微波条件下氯化锌对乙醇抽提神府煤的影响

微波条件下,研究了在乙醇抽提神府煤中加入氯化锌对其结果的影响。采用气相色谱/质谱联用的方法分析了乙醇和乙醇-氯化锌抽提物的组成;利用傅里叶红外光谱技术分析了神府脱矿物质煤、乙醇抽余煤和乙醇-氯化锌抽余煤的结构。分析结果显示:在乙醇溶剂中添加少量的氯化锌,其抽提物的组成发生了改变;乙醇-氯化锌抽余煤与原脱矿物质煤和乙醇抽余煤相比,芳环吸收强度降低,表明在抽提过程中可能伴随着烷基化反应的发生。     

吡啶抽提前后柳林3~#煤的FTIR结构特征分析

为了解处于第二次煤化跃变过程中的柳林3~#煤的大分子结构特征,采用溶剂吡啶对柳林3~#原煤进行索氏抽提,借助FTIR分析测试手段并通过分段分峰拟合对柳林3~#原煤、抽提后残煤及抽提物的结构组成及其变化进行了研究。结果表明:抽提过程中,在吡啶溶剂的作用下,部分抽提物从煤大分子结构中脱离出来,这些抽提物包括短链脂肪结构和芳香醚、酚、酯等含氧官能团结构。抽提前后煤大分子骨架保持相对稳定,与原煤和抽提后残煤相比,抽提物的苯环四取代明显增加,二取代明显减少,说明残煤的脂肪链长、支链少,抽提物的脂肪链短、支链多。抽提后残煤、抽提物与原煤显示出不同的芳香度,其由大到小依次为抽提后残煤的芳香度、原煤的芳香度、抽提物的芳香度;柳林3~#原煤、抽提后残煤及抽提物中主要羟基类型是自缔合羟基,说明煤中羟基类型以缔合结构为主。     

小分子化合物对神华煤结构组成和热行为的影响

小分子化合物是通过二硫化碳、四氢呋喃、甲醇三种溶剂对神华煤进行逐级索氏抽提获得的。利用红外光谱和热重分析分别对原煤和抽掉小分子化合物后的残煤进行测试,可知小分子化合物被抽出后,煤的结构组成及热行为均发生了变化,残煤的脂肪烃和环烷烃基团明显减少,热失重速率降低,最大失重温度向高温段移动。     

煤高温快速液化过程中的单原子与双原子氢转移机理

氢转移对煤的加氢液化至关重要,理解氢转移机理对于改善煤液化过程具有重要意义。在微型反应釜中通过考察氢气的溶解、溶剂类型以及不同类型催化剂对煤高温快速液化的影响,揭示了煤高温快速液化过程中单原子氢和双原子氢的转移机理。结果表明,在以四氢萘、氢气为条件的高温快速液化过程中,主要的活性氢来源于溶剂所提供的单原子;在以四氢萘、氮气为条件的高温快速液化过程中,不同催化剂对溶剂提供单原子氢的影响不同。在以四氢萘和萘、氢气为条件的高温快速液化过程中,双原子氢基本未参与液化反应,溶解并不是其参与液化反应的主要影响因素。以萘为溶剂、氢气气氛下的高温快速液化过程中,双原子氢参与反应需要一定的时间。在以萘或四氢萘、氢气为条件的高温快速液化过程中通过加入一定量的催化剂,可以促使双原子氢快速参与反应。     

不同溶剂抽提下高阶煤的化学组成和结构变化

以山西长治霍尔辛赫矿贫煤为研究对象,对煤样分别进行了不同溶剂的抽提,并借助柱层析法和X射线衍射技术(XRD)对抽提物和抽余物进行了测试分析.结果表明:高阶煤进行溶剂抽提后,THF对煤样的抽提率最高,其次是CS2、丙酮和乙醇,苯的抽提率最低;除CS2抽提物中非烃类含量高于总烃含量外,其余溶剂的抽提物均表现为总烃含量大于非烃类含量,同时,随着抽提效果的增强,抽提物中非烃类化合物的质量分数逐渐增大;经溶剂抽提后抽余物的基本结构单元(BSU)的芳香层间距d002、堆砌度Lc和芳香层数N均表现出大于原煤微晶结构的规律,而延展度La在溶剂抽提后却呈现出小于原煤微晶结构延展度的特性.     

铁系催化剂对煤高温快速液化的影响

以兖州煤为研究对象,采用微型反应釜研究了两种铁系催化剂对煤高温快速液化的影响.结果表明,担载Fe2S3的催化剂和高分散铁系催化剂对煤的热解行为影响较小;担载Fe2S3催化剂促进了氢气参与反应和煤液化产物向轻质化转化,在优秀和足量的供氢溶剂条件下,溶剂的供氢速度明显优于氢气转换的供氢速度,催化剂的作用不明显;对比添加高分散铁系催化剂并加助剂S和添加Fe2S3催化剂的煤高温快速液化,发现元素S的作用与S和主催化剂铁的结合形态有关.     

氢气在煤高温快速液化中的作用

首先利用实验室建立的一套平衡液相取样法实验装置测定了氢气在四氢萘和萘中的溶解规律,其次通过间歇式微型反应釜研究了氢气在煤高温快速液化中的作用。结果表明:①氢气在溶剂中的溶解度随温度与压力的增加而增加;在一定的温度与压力下,氢气在四氢萘和萘中的溶解度在5 min内达到最大溶解量的78.54%左右,之后溶解度开始逐步缓慢上升直到30 min时达到最大溶解量;②在充足的四氢萘作为溶剂的液化反应中,氢气对于煤高温快速液化反应几乎没有影响,活性氢主要来源于溶剂;在萘作为溶剂的液化反应中,钼酸铵催化剂促进了氢气参与反应,但是总转化率的变化较小,仅仅促进了沥青烯向油方向的转化。③压力对于煤高温快速液化中四氢萘的供氢性能有影响。     

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。     

不同煤阶煤的吡啶抽提FTIR谱研究

在相同的实验条件下,对四种不同煤阶的煤用搅拌抽提法进行吡啶抽提,并利用傅立叶变换红外光谱(FTIR)对原煤及残煤进行了定量测试,讨论了不同抽提率产生的原因,研究了吡啶抽提前后官能团含量的变化。分析表明,溶剂吡啶主要作用于煤基本结构单元芳核的侧链和桥键。     

微波溶胀对五彩湾煤直接液化影响的研究

采用NMP/CS(2体积比1︰1)混合溶剂,在微波辐射下对五彩湾煤进行溶胀处理,并将原煤和微波溶胀煤样进行对比表征和加氢液化实验,考察了液化反应温度、反应气氛、溶胀剂对液化效果的影响。结果表明:微波溶胀后,煤样孔隙结构显著增加,结构发生变化。在液化条件是温度450℃、氢初压6.0 MPa、溶煤比1.75︰1和反应时间60 min,油产率和转化率分别是原煤55.02%和76.76%,微波溶胀煤74.03%和84.78%。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。