Rheological characteristics of coal tar and petroleum pitches with and without additives

An extensive study of rheological characteristics of coal tar and petroleum pitches with and without additives, namely, petroleum coke, natural graphite and carbon black has been made. It is found that all pitches, pure or mixed with a carbon additive are not Newtonian as reported in the literature, but behave Theologically as Bingham plastics with certain yield stress and plastic viscosity at all temperatures of measurement between 85–180°C. The yield stress and plastic viscosity both decrease with increase in temperature of the pitch. A pure petroleum pitch having the same softening point as that of a coal tar pitch is found to have a lower viscosity compared to that of the latter at all temperatures of measurement. This suggests that the criterion of softening point as a measure of suitability of a coal tar pitch binder in the manufacture of artificial carbon is not sufficient for petroleum pitches. Addition of ten parts of carbon black by weight of pitch results in a considerable decrease in viscosity change with temperature of the coal tar pitch compared to almost insignificant change in the case of the petroleum pitch of the same softening point. However, the addition of petroleum coke or natural graphite makes the pitch more viscous but does not change the temperature dependence of viscosity of either of the two types of pitches. The implications are discussed.     

煤沥青基功能碳材料的研究现状及前景

我国煤沥青资源丰富,但深加工技术落后,产品附加值低,实现煤沥青高附加值利用是亟待解决的重大课题。本文介绍了以煤沥青为原料合成高性能功能碳材料的主要技术,重点阐述了以煤沥青为原料制备中间相沥青、多孔碳材料、碳纤维、二维纳米碳材料及碳基复合材料的研究进展。分析表明,高芳香性和高缩合度分子结构所引起的强π-π相互作用是阻碍煤沥青基高性能功能碳材料设计合成的瓶颈问题。通过催化聚合、氧化、共热解等技术手段可有效改善煤沥青分子结构及其物理、化学性质。结合模板复制、物理/化学活化、界面诱导以及催化石墨化等技术可实现多种功能性碳材料结构设计与表面化学性质调控。发展煤沥青分子结构调控新技术作为改善煤沥青基碳材料性能的重要策略,需要系统深入研究。     

Wood-Derived Tar as a Carbon Binder Precursor for Carbon and Graphite Technology

In addition to the many benefits of coal tar pitch, these materials are known to contain polycyclic aromatic hydrocarbons. For this reason, studies are being developed to elaborate new, ecologically friendly, alternative binders for carbon–graphite technology. This article presents the results of wood tar recovered during thermal degradation of selected types of woods as alternative binders in the manufacture of carbon materials. Two kinds of wood tars obtained from different raw materials were analyzed. Sawdust thermal conversion makes it possible to obtain carbon binders with a lower coking value and quinoline-insoluble matters in comparison to coal tar pitch. These binders produce significantly reduced emissions of polycyclic aromatic hydrocarbons in carbon–graphite technology. Carbon samples manufactured using wood-derived binders with carbon fillers showed similar density and mechanical compression strength values compared to those based on conventional coal tar pitch binders.     

溶剂效应对脱除煤沥青中3,4-苯并芘的影响

研究了单种溶剂、混合溶剂对3,4-苯并芘的溶解选择性及煤沥青溶解量。并以顺丁烯二酸酐为改性剂、硫酸为催化剂,考察了溶剂效应对降低煤沥青中3,4-苯并芘的影响。研究表明,环己烷、甲苯,环己烷、乙酸丁酯组成的混合溶剂具有较好的3,4-苯并芘溶解选择性和合适的煤沥青溶解量。当环己烷∶甲苯=2∶1（体积比）和环己烷∶乙酸丁酯=2∶1（体积比）为反应溶剂时,能够高效地脱除煤沥青中3,4-苯并芘,煤沥青中3,4-苯并芘降低率分别达到88.26%和90.83%。其原因认为是此类溶剂能使包裹在沥青颗粒内部的3,4-苯并芘释放出来,且3,4-苯并芘与改性剂能够形成均相反应体系,大部分不具有致癌性的高相对分子质量环芳烃与改性剂之间形成两相体系,从而提高了改性剂与3,4-苯并芘的有效反应。     

碳纤维用基体前驱体煤沥青的改性研究

煤沥青经喹啉萃取后,以三氟化硼乙醚和硝基苯作为催化剂,在氮气氛下热缩聚制得改性沥青,并对改性沥青的工艺进行初步研究;利用FT-IR、热分析仪对改性沥青的结构和热稳定性进行了分析。结果表明改性后沥青脂肪族侧链明显减少,芳构化程度增加,热失重率减小,适合用于制备碳纤维。     

压力对溶剂法脱除焦油沥青中固体颗粒物的影响

精制沥青是制备各种功能炭材料的前体,焦油沥青需要预处理脱除其中的固体颗粒物（称为喹啉不溶物,QI）以得到精制沥青,压力是脱除QI的重要条件。本文以煤焦油沥青和添加生物质沥青的混合沥青为原料,研究压力对溶剂法脱除固体颗粒物的影响,测试不同压力下精制沥青的QI含量及产率,利用纳米粒度分析仪、扫描电子显微镜和高温黏度测定仪对QI颗粒形貌、粒度及脱除体系黏度进行表征和测定,分析压力对固体颗粒物絮凝沉降的影响规律。研究结果表明,增加压力对沥青收率升高有明显影响,使精制煤焦油沥青的收率由常压的64.6%（质量分数）提升至1MPa时的84.3%（质量分数）,精制沥青的QI含量维持在0.06%~0.1%（质量分数）之间。添加15%生物质沥青的混合沥青,产率则由常压时的55.7%（质量分数）提升至1MPa时的72.5%（质量分数）。压力对精制沥青的QI含量影响较小,压力增大,溶剂对沥青组分尤其是重质组分的溶解能力增强,使精制沥青产率升高。较高压力也使体系的黏度略微增大,造成部分QI颗粒沉降困难,不过影响较小。中间相沥青制备的结果表明,精制沥青可以制备出具有流域型结构的中间相沥青,添加生物质沥青更好地改进了流域型的显微结构。     

煤沥青改性后流变性能的变化分析

为了探讨对苯二甲醛(TPA)对煤沥青改性后流变性能的变化,采用旋转黏度计测定了煤沥青及TPA改性的煤沥青的表观黏度,研究了表观黏度与温度的关系;采用示差扫描量热法研究了煤沥青和TPA改性的煤沥青的热行为。结果表明,TPA改性的煤沥青的黏度与温度的关系曲线呈现W型,在200℃～225℃处于低黏流区,表观黏度值200mPa.s～400mPa.s,可以作为浸渍剂煤沥青使用;TPA改性的煤沥青在高于225℃时,表观黏度值迅速上升;TPA改性的煤沥青在低黏度区域具有较低的活化能,这对煤沥青的浸渍工艺有益。     

贫煤与煤沥青共炭化研究

进行了不同配比的煤沥青和贫煤的共炭化研究,研究表明,煤沥青与贫煤共炭化时的相互作用是物理融合和化学相互作用的共同作用。其中物理融合表现在使焦炭界面结合状态改善,化学相互作用表现在煤沥青使贫煤的炭化性能发生变化。随煤沥青配比的增加,配煤黏结性有较大改善,焦炭OTI值增大,ISO值减小。煤沥青通过增大焦炭光学组织各向异性程度,使焦炭的反应性降低,反应后强度提高。     

炭材料用改性煤沥青的结构及性能研究

进行了对甲基苯甲醛(4-MB)改性煤沥青(CTP)的中间相微观结构研究.采用偏光显微镜研究4-MB改性煤沥青的光学结构;采用扫描电镜(SEM)观察改性后煤沥青的形貌.研究结果表明,改性煤沥青的光学组织结构显著改善,随交联剂4-MB用量的不同,可得到超镶嵌(SM)、广域(D)和小域(SD)三种光学结构;改性后煤沥青出现纤维结构,煤沥青的残碳率显著提高.因此,改性后的煤沥青有望作为优质的炭材料基体前驱体.     

“无钠低灰”煤沥青对预焙阳极质量的改善

介绍了山西焦化股份有限公司采用德国进口超级离心机脱水脱渣,引进法国IRH先进的后加碱煤焦油加工技术,生产的"无钠低灰"煤沥青产品质量指标。详细阐述了煤沥青在预焙阳极生产中的作用,重点分析了煤沥青中的灰分和钠离子对预焙阳极质量的影响。通过分析"无钠低灰"煤沥青的灰分及钠离子含量的数据,预测在电解铝过程中,该煤沥青可降低阳极炭耗约15kg/t铝,为优质煤沥青的利用找到一条出路。     

煤焦油沥青乳化用作燃料油的研究

用软化点为 38.5℃的软沥青作原料 ,在合适的工艺条件下 ,制成含沥青 6 0 %～ 70 %的沥青乳液 (乳液的沥青含量为沥青量与洗油加入量之和 )。该乳液具有流动性好、储存稳定等优点。本研究结果表明 ,沥青乳液可以用作燃料 ,对解决煤沥青的利用具有重大意义     

复合纳米材料的制备及对路用煤沥青的改性研究

通过水热共沉淀法制备了改性纳米复合材料,利用比表面积、TEM和接触角对其进行了表征。将改性纳米复合材料应用于路用煤沥青的改性中,结果显示该纳米改性煤沥青的性能指标完全达到了90#路用石油沥青指标,可以应用于实际道路的铺设。     

对甲基苯甲醛改性煤沥青的研究

以对甲基苯甲醛 ( 4 - methyl benzaldehyde,简称 4- MB)为改性剂 ,在对甲苯磺酸( PTS)的作用下对煤沥青进行了改性研究 .采用傅立叶红外光谱 ( FT- IR)和核磁共振氢谱 ( 1H-NMR)对煤沥青改性机理进行分析 ;采用扫描电镜 ( SEM)观察改性后煤沥青的形貌 ;采用光学显微镜观察改性沥青热解产物的光学结构 .结果表明 ,对甲基苯甲醛在酸性催化剂的催化作用下与煤沥青发生亲电取代反应 ,改性后煤沥青出现纤维结构 ,改性沥青热解产物的光学组织结构为较好的广域 ( D)结构 .因此 ,改性后的煤沥青有望作为优质的炭材料基体前驱体 .     

The influence of the type of quinoline insolubles on the quality of coal tar binder pitch

Seven pitches containing three types of quinoline insolubles, QI, were produced from a single coke oven coal tar. The tar was centrifuged into QI-rich and QI-lean fractions. A blend of the two fractions yielded a typical graphite electrode binder pitch. The QI content of the pitch derived from the QI-lean tar was increased through the addition of natural QI concentrate, or QI as a furnace carbon black, or QI as mesophase by means of heat treatment. The pitches were evaluated as binders by measuring the flexural strength of 19 mm diameter graphite electrodes. The results show that the typical electrode pitch is superior, and that increasing the QI content of the QI-lean material did not upgrade it. The results also show that the flexural strength of the derived graphite is not simply related to the coking value of a binder.     

Production of petro/coal tar pitch by joint distillation of coal tar and heavy pyrolytic oil

The properties of petro/coal tar pitch and distillate fractions obtained in the joint distillation of coal tar and heavy pyrolytic oil from ethylene production are described. The petro/coal tar pitch is particularly reactive in heat treatment and air-blowing. The petro/coal tar pitch may be used as less carcinogenic binder and impregnating electrode pitch.     

煤沥青流变性能初探

系统地研究了煤沥青的流变规律，以大量的图、表和算式对沥青流变性的规律进行了详细说明。并找出了煤沥青粘度随温度变化的一般规律，首次将煤沥青粘度随温度变化的整个过程划分为三个区间，以便准确地掌握其变化规律。     

Carbonization behavior of hydrogenated ethylene tar pitch

Carbonization behavior of ethylene tar pitch has been studied with respect to mesophase formation by means of modification of the chemical composition of the starting materials. The hydrogen treatment of ethylene tar pitch has been carried out over the temperature range from 473 to 673 K under a pressure of 10 MPa without catalyst. Then, the hydrogenated ethylene tar pitches were carbonized at 723 K and the optical texture of the resultant cokes were assesed by optical microscopy. It was revealed that the carbonization of the ethylene tar pitch hydrogenated at 673 K gives a coke of optical texture with enlarged flow-domain. The hydrogen-transfer ability of the ethylene tar pitches during the temperature range of mesophase formation was estimated by the method of 9,10 dihydroanthracene (DHA) formation through co-carbonization of the pitch with anthracene. It was recognized that the larger the amount of conversion of DHA, the better is the development of optical texture.     

煤焦油沥青深加工利用综述

概述了国外煤焦油沥青深加工利用现状 ,并对改质沥青 (浸渍剂、粘结剂 )、筑路沥青、涂料、碳纤维、针状焦等煤沥青深加工产品的技术开发、生产及应用进行了分析     

纳米改性路用煤沥青的试验研究

利用纳米材料对路用煤沥青进行改性,考查了纳米材料,高分子聚合物,温度,分散方式对煤沥青的性能影响,得到了改性路用煤沥青的优化工艺和配方,可应用于实际道路的铺设。     

三种不同原料中间相沥青的性质表征

为更深入地理解不同原料制备的中间相沥青的性质差别,从挥发分、饱和度、分子量分布、有序度的角度研究了以萘、煤沥青、精制煤液化沥青（DCLR）为原料的3种中间相沥青,分析手段包括偏光显微镜、元素分析、TGA、红外光谱（FTIR）、MALDI-TOF MS、XRD、拉曼。结果表明：萘系中间相沥青分子量最高且分布窄,挥发分低,饱和基团含量高,分子柔性大,平面性和规整性较差,分子堆砌紧密度较低,有序度较差,因此具有较低的软化点和广域流线型光学组织结构;煤系中间相沥青分子量较高,分布最宽,挥发分高,饱和度低,烷基侧链少,分子刚性和平面性较大,易堆积成紧密结构,因此具有较高的软化点,流动性差,较难形成流线型光学组织结构;DCLR系中间相沥青分子量低且分布窄,挥发分较高,含有一定量的饱和基团,分子具有一定的韧性,分子刚性和规整性较好,有序度高,因此流动性较差,软化点较高。