Ni/Al2O3催化剂上甲烷三重整制合成气

制备了负载于大孔容、高比表面的γ-Al2O3载体上的Ni基催化剂.采用固定床流动反应装置,考察了催化剂焙烧温度、反应条件(反应温度、压力、空速以及反应原料气组成)对甲烷三重整反应(TRM)制合成气的催化性能的影响.结果表明,650℃焙烧的催化剂具有较好的稳定性.在常压、850℃、10080h-1、n(CH4)/n(CO2)/n(H2O)/n(O2)=1/0.48/0.54/0.1的条件下,CH4转化率达到95.4%,CO2转化率达到84.6%,在此条件下连续运行9h未见活性下降.TRM反应适宜于在高温、低压下进行,原料组成的变化不会影响CH4转化率,但会影响CO2转化率和产物合成气的n(H2)/n(CO)比.     

超临界和近临界条件下Fischer Tropsch合成研究：溶剂的影响

研究了超临界和近临界条件下费托合成过程中溶剂对反应行为的影响。反应在固定床反应器中进行，催化剂为Co/SiO2，所选择的溶剂有两类：纯溶剂（正戊烷和正己烷）和混和溶剂（由正己烷和少量的C5~10烃组成）。结果表明,正己烷分压对CO转化率影响很小，但是产物中1 烯烃含量随正己烷分压增加而增加，超临界条件下1 烯烃含量明显高于非临界条件下。溶剂的种类对CO转化率、CH4和CO2选择性以及产物炭分布影响不大。这一结果表明为了减少溶剂用量，对含有适量轻组分（C5~10）的正己烷溶剂进行循环使用是可行的。结果同时表明与正己烷相比，混和溶剂（25%正己烷和75%正葵烷）具有较高的1 烯烃选择性。     

添加气对非平衡等离子体转化低碳烷烃的影响

在常压下, 研究了添加气的种类(N₂, He, Ar, H₂, NH₃, CO和CO₂)对介质阻挡放电低碳烷烃(甲烷、 乙烷和丙烷)转化制低碳烯烃的影响. 结果表明, 以甲烷或乙烷为原料时, N₂, He, Ar和CO的引入有利于提高原料的转化率和总烯烃的选择性; 而CO₂, H₂和NH₃的引入对甲烷、 乙烷的转化率无明显影响, 但H₂和NH₃的引入会使总烯烃的选择性显著降低. 以丙烷为原料时, 所研究的添加气均可提高丙烷的转化率, 而只有CO的引入可提高总烯烃选择性. 综上所述, 80%(摩尔分数) CO添加量最有利于低碳烷烃转化成低碳烯烃, 对应的甲烷、 乙烷和丙烷的转化率分别提高了14.4%, 17.6%和42.8%, 总烯烃的选择性分别提高了19.9%, 25.0%和11.9%. 以CH₄为例, 通过对放电电流波形和等离子体区物种的发射光谱(OES)研究发现, 引入CO能显著增加等离子体的电子密度, 并且体系中出现激发态O^*物种(777.5和844.7 nm), 这种O^*物种能够促进C-H键的断裂, 有利于烯烃的生成. 因此, 等离子体区电子密度的增加和激发态O^*物种的出现可能是CH₄-CO体系中CH₄有效转化的主要原因.     

Re/Ga2O3/WO3/ZrO2催化剂对正己烷异构化反应的催化性能

通过浸渍法制备了系列Re/Ga2O3/WO3/ZrO|2(ReGWZ)催化剂,采用X射线衍射、氢气程序升温还原和氨气程序升温脱附等方法对催化剂进行了表征,考察了该催化剂催化正己烷异构化反应性能.结果表明,Re的引入改变了催化剂的氧化还原性能和酸中心分布,且使催化剂由单一的酸中心催化变成由酸中心与金属中心共同催化,因而正己烷异构化率和2,2-二甲基丁烷选择性显著增加.在195℃,1.0MPa,LHSV=1.0h-1和n(H2)/n(C6)=2.0的反应条件下,1.0Re/1.0GWZ催化剂上正己烷转化率、异己烷选择性和2,2-二甲基丁烷选择性分别达到84.8%,97.7%和20%,裂解产物(C5-)选择性为2.1%.150h的稳定性实验表明该催化剂性能稳定.     

两段法甲烷催化氧化制合成气研究

提出了一种将甲烷低温催化燃烧和部分氧化相结合制取合成气的新方法 ,考察了反应条件对Pd Pt催化剂上的甲烷低温燃烧反应性能以及Ni-La2 O3 MgAl2 O4 -Al2 O3催化剂上甲烷催化氧化制合成气反应性能的影响。结果表明 :采用两个串联固定床反应器和分段进氧 ,不仅可以使反应原料偏离爆炸极限 ,确保过程的安全操作 ;而且一段反应器采用低温进料 ,通过少量甲烷催化燃烧 ,为二段反应提供含有少量CO2 、H2 O等氧化产物的反应原料。在二段反应器中 ,放热的甲烷部分氧化反应和吸热的蒸汽重整及CO2 重整反应同时进行 ,可避免催化剂床层飞温 ,使反应基本上在绝热恒温条件下进行 ,可用两个串联的固定床反应器实现甲烷部分氧化制合成气反应。在适合的反应条件下 ,甲烷转化率可达 93% ,H2 和CO选择性分别为 97%和 98%。     

Ni基催化剂上甲烷与空气或O_2/水蒸气部分氧化制合成气(英文)

在固定床反应器中考察了Ni基催化剂上甲烷氧化与空气或O2/水蒸气部分氧化制合成气的反应。用空气取代纯氧同样能获得高甲烷转化率和产物选择性。水的添加主要发生水气变换反应,同时也能降低催化剂上积炭。在甲烷与纯氧500小时反应的稳定性考察中,甲烷转化率、CO及H2选择性分别保持在90％、95％和95％以上;反应后上层催化剂的Ni含量从新鲜催化剂的7.2％下降到5.2％,在反应后的催化剂上没有发现积炭和相变。     

FeMn、FeMnNa和FeMnK催化剂上合成气制低碳烯烃的比较(英文)

研究了钠、钾助剂对FeMn合成低碳烯烃催化剂结构及性能的影响.低温N2吸附、X射线光电子能谱(XPS)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)、CO/CO2程序升温脱附(CO/CO2-TPD)、M?ssbauer谱和CO+H2反应的研究结果表明,增加Mn助剂含量促进了活性相的分散和低碳烯烃的生成,而过多锰助剂在催化剂表面的富集则降低了费托合成反应的CO转化率;钾助剂和钠助剂的加入均抑制了催化剂的还原并且促进了CO2和CO的吸附.比较还原后(H2/CO摩尔比为20)和反应后(H2/CO摩尔比为3.5)催化剂的体相结构可以发现,在FeMn、FeMnNa和FeMnK催化剂中,由于钾助剂的碱性和CO吸附能力较强,因此体相中FeCx的含量相对较高;而活性测试结果表明,FeMnNa催化剂拥有最好的CO转化率(96.2%)和低碳烯烃选择性(30.5%,摩尔分数).     

正癸烷和正己烷气相氧化裂解过程的研究

采用石英管反应器，常压下研究了正癸烷和正己烷的气相氧化裂解（GOC）过程。实验结果表明，O2的存在降低了正癸烷GOC反应的活化能，使反应在较低的温度下具有高的反应性能；O2同时起到消除积炭的作用，提高体系的抗积炭能力。于热裂解反应相比，低温下正癸烷的GOC反应更适合制备液体组分，同时联产低碳烯烃。在600℃，碳氧摩尔比为2.5时，正癸烷的GOC反应可获得39.9％的低碳烯烃收率和30.0％的液体收率。对于直链烷烃的GOC反应，低温下O2主要进行氧化脱氢反应，高温下则更多的进行 CO x(x=1,2)的生成反应；和正己烷分子相比，相同反应条件下O2更容易引发正癸烷分子的部分氧化反应生成CO。     

添加贵金属的Ni/α-Al2O3催化剂甲烷部分氧化制合成气的研究

甲烷部分氧化制合成气因其高空速、高转化率、低H2/CO比而引起人们的重视[1～5].本文研究了在Ni/α-Al2O3催化剂中添加的Rh、Ru、Pt和Pd等贵金属在甲烷部分氧化制合成气反应中的催化作用,重点研究了添加Pt对Ni/α-Al2O3催化剂反应性能的影响.     

焦炭与重质油共气化联产烯烃技术研究

针对中国乙烯、丙烯等低碳烯烃生产原料供需日益尖锐的矛盾和重质油利用技术的不足，提出焦炭与重质油共气化联产烯烃技术。阐述了焦炭与重质油共气化联产烯烃的技术原理及过程设计，并以固定床为反应器，焦炭和常压渣油为原料进行实验模拟。结果表明，当裂解温度为750℃~800℃，停留时间τ＜0.5s时，渣油在焦炭介质中裂解，其低碳烯烃含量最高；渣油在模拟气化裂解区、750℃下裂解时，得到出口气体中低碳烯烃（C2H4＋C3H6）、烷烃（CH4＋C2H6）及合成气（H2＋CO）的体积分数分别为20%、28%及46%。应用扫描电镜观察了焦炭介质表面上结焦生成物的形貌，发现通氧气后结焦生成物残留量较少。实验模拟结果证明，焦炭与重质油共气化技术可以制备低碳烯烃并联产合成气，且能有效地解决重质油裂解造成的结焦问题。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。