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21.
Jeevan S. Abichandani Yatish T. Shah Donald C. Cronauer Raffaele G. Ruberto 《Fuel》1982,61(3):276-282
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. 相似文献
22.
木材液化及其在高分子材料中的应用 总被引:9,自引:1,他引:9
木材通过液化可转化为具有反应活性的液态产物,进一步反应可以制备胶粘剂、聚氨酯材料等新型高分子材料。文章从方法、机理以及其产物在制备高分子材料等方面对木材液化的研究进展进行了评述。 相似文献
23.
Semih Eser Robert G. Jenkins Guangquan Wei Harold H. Schobert Joseph T. Joseph 《Fuel》1991,70(12):1445-1455
High pressure microdilatometer experiments were performed on a subbituminous (Wyodak) and a bituminous (Illinois no. 6) coal in helium and hydrogen atmospheres with and without added tetralin. Wyodak coal samples showed no swelling but contractions ranging between 24 and 40 vol% upon heating at 20 and 100 °C min− 1 under helium or hydrogen pressures between 150 and 1000 psig (˜1.0–6.9 MPa). Under the same conditions, Illinois no. 6 coals displayed contractions (25–60 vol%) prior to swelling up to 117 vol%. Upon tetralin addition (at 35–190 wt% of the coal), Wyodak coal samples did not swell but showed an increasing contraction with increasing helium or hydrogen pressure due to a slight softening and fusion of the coal particles. In contrast, addition of tetralin at much lower concentrations (5–35 wt%) had a marked effect on the contraction and swelling behaviour of Illinois no. 6. A maximum swelling of 200 vol% was obtained at a tetralin addition of 30 wt%. The increased swelling results from more extensive softening and fusion of coal particles in the presence of tetralin. Both coals showed a decreasing char yield with increasing tetralin concentration. The substantially lower extent of interaction observed between Wyodak coal samples and tetralin compared to Illinois no. 6 coal can be attributed to the differences in pore structure and/or chemical constitution of the two coal samples. Examination of the resultant solids by optical microscopy revealed the microstructural changes produced by thermal treatment in dilatometer experiments. 相似文献
24.
Isao Mochida Kenjiro Iwamoto Tsutomu Tahara Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):603-609
Reactivities of several coals of different ranks have been examined in degrading extractions with aromatic solvents under apparently non-hydrogenative reaction conditions. Pyrene and A240 pitch liquefied the fusible coals in high yields and the slightly-fusible coals in moderate yields, indicating the importance of fusibility in such liquefaction processes. A240-LS pitch is a powerful solvent for slightly-fusible coals. Considerable amounts of pyridine- or THF-soluble fractions were produced especially with A240-LS pitch. A240 pitch is a better solvent than pyrene for some slightly-fusible coals. However, the extent of depolymerization of liquefied coal, pyridine- or THF-solubility, was definitely inferior. Yields of such fractions are higher for lower-rank coals. The mechanism of coal liquefaction under apparently non-hydrogenative conditions is discussed with emphasis on the stabilization of thermal fragments derived from the coal. 相似文献
25.
26.
Model compound studies have shown that 1,2,3,4-tetrahydroquinoline is an exceptionally good coal solvent. In the pure compound, subbituminous coal conversion to THF-soluble products approaches 100% under relatively mild reaction conditions. The effectiveness of tetrahydroquinoline for coal conversion appears to be related to its concentration relative to coal. The unique behaviour of tetrahydroquinoline is ascribed to its being a highly active H-donor; the fact that it is regenerable under reaction conditions by the reaction of hydrogen and quinoline; and that its polarity allows penetration of the coal structure and aids in dispersion of the dissolved coal. It has been found that, during reaction with coal, tetrahydroquinoline and other nitrogen compounds undergo extensive condensation reactions which result in an increase in the nitrogen content of the high boiling and non-distillable liquefaction products. 相似文献
27.
Hydrogen transfer from donor solvent to coal must involve reactions such as hydrogen donation to free radicals and hydrogenation of aromatic structures. The relative reactivities of five typical hydrogen donor solvents, more reactive than tetralin, were determined using a competing elimination reaction in the liquefaction of a bituminous coal at 400 °C and a brown coal at 350 °C. 9,10-Dihydroanthracene, 9,10-dihydrophenanthrene and 1,2,3,4-tetrahydroquinoline exhibited outstanding hydrogen donating ability. Further, the relative reactivities of five mild hydrogen donor solvents such as acenaphthene and indan were determined by a similar elimination reaction using a bituminous coal at 450 °C. 相似文献
28.
To obtain fundamental information about hydrogen transfer, the relationships between hydrogen donor ability and chemical structure of model compounds representing donor solvents is studied using gas chromatography,1H n.m.r. and computing calculation methods. The order of the model compounds in terms of the ability as donor solvent to release hydrogen is: decalin < tetralin < 1,2-dihydronaphthalene < < 1,4-dihydronaphthalene. This trend closely correlates with the difference in binding energies of the hydroaromatic compounds and their radicals, determined by intermediate neglect of differential overlap (INDO) calculation. Electron spin resonance spectroscopy (e.s.r.) confirms that radical species are created after heat-treatment of the donor compounds. The ability of model compounds representing coal to accept hydrogen is assessed from a comparison of the1H n.m.r. spectra. It is established that donor and acceptor efficacies are dependent upon chemical structure. 相似文献
29.
通过对改进一次二阶矩可靠性分析方法进行研究,提出了一种基于标准贯入击数极限状态方程的地震液化可靠度评估方法,并用Matlab 7.0编制了相应的地震液化概率判别程序。用该可靠性分析方法对1976年河北唐山大地震的资料进行了液化概率分析,并与实测值和规范判别法计算结果进行了对比。结果表明:该方法具有可行性和精确性,为砂土液化势评估提供了一种有效的新方法。 相似文献
30.
阐述了国内外利用直接热化学液化法处理污泥的研究进展和应用前景,并介绍了将其转化为油的典型液化工艺及其影响油产量的主要因素,阐明此种方法的发展趋势,并指出资源化利用和能源回收应该是今后污泥处置的方向. 相似文献