不同溶剂可保煤超临界萃取产物成分分析

选用了我国适于液化的褐煤──可保褐煤为原料，在半连续装置上，以甲苯、水及水／一氧化碳体系中加入少量氢氧化钠为溶剂进行超临界萃取研究。萃取物分离成油、沥青烯及前沥青烯三个族组分。ＧＣ／ＦＴＩＲ的分析结果表明，可保煤水萃取产物主要是含氧有机物、少量的烃类及烃类衍生物。在水／一氧化碳体系中加少量氢氧化钠催化剂萃取的产物主要是烃类及其衍生物。     

C4烃类含氧化合物脱除工艺研究进展

综述了现行C4烃类化合物中含氧化合物脱除的工艺方法--精馏法和吸附法,对不同脱除工艺的工业应用状况进行了分析比较,提出吸附分离工艺是一个重要的发展方向.     

费托合成水相中含氧化合物的分析和分离研究进展

费托合成是煤炭间接液化的核心反应,生成烃类产品的同时产生大量的反应水以及含氧有机物,包括醇、醛、酸、酮、酯等,对这些含氧有机物组分分析手段有气相色谱、气相色谱-质谱联用、离子色谱等;含氧有机物的分离回收无论是对间接液化技术的经济效益还是对环保都具有重要意义。该文综述了现有费托合成水相中含氧化合物的分析和分离研究,并指出了产品分析标准建立的迫切性和反应水分离工艺研究的重要性。     

漆树皮中挥发油的成份研究

本工作水蒸气蒸馏法对漆树(Rhus verniciflua)树皮中的挥发物进行提取,经过柱层析预分离,对挥发物中烃类化合物用色谱一质谱联用的方法分离测定了挥发物中烃类化合物的组成,确定了十二个化合物的结构,并对从漆树皮中提取的挥发油中烃类化合物的质谱裂解规律进行了讨论。     

胜利褐煤超临界乙醇脱氧实验研究

为有效脱除褐煤中含氧官能团,采用超临界乙醇工艺处理胜利褐煤,研究温度、停留时间和醇煤质量比对胜利褐煤脱氧效果的影响,并利用FT-IR和GC/MS对固液相产物进行表征。结果表明,胜利褐煤超临界乙醇脱氧的最佳工艺条件为:温度270℃,停留时间90 min,醇煤质量比5∶1,此时煤样总氧含量为9.29%,脱氧率为61.40%,固相产率为89.62%。在220℃得到的液相产物中,80%左右为芳香族类化合物,酚类和酯类含氧化合物体积分数低于5%,其他含氧类化合物11.29%。270℃得到的液相产率中芳香族类化合物体积分数降低31.69%,含氧类化合物体积分数增加2.81%,酚类和酯类含氧化合物增至35%左右。褐煤经超临界醇解后,乙醇与煤分子作用发生了醚氧桥键的断裂反应,煤分子发生了脱羧反应,液相产物中含有大量酚类(主要为苯酚及其取代物)和酯类(主要为乙酯类)。     

冷溶剂-气相色谱/质谱联用分析卷烟主流烟气气相成分

以冷溶剂收集法捕集卷烟主流烟气气相成分,利用气相色谱/质谱联用仪对卷烟主流烟气气相成分进行了分析.分离和鉴定了93种化合物,其中烃类29种、醛类9种、酮类23种、醇类5种、酸类2种、酯类1种、含氮化合物12种、含氧杂环化合物10种、含硫化合物2种.     

中心切割气相色谱法测定液化石油气中甲缩醛等9种含氧化合物

采用微板流路控制Deans Switch中心切割技术、双火焰离子化检测器的双柱气相色谱系统,建立了测定液化石油气中甲缩醛等多种含氧化合物的方法。在优化的色谱条件下,将适量试样直接注入气相色谱仪中,通过阀的两次切换,将强极性的含氧化合物组分从非极性柱导入到极性柱,使得甲缩醛、二甲醚、甲基叔丁基醚、丙酮、甲醇、乙醇、丙醛和丁醛共9种含氧化合物与液化石油气中烃类组分完全分离。结果显示,甲缩醛等9种含氧化合物在0.01%(v/v)~5.0%(v/v)范围内呈现良好的线性,相关系数均大于0.99,样品重复测定5次,相对标准偏差小于3%,加标回收率在92.11%~104.40%之间,含氧化合物检出限可达0.0003%(v/v)~0.0021%(v/v)。     

航空发动机喷气燃料颜色变化研究

颜色变化是喷气燃料质量变化最为直接的外观质量指标;概述了喷气燃料中烃类化合物、非烃类组分、含氮杂原子化合物、含硫杂原子化合物和含氧杂原子化合物等颜色变化不安定组分;简介了颜色变化的化学反应机理和氧化反应机理。     

H_2O_2氧解对褐煤腐植酸及含氧官能团的影响

采用H_2O_2氧解褐煤,研究了氧解条件对褐煤腐植酸含量的影响。通过Boehm滴定和FTIR分析研究了氧解条件对含氧官能团含量和基团结构的影响。结果表明,H_2O_2可有效提高褐煤中腐植酸含量、腐植酸含氧官能团含量和褐煤活性;最佳氧解条件为:氧解时间24 h,H_2O_2浓度20%,液固比0.8 m L/g,在此条件下,褐煤中总腐植酸含量增加了12.53%;氧解反应仅使褐煤中含氧官能团含量增加,腐植酸含量增大。     

H_2O_2氧解对褐煤腐植酸及含氧官能团的影响

采用H_2O_2氧解褐煤,研究了氧解条件对褐煤腐植酸含量的影响。通过Boehm滴定和FTIR分析研究了氧解条件对含氧官能团含量和基团结构的影响。结果表明,H_2O_2可有效提高褐煤中腐植酸含量、腐植酸含氧官能团含量和褐煤活性;最佳氧解条件为:氧解时间24 h,H_2O_2浓度20%,液固比0.8 m L/g,在此条件下,褐煤中总腐植酸含量增加了12.53%;氧解反应仅使褐煤中含氧官能团含量增加,腐植酸含量增大。     

Solubilization of Neyveli lignite by oxidative degradation: A potential source of carbochemicals

The recent and possible future shortages of petroleum-derived hydrocarbons for use as starting materials for the synthesis of organic chemicals/products have stimulated renewed interest in the use of coal as raw material for chemical production. Oxidatively solubilized coal and or lignite (OSC) in alcohol is a potential substitute for value added carbo-chemicals of the future. Phenomenal increase in the solubility of lignite in organic solvent consequent on treatment with dilute nitric acid under mild conditions was considered to be an expedient pathway for its direct utilization. The primary requirements for the solubilization are generation of functional groups like free carboxyl groups and size degradation. For the desired product the reaction should also be guided in such a manner, so that the aromatic/hydroaromatic moieties of the coal/lignite are preserved. The present study aims at the selection of the required reaction parameters for the conversion of lignite to such a product. Characterization of the original lignite and the products have been done chemically and spectroscopically. FT-IR, ¹³C (solid state) and ¹H NMR spectra have shown that substances posses both aromatic and aliphatic characteristics. The dominant functional groups which contribute to the reactivity of the substances are phenolic and carboxylic acids.     

Aspects of structural features in lignite and lignite humic acids

Structural features of a South Moravian lignite and its humic acid (HA) fraction were studied by means of UV–vis, ¹H and solid-state ¹³C NMR, and FT-IR spectroscopy in addition to basic elemental analyses. The structural differences between the original lignite and its HA-type fraction were relatively minor, and their unambiguous differentiation into distinct categories was possible only by statistical methods. The tested model functions speak strongly for the importance of choosing enough sensitive and meaningful structural parameters which most likely reflect the character or type-rank of the coal-like carbon in question. The results verified that certain aliphatic compounds have their special tasks in the complicated structural network of lignite HA material, and powerful aprotic solvents are needed to obtain a fully dissolved HA solution. Despite some organic material was lost during different effective washing purification operations, the purified lignite HA was typified without significant loss of structural information on the original HA fraction. FT-IR experiments correlated well with those obtained by ¹³C NMR. From environmental points' of view, some water soluble organic trace components released from the original lignite material may be potential troublemakers within the area surrounding the deposit.     

催化燃烧脂肪族氯代易挥发性有机物的研究进展

催化燃烧是处理低浓度挥发性有机物废气的有效方法。阐述了催化燃烧脂肪族氯代易挥发性有机物的反应机理,对贵金属、过渡金属氧化物、钙钛矿型复合氧化物和分子筛近年来研究较广泛和深入的催化剂体系的性能和特点进行了论述,分析催化剂的优缺点。讨论了反应原料气中水和非氯代有机物的加入对催化反应效果的影响,对今后研究和发展方向进行展望。     

CONDITIONING COAL GAS WITH REFRIGERATED METHANOL IN A SYSTEM OF PACKED COLUMNS

Experience with the operation of a pilot-scale unit is used to outline potential difficulties in the operation of acid gas removal systems on gases produced from coal. The pilot plant has been used to condition gases produced from subbituminous coal, devolatilized char, peat and lignite. The solvent used in the acid gas removal system has been refrigerated methyl alcohol. Data from this study document accumulation of hydrocarbons, sulfur and nitrogen compounds, and mercury in the circulating solvent.     

Characterization of surface properties of nitrogen-enriched activated lignites by spectroscopic and chromatographic coupled with LSER modelling measurements

One investigated way to prepare selective adsorbents towards mixtures of volatile organic compounds (VOCs) is to modify lignite by nitrogen-enrichment. These chemically modified coals are prepared by condensation of urea with the lignite before the carbonization/activation steps. This study describes a set of analytical tools able to explain in term of surface composition and of quantitative molecular interaction parameters the evolution of the selective behavior of three adsorbents. For this purpose, the evolution of the surface chemistry and the selectivity with three percentage of burn-off of a nitrogen-enriched lignite is followed by infrared and X-ray photoelectron spectroscopies and gas chromatography (GC)/linear solvation energy relationship (LSER) method. Then, the selectivity of these materials towards two test-pairs of VOCs is discussed. This QSBR investigation reveals the complementarity of these methods linking composition data of the active carbons and their selective properties.     

Hydrogenolysis of coal-related model compounds by carbon monoxide-water mixture

Model organic compounds have been subject to hydrogenolysis reactions using CO and H₂O under industrial conditions as used for lignite and residual oil. Twenty-eight compounds, including diphenylmethane, indane, tetralin, anthracene, diphenyl ether, indene, benzophenone and xanthene were used. The purpose is to study the hydrogenolysis behaviour of compounds with structures as found in coal and residual oil. Using a Co-Mo catalyst, scission of the CC chain connecting two aromatic rings is enhanced by increased chain length of the molecule. Ether bonds are broken more easily than CC bonds. With the exception of decalin, cyclic CC bonds are more resistant to cleavage than linear bonds. Alcohol hydroxyl, and carbonyl groups of stilbene are the easiest to reduce but phenolic hydroxyl groups are stable. The Co-Mo catalyst promoted hydrolysis of ether bonds as well as hydrogenolysis. The method of the study is considered to be more effective for hydrogenolysis of organic compounds than the reported use of alkali and tetralin because of milder reaction conditions which are required.     

Chromatographic separation of alkylated depolymerized Neyveli lignite

The study of macromolecular structure of coal has been subjected to intense research. Neyveli lignite was depolymerized using phenol and phosphotungstic acid and the resultant product was subsequently alkylated. The t-butylated depolymerized lignite exhibited enhanced extractability in organic solvents. The t-butylated depolymerized lignite was fractionated into different components using column chromatography (CC). Three major compounds were isolated and were characterized by FTIR, ¹H NMR and Mass spectral techniques.     

The influence of demineralisation and ammoxidation on the adsorption properties of an activated carbon prepared from a Polish lignite

The preparation of cheap nitrogen-enriched materials with large adsorptive capacities and selectivity towards volatile organic compounds remains a challenge. Ammoxidation has been used to prepare nitrogen-enriched activated carbons using a demineralised Polish lignite. The lignite samples were demineralised by two different methods before nitrogen-enrichment by ammoxidation and physical activation in steam. The surface chemistry was investigated by elemental analysis, Boehm titration, infrared and XPS spectroscopies and adsorptive properties by a linear solvation energy relationship approach. Results show a quasi-total demineralisation and a higher reactivity towards nitrogen for the demineralised samples. The BET surface is also higher than for the non-demineralised lignite. Active carbons previously ammoxidated and demineralised are more interesting in terms of selective removal of gaseous pollutants.