Analysis of coal-derived liquid obtained by mild hydrogenation: 1. Neutral oil distilling at 186–343 °C

Taiheiyo coal (77% C) was hydrogenated under mild conditions to preserve the unit structure of the parent coal as far as possible. The n-hexane-solubles (yield, 49.8 wt% daf coal) were washed with acid and base and the neutral material separated into 7 fractions by vacuum distillation. The three lower boiling fractions, DS01 (7.3 wt% neutral oil), DS02 (3.6 wt%) and DS03 (4.8 wt%), were further separated by liquid chromatography into hydrocarbon subfractions which were analysed by g.c. and g.c.-m.s. Saturates are most abundant, especially the n-alkanes which comprise ≈9–13 wt% of each fraction. The saturates also contain isoprenoids (C₁₅, C₁₆, C₁₈, C₁₉ and C₂₀), branched alkanes, n-alkyl cyclohexanes, terpanes and others. With increasing boiling point, smaller amounts of monoaromatic ring hydrocarbons and more di- or triaromatic ring hydrocarbons are found. The alkyl side-chains of aromatic nuclei have a large carbon number, especially in the smaller rings. The existence of phenyltetralin or phenylnaphthalene shows a feature of bonding between aromatic nuclei.     

Structure of coal hydrogenation products obtained in the presence of oil and coal paste-forming agents

The structure parameters of hydrogenation products were analyzed in relation to the composition of oil and coal (intrinsic) paste-forming agents used in the process of coal hydrogenation under a low pressure of hydrogen (6–10 MPa). It was found that the structure characteristics of liquefaction products essentially differed at close values of the structure unsaturation parameter δ; this was likely due to a difference in the material composition of solvents (other than aromatic structures).     

Chemical structure of heavy oil from coal hydrogenation 1. Hydrogenation with zinc chloride catalyst

Oil product from the hydrogenolysis of a high-volatile bituminous coal was separated by solubility, fractionated by gel permeation chromotography and characterized by structural analysis. The average structural unit in the hexane-soluble, aromatic oil fraction consists of 1–3 aromatic rings with 0.3-0.5 of the ring carbons substituted by alkyl groups and oxygen containing groups. Molecular weights vary from 200 to 500. The larger molecular weight fractions have longer alkyl chains and lower carbon aromaticities. The molecules are mainly of single unit structures. The average structural units in asphaltene fractions contain from 2.5-4 aromatic rings, are of higher carbon aromaticities and contain shorter alkyl groups. The asphaltene molecules consist of two or more structural units, crosslinked together, and have molecular weights of 300–1400. The oxygen content of the fractions decreases with decreasing molecular weight. Increasing the amount of ZnCl₂ catalyst during hydrogenolysis resylts in an increased yield of lower-molecular-weight material, but no change in the structural properties of the product. This is interpreted to mean that ZnCl₂ is active in the scission of covalent bonds between structural units during liquefaction and that the hydrogenolysis reaction is mostly cleavage of crosslinks between structural units with minimal reaction of the units themselves.     

煤焦油加氢尾油的循环加氢工艺研究

煤焦油通过一次加氢会产出大量的未转化油——加氢尾油,为了提高煤焦油加氢轻质油总转化率,文中借鉴石油基加氢尾油的处理方法,对煤焦油加氢尾油循环加氢工艺进行了初步探讨。在一定循环油切割点和循环比下分析了裂化剂床层温度、反应压力和氢油体积比对尾油循环加氢总转化率的影响;并以汽柴油收率为目标,对裂化剂床层温度和反应压力2个因素进行了优化,获得了优化工艺条件。     

Structures of the distillates obtained from hydrogenation and pyrolysis of Liddell coal

The structures of the distillable fractions (oils, b.p. >200 °C and volatile fractions, b.p. <200 °C) of the products from hydrogenation and pyrolysis of an Australian bituminous coal (Liddell) were investigated by gas chromatography-mass spectrometry (g.c.-m.s.) and nuclear magnetic resonance spectroscopy (n.m.r.). The distillable oil generated from hydrogenation of Liddell coal at 400 °C, using nickel molybdenum ortin (II) chloride as catalyst and tetralin or recycle oil as vehicle, consisted of a wide range of compounds. Long straight-chain alkanes were important components together with alkyl-substituted benzenes and tetralins, phenols and polycyclic material. When yields were low, as in the case of catalytic experiments with nickel molybdenum catalysts and no vehicle, isoprenoids could be identified. When a substantial proportion of the coal was converted to oil, branched-chain alkanes were not important components of the product. The replacement of tetralin and nickel molybdenum catalyst with stannous chloride reduced the amounts of methyl tetralins in the product. When tetralin was replaced by recycle oil, alkanes were more important components of the liquid products. Although alkenes were absent in oils generated by hydrogenation, they were important components of oils generated by pyrolysis. The highly volatile fractions (b.p. <200 °C) produced during hydrogenation consisted of alkyl-substituted benzenes, decalins, methylindan and straight-chain alkanes. Straight-chain alkanes were more abundant in those volatile fractions generated by hydrogenation with recycle vehicle than with tetralin. The Brown-Ladner method of estimating the fraction of aromatic carbon in distillable oils was adequate for less volatile fractions but was inadequate for the highly volatile fractions because of the large amounts of α-CH₃ and β-CH₃ alkyl groups present.     

A mechanistic study of hydrogenation of coal. 1.

Kinetics of the coal-hydrogenation reaction have been studied using three systems: (1) catalyst and solvent (vehicle), (2) vehicle only, and (3) catalyst only; within a temperature range of 390–410 °C. The orders of reaction and the rate constants were calculated using a modified differential equation with respect to the organic benzene-insolubles. For all the three systems the reaction course can be broadly divided into four steps, of which the first two were significant. The reaction orders varied not only from one step to another but also within each step, though over a small range, with temperature. Taking systems (1) and (2), in particular, the reaction orders can be very broadly approximated to 1.0 for the first step, between 1.5 and 2.0 for the second step, and between 0.5 and 1.0 for the third step. Assuming the applicability of the Arrhenius Law, the calculated activation energies for the first step of the three systems are 182, 332.5 and 345.5 kJ/mol respectively. The difference in the activation energies for step 2 of systems (1) and (2) narrowed down to 70 kJ/mol. The distinct sequential variations of the reaction orders indicate not only the interplay of multiple reactions but also the possible influence of intermediates formed during the reaction. In this context, the measured activation energies have limited significance because of the dissimilar temperature coefficients of these reactions and also of the heterogeneity of the reaction species. The mechanistic interpretation of the variation of reaction order will be discussed in Part 2 of the study.     

Flash hydrogenation of coal. 1. Experimental methods and preliminary results

A laboratory reactor system has been developed for the determination of products obtainable from the flash heating of raw coal in flowing hydrogen at pressures up to 100 atm. The system provides for control of heating rate, solids-contact time and vapour-product residence time. A comparison of results in which each of these time parameters was varied in turn illustrates their importance in determining the yields of alkanes and single-ring aromatics.     

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.     

Reaction mechanism of coal hydrogenation: 1. Two-ring solvent system

Taiheiyo coal was hydrogenated in naphthalene, tetralin and decalin under 10 MPa (initial pressure) of hydrogen or nitrogen with stabilized nickel as catalyst at 400 °C for 15 min. Preasphaltene, asphaltene and oil conversions and the conversion of the solvents were measured. The hydrogen absorbed by coal from molecular hydrogen and from the donor solvent was calculated. The main reaction route appears to be the direct hydrogenation of coal by molecular hydrogen, with the side reaction via solvent by molecular hydrogen occurring only slightly, when an active catalyst such as stabilized nickel is present.     

Cocoa butter-like fats from fractionated cottonseed oil: II. Properties

Previously it was reported that the stearine obtained as a byproduct in the solvent winterization of cottonseed oil is a good starting material for the preparation of cocoa butter-like fats by way of hydrogenation and fractionation. The composition, physical properties, and compatability with cocoa butter have been determined for some of these fats. While the products contained triglyceride species other than those in cocoa butter, the major components were similar in that they were 2-oleodisaturated glycerides. The cocoa butter-like fats underwent slow polymorphic transformations, but made confectionery coatings remarkably resistant to bloom. Cooling curves resembled those of cocoa butter. Hardness was related to melting point; those fats melting below 35 C were softer than cocoa butter at room temperature, but fats melting above 35 C could be made to resemble cocoa butter in hardness. Adding cocoa butter to the cocoa butter-like fats had little effect on the softening point. X-Ray diffraction studies of 1:1 mixtures gave no evidence of mixed crystal formation; the long spacings resembled those of mechanical mixtures. In some other mixtures, certain short spacings became more pronounced. ARS, USDA.     

Cocoa butter-like fats from fractionated cottonseed oil: I. preparation

The manufacture of salad oil from cottonseed oil can produce a byproduct stearine fraction consisting essentially of 1-palmito and 1,3-dipalmito triglycerides of oleic and linoleic acids and having an iodine value of ca. 72. Hydrogenation of this fraction to an iodine value of ca. 28–42, under conditions simultaneously selective and conducive to a low rate oftrans-isomer formation, yielded a product that could readily be fractionated to produce over 60% of a cocoa butter-like fat. The conditions of fractionation influenced the yield and properties. Fractionation was most easily accomplished by tempering the solidified hydrogenation product and leaching with a petroleum naphtha or acetone. ARS, USDA.     

中低温煤焦油加氢技术对比与分析

对国内几种主要的中低温煤焦油加氢技术——固体热载体热解-全馏分加氢工艺、煤气化焦油-宽馏分加氢工艺、块煤干馏-延迟焦化-焦油加氢工艺以及VCC工艺等技术进行了对比分析。由于这一领域仅仅处于一个起步阶段,因此各个技术各有特色,然而随着这些技术的不断日趋完善,煤热解耦合煤焦油加氢领域一定会有一个质的飞跃,不但可缓解石油资源紧缺的压力,而且可有效的解决煤热解行业只焦不化、污染环境等长期以来困扰焦化行业难题。     

Chemical structure of asphaltenes and preasphaltenes obtained by coal hydrogenation under high-speed heating conditions

The results of experimental studies on the determination of the chemical structure of asphaltenes and preasphaltenes in the liquid hydrogenates of coal from the Zashulanskoe field in Transbaikalia are reported. These results were obtained under the conditions of high-speed heating (～200 K/min; reaction time, 10 min). It was found that the structural characteristics of asphaltenes and preasphaltenes obtained by high-speed hydrogenation at 425°C and 10 MPa exhibited a number of special features. At similar fractions of aromatic carbon, these products differed from the coal hydrogenates obtained at a slow rate of heating (5 K/min; reaction time, 120 min) in terms of the distribution of hydrogen and oxygen over structural groups. In them, the hydrogen content of CH₂ and CH_ar groups was smaller and that of CH₃ groups was greater. The highest concentration of total oxygen-containing groups was detected in the high-speed process preasphaltenes, whereas it was lower in the asphaltenes.     

煤加氢热解物制备中间相炭微球研究

对煤加氢热解物所得精制沥青的中间相转化行为进行了研究,发现其在440℃、1 MPa下保温6 h即可形成广域流线型中间相组织,说明融并性能良好;在常压、420℃、6 h的热处理条件下,添加1%炭黑,制备出了表面光滑、球形度好、粒径集中的中间相炭微球。该精制沥青可以作为高性能炭材料的优良前躯体。     

Manufacture of aromatic hydrocarbons from coal hydrogenation products

The manufacture of aromatic hydrocarbons from coal distillates was experimentally studied. A flow chart for the production of benzene, ethylbenzene, toluene, and xylenes was designed, which comprised the hydrogen treatment of the total wide-cut (or preliminarily depehenolized) fraction with FBP 425°C; fractional distillation of the hydrotreated products into IBP-60, 60–180, 180–300, and 300–425°C fractions; the hydro-racking of middle fractions for increasing the yield of gasoline fractions whenever necessary; the catalytic reform of the fractions with bp up to 180°C; and the extraction of aromatic hydrocarbons.     

Catalysts for selective hydrogenation of soybean oil.1 II. Commercial catalysts

A survey of commercial hydrogenation catalysts demonstrated the higher selectivity (S_L= 2.4\s-2.7) of certain platinum, palladium and rhodium catalysts for hydrogenating linolenic components in soybean oil. Nickel catalysts generally showed selectivities below S_L=2.0 although skeletal nickel achieved higher values.Trans-isomers were in the range 7.8\s-15.4% for the above noble metal catalysts. Nickel catalysts provide a lesser degree of isomerization, 5.2\s-7.4% oftrans-isomers for the most selective catalysts. Presented at the AOCS Meeting at Toronto, 1962.     

Formation and stability of mesophase during coal hydrogenation. 1. Formation of mesophase

Vitrinite samples from Australian bituminous coals were hydrogenated in autoclaves without vehicle solvent, and the solid products were examined microscopically. When a vitrinite sample was stirred during hydrogenation, the yields of liquid and gaseous products were high. However, when the samples were not stirred, the yields were low, and the solid products contained a high proportion of mesophase. In a vertical section of a vitrinite sample which was unstirred during hydrogenation, the surface in contact with hydrogen was covered by isotropic material, underlaid by a zone of mixed isotropic and mosaic-textured material. Away from the surface, the proportion of isotropic material decreased. The authors conclude that mesophase is formed from material previously liquefied, more readily under hydrogen-deficient conditions than under conditions in which hydrogen is freely available. Application of this conclusion may increase the efficiency of hydrogenation processes by reducing the deleterious effects of mesophase formation.     

甲醇制汽油副产重油的加氢改质催化剂的研究

开发出了一种甲醇制汽油(MTG)重油加氢改质催化剂。研究了制备方法、分子筛、粘结剂以及工艺条件对催化剂性能的影响,同时还对催化剂进行了300 h寿命考察,结果表明,催化剂具有良好的活性和稳定性。     

Application of the Shvo catalyst in homogeneous hydrogenation of bio-oil obtained from pyrolysis of white poplar: New mild upgrading conditions

Upgrading of bio-oils obtained from the fast pyrolysis of biomasses requires the development of efficient catalysts able to work under mild conditions and to cope with the complex chemical nature of the reactant. The present work focuses on the use of the ruthenium based Shvo homogeneous catalyst for the hydrogenation of model mixtures (vanillin, cinnamaldehyde, methylacetophenone, glycolaldehyde, acetol, acetic acid) and of a real bio-oil. The hydrogenation of model compounds has been investigated both in mono- and biphasic mixtures under a P(H₂) = 10 atm in the temperature range of 90-145 °C varying the substrate to catalyst molar ratio from 2000:1 to 200:1. Employing the most active reaction conditions (substrate/catalyst 200:1, T = 145 °C, P(H₂) = 10 atm) the Shvo catalyst maintains its performances under acidic “bio-oil conditions” leading to the almost quantitative conversion of the polar double bonds within 1 h. The activity of the Shvo catalyst was also investigated for the hydrogenation of a bio-oil from poplar in solvent free conditions. Hydrogenation deeply changed the chemical nature of the pyrolysis oil. Aldehydes, ketones and non-aromatic double bonds were almost totally hydrogenated. The catalytic system also promoted the hydrolysis of sugar oligomers into monomers.