模型化合物的煤液化研究中的应用

本文主要论述了目前世界上应用模型化合物研究煤液化过程的概况。研究内容包括：全煤结构经合物的研究，煤液化时桥键裂解过程的作用，氢转移及煤和溶剂之间的相互作用，以及利用模型化合物考查煤液化中缩聚反应的研究等。并指出利用模型化合物研究煤液化的局限性。     

煤液化基础研究进展

综述了煤结构、煤相关模型化合物反应及煤与生物质共液化的研究进展 .着重讨论了煤结构的研究方法、煤的物理结构及煤分子结构的发展情况 ,供氢溶剂、金属及其硫化物在煤液化中的作用 ,模型化合物的分子结构和反应性的关系及模型化合物反应的动力学 ,煤与废塑料和木屑共液化等 .指出基于煤分子结构和煤液化理论研究的突破 ,可望开发出可行的煤液化工艺 ,实现煤的高附加值转化 .     

溶剂对二苯甲烷氢化裂解的影响

溶剂对二苯甲烷氢化裂解的影响人们已广泛研究了各种氢化芳香族化合物对煤液化及模型化合物反应的供氢能力。传统的观点认为，供氢溶剂通过稳定热分解生成的自由基对煤液化起着促进作用，催化剂借助于供氢溶剂促进气相氢分子向煤转移，在这一过程中供氢溶剂起着氢的运载工...     

两种煤液化残渣氧化萃余物中有机化合物的分析

在40 oC恒温水浴下用次氯酸钠用Na Cl O对两种煤液化残渣进行氧化,利用GC/MS手段分析了氧化萃余物中化合物的组成和结构特征,检测到的化合物主要包括酯、酮、酸和一些杂原子化合物。同时阐述了煤液化残渣中结构组成常用的研究分析手段,为研究煤液化残渣的性质及高附加值利用提供了有益的信息。     

煤直接液化低分油加氢脱硫脱氮反应动力学研究

为了进一步了解煤直接液化油中硫氮化合物的形态和性质,采用石油研究中的先进分析手段GC-PFPD和GC-NCD,对煤直接液化低分油进行了分析,获得了详细的硫氮化合物组成含量。结果发现:煤直接液化低分油中含有大量的杂环化合物,S主要以苯并噻吩类和二苯并噻吩类化合物存在,N主要以五元环化合物形式存在。在高压釜中进行了催化剂添加量和不同温度条件下的加氢实验,对总硫总氮的加氢反应动力学进行了研究。通过计算得到了高压釜煤液化油加氢脱硫反应的一级反应动力学模型,且通过模型计算的S含量与反应实测的S含量相对误差仅为7.8%;对实验得到的震荡式高压釜中煤液化油加氢脱氮反应的一级反应动力学模型进行验证,发现相对误差也仅为0.97%。     

煤直接液化动力学模型及其研究进展

简述了煤直接液化机理,详细介绍了煤直接液化动力学模型及其研究方法,包括单组分分析模型、多组分分析模型及煤液化过程的分段处理研究。通过对煤直接液化动力学模型研究进展的综述,认为近年来煤直接液化动力学的主要发展方向之一是通过分段处理,并根据多组分"集总"反应模型来处理煤直接液化动力学模型。     

煤炭直接液化产品油中酚类物质分析与提取

酚类物质煤液化油中占绝对多数的含氧化合物,也是目前的煤液化油中附加值最高的一类化合物。以开发酚类副产品为目标,顺序研究煤液化油中酚类物质组成和提取方法,是拓宽煤液化油利用方式,实现煤液化油综合利用的重要工作之一。文中归纳了已应用于定性定量煤液化油中酚类物质的各种分析方法,并简要介绍分析结果。总结介绍了从煤液化油中提取酚类物质的各种方法,比较了各种方法了优缺点。对后续开发更为准确的煤液化油中酚类物质分析方法和高效便捷的提取方法具有借鉴意义。     

煤中低分子化合物及对煤炭转化性能的影响

介绍了煤中低分子化合物的组成和来源、几种煤化学结构模型以及低分子化合物的主要研究方法。温和条件下的溶剂萃取和有机波谱法是研究煤中低分子化合物的有效方法,低分子化合物游离或镶嵌在煤大分子主体结构中,明显影响煤的成焦性能、加氢液化以及其他加工转化性能。     

煤炭液化技术的研究

煤炭液化是将煤转化为液态燃料及软化为高品质化学品的利用方式。石油的供需矛盾使我国对煤炭液化技术的需求更加紧急,且煤液化产物中分离出具有特殊结构的化合物用作高附加值化学品及聚合材料的原料,经济效益可观。本文围绕煤液化技术为出发点,分析了煤炭资源现状与存在问题,重点阐述了煤液化技术和煤液化残渣的性能与利用,指出了煤液化技术面临的问题和发展前景。     

煤直接液化油中硫氮化合物的类型分布

为研究煤直接液化油中硫氮化合物的类型分布,根据煤直接液化油的特点,采用GC-PFPD和GC-NCD方法分别优化煤直接液化油中硫氮化合物的分析条件,获得了煤直接液化油中硫、氮化合物的组成及含量。结果表明,煤直接液化油中硫主要以苯并噻吩类和二苯并噻吩类化合物存在,两者占原料油中总硫含量的90%以上,是煤直接液化油加工脱硫的主要对象;煤直接液化油中氮主要以五元杂环含氮化合物形式存在,占比32%,主要代表物质是吲哚类和咔唑类化合物,两者占原料中总氮含量的50%左右,是煤直接液化油加工脱氮的主要对象。     

Effects of ion-exchanged calcium, barium and magnesium on cross-linking reactions during direct liquefaction of oxidized lignite

In this work the influences of alkaline earth metals on cross-linking reactions (CLRs) during direct liquefaction of lignite were investigated. The oxidized lignite, which has been proved to be appropriate for quantitatively examine the extent of CLR during direct liquefaction, was used as a model coal to study the effects of ion-exchanged calcium, barium and magnesium on CLR during direct liquefaction of the oxidized lignite. The amounts of tetrahydrofuran (THF) insoluble solid products after liquefaction were used to quantitatively evaluate the CLR during liquefaction of the ion-exchanged coal. The results show that the oxidized coal is appropriate to quantitatively examine the extent of CLR and the targeted ions are exchanged to the oxidized coal in the form of highly-dispersed ion. The ion-exchanged Mg^2 + suppresses the CLR during direct liquefaction of coal at both low and high temperature. However, the exchanged Ca^2 + always promotes the CLR at the selected temperatures. While the exchanged Ba^2 + promotes the CLR at low temperature, but suppresses it at high temperature.     

煤炭直接液化油中酚类化合物的分离与利用

酚类化合物是煤炭直接液化产物中具有较高附加值的主要含氧化合物,也是煤液化油酸性物质的主要成分。它不仅对油品的提质加工的技术路线有影响,而且也对煤炭直接液化的经济性具有较大的影响。由于该方面的研究工作尚属起步阶段,借鉴煤焦油和石油系产品中酚类化合物的有关分离与利用情况,结合笔者的研究实践和认识,提出了在煤直接液化油中酚类的分离与利用方面应开展的工作和研究方向。     

The characterization of asphaltenes and preasphaltenes obtained under various coal liquefaction conditions

A CP-MAS ¹³C NMR study of asphaltenes and preasphaltenes obtained under various coal liquefaction conditions is reported. The carbon aromaticity, f_a, of the solid extracts from the reaction products has a close relation with the reaction conditions. By plotting f_a against the atomatic $\text{H}\text{C}$ ratio for these solid products on the characterization chart for model polycyclic aromatic compounds, the molecular structures with relation to the liquefaction pathway from coal to oil can be proposed.     

Kinetics of thermal liquefaction of coal

A model is presented for the kinetic study of the thermal liquefaction of Belle Ayr subbituminous and Burning Star bituminous coals with anthracene oil, hydrogenated anthracene oil and hydrogenated phenanthrene. All experiments were performed in a continuous-feed, stirred tank reactor, at a temperature of 450 °C and a space time of approximately 5 to 55 min. A kinetic model which includes a reaction: coal + oil→more reactive coal, correlates the data reasonably well. This reaction explains the net consumption of anthracene oil during the initial stages of liquefaction. Such a reaction may account for a portion of the swelling of coal at low space times and the sizable increase of viscosity of reaction slurry during these initial stages of liquefaction. It is also observed that the yield of oil increases when solvents of increasing hydrogen donor capacity are used.     

液化条件下煤中共价键断裂难度降低原因分析

通过对四十余种常见煤液化模型化合物键能的分类、排序与分析,发现仅桥键的热致裂解远不足以让煤直接液化的转化率达到常见的70%以上的转化率.除了由于煤的高芳香性导致共振稳定和反应时间延长导致活化能量积累作出贡献以外,还有三个因素对桥键的广泛断裂和煤液化的高转化率作出了贡献,即溶剂、氢压和矿物质等催化剂.     

Effects of solvent and iron-compounds on the liquefaction of brown coal

Hydrogen-donor solvents such as hydrophenanthrene are the most effective aromatic solvents for the liquefaction of brown coal. The hydrogen-donating ability of the solvent is more important for brown coals than for bituminous coals, because the thermal decomposition and subsequent recombination of the structure of the brown coals occurs rapidly. Three-ring aromatic hydrocarbons are more effective solvents than two-ring aromatics, and polar compounds are less effective solvents with brown coals than with bituminous coals. The thermal treatment of brown coal, accompanied by carbon dioxide evolution at temperatures > 300°C, in the presence of hydrogen-donating solvent did not affect the subsequent liquefaction reaction. However, thermal treatment in the absence of solvent strongly suppressed the liquefaction reaction, suggesting that the carbonization reaction occurred after the decarboxylation reaction in the absence of hydrogen donor. To study the effect of various iron compounds, brown coal and its THF-soluble fraction were hydrogenated at 450°C in the presence of ferrocene or iron oxide. The conversion of coal and the yield of degradation products are increased by the addition of the iron compounds, particularly ferrocene, and the yield of carbonaceous materials is decreased.     

Prediction of coal liquefaction reactivity by solid state 13C NMR spectral data

A method for the deconvolution of ¹³C NMR spectra of coals has been developed by using coal-like model compounds and various lithotypes separated from Yallourn brown coal which is rich in various types of oxygen-functional groups. The spectrum of coal was resolved into 24 peaks which were classified into nine types of carbon-functional group. This analytical method can be applied to all ranks of coal from lignite to anthracite. In addition, the liquefaction data of seven kinds of coal collected from five different countries were obtained by the operation of 1 t/d process support unit and 150 t/d pilot plant NEDOL process liquefaction plants. A good correlation was obtained for every reaction product between structural data derived from solid state ¹³C NMR spectra and liquefaction data of coals. This means that the yields of liquefaction products could be predicted from ¹³C NMR spectral data of coal.