Coal-oil mixture from a synthetic oil obtained by hydroliquefaction of a South African coal

A coal-oil mixture (COM) was prepared from a South African coal and a synthetic oil derived from the same coal by hydroliquefaction. The settling and rheological properties of this mixture were compared with those of a mixture of the same coal with fuel oil. The synthetic oil mixture showed greater settling stability, comparable with that of a commercial COM containing additives. The increased stability may be related to polar compounds present in the oil and on the coal surface.     

煤直接液化粗油提质加工工艺研究现状

分析对比了煤直接液化油的汽油和柴油馏分与石油基汽油和柴油馏分杂原子含量和族组分的差异,指出煤直接液化油中氮和芳烃含量高,需要经过苛刻的加工改质,才能作为车用内燃机燃料使用。介绍了煤液化粗油提质加工的研究现状,讨论了油品加氢催化剂和不同馏分产物的加氢提质工艺,展望了该工艺的发展趋势。     

Determination of functional groups of coal-derived liquids by n.m.r. and elemental analysis

A new method of structural analysis was applied to a group of hydroliquefied coal samples. The method uses elemental analysis and n.m.r. data to estimate the concentrations of functional groups in the samples. The samples included oil and asphaltene fractions obtained in a series of hydroliquefaction experiments, and a set of nine fractions separated from a coal-derived oil. The structural characterization of these samples demonstrates that estimates of functional group concentrations can be used to provide detailed structural profiles of complex mixtures and to obtain limited information about reaction pathways.     

煤的一段加氢液化的催化剂

煤的一段加氢液化使用的催化剂有可弃性催化剂,铁和钼氧化物及溶于水或油的催化剂和浸渍催化剂,其中以Co-Mo/Al_2O_3,Ni-Mo/Al_2O_3和钼酸铵为最广泛;黄铁矿能促进煤向油的转化,但却降低了脱硫率:Fe(OH)3-MoO_3-S在较低和较高温度下都是一种较活泼的催化剂;SnMo混合物明显优于纯SnO_2或无助催化剂的MoO_3/Al_2O_3;硫化的Mo(CO)_6是一种性能很好的煤加氢液化催化剂。     

Hydrogenation of brown coal: 5. A study of coal-derived materials as vehicles for brown coal hydroliquefaction reactions

A series of batch autoclave experiments has been conducted in which the product boiling in the range 220–450°C was recycled several times to test the suitability of this liquid as a vehicle for the hydroliquefaction of Victorian brown coal. The product liquid was used at the end of each cycle as a vehicle for an independent small-scale coal hydrogenation and repetitive hydrogenations of the parent solvent were also carried out to help facilitate understanding of the role and chemical changes associated with the vehicle. It has been shown that the distillable coal-derived liquid, even without recycling part of the bottoms, has a hydrogenation potential in the same range as tetralin and hydrogenated anthracene oil, despite its relatively poor quality. However, the amount of liquid produced was less than the amount of solvent used.     

Dehydrogenation activities of coal liquefaction catalysts on various ranks of coals

The amount of hydrogen evolved from a coal during pyrolysis at atmospheric pressure in the presence of coal hydroliquefaction catalysts can be used to compare the activity of different catalysts for the highpressure hydrogenation of coals. This technique has now been used to compare the variation in the effectiveness of MoO₃-TiO₂, and Fe₂O₃-SO^2?₄, as hydroliquefaction catalysts with change in coal rank. It is indicated that coals with carbon contents of ≈ 82 wt% are the most amenable to hydroliquefaction at high pressure.     

Oil agglomeration as a pretreatment for coal liquefaction

Laboratory experiments demonstrated that a variety of distillate coal liquefaction recycle oils were satisfactory agents for cleaning Illinois no. 6 bituminous coal by oil agglomeration. Ash rejection up to 41% with 98% organic recovery was attained with conventionally cleaned coal, and ash rejection up to 67% with 90% organic recovery with run-of-mine coal. Agglomerates of > 1 mm average diameter were produced under a variety of conditions. Similar results were obtained in the scaled-up production of 268 kg of agglomerates. Oils with lower hydrogen aromaticities and higher hydrogen contents performed better than more aromatic oils. Fe, Ti and Mg were selectively enriched in the ash of the product coal, while Ca, Si, and Al were selectively rejected. The mineral pyrite was rejected only ≈ 30–40% as extensively as the bulk of the ashforming minerals. The coal cleaned by oil agglomeration performed similarly to the feed coal in batch donor liquefaction tests. In continuous hydroliquefaction tests, run-of-mine coal cleaned by oil agglomeration performed substantially better than coal cleaned to the same ash level by conventional means, because of the selective enrichment of catalytic iron minerals.     

Solubilization of Illinois bituminous coal: the critical importance of methylene group cleavage

The extent of solubilization of an Illinois bituminous coal achieved by hydroliquefaction at various temperatures with and without catalyst was determined. The coal was also solubilized by treatment in suspension in THF with potassium in the presence of naphthalene. The original coal was also extracted with THF without prior treatment. After removal of solvent the soluble fractions were examined by ¹H n.m.r. spectroscopy. It is concluded that there are two temperature regimes which affect coal conversion: in the 350–400 °C region, hydroliquefaction proceeds principally by ether cleavage; whereas in the 400–450 °C range, hydroliquefaction results in additional cleavage of methylene groups joining aromatic or heteroaromatic units. Comparison of solubilization by hydroliquefaction with solubilization achieved with potassium in THF seems to indicate the initial degradation of coal by both techniques proceeds by ether cleavage and that further degradation is achieved in both cases by attack at the methylene bridge. The n.m.r. studies on hydroliquefaction products indicate that Illinois bituminous coal is structurally quite homogeneous because the product composition is largely independent of the degree of solubilization. Thus, solubilization results from molecular weight degradation rather than from preferential-degradation to different structural units.     

神府煤的液化性能及其重质产物结构表征

利用管式高压反应釜,以四氢萘为溶剂、FeS和S为催化剂,对神府煤进行了加氢液化研究,考察了催化剂、反应温度和反应气氛等因素对煤液化性能和产物组成分布的影响,同时对液化产物进行了红外光谱、元素分析以及酸性含氧官能团等结构表征。结果表明,FeS+S催化神府煤液化的最高四氢呋喃(THF)抽提率和油+气收率分别为69.5%和35.9%;未加催化剂时,神府煤液化THF抽提率和油+气收率都是最低的。     

马来酸酐-丙烯酸酯类共聚物作油煤浆燃料稳定剂研究

以马来酸酐与丙烯酸酯的共聚物为稳定剂,当共聚物中,n(马来酸酐):n(丙烯酸丁酯)=1:5,用吡啶中和,稳定剂的添加量为0.4%时,油煤浆(COM)燃料在3个星期后的棒惯时间仍然小于2 s,碳粉的最高质量含量可达59.4%.该稳定剂用量少、原料易得,有较好的应用前景.     

煤的温和液化及共处理技术的研究和开发

在综述煤的温和液化及煤与有机废弃物共处理研究现状的基础上，指出煤直接液化的发展方向是温和液化；煤与废塑料的共液化为这类有机废弃物及煤的非燃料利用开辟一条新途径。     

10万t/a高温煤焦油加氢装置的技术标定

以黑龙江省七台河宝泰隆煤化工股份有限公司10万t/a炼焦油轻质化项目为例,介绍了高温煤焦油加氢工艺。在高温煤焦油加氢生产燃料油的过程中,为得到高燃料油收率,采用了加氢精制和加氢裂化相结合的工艺。主要对本套煤焦油加氢装置进行了操作条件和物料分析的技术标定总结,并进行技术分析,提出了合理化建议,以对今后的生产操作提供依据,保证装置的连续稳定运行。     

Maceral and microlithotype response to oil agglomeration for selected eastern Kentucky high volatile A bituminous coals

The petrographic response of three high volatile A bituminous, petrographically complex eastern Kentucky coals to oil agglomeration was tested using several agglomerating oils. Four oils, hexane, fuel oil, kerosene, and pentane, were tested on the Leatherwood coal, the intermediate coal in the rank series. The testing scheme for the other two coals consisted of using only the hexane and fuel oil with a lesser number of tests than on the initial coal tested. Coal rank emerges as a significant parameter in the behavior of the coals. Particularly for the hexane agglomeration, the coals had quite different behaviors, with the highest-rank coal having greater clean-coal yield at lower oil concentrations than the other two coals. The two high-rank coals exhibit similar yield curves for fuel oil, with the lower-rank coal achieving the yield of the latter coals at higher oil concentrations. The role of the organic petrography and the mineral matter, both closely associated with the macerals in carbominerite microlithotypes and organic-dominant microlithotypes, is an obvious complicating factor. A tendency for duroclarite, the vitrinite-rich trimaceral microlithotype, to partition between vitrinite-rich varieties in the concentrate and vitrinite-poor varieties in the tails was noted at higher oil concentrations for all three coals.     

Catalytic effects of MoCl3- and NiCl2-containing molten salts in hydroliquefaction of Akabira bituminous coal with and without hydrogen-donor vehicle

Catalytic effects of MoCl₃-LiCl-KCl and NiCl₂-LiCl-KCl molten salts in hydroliquefaction of Akabira bituminous coal were studied. In the absence of solvent, both catalysts showed high coal conversion activity and high selectivity for the formation of hexane-soluble oil product. Oil yields from the catalytic runs were 3.4–3.0 times that from a non-catalytic run. Addition of hydrogen-donor tetralin considerably increased the oil yield and conversion and reduced the total hydrogen consumption. About 95 and 91 wt% daf coal was converted into pyridine-solubles and 59 and 54 wt% into oil with relatively low total hydrogen consumption (3.5 and 3.1 wt% daf coal) with the MoCl₃ and NiCl₂ catalysts respectively, in the presence of tetralin. Thermogravimetric analysis indicated that these catalysts enhanced the depolymerization of the coal organic matrix. Analysis of the liquefaction products suggested that the catalysts effectively catalysed the hydrocracking of polyaromatic structures contained in heavy products to hydroaromatics with relatively small ring sizes, explaining the high oil selectivity.     

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     

Fuel mixtures of low rank, lignite coal with fuel oils

Coal-oil mixture technology is progressing at an accelerated rate not only within the USA but also abroad because many combustion chambers currently existing have been designed to fire only fuel oil without the capability to convert to total coal firing. Research is needed concerning the combustion phenomena associated with mixtures of low rank, lignite coal and fuel oils. This study examines combustion phenomena of lignite-fuel oil mixtures. Significant results include: (1) Up to 35 wt% of lignite was mixed with number 6 fuel oil and successfully fired resulting in a stable, compact flame with the characteristics of a heavy residual fuel oil flame, (2) Up to 20 wt% of lignite was mixed with number 2 fuel oil exhibiting the same stable characteristics, and (3) pumping problems associated with these slurries can override combustion limitations. Additives were not used in the fuel mixtures. All tests were conducted in a full scale research combustion chamber.     

Short contact-time liquefaction of subbituminous coal: Directions for improving coal conversion

This study was undertaken to find ways to solubilize subbituminous coal in high yield at short contact times. Short contact-time hydroliquefaction runs were carried out in a continuous unit using Belle Ayr subbituminous coal with a solvent rich in hydrogen-donor molecules derived from the Lummus ITSL process, and also with solvents lower in donor concentration derived from the SRC processes. Catalysis by pyrite, molybdenum and supported cobalt-molybdenum was also studied. It was found that pyrite and other hydrogenation catalysts enhanced solubilization and also increased production of distillate oil. Solvent quality seemed to have no effect on the solubilization of Belle Ayr coal. The availability of H₂S also appeared to have no effect. Provided that pyrite was present, reaction could be carried out at severities high enough to give insoluble organic matter yields equivalent to those obtained with bituminous coals (5–10 wt% daf coal). At equivalent levels of solubilization, however, hydrocarbon gas and distillate yields were invariably higher for the subbituminous coal. Implications for two-stage processing of Belle Ayr coal are discussed.     

Superacid coal chemistry: 1. HF:BF3 catalysed depolymerization—ionic hydroliquefaction of coals under mild conditions

HF:BF₃:H₂ catalysed depolymerization and hydroliquefaction of coal was studied. This superacidic system was found to be extremely effective for low temperature liquefaction of coal. Illinois No. 6 coal could be solubilized in pyridine to the extent of > 90% by treating it at ≈ 105 °C for 4 h. Under somewhat more elevated temperature (150–170 °C) cyclohexane extractabilities of up to 22% and distillability of up to 28% is achieved. A hydrogen donor solvent such as isopentane is shown to improve the efficiency of the superacidic catalyst for the conversion of coal to cyclohexane soluble products.     

Mössbauer study of iron catalysis in Victorian brown coal liquefaction

Mössbauer spectroscopy was used to investigate the means by which iron promotes the hydroliquefaction of Victorian brown coal. Microparticulate ferric oxyhydroxide incorporated in the initial coal is reduced during hydrogenation through magnetite and troilite to α-iron, which transforms to cementite at 380 °C. It is proposed that a transient divalent iron species slows the initial thermal degradation of coal and that α-Fe is responsible for enhancing the ultimate liquefaction yield.     

Differential thermal analysis study of lignite hydrogenation

Several New Zealand lignites and three other coals have been compared by differential thermal analysis in hydrogen at a pressure of 8.0 MPa. Most coals showed two exothermic peaks at ≈350 and 500 °C, but the relative magnitude of the two peaks varied from one coal to another. Ion-exchanging one of the lignites with Zn, Fe, Ni, Pb and Sn reduced the temperature of the peak maximum. Both Fe and Sn are known to catalyse coal hydrogenation. The results show that nickel and lead warrant further investigation as potential catalysts for coal hydroliquefaction, since they reduced the reaction temperatures even more than Fe or Sn. The reaction of lignite with tetrahydronaphthalene, in the absence of hydrogen, has been shown to be endothermic; a factor of interest in the context of donorsolvent hydroliquefaction facilities.