溶剂对完全液相法制CuZnAl浆状催化剂结构和性能的影响

采用完全液相法,以拟薄水铝石为铝源,选择不同溶剂溶解催化剂前体硝酸铜和硝酸锌制备了CuZnAl浆状催化剂,并采用X射线粉末衍射、氮吸附.X射线光电子能谱和程序升温还原对其进行了表征,考察了CuZnAI浆状催化剂在合成气一步法合成二甲醚反应中的催化性能.结果表明,不同的溶剂对催化剂性能有显著的影响,其中以乙二醇为溶剂制备的催化荆相结构稳定,孔径及孔体积最大,表面铜含量高,可还原铜量较多且还原温度偏低,从而在保证DME选择性不变的条件下显著提高了催化剂CO转化率.     

不同加料方式对完全液相法制CuZnAl浆状催化剂结构和性能的影响

采用完全液相法,以拟薄水铝石为铝源,选择不同加料方式制备了CuZnAl浆状催化剂,并采用X射线粉末衍射、氮吸附、X射线光电子能谱和程序升温还原对其进行了表征,考察了CuZnAl浆状催化剂在合成气制取甲醇、二甲醚反应中的催化性能.结果表明,不同加料方式对催化剂性能有显著的影响,其中采用铜与锌同时加入的方式制备的催化剂相结构稳定,比表面积较大,催化剂表面元素铜含量高,可还原铜量多,且还原温度低,从而提高了催化剂的CO转化率和醇醚总选择性.     

完全液相制备催化剂上合成二甲醚动力学研究

采用浆态床反应器,研究了用完全液相法制备的Cu-Zn-A l双功能催化剂上CO加氢直接合成二甲醚(DME)的反应动力学。按CO加氢先合成CH3OH,再由CH3OH脱水生成DME二步串联的反应机理,根据不同的中间产物及控制步骤分别建立了动力学模型,以反应物的平衡浓度代替逸度进行计算,最终选取的模型计算值和实验值吻合较好,说明采用L-H型动力学模型可以合理地描述催化剂表面的反应过程,模型参数计算结果表明,催化剂表面对CO2的弱吸附是该催化剂在浆态床中稳定性较好的主要原因之一。     

合成气液相一步法制备二甲醚

介绍了二甲醚的液相合成气一步法制备工艺及其应用。     

共沉淀法制备浆状催化剂前躯体对一步法合成二甲醚的影响

用共沉淀法制备一步法合成二甲醚浆状催化剂的前躯体,完全液相热处理后,在浆态床中对其催化性能进行了测试,通过XRD、BET和元素分析对其进行了表征。结果表明,将Zr组分引入CuZnSiAl催化剂后,催化剂二甲醚的选择性提高。     

浆态床合成二甲醚用CuZnAlSi催化剂的完全液相法制备及表征

采用完全液相法制备了不同SiO₂含量的二甲醚(DME)合成CuZnAlSi双功能催化剂,并在浆态床反应器中评价其催化反应活性,通过in-situ XPS、XRD、BET、NH₃-TPD等方法对其物理化学性能进行研究。结果表明,CuZnAl催化剂中加入SiO₂组分,能够促进活性组分Cu的分散,并通过与AlOOH的作用调变催化剂的孔结构和表面酸性,从而提高催化剂在DME合成反应中的活性。准原位 XPS表征结果显示,还原后的催化剂表面Cu⁰和ZnO共同构成DME合成反应中的甲醇合成活性中心。SiO₂的加入可能导致Cu、Zn和Al组分间的相互作用减弱,催化剂稳定性降低。     

Ti助剂对完全液相法制备CuFe浆状催化剂低温合成低碳醇性能的影响

采用完全液相法制得不同Ti含量的CuFeTi浆状催化剂。通过XRD、H₂-TPR、BET、CO-TPD-MS、NH₃-TPD-MS等进行表征,探究在220℃、3 MPa下低温催化CO加氢合成低碳醇的性能。结果表明,适宜含量的Ti助剂有助于降低Cu⁰晶粒尺寸,增强Cu⁰晶粒的稳定性,提高催化剂中Cu⁺和Fe_xC含量,增强CuFe间的协同作用,显著抑制了水煤气变换反应,降低了CO₂选择性。其中CF-Ti_0.6表现出最佳的催化性能,在220℃、3 MPa下,总醇选择性45.09%,低碳醇占比54.85%,CO₂选择性仅为14.89%。     

完全液相法催化剂上甲醇脱水合成二甲醚的动力学及DFT研究

采用完全液相法制备AlOOH催化剂并进行了浆态床反应器中甲醇脱水制备二甲醚的反应动力学和DFT的研究。在3种甲醇脱水制备二甲醚的反应机理中,以表面反应即两个同时吸附的甲醇反应生成二甲醚作为速控步骤,所建立动力学模型的计算值和实验值吻合较好。采用DFT计算了液体石蜡环境中AlOOH(100)面的脱水反应,其反应过程和活化能结果与动力学模型结果基本一致,进一步表明采用该模型可以合理描述完全液相法制备的AlOOH催化剂表面甲醇脱水反应过程。     

以不同含Si复合氧化物为基体合成二甲醚浆状催化剂的研究

采用完全液相法制备了CuZn/SiAl、CuZn/SiZr和CuZn/SiTi三种含Si二甲醚合成催化剂。利用X射线粉末衍射、NH3-TPD等方法对催化剂进行了表征。研究表明,3种含Si催化剂合成二甲醚的活性次序为:CuZn/SiAl>CuZn/SiZr>CuZn/SiTi;Si-Zr复合氧化物作为载体有利于表面Cu物种的分散;3种催化剂具有不同的酸量和酸强度,中强酸对二甲醚的生成有利。另外,3种催化剂均表现出了不同程度的失活,这与Si组分的存在有关。     

合成气一步法制二甲醚工艺及催化剂研究进展

二甲醚在车用燃料和民用燃料方面具有良好发展前景。合成气一步法制二甲醚工艺分气相法和浆态床法。综述了合成气一步法制取二甲醚的工艺和催化剂的研究进展以及工业化前景。     

Synthesis of methanol and ethanol over CuZnAl slurry catalyst prepared by complete liquid-phase technology

A new method, named the complete liquid-phase technology, has been applied to prepare catalysts for methanol synthesis. Its main innovative thought lies in preparing slurry catalysts directly from raw solution. Activity tests indicate that the CuZnAl slurry catalyst prepared by the new method can efficiently catalyze conversion of syngas to ethanol in a slurry reactor, while CO conversion reaches 35.9% and ethanol selectivity is more than 20%, with a total alcohol selectivity of more than 87%. No deactivation was found during the 192 h reaction.     

非金属改性CuZnAl催化性能研究

考察非金属络合剂改性CuZnAl催化剂的催化性能和结构特征。通过完全液相法制备络合剂改性CuZnAl催化剂,在500 mL浆态床中进行CO加氢反应,并用XRD,H_2-TPR,NH_3-TPD,CO_2-TPD表征催化剂表面性质。在250℃,5 MPa,n(H_2)/n(CO)=2/1和空速360 mL/(h·g)下,N-甲基吡咯烷酮和三乙醇胺络合物改性CuZnAl催化剂产物中乙醇选择性达24.5%;表征显示该催化剂特征是表面Cu~+和Cu~0共存,且有高碱酸比。研究表明:络合剂改性CuZnAl能改变活性组分物相状态和表面酸碱性质,能增强碳链增长能力,为合成气合成乙醇展示良好的发展前景。     

胶溶剂对完全液相法制备的Cu/Zn/Al催化剂结构和性能的影响

采用完全液相法制备了Cu/Zn/Al浆状催化剂,考察了胶溶剂HNO3用量对催化性能的影响。结果表明,适量的胶溶剂HNO3用量可以减小Cu0晶粒度,提高催化剂的活性;胶溶剂的用量可以改变催化剂各组分之间的相互作用,过多的HNO3会导致催化剂活性的降低。     

Direct synthesis of iso-paraffins from syngas with slurry phase reaction

The direct synthesis of gasoline-range iso-paraffins from synthesis gas (CO + H₂, syngas) via modified Fischer–Tropsch (FT) reaction was investigated in the slurry phase reaction system, the contact state of hybrid catalyst components and the composition of hybrid catalyst were optimized in this reaction system. The results show that the FT reaction and the in situ hydroconversion of its products occurred over hybrid catalysts containing Co/SiO₂, very high selectivity of gasoline-range iso-paraffins could be achieved.     

完全液相法Mo改性CuZnAl的结构与性能研究

考察了过渡金属钼作为助催化剂添加到完全液相法制备的CuZnAl浆态催化剂中,对催化剂结构和CO加氢液相反应的产品分布的影响。Mo改性CuZnAl催化剂在250℃,5.0 MPa,空速为360 mL/(g·h)和V(H2)/V(CO)=1条件下进行活性评价,在500 mL浆态床中CO加氢反应120 h;并运用XRD,H2-TPR,NH3-TPD和BET对催化剂进行表征。结果表明:完全液相法制备的Mo-CuZnAl催化剂对液相CO加氢反应有良好稳定性;Mo助剂能促进铜氧化物在较低温度还原,增强催化剂表面酸性,在温和条件下提高烃,特别是甲烷的选择性。     

Simulation of DME synthesis from coal syngas by kinetics model

DME (Dimethyl Ether) has emerged as a clean alternative fuel for diesel. There are largely two methods for DME synthesis. A direct method of DME synthesis has been recently developed that has a more compact process than the indirect method. However, the direct method of DME synthesis has not yet been optimized at the face of its performance: yield and production rate of DME. In this study it is developed a simulation model through a kinetics model of the ASPEN plus simulator, performed to detect operating characteristics of DME direct synthesis. An overall DME synthesis process is referenced by experimental data of 3 ton/day (TPD) coal gasification pilot plant located at IAE in Korea. Supplying condition of DME synthesis model is equivalently set to 80 N/m³ of syngas which is derived from a coal gasification plant. In the simulation it is assumed that the overall DME synthesis process proceeds with steadystate, vapor-solid reaction with DME catalyst. The physical properties of reactants are governed by Soave-Redlich-Kwong (SRK) EOS in this model. A reaction model of DME synthesis is considered that is applied with the LHHW (Langmuir-Hinshelwood Hougen Watson) equation as an adsorption-desorption model on the surface of the DME catalyst. After adjusting the kinetics of the DME synthesis reaction among reactants with experimental data, the kinetics of the governing reactions inner DME reactor are modified and coupled with the entire DME synthesis reaction. For validating simulation results of the DME synthesis model, the obtained simulation results are compared with experimental results: conversion ratio, DME yield and DME production rate. Then, a sensitivity analysis is performed by effects of operating variables such as pressure, temperature of the reactor, void fraction of catalyst and H₂/CO ratio of supplied syngas with modified model. According to simulation results, optimum operating conditions of DME reactor are obtained in the range of 265–275 °C and 60 kg/cm². And DME production rate has a maximum value in the range of 1–1.5 of H₂/CO ratio in the syngas composition.