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癸二睛加氢制癸二胺骨架镍催化剂的研究 总被引:3,自引:0,他引:3
本文介绍了癸二脯加氢制癸二胺用骨架镍催化剂的制备方法、活化条件,以及反应温度、压力、接触时间等因素对转化率的影响,揭示了骨架镍催化剂的反应特性和用于癸二脑加氮的最佳操作条件。 相似文献
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Structured catalysts consisting of metal sheets on which Raney nickel was deposited by the thermal spraying method were tested for the liquid‐phase hydrogenation of glucose to sorbitol and 2‐nitrotoluene to 2‐methylaniline, used as model reactions. Catalytic tests performed in a bench‐scale (1 L) reactor showed that the catalytic activity of Raney Ni sheets is significantly higher than the one of the pellets used for fixed‐bed applications, but lower than the activity of the powder catalyst used in slurry mode. The activity could be significantly improved when applying a two‐phase co‐current flow through a monolith. In this case, the activity was superior to the one obtained with the slurry catalyst. These results confirm the potential of Raney Ni monoliths as structured catalysts. 相似文献
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The liquid‐phase catalytic hydrogenation of iso‐valeraldehyde to iso‐amyl alcohol was studied in a slurry reactor. The kinetics of liquid‐phase hydrogenation of iso‐valeraldehyde over a 5% Ru/Al2O3 catalyst was studied in the range of temperature 373‐393 K and H2 pressure 0.68‐2.72 MPa using 2‐propanol as the solvent. The selectivity to iso‐amyl alcohol was 100%. The kinetic data were analyzed using a simple power law model. A single site Langmuir‐Hinshelwood type model suggesting dissociative adsorption of hydrogen and surface reaction as the rate‐controlling step provided the best fit of the experimental data. The catalyst could be reused thrice without any loss in activity. 相似文献
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用细粉末Raney-Ni催化剂研究了木糖水溶液加氢的本征反应动力学。在考察的温度(373~393K)、压力(1~6MPa)和木糖浓度(0.02~1.3mol/dm3)范围内,速率与木糖浓度成1级。氢压低于4~5MPa时,符合Langmuir-Hinshewood形式的方程,用非线性优化法关联其参数,得到本征速率方程。反应机理推测为吸附氢原子与吸附木糖分子反应,表面反应生成的中间物被木糖解吸而成产物是控制步骤。373K以上在高压区出现的速率剧增现象可能与低能吸附位的激活有关 相似文献
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采用骨架钴和骨架镍催化剂加氢还原制备糠醇的研究 总被引:3,自引:1,他引:2
从钼、铬、铜和铁中筛选金属铬和铁作为助催化剂加入骨架钴或骨架镍催化剂,铬和铁的量分别为催化剂质量的3%和1%。在100~120℃、10~12MPa条件下,用上述骨架钴或骨架镍催化剂在乙醇溶剂中,氢化还原糠醛制备糠醇。用骨架镍催化剂,反应产物含有785%的糠醇和196%的四氢糠醇;用骨架钴催化剂,反应产物含有988%的糠醇和08%的四氢糠醇,收率94%。在无乙醇溶剂条件下,反应产物含有905%的糠醇、03%的四氢糠醇和92%的糠醛。在180℃条件下,反应产物含有908%的糠醇和89%的四氢糠醇。 相似文献
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采用非晶态雷尼镍催化剂,在高压反应釜内对二丙酮醇、糠醛、苯酚和愈创木酚等生物油模型化合物进行低温催化加氢实验,研究了模型化合物催化加氢特性、反应机理以及催化剂性质。实验结果表明:温度是影响此类催化剂活性的最主要因素,温度过高容易导致催化剂晶化而降低催化活性;在反应温度180℃、压力3MPa、反应时间4 h以及催化剂量8%(wt)时,模型化合物的转化率和饱和醇的选择性分别达到100.00%和97.74%以上;在此反应条件催化真实生物油的体系中,饱和醇的收率达到44.00%,p H从4.08升至5.13;通过对模型反应机理的探讨,得出模型主要通过两种加氢方式进行:即不同化合物分别以其O上的孤对电子选择性地与催化剂上的两种活泼态H(弱吸附的Ni-H、游离的原子态氢)进行加氢反应,完成催化加氢过程。 相似文献
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Yingxin Liu Zuojun Wei Shuguang Deng Jiyan Zhang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(9):1381-1389
BACKGROUND: Liquid‐phase catalytic hydrogenation of m‐dinitrobenzene is an environmentally friendly routine for m‐phenylenediamine production. The key to increasing product yield is to develop catalysts with high catalytic performance. In this work, La2O3‐modified Ni/SiO2 catalysts were prepared and applied to the hydrogenation of m‐dinitrobenzene to m‐phenylenediamine. The effect of La2O3 loading on the properties of Ni/SiO2 was investigated. The reaction kinetic study was performed in ethanol over Ni/3%La2O3–SiO2 catalyst, in order to clarify the reaction mechanism of m‐dinitrobenzene hydrogenation. RESULTS: It was found that the activity of the silica supported nickel catalysts is obviously influenced by La2O3 loading. Ni/3%La2O3–SiO2 catalyst exhibits high activity owing to its well dispersed nickel species, with conversion of m‐dinitrobenzene and yield of m‐phenylenediamine up to 97.1% and 94%, respectively. The results also show that Ni/3%La2O3–SiO2 catalyst can be reused at least six times without significant loss of activity. CONCLUSION: La2O3 shows strong promotion of the effect of Ni/SiO2 catalyst for liquid‐phase hydrogenation of m‐dinitrobenzene. La2O3 loading can affect the properties of Ni/SiO2 catalyst. Based on the study of m‐dinitrobenzene hydrogenation kinetics over Ni/3%La2O3–SiO2 catalyst, a possible reaction mechanism is proposed. Copyright © 2009 Society of Chemical Industry 相似文献
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甘油的间接氢解是新近发展的制备1,3-丙二醇的方法.研究发现甘油的间接氢解中间体TPD(2-对甲苯磺酰氧基-1,3-丙二醇)加氢过程产生的对甲苯磺酸腐蚀催化剂,导致催化剂无法重复利用.为了避免催化剂被腐蚀,选用几种缚酸剂,研究了缚酸剂对TPD加氢反应的影响,通过单因素实验考察了温度、压力和催化剂(Raney Ni)用量对反应的影响,并对反应机理作了讨论.结果表明:三乙胺作为缚酸剂时较优的反应条件为:温度100℃,压力4 MPa,催化剂用量2.0 g(TPD质量的57%),在此反应条件下,TPD转化率为89.1%,1,3-丙二醇的选择性为33.7%.催化剂重复实验结果表明加入缚酸剂能在一定程度上保护催化剂. 相似文献
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改性Raney Ni催化剂用于加氢合成间苯二甲胺 总被引:2,自引:1,他引:1
采用改性RaneyNi催化剂 ,研究了溶剂、温度、压力、催化剂用量对间苯二甲腈 (IPN)加氢合成间苯二甲胺 (m XDA)反应的影响。结果表明 ,该催化剂在以甲醇、甲苯为混合溶剂 ,V(甲醇 )∶V(甲苯 )=1∶2 ,当m(溶剂 )∶m(IPN) =3∶1,反应温度 70℃、压力 6 0~ 7 0MPa、催化剂用量为原料质量 10 %时 ,IPN转化率接近 10 0 % ,m XDA收率达 97%。失活催化剂经再生 ,即能恢复其性能。 相似文献
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糠醛液相加氢制糠醇骨架钴催化剂反应动力学研究 总被引:1,自引:0,他引:1
采用合金架钴催化剂在间隙高压反应釜中进行了糠醛液相加氢反应动力学及失活动力学的研究。提出了该反应的动力学及失活动力学的数学模型,并求得了该反应的反应级数、反应活化能值、反应速率常数及失活速率常数值,还测得了钴催化剂的使用寿命。 相似文献
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Pavel Kukula Martin Studer Hans‐Ulrich Blaser 《Advanced Synthesis \u0026amp; Catalysis》2004,346(12):1487-1493
The chemoselective hydrogenation of cinnamonitrile to 3‐phenylallylamine proceeds with up to 80% selectivity at conversions of >90% with Raney cobalt and up to 60% selectivity with Raney nickel catalysts. Best results were obtained with a doped Raney cobalt catalyst (RaCo/Cr/Ni/Fe 2724) in ammonia saturated methanol at 100 °C and 80 bar. Major problems are the formation of hydrocinnamonitrile and of secondary amines, and overreduction to 3‐phenylpropylamine. Important parameters are the catalyst type and composition, the solvent type and the presence and concentration of ammonia. The catalytic system tolerates functional groups like OH, OMe, Cl, CO, but not aromatic nitro groups. Preliminary experiments indicate that other unsaturated nitriles with di‐ or trisubstituted CC bonds are also suitable substrates. 相似文献
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Haoan Fan Bolong Li Xuezhi Zhao Zhecheng Fang Chao Chen Wenhua Zhou Wulong Yang Mian Li Xiuyang Lu Jie Fu 《American Institute of Chemical Engineers》2023,69(7):e18056
The kinetics and mechanisms of selective maltose hydrogenation over Raney Ni remain poorly understood, which hinders the industrial advancement of maltitol production for biorefining. Herein, the impact of hydrogenation conditions and in-depth mechanistic characterizations were carefully investigated in this research. Optimization of reaction conditions illustrated that maltitol formation was favored by moderate reaction temperatures (≤130°C), high hydrogen pressures (>7 MPa), and near-neutral sodium phosphate buffer (pH = 6.47). Kinetic studies demonstrated the Ea of 45.5 kJ/mol for the hydrogenation of maltose. The in situ IR revealed that the hydrogenation of maltose over Raney Ni occurs in the order of ring opening and adsorption via CO of the aldose form followed by hydrogenation. The UV–vis spectra demonstrated the near-neutral setting (pH = 6.47) promoted the production of open-chain aldose conformation and selective CO hydrogenation to the corresponding alcohols. The present study on concentrated-maltose hydrogenation paves the way for the industrial development of maltitol manufacturing. 相似文献
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以Pd/C为催化剂的松香加氢本征动力学 总被引:1,自引:1,他引:1
在温度403~433K,压力3.0~7.0MPa下,研究了以Pd/C为催化剂的松香催化加氢本征动力学,为工业反应过程的开发和操作提供了理论依据.通过减少催化剂粒度和提高搅拌转速,以消除内外扩散的影响,在松香加氢反应过程中,在线跟踪了反应物和产物浓度随反应时间的变化关系.根据实验数据,采用EVIEWS软件对10个可能的反应机理模型进行筛选,认为最可几的反应机理为松香中的主要成分枞酸分子不吸附,枞酸分子与催化剂表面上被吸附的氢原子进行反应,氢原子的吸附为控制步骤;其反应动力学方程为, 据此导出反应速率常数和吸附平衡常数分别为 (Hk =5.695exp((2498.5/T), bs =9.4(10(3exp(1920.8/T). 相似文献
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用固定床反应器作为气相加氢装置,将自制Cu硅胶催化剂用于间硝基甲苯催化加氢制备间甲苯胺的反应。通过考察Cu含量以及助剂N i、Co、Cr、Mn对催化剂性能的影响,筛选出催化性能最佳的Cr-Cu硅胶催化剂。分析了各反应因素对间甲苯胺产率的影响:当反应时间1.5 h,反应温度270℃,氢气与间硝基甲苯摩尔比为9∶1时,间甲苯胺的产率达到最大值99.4%,此时Cr-Cu硅胶催化剂的最大负荷为1.1 mL/(h.mL-cat.),满足工业化应用水平。目前该工艺的中试生产线正在805厂调试中。 相似文献
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Hydrogenation of heptaldehyde to heptyl alcohol was studied with W2 Raney nickel catalyst, prepared in the laboratory, commercial
Raney nickel catalyst and Rufert nickel catalyst by varying temperature, catalyst concentration, hydrogen pressure and reaction
time. The products were analyzed by gas-liquid chromatography on SE-30 column. The optimum conditions found for quantitative
conversion (99.6%) of heptaldehyde to heptyl alcohol were: temperature, 100°C, W2 Raney nickel catalyst concentration, 2%
based on heptaldehyde (w/w), hydrogen pressure, 145 psig and reaction time, 1 h.
IICT Communication No. 3085. 相似文献
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介绍了己二胺生产中用高活性雷尼镍催化剂的制备过程,确定了催化剂活性与水洗水流量、活化合金粉用量的对应关系。并探讨了在己二胺生产中最佳的催化剂浓度。 相似文献