文是在10kg/h固体热载体干馏实验装置上用扎赉诺尔褐煤制取高炉喷吹料和中热值煤气的研究结果。在干馏温度450℃~650℃范围制得煤气110Nm^3/t~400Nm^3/t,煤气热值为14.7MJ/Nm^3~17.5MJ/Nm^3,属中热值煤气,可供民用,也可用于补充钢铁企业燃气不足,平衡能源,得低温焦油2%~9%,可加工成化工产品和燃料油,半焦可用于高炉喷吹。 相似文献
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为实现神东煤的深度加工利用,利用热重分析仪及管式热解炉对神东煤的热解特性进行分析,研究热解半焦用作高炉喷吹原料的适用性,提出热解半焦利用的新途径。结果表明,神东煤的煤质特性优良,格金焦油产率高达8.15%,比较适宜用作低温热解;550℃时焦油产率最大,焦油灰分低,馏出温度350℃占比50%以上。随着热解温度升高,热解气中CH4和CO2含量降低,而H2和CO含量增多。热解水产率基本保持在16%。热解半焦喷吹特征与目前国内主流的喷吹煤性质相当,比较适合用作高炉喷吹原料。轻度热解半焦可直接用于高炉喷吹,提取焦油剩余半焦用作喷吹配煤可实现煤炭分质转化利用。 相似文献
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为了研究不同热解终温对低阶煤热解产品产率及性质的影响,在750,800,850℃的热解温度下,利用1 kg热解和化产品回收装置对煤样进行了模拟热解实验研究。结果表明:3个温度所得兰炭都属于V-1级和FC-1级,750℃时兰炭产率、Vd均较高。气相产物中,H2和CO含量均较高,3个温度中的H2产量均大于40.00%,且850℃含量最高;CO则在750℃时取得最大值(17.14%)。最后对热解化产品的组成及收率进行了分析测定。为了更好地指导生产,对化产品收率及性质的预测应在理论研究的基础上,结合模拟热解实验研究。 相似文献
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喷动载流床中温度对霍林河褐煤快速热解产物的影响 总被引:8,自引:1,他引:8
在喷动载流床反应器内对霍林河褐煤的快速热解进行了研究,并对该煤的热解机理进行了初步分析。考察了在500~850℃范围内温度对热解产品产率分布及气体和液体产品具体组成的影响。分别利用气相色谱和色质联用仪来分析气体和液体产物的组成。实验结果表明,气体总产率及CO、H2和C1~5烃类的产率随热解温度的提高而增大;在热解温度为650℃时,液体产率最高,在煤粉粒径为0.125~0.18mm,液体产品的总产率可达23%,其中正己烷可溶物的产率可达30%以上,沸点340℃前馏分也达30%以上。液体产品中酚类产品较多;温度对液体产品的组成有极大的影响。 相似文献
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The kinetics of pyrolysis of predried coconut shell sample has been investigated in the temperature range of 523 K to 1023 K in an inert atmosphere by captive sample technique. A kinetic scheme has been proposed where two parallel reactions are given for the production of volatiles and char. The reaction rate constants are found to decrease with high temperatures above 673 K due to chemical and physical changes of the reactant during devolatilisation reaction. Several deactivation models have been proposed to give good agreement with the experimental data. 相似文献
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低温热解处理对兖州煤孔结构的影响 总被引:5,自引:0,他引:5
对低温热解前后的兖州煤进行了各项指标的研究。结果表明,低温热解后,兖州煤中Oactive/Cdaf降低,微孔容积及面积增加,分形维数发生了变化。因含氧官能团的部分脱除,引起了煤分子结构的重排,致使兖州煤孔结构发生变化。 相似文献
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神府煤田部分矿区煤基础性质的研究 总被引:4,自引:0,他引:4
本文以我国新开发的大煤田——神府煤田部分矿区煤为对象,对其基础性质进行了较详细的研究,研究包括工业分析、元素分析、粘结性,岩相分析、热重分析、热解动力学和低温干馏等内容.结果表明,神府煤具有低灰,低硫,高挥发分,高发热量的特性.煤燃点低,反应性好.所研究的四种煤开始分解温度在380℃左右,主要热解区段在350℃~580℃范围内,热解过程可用一级动力学方程来描述,主要热解阶段的表现活化能介于75-125KJ/mol.以大柳塔2层煤为原料的低温干馅,获得12.50%的焦油,所得焦油高沸点馏分少,油含量高,适于进一步加氢精制. 相似文献
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Pyrolysis experiments on Maoming oil shale lumps (10–60 mm in diameter) were carried out with the aid of large-particle thermogravimetric analysis apparatus at constant heating rates of 1, 2 and 5 °C min−1. A pyrolysis kinetic model was developed which took into account both the pyrolysis reaction and intraparticle heat transfer. Oil shale pyrolysis kinetic parameters were then determined on the basis of experimental data concerning weight loss, shale oil production, gas evolution and intraparticle temperature distribution versus time, by using the developed model. Furthermore, the effects of variables (e.g. temperature, lump size, heating rate) on oil shale pyrolysis were assessed during experimentation. It is found that model predictions agree reasonably well with experimental data. 相似文献
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At high temperatures (s> 1100°C), pyrolysis of coal plays an increasingly important role in the overall coal conversion process. This Paper presents experimental data on the extent of pyrolysis of coal at 800–1600°C. In addition, the effects of the following parameters are examined: gaseous environment (N2, CO2 and H2O), pressure (1–20 atm), particle size, moisture content and type of coal. Previous data on some of these parameters are non-existent. A unique TGA apparatus constructed for this work allows high heating rates (102–103°Cs?1) due to the direct radiation heating. In all the gaseous environments, a plateau in per cent pyrolysis is noticed at 1200–1400°C followed by a sharp increase in the amount of pyrolysis as the temperature is raised. This is found consistent with the three-stage mechanism proposed for the evolution of volatiles. In CO2 and steam environments, there is slightly less pyrolysis than in pure nitrogen, while considerably more pyrolysis is noted for predried coal and for smaller particle sizes. The results suggest a strong influence of secondary volatile reactions on the extent of pyrolysis. Pyrolysis in steam at 800–900°C shows an increase with pressure similar to that reported for pyrolysis in hydrogen. Finally, gasification rates of chars immediately following the pyrolysis are found to be much higher than those of chars prepared separately and then reacted. These results suggest morphological rearrangements and crystallization effects. 相似文献
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The formation of porosity during heat treatment of an extruded mixture of coke particles and a binder pitch was investigated using image analysis of polished cross-sections of shaped samples. The porosity due to pitch devolatilisation takes place during a rather narrow interval of temperature when the sample is heated at 12 K/hour. Only a small fraction of pores is formed when the shaped sample is submitted to an intermediate isothermal step which allows the departure of volatile compounds from the binder. Physico-chemical changes occurring in the pitch during pyrolysis were followed by measuring glass transition temperature in relationship with weight loss. The results indicate that in sufficiently slow heating conditions, low molecular compounds essentially diffuse through the fluid pitch and evaporate at the external surface of the sample during pyrolysis. As a result, no marked porosity is formed during baking. In contrast, a high heating rate allows low molecular mass compounds to accumulate inside the sample and the formation of a significant porosity is due to the evaporation inside the shaped sample of accumulated low molecular mass compounds. 相似文献
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在固定床中研究了新疆低阶煤的热解性能,根据热重结果确定了热解的温度范围,利用气象色谱分析热解气组成,借助Origin软件绘制出合格的图形。该实验涉及从煤样制备到性能分析的系统性工作,适合作为一个专业性实验进行开展。 相似文献