煤加氢液化制取芳烃研究进展

芳烃化合物是一类主要有机化工原料，目前主要从石油化工中获得．我国石油资源紧缺已成为生产芳烃的瓶颈，而煤由于其特殊的芳香性，在一定条件下经加氢液化后得到主要富舍芳烃的液体产品，有望成为石油代替和减缓石油供需矛盾的有效途径之一．对煤加氢液化制取芳烃的可能性、加氢液化工艺进展、煤液化油的组成以及液化油如何制取芳烃的方法等进行了综述和讨论，为进一步开展这一领域的研究工作奠定了基础．     

煤加氢液化制取芳烃可能性探讨及当前进展

从煤的结构特点、液化机理等方面,对煤加氢液化制取芳烃,进行了可行性探讨,并简述了其当前的发展状况。     

固相萃取分离煤直接液化全馏分油族组成研究

煤直接液化全馏分油组成复杂,深入认识煤直接液化油化学组成时,一般要分离成饱和烃、芳烃、胶质等不同的族组分,然后再对每一组分进行详细的分析表征,固相萃取是快速、高效分离油品族组成的方法之一。根据煤直接液化全馏分油的特点,重点研究了固相萃取法分离煤直接液化油族组成时,固相萃取材料与样品重量比、饱和烃洗脱溶剂加入量、溶剂洗脱速率等对煤直接液化油中饱和烃和芳烃组分分离效果的影响,获得了最佳分离条件。     

煤及煤液制取芳烃高聚物的发展与机遇

近年来，先进的高聚物新型芳香工程塑料、耐热塑料和液晶高聚物与膜材料的开发与应用取得了重大进展。这些塑料的单体来自１环到４环的芳烃化合物，都能由煤和煤液中取得，如烷基苯、萘、联苯、蒽、菲、芘、酚类和咔唑等，其中特别重要的单体有２，６－二烷基萘，４，４＇－二烷基联苯和１，４－二烷基苯。探索由煤及煤液来制取芳香高聚物的工艺路线和方法是十分重要的，因为从石油和天然气来制取这些材料相当困难。作者根据国外的最新文献编译了此文，主要阐述开发煤及煤液制取芳烃高聚物的机遇。这种高价值化学制品和材料将大力促进高科技的发展。这样，就需要对煤建立新的概念。到下世纪，煤化学学科将出现一个新分支。     

煤炭直接液化技术研究

我国煤炭直接液化技术研究已达到国际先进水平．兖州、天祝、神府烟煤和先锋．沈北、东胜褐煤都是较好的直接液化原料煤。煤直接液化的馏分油最适宜生产高辛烷值汽油、优质喷气燃料和催化重整制取芳烃原料油．两段催化液化由1t无水无灰煤生产5bb1馏分油．煤油共炼与直接液化相比较，简化了工艺过程，改进了馏分油产率和质量。我国煤直接工艺发展方向是煤油共炼或两段催化液化工艺。     

神府煤液化油石脑油馏分重整生产芳烃的研究

由于煤液化油石脑油馏分(200℃)中芳烃潜含量较高,利用煤液化油石脑油馏分为原料,进行加氢精制,将原料中的硫氮含量降至1 mg/kg左右,满足重整进料要求,然后在小型固定床连续反应器上进行加氢重整生产芳烃试验。着重考察重整反应前、后族组成的变化及主要芳烃化合物的产率。结果表明,加氢重整过程中发生正构烷烃异构化反应;环烷烃主要发生脱氢芳构化反应转化为芳香烃;煤液化油石脑油馏分适宜进行催化重整,C_1~C_4烃气产率6.03%,氢气产率3.60%;重整后,芳烃含量达83.20%,其中C_6~C_8芳烃含量61.03%,是提取BTX的良好原料。石脑油的馏程对芳烃的组成和产率有一定影响,适宜的馏程为60~160℃。     

关于煤制芳香化合物的探讨

由煤制取高附加值芳香化学品是实现煤的清洁高效利用的有效途径,在对国内外相关研究现状分析的基础上,对煤的快速热解技术、煤热解物定向催化转化技术和煤加氢液化技术制取芳香化学品技术进行了探讨,提出了由煤制取高附加值芳香化学品的新思路。     

由煤制石脑油生产芳烃

煤催化加氢液化的石脑油馏分适于用石油工业催化剂加氢精制和催化重整方法来生产高辛烷值汽油和芳烃化工原料。本试验研究了加氢精制和催化重整的煤制石脑油主要化合物含量,列出生产芳烃流程,发现煤制石脑油终馏点影响催化重整转化率。     

煤与生物质的共热解液化研究进展

煤与生物质共热解液化将是燃料与化学品重要的转化技术之一。本文从共热解液化机理、共热解液化反应动力学、煤与生物质的协同作用、催化剂、共热解液化工艺、共热解液化产物等方面对煤与生物质共热解液化研究进展进行了综述,指出煤与生物质的快速共热解液化将是重要的发展方向,催化剂的应用和液化产物的精制将对提升液化油的品位和降低成本,对实现共液化油替代现行石化液体油具有更重要的意义。     

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。     

Coal dissolution in high boiling process solvents

The liquefaction of a bituminous coal has been studied using distillate and non-distillable, coal-derived solvents. Different classes of solvent components can interact non-additively during reaction with coal to either promote or retard the process of coal dissolution. Above certain concentrations, polyfunctional compounds in heavy coal-derived liquids effect a measurable reduction in coal conversion and product selectivity by accentuating the degree of condensation reactions. Substantial removal of these compounds can be achieved by precipitation in a paraffinic solvent. Retrogressive reactions are reduced and positive synergistic interactions can be realized by the blending of heavy solvents with selected components, such as polycondensed aromatics, and with lower boiling, hydrogen-donor species.     

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.     

Nitrogen bases in solvent-refined coal

The basic components contained in a coal liquefaction product obtained from the Wilsonville, Alabama coal liquefaction pilot plant were examined by means of capillary-column Chromatographic-mass spectroscopy. A total of 62 of the 150 components observed were identified. The most interesting of the newly identified compounds are phenoxazine, butyl quinolines and isoquinolines, diarylamines and aminobiphenyl derivatives. The possibility of removing amino aromatics from coal liquefaction products by condensing them with the phenols in the mixture is discussed.     

Effect of cresol as a co-solvent in coal liquefaction and product analysis

The influence of o-cresol on conversions of Bruceton coal to tetrahydrofuran (THF) extract was determined over the full range of composition for mixtures of o-cresol with either tetralin, phenanthrene, anthracene or pyrene. A maximum was found in both of the plots of coal conversion versus cresol content for mixtures with phenanthrene or pyrene. By comparison, the conversion found in pure tetralin was significantly higher than those found in the polynuclear aromatics and was not increased by addition of o-cresol. The enhancement of conversion by addition of cresol to the polynuclear aromatics was determined to be due to its action during the liquefaction itself, and not due to any influence exerted on post-liquefaction product separation. The relationship of these results to other studies showing the effect of cresol on both liquefaction chemistry and on post-liquefaction product work-up is discussed.     

Effect of coal minerals on the thermal treatment of aromatic ethers and carbonyl compounds

To elucidate the effect of mineral matter in coal on coal liquefaction, the thermal decomposition of some model compounds of coal structure, aromatic ethers and carbonyl compounds, has been carried out in tetralin solvent and in the presence of coal ash obtained by low temperature combustion. The conversion of benzyl phenyl ether and dibenzyl ether was considerably enhanced; alkylated products such as benzyltetralin were obtained. The conversion of phenoxyphenanthrene and phenoxynaphthalene also was increased to some extent in the presence of coal ash. These effects can be attributed to the acidic components of coal minerals, because silica-alumina has shown the same effect, which is suppressed by quinoline. The addition of coal ash increases the yield of hydrocarbon from the corresponding aromatic carbonyl compounds by reduction. This effect is attributable to iron sulphide.     

从低阶煤直接制取苯类产品的项目研究

基于市场对粗苯的需求,进行以低阶煤为原料直接制取粗苯的研究。我国低变质程度煤炭资源丰富,且储量巨大,选择性地对某些低阶煤在一定的溶剂、催化剂、温度、压力条件下加氢液化,可得到含芳香烃较高的油品,经过重整精馏可进一步得到苯、甲苯、二甲苯等产物。初步探讨了低阶煤加氢液化制粗苯的工艺过程和过程条件。     

低温煤焦油中特定芳烃组分的选择性分离

以研究低温煤焦油中特定芳烃组分的选择性分离为目标, 通过预处理分离酚类化合物和富集特定芳烃组分, 采用多元溶剂萃取方法选择性分离芳烃和非芳烃组分, 采用Hansen溶度参数理论进行多元溶剂的设计和萃取条件的优化。结果表明, 溶剂对原料焦油的选择性随Hansen溶度参数“距离”(R_a)增加而增大, 萃取能力则相反。研究得到的多元萃取剂是含水量为体积分数6%的N,N-二甲基甲酰胺溶液, 优化萃取条件是温度25℃、剂/油比6:1。萃余物经多次萃取进一步分离芳烃组分, 萃出物经甲酰胺多次萃取以分离出杂环化合物和极性组分。芳烃组分在最终分离产物中的质量分数为94%, 其总萃取收率为95%。另外非芳烃化合物、杂环化合物和其他极性组分也在本过程中得到了有效富集。     

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。     

煤直接液化研究评述

比较了中国与国际基础研究水平的差距,对主要的新老工艺进行了分类和比较,发现成功的液化工艺都符合煤分子结构的特点。高温快速液化是一种基于煤分子结构特殊性的直接液化方案,在理论上提供了实现最高液化效率和最低液化成本的可能性,联产芳香族化合物和燃料油,开辟了一个新的研究方向。