Composition of an SRC-II coal-derived liquid: Changes in composition resulting from hydrotreatment at different levels of severity

An SRC-II coal-derived liquid fuel and eight upgraded coal liquids derived from it were separated into chemical class-type fractions by preparative liquid chromatography. Mass and infrared spectroscopy, gas chromatography and non-aqueous titration were used, together with the mass balance data from the l.c. separations, to describe changes in composition of the liquids as a function of severity of hydrotreating conditions. The relative abundance of the following classes of compounds was determined in each of the liquids : saturates, monoaromatics, diaromatics, polyaromatics, total acids, total bases, hydroxyarenes, strong acids, pyrrolic benzologs, carbonyl compounds (amides), basic diarylamines, basic monoarylamines, azaarenes, and strong bases. The results are discussed in the light of known reaction pathways for aromatic ring saturation and heteroatom removal.     

Stability studies of coal-derived liquids

The ageing characteristics of liquid products derived from the hydrogenation of coal have been studied. Viscometric, spectrometric, ultimate analysis, solvent separations and oxygen consumption measurements have been employed to monitor the storage properties of the coal-derived liquids under a variety of environmental conditions. These studies show that the coal-derived liquids are very susceptible to oxidative degradation. Rates of this degradation process, based on viscosity measurements, are related to the initial viscosity of the coal-derived liquid, storage temperature and concentration of oxygen in the gaseous environment over the liquids. Analysis of aged samples show the components of higher molecular weight with functional components are most susceptible to the oxidation process. Although the total coal-derived liquids are more susceptible to oxidative degradation than the petroleum-derived boiler feedstocks, removal of the most reactive components from the coal-derived liquids, by solvent separation, results in a fuel that has analogous stability characteristics as the petroleum products.     

Viscosity of coal-derived liquids

A coal-derived liquid was separated into toluene insolubles, asphaltene and pentane soluble oil by conventional solvent analysis. The asphaltene was separated further into an acid-neutral and a basic component by a previously reported procedure from our laboratory. The viscosities of liquids reconstituted from toluene insolubles, asphaltenes, acid-neutral asphaltene or basic asphaltene in the pentane soluble oil were determined. The logarithm of the viscosity ratio is a linear function of concentration for each of the solutes. On a weight basis, the toluene insolubles produce about twice the viscosity as the asphaltenes. The viscosity of mixtures of acid-neutral and basic asphaltene in pentane soluble oil is greater than either component determined separately, presumably due to complex formation. The variation of the reduced specific viscosity with concentration indicates that aggregation of the asphaltene and toluene insoluble fractions plays a significant role in the viscosity of coal-derived liquids.     

Upgrading of coal-derived liquids: 4. Characterization of upgraded liquids by field-ionization mass spectrometry

The mass range and the number-average molecular weight of coal-derived liquids upgraded with various catalysts were determined by field-ionization mass spectrometry (FIMS). The differences in the main components in liquids upgraded with HDS (hydrodesulphurization) and zeolite catalysts were clarified. Upgraded coal-derived liquids hydrogenated and deoxygenated with HDS catalysts contain alkyl-tetralins or indans as the main component. On the other hand, coal-derived liquids upgraded with zeolite catalysts and without catalyst contain alkyl-naphthalenes and/or alkyl-tetralins (or indans) and/or alkyl-phenols as the main component.     

A study of the colour of coal liquids: 1. Structural analysis of the coloured materials formed during storage of Wandoan coal-derived liquids

The coloured materials separated from degraded Wandoan coal-derived liquids were characterized by spectroscopic and elemental analyses. The coloured materials with a wider absorption range and stronger absorption intensity in the visible region are of highly polar condensed structures of larger molecular weight. Elemental composition of the coloured materials enriched in nitrogen and oxygen indicates that heteroatom compounds are principally responsible for formation of the coloured materials from coal liquids.     

Analysis of upgraded SRC-11 and H-coal liquid products

Upgraded coal-derived liquids obtained from catalytic hydroprocessing of SRC-11 and H-coal syncrudes have been studied by i.r., p.m.r., g.c.-m.s., and silica gel chromatography. With increase in residence time, nitrogen, oxygen and aromatics decrease, while naphthenes increase substantially. All the upgraded liquids show low viscosity at 298 K (1.3–1.4 mN s m^?2), even though saturate and aromatic fractions varied with processing severity. In the aromatic-1 fraction, 1 -ring aromatics increase, and 3-ring aromatics decrease, with increase in severity of hydroprocessing. G.c.-m.s. analyses indicate a marked qualitative similarity for saturate and aromatic fractions irrespective of syncrude source. Only the heavier end of the aromatic-1 fraction is noticeably different. Tentative identifications based on m.s. and g.c. retention times are made for most of the significant components. 600 M Hz p.m.r. spectra of the upgraded SRC-11 and H-coal liquids appear identical, but the n.m.r. difference technique revealed slight differences between the two liquids in concentrations of certain species.     

Light scattering studies of the stability of liquid fuels

Storage stabilities of upgraded coal-derived liquids (H-coal and SRC-II), JP-5 jet fuels derived from petroleum and oil shale, and a petroleum-derived diesel fuel were compared using laser light scattering measurements. The most severely hydrotreated coal-derived liquids have stability characteristics comparable to the jet fuels derived from petroleum and oil shale. Fuel degradation was monitored in the presence of added specific heteroatomic compounds. Very pronounced enhancement of light scattering intensity has been observed for coal-derived liquids containing the following additives: 1. phenol + pyridine + Cu; 2. 2,6-di-tertbutylphenol (DTBP) + pyridine + Cu; 3. phenol + dimethylquinoline, (DMQ) + (Cu; and 4. 2,5-dimethylpyrrole (DMP) + thiophenol. Previous studies have shown that phenolic oxidative coupling is an important reaction responsible for the ageing of coal-derived liquids and this observation is confirmed here. Pyridine and DMQ complexed with Cu are shown to be effective catalysts for oxidative coupling. DMP by itself is deleterious to fuel stability, in that it promotes sediment formation and light scattering. During accelerated ageing of upgraded H-coal in the presence of DMP a sediment formed with empirical formula C₇H₈NO_1.3, which was further characterized by solid-state C 13 n.m.r. and X-ray photoelectron spectroscopy.     

Hydrotreating a distillate liquid derived from subbituminous coal using a sulphided CoO-MoO3-Al2O3 catalyst

A coal-derived heavy naphtha distillate containing 4.76, 0.51 and 0.004 wt% oxygen, nitrogen, and sulphur, respectively, has been hydro-treated. Even with severe processing conditions, the conversions of heteroatom species is less than desired. An empirical equation based on the experimental data indicates greater conversions would be attained at greater pressures and residence time. Severe catalyst deactivation is attributed primarily to carbonaceous deposits. However, smaller concentrations of zinc also accumulate on the catalyst.     

Upgrading of syncrude from coal

The processing of coal-derived liquids to produce marketable products is being jointly investigated by Ruhrkohle AG and VEBA Oel. Experimental work was performed in process development units to find optimum process parameters for hydrotreating, hydrocracking and reforming. The removal of heteroatoms, hydrogen consumption, conversion rates and gas formation have been investigated under various process conditions. The range of applications of the different products has been studied.     

Role of nitrogen- and sulphur-containing compounds in the ageing of liquid fuels

Insoluble and adherent sediments are formed during ageing of liquid fuels. In this research, the extent of deposit formation was studied by adding specific nitrogen- and sulphur-containing compounds to upgraded coal-derived liquids, petroleum-derived JP-5 jet and diesel fuels. Of the nitrogen compounds tested, the ability to promote sediment formation is much greater for 2,5-dimethylpyrrole (DMP), than 2,6-dimethylquinoline (DMQ). Of the sulphur-containing compounds tested, the decreasing order is: thiophenol, tetrahydrothiophene, thiophene. Synergistic effects between DMP and thiophenol can occur. Degradation products obtained by heat stressing of fuels enriched with specific heteroatomic compounds were analysed by solid-state nuclear magnetic resonance, infrared, and X-ray photoelectron spectroscopy.     

页岩油含氮化合物分离研究

探讨了用Lewis酸为络合剂除掉富集在页岩油中含氮化合物的最佳条件,考察了不同Lewis酸的脱氮效果;同时考察了Lewis酸的加入量、反应温度、反应时间、溶剂对脱氮效果的影响。实验表明,对于未经蒸馏分离的页岩油四氯化钛为主要成分的络合剂脱氮效果最好。     

Effect of various phenol additives on viscosity of SRC blends

Coal-derived liquids are susceptible to oxidative degradation. Two different weight ratios of SRC-I/SRC-II blends, with or without phenol derivatives, have been subjected to accelerated ageing studies. Viscosity, infrared, elemental analysis, molecular weight determination, and solvent analysis are used to examine the properties of the degradation products. On ageing, there is a large increase in the amount of toluene-insoluble material, decrease in oil components, and a relatively constant amount of asphaltenes. The oxygen content increases in the aged toluene-insoluble and asphaltene fractions, and a new absorption at ≈1700 cm^?1 (the C = 0 group) appears in these two fractions only. On the addition of phenol itself and the less hindered phenol derivatives, the original hydrogen-bonding between the acidic and basic fuctional groups in the coal liquids is apparently disrupted because the added phenol can now interact with the proton-accepting species in the liquids, thus leading to a lower viscosity. This does not mean that the unhindered phenols retard the rate of ageing. The original hydrogen-bonding in the coal-derived liquid now gives way to a new hydrogen-bonding, and ageing occurs with the latter. The more hindered phenol derivatives are not as effective as phenol in disrupting the original hydrogen-bonding in the coal-derived liquids.     

Upgrading of coal-derived liquids: 3. Characterization of upgraded liquids by thin-layer chromatography combined with flame-ionization detection

Four components, namely, saturates, aromatics, resins and asphaltenes, in upgraded coal-derived liquids were determined by thin-layer chromatography combined with flame-ionization detection (t.l.c./FID method). The results agree with previous results using various analytical methods. The t.l.c./FID method was found to be a simple and effective method for screening of hydroconversion catalysts and also for a follow-up investigation of the chemical changes of coal-derived liquids during the hydroconversion process.     

Coal-derived asphaltenes. Relationship between chemical character and process history

The chemical character of asphaltenes isolated from coal-derived liquids and the relative ease of their catalytic and noncatalytic conversion to oil has been found to depend upon their processing history. To facilitate chemical characterization, a simple analytical method was developed for separation of the asphaltenes into three subfractions according to their relative strength of absorption on silica gel. Using this separation technique, differences in the relative content of polar molecules were found among asphaltenes of various processing histories. In general, the relative content of polar compounds in the asphaltenes decreases with increasing conversion to oil. The relative rate of conversion also declines after the asphaltene content reaches a low level. The asphaltenes remaining after long hydrotreatment are more aromatic, contain fewer polar functional groups and are of somewhat smaller molecular size than those obtained after short hydrotreatment. The initial rates of asphaltene conversion were considerably enhanced by a commercial CoMo hydrodesulfurization catalyst. The catalyst increased the conversion of the nonpolar subfraction to a greater extent than the polar subfraction.     

Effects of solvent composition on coprocessing coal with petroleum residua

The effect of solvent composition on coprocessing of coal and petroleum solvents is examined under a variety of reaction conditions. The effects of solvent modification procedures on enhancing methylene chloride/methanol (MeCl/MeOH) soluble coal conversion and pentane soluble oil production are studied. Solvent modification procedures performed prior to coprocessing reactions include pentane deasphalting, catalytic hydrotreatment, H-donor addition, and blending of coal-derived liquids with petroleum solvents. Oil production and coal conversion were variously affected by the different solvent modifications. Prior hydrotreatment of petroleum solvents generally enhanced coal conversion, as did H-donor addition. The presence of a hydrotreating catalyst exerted a leveling effect on the effects of solvent modification. Blending of coal liquids and petroleum solvents resulted in complex and not readily predictable interaction. Solvents yielding the highest MeCl/MeOH soluble coal conversion were not generally the optimal solvents for pentane soluble oil production.     

LIR对NR/BR混炼胶加工性能的影响

采用RPA2000橡胶加工分析仪研究液体聚异戊二烯（LIR）、芳烃油和LIR/芳烃油并用体系对NR/BR混炼胶加工性能的影响.结果表明,LIR和LIR/芳烃油并用体系均能有效改善NR/BR混炼胶的加工性能,且后者的增塑效果较LIR或芳烃油单用时更为显著,其对应的混炼胶粘度较小,工艺能耗和成本较低;LIR/芳烃油并用体系对应的NR/BR硫化胶性能良好,炭黑在其中的分散性也较好.     

[Cnmim]Br/FeCl3型离子液体萃取脱除二苯并噻吩

合成了6种咪唑型离子液体[C_3-8mim]Br/FeCl₃,采用红外光谱和拉曼光谱对其进行表征,并考察了离子液体对二苯并噻吩的萃取脱除效果。结果发现,[C₃mim]Br/FeCl₃的萃取脱硫效果最佳,升高温度和增大剂油比均有利于脱硫率的提高,剂油比1:1(体积比)时,萃取时间达到12 min就可使脱硫率高达92%。且萃取反应完成后,离子液体不做处理继续重复使用,重复使用5次,脱硫率可以达到60%。     

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.     

Characterization of needle coke feedstocks by magnetic resonance spectroscopy

Decant oil is the traditional petroleum-derived feedstock for the production of needle coke. However, with the dwindling supply of high-quality decant oil and potential availability of coal-derived liquids, alternative feedstocks are receiving attention. One of these is ethylene pyrolysis tar. The new materials are less suitable needle coke precursors and may need to be upgraded by structural alterations. Therefore, the structure of these materials is examined at the molecular level. The average molecular parameters for the aromatic and asphaltene fractions of decant oil and pyrolysis tar are reported, along with a method for calculating these parameters which is slightly different from the previously available procedures. These parameters indicate that the average molecule in the aromatic and asphaltene fractions of decant oil and pyrolysis tar differ in certain structural units. This difference possibly may be responsible for their different behaviour on pyrolysis.     

PPS/TLCP共混体系结构与流变研究

采用热致液晶聚合物（TLCP）与聚苯硫醚（PPS）熔融共混的方式制备了PPS／TLCP复合材料,研究了PPS／TLCP共混体系的形貌、流变性能以及加工参数对微纤形成的影响。结果表明：TLCP可明显改善体系的加工特性,并能原位生成微纤化复合材料,TLCP对体系黏度有较大影响,在低剪切速率区黏度下降幅度较大,在高剪切速率区,黏度降低幅度小。PPS／TLCP复合材料存在皮芯结构,工艺参数对TLCP微纤的形成起着重要作用,通过提高注塑速度,对TLCP微纤的形成特别有利。