硫在煤中的存在形式及其随煤粒径的分布

介绍了我国煤中疏的含量分布及硫的存在形式,并研究了含硫量随粒径的分布规律。这有利于研究和选择原煤脱硫方法。     

硫在原油加工过程中的分布及应用

分析了惠州炼油分公司加工以蓬莱、达里亚原油为主时,硫在常减压蒸馏、延迟焦化、催化裂化、加氢装置的分布情况.原油中的硫,85％进入二次加工装置,近50％分布在减压渣油中,减压蜡油中的硫含量在35％左右.原油总硫的58.33％、22.72％、13.24％分别进入焦化装置、蜡油加氢裂化装置、催化装置.加氢装置除汽、柴油加氢外,原料硫几乎全部转化为硫化氢.转化率接近100％;催化装置硫化氢转化率接近50％,焦化装置硫化氢转化率不到35％.根据惠炼原油的硫分布情况,估算了原油加工过程中总硫中的硫化氢的转化率为79.4％,总硫回收率为77.7％;估算了惠炼在原油硫含量增加后,脱硫单元的负荷变化情况及对产品质量和尾气排放的影响.脱硫单元最大负荷允许原油硫含量最高为0.36％;在原油硫含量超过0.32％时,催化烟气硫排放将会超标,需要考虑降低烟气硫含量的措施;生产欧Ⅲ汽油时,原油硫含量最好不高于0.40％.     

煤中有机硫的电化学脱硫机理

在研究煤中有机硫的电化学脱硫基础上，利用X光电子能谱（XPS）和红外光谱（FT－IP）等现代测试手段研究了煤中有机硫的电化学脱硫机理。研究表明煤中有机硫在不同介质中脱硫机理不同。酸性条件下的脱硫机理是以锰离子为催化剂，在阳极表面Mn^2 被氧化Mn^3 ，后者氧化煤中有机硫为亚砜，亚砜进一步被氧化为砜，砜在热水中水解为可溶的磺酸根或硫酸根。碱性条件下脱硫机理是在碱性条件下脱硫反应以电解阳极产生的活性氧为氧化剂，将煤中有机硫氧化为亚砜和砜，砜在碱的作用下于热水中水解为能溶于水的磺酸根或硫酸盐。     

煤液化残渣硫析出动态特性的研究

研究了煤液化残渣燃烧过程中硫动态析出特性。实验结果表明,煤液化残渣燃烧硫析出有两个明显的峰值,其析出过程与煤中硫赋存形态有很大关系,温度对硫析出影响很大。随着温度的提高,硫析出量逐渐增加,析出速率峰值逐渐提高,析出峰值时间逐渐提前。此外,研究了石灰石添加剂对硫动态析出的影响,随着添加剂粒径的减少,硫析出量逐渐增加,但是增幅逐渐减弱。图7表1参6     

钙基固硫过程中硫存在形态的转变

为了控制燃煤SO2的排放,研究了高温下钙基固硫过程中硫存在形态变化机理.采用定碳炉研究添加钙基前后硫析出特性,采用XRD实验检测燃烧不同阶段硫的存在形态,通过热力学平衡计算预测燃烧产物中不同含硫物相分布.原煤燃烧时硫主要以SO2形式在燃烧初期析出,添加钙基后,燃烧初期SO2析出浓度剧烈下降,硫析出曲线呈双峰状.添加钙基后,CaS在燃烧初期的大量生成以及在燃烧后期的氧化,是造成硫析出曲线变化的主要原因.热力学平衡计算表明:贫氧条件下原煤燃烧时,H2S、FeS、CaS、S2、COS为主要含硫物相,添加钙基后,贫氧工况下硫主要以CaS和H2S的形式存在,富氧环境下,硫主要以CaSO4、SO2、SO3形式存在.     

硫元素对烟气中汞的形态和分布的影响

采用化学热力平衡分析方法研究了在煤燃烧和气化过程中产生的烟气里痕量元素汞的形态及分布。在0．1MPa下，400—2000K温度范围里，研究了汞—煤系统、汞—煤—硫系统和汞—煤领—氯系统中汞在还原性气氛和氧化性气氛的烟气中的化学形态和分布，着重探讨了煤中的硫元素对汞在烟气中的形态和分布的影响。化学热力平衡分析结果表明，在煤燃烧和气化的最高温度区域里，单质汞是汞的主要形式；在气化的还原性气氛烟气中，汞的主要形式是单质汞，在氧化性气氛的燃煤烟气中，随着烟气温度的降低，单质汞将发生化学反应而生成二价汞的化合物；硫元素的存在可以促进汞元素以固相硫酸汞(HgSO4)的形式沉积，但烟气中高硫含量会抑制汞元素蒸气的氧化以及氮化汞的形成。     

MgO硫酸盐化反应动力学及镁基固硫剂型煤燃烧实验研究

用ＴＧ法对ＭｇＯ硫酸盐化反应动力学进行了研究，求出了该反应的动力学参数。在以ＭｇＣＯ３为固硫剂的型煤燃烧实验中，得出了固硫效率与Ｍｇ／Ｓ摩尔比，温度和粒度的关系，其中镁硫摩尔比是最重要的影响因素。     

MgO 硫酸盐化反应动力学及镁基固硫剂型煤燃烧的实验研究

用ＴＧ法对ＭｇＯ硫酸盐化反应动力学进行了研究，求出了该反应的动力学参数。在以ＭｇＣＯ３为固硫剂的型煤燃烧实验中，得出了固硫效率与Ｍｇ／Ｓ摩尔比、温度和粒度的关系，其中镁硫摩尔比是最重要的影响因素。     

煤燃烧过程中硫析出特性的影响因素研究

由于煤中硫赋存形态和实际操作条件的不同,硫的析出受多种因素的影响。本文通过结合改造后定硫仪的实际燃烧条件来设计正交实验,用以考察不同因素对硫析出的影响。实验结果表明:停留时间对硫析出的影响最大,炉内温度的影响次之,空气流量的影响最小。本文并进一步分别考察了不同停留时间、炉温、空气流量等因素各自对硫析出的影响。     

梅山矿区煤中微量元素分布规律和赋存状态分析

对梅山矿区煤灰的化学成分、微量元素分布及煤灰的岩石学特征等进行了详细研究,并讨论了微量元素与三态硫、挥发分的相关性.研究结果表明,梅山矿区煤为中低磷煤,煤中U元素的含量低于地壳中的平均含量,煤中Ge和Ga的含量略高于地壳中的平均含量.煤中微量元素的赋存状态对煤炭的加工利用和燃烧工艺起着重要作用,并能为其成因提供相关地质...     

高硫煤脱硫技术及展望

高硫煤的直接燃烧会产生严重的环境污染,为此需要开发有效的高硫煤脱硫技术。介绍了我国高硫煤中硫的赋存状态和分布规律,分析了目前高硫煤脱硫的物理方法、化学方法和生物方法及目前各种脱硫方法存在的关键问题,最后对高硫煤脱硫技术的发展方向进行了阐述。     

Agglomeration of Pakistani coal (Lakhra) using diesel oil

The upgradation of a low quality coal enables it suitable for wider applications. The Lakhra coal (Pakistan) belongs to the lignite coal category. This study investigates the agglomeration technique for beneficiation of Lakhra coal using diesel oil as an agglomerant. Three parameters were investigated such as the solid–liquid ratio, residence time, and shear velocity. Characterization of the Lakhra coal before and after agglomeration was carried out in order to determine its volatile matter, fixed carbon, ash and sulfur contents, and gross calorific value. According to the results, agglomerates contained fixed carbon 35.63%, volatile matter 42.21%, gross calorific value (GCV) 5570.6 kcal/kg, ash 17.07%, and sulfur 4.03%. The ash and sulfur reductions were 42.3% and 58.4%, respectively, suggesting significant reduction in ash and sulfur compared to the original coal. The clean coal, resulting from this cleaning process, is a good grade product which may be valued as a good fuel source for any coal fired utility.     

The characterization of coal quality from the Jining coalfield

The Jining coalfield in the west Shandong Province contains coal of Permian and Carboniferous age. The 3₁ and 3₂ seams of the Permian Shanxi Formation and seams 6, 10, 15, 16 and 17 of the Carboniferous Taiyuan Formation were analyzed for coal petrogrophy, mineralogy and geochemical parameters. The coal rank parameters indicate that the coal grade is a high volatile bituminous rank. The coal of the Taiyuan Formation is characterized by high vitrinite, low to medium inertinite and liptinite contents, lower ash yield and higher sulfur content than the Shanxi Formation. These properties may be related to the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironmental conditions in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of hazardous elements in coal. The major form of sulfur in coal is pyritic sulfur. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. The sulfur content is positively correlated with pyritic sulfur.     

煤燃烧过程中SO3生成的试验研究

采用离子色谱法,在实验室小试装置中试验研究了煤燃烧过程中SO3的生成机理。测定了煤中S转化为SO3的百分率随燃烧温度、燃烧空气量、煤种、煤中含S量及添加石灰石的量的变化情况。     

Cleaning of Pakistani low-grade coal by agglomeration

This study was carried out for the beneficiation of Dukki (Pakistani) coal using agglomeration technique. The effect of six parameters, particle size, solid to liquid ratio, xylene concentration, agitation speed, agitation time, and pH, was investigated to improve the quality of coal in terms of reduced ash and sulfur content. The clean coal obtained at optimum parameters was found to have 69.25 and 26.6% reduction in ash and sulfur, respectively. The gross calorific value (GCV) increased to 6,377 kcal/kg compared with 5,300 kcal/kg in the original sample. A maximum reduction in ash and sulfur contents was achieved by the following input parameters: particle size, 100 mesh (150 µm); solid to liquid ratio, 20:80 (w/v); xylene dose, 6.8 mL; agitation time, 10 min; pH 7; and stirring speed, 2,520 rpm. Significant reduction in ash (%) and sulfur (%) showed the effectiveness for agglomeration of Dukki coal using xylene as agglomerant. The final product thus obtained may be used efficiently in various energy recovery schemes.     

Agglomeration of Makarwal coal using soybean oil as agglomerant

The study was carried out for beneficiation of Makarwal coal using soybean oil as agglomerant. The effect of six parameters – pH, mesh size of coal particles, slurry ratio, stirring speed, soybean oil concentration, and time of agglomeration – was investigated to reduce ash and sulfur from Makarwal coal and to enhance the gross calorific value. In the cleaned product obtained after the agglomeration process, the gross calorific value was increased from 4900 to 7115 Kcal/kg. The ash of agglomerates was reduced from 30% to 7.5% and sulfur was reduced from 5.4% to 2.0% The optimum operating conditions were concentration of soybean oil 10 mL, pH 9, stirring speed 2800 rpm, mesh size 200, coal to water ratio of 15:450 (W/V), and time of agglomeration 20 min. Significant reduction in ash and sulfur showed the effectiveness for agglomeration of Makarwal coal using soybean oil as the agglomerant. The final product thus obtained may be used efficiently in various energy recovery schemes.     

Recent Advances in Precombustion Coal Cleaning Processes

ＲｅｃｅｎｔＡｄｖａｎｃｅｓｉｎＰｒｅｃｏｍｂｕｓｔｉｏｎＣｏａｌＣｌｅａｎｉｎｇＰｒｏｃｅｓｓｅｓ￥Ｓｈｉａｏ－ＨｕｎｇＣｈｉａｎｇ；ＤａｘｉｎＨｅ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｃａｌａｎｄＰｅｔｒｏｌｅｕｍＥｎｇｉｎｅｅｒｉｎｇ，Ｕｎｉｖｅ...     

藤田矿区梓山组煤中硫分特征及其成因分析

基于藤田矿区地质资料进行综合分析研究,阐述梓山组煤中硫分特征,并对其成因进行分析。发现梓山中期海侵高潮时海水从西南方向浸漫至藤田,该期水体停滞所致的强还原条件是导致本区硫分形成的主要因素,另外煤层形成之后受到海相灰岩顶板影响使煤中硫含量增高且区内煤中硫分具有由西南至北东降低趋势。     

Cleaning of high sulfur Indian coal by oil agglomeration and leaching

The present paper reports an attempt for cleaning of high sulfur Indian coal with two consecutive steps of oil agglomeration at ambient temperature followed by leaching at various conditions. The physico-chemical characterizations of the raw and treated coal samples were carried out by using Fourier transform infrared (FTIR), FESEM, Thermogravimetric analysis and Differential Thermal Analysis (TGA-DTA), and petrographic techniques to assess the product quality. The petrographic and FTIR spectral analyses reveal reduction in different forms of sulfur contents in coals by the use of oil agglomeration and leaching. Scanning electron microscope morphology of the treated coal samples are attributed to the occurrence of the cavitations in the coal structure.