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采用超声辐射和机械搅拌相结合的方法,利用二硫化碳对陕北中低温煤焦油进行多次萃取,最终获得煤焦油全组成,利用GC/MS测定分析煤焦油全组成的化学成分。结果表明,陕北中低温煤焦油中共检测出170种组分,主要成分是芳烃、芳酚和正构烷烃,其相对含量分别为53.1%、19.2%和14.1%。另外,芳烃的种类高达97种,主要是2~4环芳烃,芳酚主要是由25种苯酚类和萘酚类物质组成,相对含量较高的组分是甲基苯酚和二甲基苯酚,正构烷烃中有14种烷烃类,分布于C13~C26,范围较宽。 相似文献
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用GC/MS和FTIR技术结合气相色谱外标定量分析方法,对神府煤甲醇萃取物进行了定性和定量分析,讨论了神府煤甲醇萃取物的化学组成及其结构特征.结果显示,神府煤甲醇萃取物的GC/MS可测组分主要由多环芳烃和含氧化合物组成,其中芳烃以2~3环的烷基取代稠环芳烃为主,含氧化合物中以酮类和酯类化合物居多;结果还检测到种类较多的含氮化合物和少量的含硫、磷、氯的化合物.GC/MS不可测组分的IR分析显示,其中主要官能团有各类羟基、羰基、芳环和亚甲基、甲基等,表明其中可能存在分子量较大的稠环芳香族或其酚、酸、酮、酯类及烷基衍生物的化合物. 相似文献
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随着环保要求的日益严格和清洁燃料的需求增加,低芳烃含量溶剂油亦需进一步脱芳烃。液液萃取脱芳技术因具有操作条件缓和、萃取剂可循环利用、可得到芳烃副产品等优势被广泛应用,但针对低芳烃含量的原料,萃取剂的研发是关键问题。本实验采用N,N-二甲基甲酰胺(DMF)+乙二醇复合萃取剂萃取分离低浓度芳烃溶剂油体系,从萃取剂对甲苯的选择性系数(S)和分配系数(K)两方面出发优化了脱芳萃取剂配方,确定乙二醇质量分数为15%的复合萃取剂适用于萃取分离芳烃质量分数小于15%的低芳烃原料。测定了常压、40℃时 DMF-甲苯-正庚烷和复合萃取剂-甲苯-正庚烷体系的液液相平衡数据,并用Othmer-Tobias 方程对实验数据进行关联。相平衡数据证实了复合萃取剂更适用于低芳烃原料油脱芳。将优化的复合萃取剂用于溶剂油脱芳烃,实验结果表明在萃取温度40℃、萃取时间5min、分相时间10min、单级剂油质量比0.5的操作条件下,经7级错流萃取,溶剂油的芳烃质量分数可从9.15%降至0.76%,具有一定的工业应用前景。 相似文献
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以KH2PO4/Al2O3为催化剂,针对以甲醇为烷基化试剂的酚油醚化体系,研究了5种混配组分(乙酸、甲酸、丙酮、呋喃、乙酸乙酯)对酚油醚化反应规律的影响。结果表明,丙酮对促进烷基酚转化为芳醚的作用效果最强。基于丙酮混配组分,500℃下探究了丙酮质量配比的影响,基于最佳丙酮添加量(50wt%),进一步考察了温度对反应体系的影响,并进行机理分析。结果表明,丙酮含量不高于70wt%时,液体收率随丙酮含量升高而降低,进一步提高丙酮含量时液体收率基本稳定。各丙酮含量下,液体产物中均未检出邻甲氧基苯酚或其它任何烷氧基酚。较高丙酮含量时烷基酚含量显著降低。丙酮含量为50wt %时,芳醚含量出现极大值(29.06area%),进一步提高丙酮含量,芳烃及其它组分显著增加,导致产物中芳醚含量降低。随反应温度升高,产物中的芳醚和芳烃含量分别在500和450℃时出现极大值。综合考虑液体收率和产物极性两方面因素,确定该反应体系的最佳反应温度为450℃,丙酮添加量为50wt%,最佳条件下产物中芳醚与芳烃总量达52.90area%。丙酮分子中的羰基与酚系物中的羟基发生作用,分解产生CO2,同时烷基酚与烷氧基酚脱羟基后分别得到芳烃和芳醚两类主要液相产物。 相似文献
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两种亮煤用CS2-NMP溶剂抽提后的结果分析 总被引:2,自引:0,他引:2
研究了童亭亮煤和洼里亮煤在CS2 - NMP混合溶剂中的可溶性,重点考察了原煤,萃取物,萃余物在工业分析、真密度和黏结指数方面的联系;同时运用红外光谱( FTIR)现代分析技术对原煤及其萃取物和萃余物的组成和结构特征进行了对比分析,在此基础上提出了煤中主要存在两种组分即“致黏组分”和“不黏组分”的概念,并据此对胶质体液相的来源作了初步解释.最后得出了萃取物中主要是煤中富含脂肪族和酚,醇,醚结构的组分,而萃余物中主要是富含缩合芳环的组分. 相似文献
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《过程工程学报》2019,(6)
以KH_2PO_4/Al_2O_3为催化剂,针对以甲醇为烷基化试剂的酚油醚化体系,研究了5种混配组分(乙酸、甲酸、丙酮、呋喃、乙酸乙酯)对酚油醚化反应规律的影响。结果表明,丙酮对促进烷基酚转化为芳醚的作用效果最强。基于丙酮混配组分,500℃下探究了丙酮质量配比的影响,基于最佳丙酮添加量(50wt%),进一步考察了温度对反应体系的影响,并进行机理分析。结果表明,丙酮含量不高于70wt%时,液体收率随丙酮含量升高而降低,进一步提高丙酮含量时液体收率基本稳定。各丙酮含量下,液体产物中均未检出邻甲氧基苯酚或其它任何烷氧基酚。较高丙酮含量时烷基酚含量显著降低。丙酮含量为50wt%时,芳醚含量出现极大值(29.06area%),进一步提高丙酮含量,芳烃及其它组分显著增加,导致产物中芳醚含量降低。随反应温度升高,产物中的芳醚和芳烃含量分别在500和450℃时出现极大值。综合考虑液体收率和产物极性两方面因素,确定该反应体系的最佳反应温度为450℃,丙酮添加量为50wt%,最佳条件下产物中芳醚与芳烃总量达52.90area%。丙酮分子中的羰基与酚系物中的羟基发生作用,分解产生CO_2,同时烷基酚与烷氧基酚脱羟基后分别得到芳烃和芳醚两类主要液相产物。 相似文献
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裂解汽油是含有烯烃的重要芳烃资源,二甲基亚砜(DMSO)能够从高烯烃含量组分中选择性萃取芳烃,测定相应体系液-液平衡是裂解汽油中的芳烃萃取过程研究开发的理论基础。测定了常压下293.15、298.15、303.15 K时甲苯-正己烯-DMSO体系液-液平衡数据,获得了三元体系的相图和褶点,并采用Hand方程和NRTL方程进行关联。体系中甲苯对正己烯选择性系数为2~6,表明DMSO萃取分离甲苯和正己烯理论上可行。通过体系液-液平衡关联获得了NRTL方程模型参数,利用NRTL模型对该体系进行计算,计算值与实验值的平均偏差较小,说明NRTL模型适用于该体系的液-液平衡。 相似文献
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A new ampholytic homopolypeptide, , which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO4 and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu2+ and Ca2+, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu2+ complex near 240 nm. Dependence of the peak intensity on pH at various q values () indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu2+ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu2+ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu2+-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation. 相似文献
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Silvia Schicker Daniel E. García Igor Gorlov Rolf Janssen Nils Claussen 《Journal of the American Ceramic Society》1999,82(10):2607-2612
Wet milling of Al2 O3 -aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al2 O3 and Fe2 O3 /Al/Al2 O3 powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe2 O3 /Al/Al2 O3 powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al2 O3 powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8. 相似文献
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Sintering kinetics of the system Si3 N4-Y2O3 -Al2 O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si3 N4 were studied with additions of 4 to 17 wt% Y2 O3 and 4 wt% A12 O3 . Sintering occurs by a liquid-phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X-ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β ' -Si3 N4 and glass or β '-Si3 N4 , α '-Si3 N4 , and glass. The compositions and amounts of the residual glassy phases are estimated. 相似文献
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Akira Akimoto 《Polymer》1974,15(4):216-218
The polymerization of vinyl chloride has been investigated using an catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed. 相似文献
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Mats Carlsson Mats Johnsson Mats Nygren 《Journal of the American Ceramic Society》1999,82(8):1969-1976
Ta0.33 Ti0.33 Nb0.33 C and Ta0.33 Ti0.33 Nb0.33 C x N1− x whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N2 . The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO2 , Ta2 O5 , Nb2 O5 , C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl2 ( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature. 相似文献