共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
煤化工工艺技术评述与展望Ⅱ.合成乙烯和二甲醚 总被引:7,自引:0,他引:7
评述了由合成气合成乙烯和二甲醚的研究进展和工业开发状态,比较和讨论了合成乙烯和二甲醚的各种工艺路线,提出我国合成乙烯和二甲醚的工业开发方向。 相似文献
4.
5.
6.
7.
8.
9.
合成甲醇反应中CO_2和微量O_2的作用以及反应机理的研究 总被引:2,自引:0,他引:2
本文采用TPD-MS联用,“原位”X-射线衍射和原位红外光谱等实验技术以及催化反应动力学装置,对合成甲醇反应CO_2和微量O_2的作用进行了深入研究。当CO_2浓度在1.0—8.0%范围内,可使甲醇合成反应速率加快。合成反应中适量O_2的作用是在反应过程中先转变为CO_2或吸附态CO_2,然后反应在含适量CO_2的合成气氛下进行。对CO_2的作用机制得出了明确的结论,并对CO_2存在下的多途径反应机理进行了探讨。根据实验结果和理论分析,提出反应气氛中CO_2浓度在1.3%左右,即可维持高反应速率和催化剂的稳定性,以可降低甲醇中的水含量。此结果对改进合成甲醇工艺有参考价值。 相似文献
10.
11.
12.
保护的预酯化紫杉醇侧链的合成 总被引:1,自引:1,他引:0
以市场可购得的(2R,3S)-苯基异丝氨酸盐酸盐为起始原料,通过在甲醇的氯化亚砜溶液中进行酯化反应,及随后对氨基进行苯甲酰化,氨基羟基的环化保护,最后对其酯进行水解,合成得到保护的预酯化的紫杉醇侧链.整个过程无需柱层析操作,适于工业化生产.为制备保护的预酯化紫杉醇侧链提供了一种有效而又实用的合成方法. 相似文献
13.
针对小试制剂过程建立的近红外定量模型难以直接应用于中试或大生产过程中的问题,该文以小试和中试条件下多批次药用糊精流化床制粒过程为载体,在线采集其近红外光谱数据并测定水分含量,建立小试过程水分近红外定量模型,提出并应用有指导的正交投影技术结合斜率/截距校正的模型传递方法跨尺度预测中试样本,使中试两个测试集A和B的水分相对预测误差分别由51.04%和26.64%降至4.90%和3.99%,显著提高了模型预测的准确度。将该结果与无指导的正交投影技术结合斜率/截距校正法以及模型更新相比较,该方法能更加有效地去除待测样本光谱中的干扰信息,适用范围广,为小试建立的模型放大应用到中试甚至大生产过程提供了新方案。 相似文献
14.
B. I. Podlovchenko R. A. Manzhos Yu. M. Maksimov 《Russian Journal of Electrochemistry》2006,42(10):1061-1066
The method of transients of the open-circuit potential, combined with cathodic potentiodynamic pulses, is used for studying the methanol interaction with preliminarily adsorbed oxygen (Oads) in 0.5 M H2SO4. It is established that, for the larger part of the time period required for a full reduction of a monolayer of Oads in solutions of methanol on polycrystalline platinum, the process occurs at large coverages of the surface by Oads (?O). In the region of medium coverages, transients of the open-circuit potential are accurately described by the equation that corresponds to the mechanism of “conjugated reactions.” The mechanism of the methanol interaction with Oads happens to be close to that for formic acid, which is explained by a dissociative character of these HCO compounds. Kinetic parameters characterizing the methanol reaction with Oads in the region of large and medium coverages are determined and analyzed. 相似文献
15.
二甲醚(DME)由于具有高的十六烷值,在燃烧过程中可降低氮氧化物等有害气体的排放,实现无烟燃烧,可作柴油发动机的洁净替代燃料,被认为是"二十一世纪的洁净燃料"。此外,DME液化气的物性与液化石油气相似,燃烧性能优于液化石油气(LPG),可作优良的民用洁净燃料。九十年代初,中国科学院山西煤炭化学研究所在国内首先提出以DME替代LPG作洁净民用燃料。他们在实验室研究开发了氧化铝和分子筛两种类型的甲醇脱水制二甲醚催化剂,考察了工艺条件对反应的影响;确定了产品的分离、精制过程;对催化剂制备放大后进行了寿命试验并在1升催化剂的模试装置上进行了验证;提出了适合中、小规模生产的甲醇催化脱水制DME液化气工艺流程并进行了500t/a甲醇脱水制DME液化气的工业试验,甲醇单程转化率为~78%,DME收率为~98%:对所生产的DME液化气进行燃烧试验、环境卫生及卫生防疫检测,结果符合国内有关标准。 相似文献
16.
Amanda‐Lynn Marshall Peter J. Alaimo Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(17):4970-4980
A rapidly expanding area of inquiry is the use of plant biomass for the industrial production of organic compounds for which there is high demand. This interest is fuelled largely by the anticipated decline in the supply of petroleum, and the inevitable concomitant rise in cost. Over the past 30 years, significant progress has been made toward the large‐scale conversion of plant biomass to common chemicals such as methanol, ethanol, glycerol, substituted furans, and carboxylic acids. However, examination of the list of top production organic chemicals reveals numerous opportunities for future development, including simple halocarbons, alkenes and arenes. Progress toward efficient and economical production of these challenging targets from biomass has recently been reported, and future success is likely to continue through academic and industrial collaboration. 相似文献
17.
《Journal of Energy Chemistry》2017,26(6):1067-1076
Direct methanol fuel cells are one of the most promising alternative energy technologies in the foreseeable future, but its successful commercialization in large scale is still heavily hindered by several technical shortfalls, especially the undesirable activity and durability issues of electrocatalysts toward methanol oxidation reaction. In light of these challenges, the inherent advantages of unsupported Pt based nanostructures demonstrate their great potentials as durable and efficient electrocatalysts for direct methanol fuel cells. This review will summarize recent achievements of unsupported Pt-based electrocatalysts toward methanol oxidation, with highlighting the interactions between the performance and structure tailoring and composition modulating. At last, a perspective is proposed for the upcoming challenges and possible opportunities to further prompt the practical application of unsupported Pt-based electrocatalysts for direct methanol fuel cells. 相似文献
18.
把虚拟仿真实训系统引入中职化工专业必修课"甲醇生产工艺"教学,探究虚拟仿真实训系统对中职教学的作用。选取平行和实验班设计了传统、虚拟仿真2种教学方案,用虚拟仿真实训系统构建甲醇工业生产虚拟场景,模拟生产操作流程、控制、危险因素演示等,使学习者在无毒无害环境下轻松操作练习甲醇生产流程。结果显示虚拟仿真实训系统能有效弥补实训手段的不足,促进学生知识原理和操作过程的掌握,改善学习态度,有效提升学习兴趣和成就感,在提升学习效果和质量方面具有显著的促进作用。 相似文献
19.
20.
Graham McLaurin Dr. Kyuchul Shin Dr. Saman Alavi Dr. John A. Ripmeester 《Angewandte Chemie (International ed. in English)》2014,53(39):10429-10433
Contrary to the thermodynamic inhibiting effect of methanol on methane hydrate formation from aqueous phases, hydrate forms quickly at high yield by exposing frozen water–methanol mixtures with methanol concentrations ranging from 0.6–10 wt % to methane gas at pressures from 125 bars at 253 K. Formation rates are some two orders of magnitude greater than those obtained for samples without methanol and conversion of ice is essentially complete. Ammonia has a similar catalytic effect when used in concentrations of 0.3–2.7 wt %. The structure I methane hydrate formed in this manner was characterized by powder X‐ray diffraction and Raman spectroscopy. Steps in the possible mechanism of action of methanol were studied with molecular dynamics simulations of the Ih (0001) basal plane exposed to methanol and methane gas. Simulations show that methanol from a surface aqueous layer slowly migrates into the ice lattice. Methane gas is preferentially adsorbed into the aqueous methanol surface layer. Possible consequences of the catalytic methane hydrate formation on hydrate plug formation in gas pipelines, on large scale energy‐efficient gas hydrate formation, and in planetary science are discussed. 相似文献