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1.
A new process of low-temperature methanol synthesis from CO/CO2/H2 based on dual-catalysis has been developed. Some alcohols, especially 2-alcohol, were found to have high catalytic promoting effect on the synthesis of methanol from CO hydrogenation. At 443 K and 5 MPa, the synthesis of methanol could process high effectively, resulting from the synergic catalysis of Cu/ZnO solid catalyst and 2-alcohol solvent catalyst. The primary results showed that when 2-butanol was used as reaction solvent, the one-pass average yield and the selectivity of methanol, in 40 h continuous reaction at temperature as low as 443 K and 5 MPa, were high up to 46.51% and 98.94% respectively. The catalytic activity was stable and the reaction temperature was 80 K or so lower than that in current industry synthesis process. This new process hopefully will become a practical method for methanol synthesis at low temperature.  相似文献   

2.
Methanol synthesis from CO2 and H2 can be a useful process for conversion and transportation of hydrogen energy derived from non-fossil energies. More than ten research groups in Japan have extensively investigated the methanol synthesis from both academic and practical points of view. Recent R&D activities in Japan for developing high performance catalysts, for elucidating the reaction mechanism and also for operating a bench scale plant have been reviewed in this paper.  相似文献   

3.
采用低温氮气吸脱附、X射线衍射(XRD)、电镜(TEM)以及热重差热(TG-DSC)等手段,对不同反应时间下Cu/ZrO2催化剂的物理结构、微观形貌以及积炭情况进行了表征,分析了催化剂的失活原因。结果表明,造成催化剂失活的主要因素是活性组分烧结;其次,表面积炭覆盖其活性中心也造成催化剂活性在一定程度上的降低;而催化剂比表面积对其活性的影响较小。  相似文献   

4.
采用柠檬酸盐凝胶法制备出纳米CuO-ZnO-ZrO_2(CZZ)催化剂,应用XPS、BET、XRD、H_2-TPR、H_2-TPD、CO_2-TPD和TG-DTA等检测手段对催化剂及前驱体的结构进行表征。研究了湿凝胶干燥时间和柠檬酸用量对催化剂结构的影响,并与燃烧法制得的催化剂进行对比,考察了不同催化剂CO_2加氢制甲醇的性能。研究表明,延长湿凝胶干燥时间可有效防止催化剂焙烧时发生喷溅,有利于催化剂中各组分的分散,提高催化剂对H_2和CO_2的吸附能力;112℃干燥48h制得的催化剂(CZZ-48h)BET比表面积为43.5m~2/g,高于燃烧法;柠檬酸用量等于化学计量比时催化剂的性能最佳,在240℃、2.6MPa、空速为3600h-1、H_2/CO_2(体积比)为3的条件下甲醇时空收率达109.4g/(kg·h);柠檬酸过量会影响催化剂组分的分散度,并造成分解残留覆盖催化剂表面活性位而不利于CO_2加氢反应。  相似文献   

5.
用CaO作为改性助剂,采用并流共沉淀法制备了CuO∶ZnO∶ZrO_2为5∶4∶1(物质的量比),CaO添加量为0、1%、2%、4%、8%、16%(摩尔分数)的六组催化剂。用X射线衍射(XRD)、微商热重(TG-DTG)、傅里叶红外(FT-IR)、N2吸附脱附(BET)、X射线光电子能谱(XPS)、氢气程序升温还原(H_2-TPR)、CO_2程序升温脱附(CO_2-TPD)、NH_3程序升温脱附(NH_3-TPD)对催化剂进行了表征。用自制固定床评价了催化剂活性。结果表明,添加CaO后,催化剂路易斯酸性和表面碱性增强;催化剂母体中高温碳酸盐含量增加,热稳定性增强,CuO颗粒粒径变小,Cu-Zn协同作用增强,Cu比表面积增大,分散性变好。催化剂活性受到表面酸碱性、铜比表面积、Cu-Zn协同作用和铜分散性共同影响。当CaO为2%时,铜比表面积为79.3 m2/g、铜分散度为34.8%、CO_2转化率为24.55%、甲醇选择性为19.01%、甲醇收率为0.044 g/(gcat·h),催化剂活性最好。过量CaO占据催化剂孔道和覆盖表面活性位,使催化剂路易斯酸性和表面碱性过强,CuO与H_2有效接触减少,CO_2难以脱附,催化活性下降。因此,适量CaO(2%)添加可促进CO_2加氢反应合成甲醇。  相似文献   

6.
Cu/ZnO catalysts were prepared by the co-precipitation method with the addition of OP-10 (polyoxyethylene octylphenol ether) and were chemically and structurally characterized by means of XRD, BET, H2-TPR, CO-TPD and N2O-titration. The effect of OP-10 addition on the activity of Cu/ZnO for the slurry phase methanol synthesis at 150 °C was evaluated. The results showed that Cu/ZnO prepared with addition of 8% OP-10 (denoted as C8) exhibited the promoted activity for the methanol synthesis. The conversion of CO and the STY (space time yield) of methanol were 42.5% and 74.6% higher than those of Cu/ZnO prepared without addition of OP-10 (denoted as C0), respectively. The precursor of C8 contained more aurichalcite and rosasite, and the concerted effect of Cu-Zn in C8 was found to be stronger than that in C0. Compared with C0, C8 showed smaller particle size, lower reduction temperature and larger BET and Cu surface areas.  相似文献   

7.
采用并流沉淀法分别制备了CuO-CeO2(物质的量比为5:1)、CuO-ZnO(物质的量比为5:4)、CuO-ZnO-CeO2(物质的量比为5:4:1)三组目标催化剂,通过X射线衍射(XRD)、氢气升温还原(H2-TPR)、CO2程序升温脱附(CO2-TPD)、氮气吸附-脱附、X射线光电子能谱(XPS)、N2O滴定表征技术对催化剂的物化性能进行了测试,并在高温高压微催化反应器中对催化剂进行活性评价。研究了CuO-ZnO-CeO2组成对CO2加氢合成甲醇的影响。结果表明,与二组分催化剂相比较,三组分CuO-ZnO-CeO2催化剂物化性能及催化活性发生了很大变化,催化剂表面碱性位增强,热稳定性增强,CuO颗粒粒径变小,铜分散度以及氧空位浓度提高,最终催化活性显著提高。其中,CuO-ZnO-CeO2催化剂中,CuO颗粒粒径为8.2nm,铜的比表面积为68.4m2/g,铜分散度为7.19%,甲醇的选择性和收率分别为48.6%和0.057mmol/(g·min),催化剂活性较好。  相似文献   

8.
通过共沉淀法制备了Al、Zr和Ce改性的Cu-ZnO基低温甲醇合成催化剂,采用氮气物理吸附、H2-TPR、CO2-TPD、N2O滴定、XRD和TEM等技术对其进行了表征,并考察了改性组分和煅烧温度对其在170℃下合成气制甲醇催化性能的影响。结果表明,经Zr改性的Cu-ZnO基催化剂,其低温甲醇合成性能较好;随着煅烧温度的降低,Cu在催化剂表面的分散度逐渐变大、颗粒逐渐变小,所得到的催化剂其活性也较高;其中,未经煅烧的Cu-ZnO/ZrO2催化剂的活性最佳,其甲醇时空产率为106.02 g/(kg·h),选择性达87.04%。  相似文献   

9.
锆助剂对低温液相合成甲醇用铜铬硅催化剂性能的影响   总被引:3,自引:2,他引:3  
考察了含锆的铜铬硅催化剂低温液相合成甲醇性能,并进行了BET、TPR-H2、TPD-H2、TPD-CO、XRD和XPS表征。结果表明,锆作为结构助剂及电子助剂对催化剂在低温液相合成甲醇反应中具有显著的促进作用,反应活性可提高32.25 %。锆助剂能有效提高催化剂的比表面积,促进催化剂中铜铬组分的分散及表面富集。ZrO2加入在催化剂表面产生的Cu+与催化活性的改善密切相关,Zr4+、Cr3+、Cu+可形成复合中心,为价态的稳定性提供微环境,在H2活化及C O键的断裂等反应步骤中起重要作用。  相似文献   

10.
By metal impregnation of selected naturally occurring organic materials followed by controlled carbonization, metal semicoke catalysts can be readily prepared. These catalysts have been tested in the synthesis of hydrocarbons and alcohols from CO/H2 and CO2/H2 mixtures. Fe and Co preparations have been used. Relatively high temperatures are required when using these catalysts, which are quite active for synthesis using CO2 and H2. The pressure (5150 kPa) is very favorable both for the synthesis of liquid hydrocarbons (C5–C30) and alcohols (C1–C5).
. CO/H2 CO2/H2. Fe Co. , CO2 H2. 5150 ) (C5–C30) (C1–C5).
  相似文献   

11.
The hydrocondensation of CO2 and CO with and without added MeOH, HCHO and (CH3)2CHOH has been studied on CuO/ZnO contact masses in a static reactor at different pressures and reaction times.
CO2 CO MeOH, HCHO (CH3)2CHOH CuO/ZnO .
  相似文献   

12.
Pd/Al2O3 catalysts were prepared by the impregnation method and were used for the direct formation of hydrogen peroxide from H2 and O2. The H2O2 concentration and selectivity were strongly dependent on the solubility of hydrogen in the reaction medium. The modification of the support by halogenate has a beneficial effect on the selectivity. The state of the active Pd on Pd/Al2O3 catalysts was studied using X-ray photoelectron spectroscopy, and Pd(0) was found to be active.  相似文献   

13.
采用沉淀法将ZIF-67负载到CeO2上,制备了具有多重活性位点的非均相催化剂ZIF-67/CeO2,并研究其催化CO2和甲醇直接反应生成碳酸二甲酯(DMC)的性能。采用X射线衍射、N2吸附-脱附、傅里叶变换红外光谱和X射线光电子能谱研究了ZIF-67/CeO2的各种理化性质。结果表明,ZIF-67的引入使ZIF-67/CeO2催化剂产生更多的氧空位。在考察的ZIF-67/CeO2系列催化剂中,0.3-ZIF-67/CeO2(0.3为Co、Ce物质的量之比)在具有高的比表面积的同时还能保持介孔结构,具有丰富的酸碱位点,并且具有较高的CO2吸附容量,表现出最好的催化性能。在反应温度为140℃、压力为4.5 MPa的条件下反应4 h,DMC收率可达到3.79 mmolDMC·gcat-1。  相似文献   

14.
采用沉淀法将ZIF-67负载到CeO2上,制备了具有多重活性位点的非均相催化剂ZIF-67/CeO2,并研究其催化CO2和甲醇直接反应生成碳酸二甲酯(DMC)的性能。采用 X 射线衍射、N2吸附-脱附、傅里叶变换红外光谱和 X 射线光电子能谱研究了ZIF-67/CeO2的各种理化性质。结果表明,ZIF-67的引入使ZIF-67/CeO2催化剂产生更多的氧空位。在考察的ZIF-67/CeO2系列催化剂中,0.3-ZIF-67/CeO2(0.3为Co、Ce物质的量之比)在具有高的比表面积的同时还能保持介孔结构,具有丰富的酸碱位点,并且具有较高的CO2吸附容量,表现出最好的催化性能。在反应温度为140℃、压力为4.5 MPa的条件下反应4 h,DMC收率可达到3.79 mmolDMC·gcat-1。  相似文献   

15.
以γ-Al2O3为原料采用原位合成法制备CuAl2O4催化材料,通过XRF、XRD、BET和H2-TPR等手段对催化材料进行表征,考察铜铝物质的量比对CuAl2O4催化材料结构、性质及其催化甲醇水蒸气重整制氢性能的影响。结果表明,不同铜铝物质的量比主要影响了铜物种的还原性能,从而影响了其催化甲醇水蒸气重整制氢的性能。当铜铝物质的量比为1:2时,CuAl2O4催化材料的催化性能较好,在反应温度为260℃,水醇物质的量比为1.2,甲醇气体空速为800 h-1时,甲醇转化率为100%,产氢速率为895 mL/(kg·s)。  相似文献   

16.
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18.
A review of recent studies on the Fischer–Tropsch synthesis of heavy paraffins is presented. The effects of temperature, pressure, feed composition, active metal, promoters and carriers on the formation of heavy products are discussed. New approaches to wax-selective processes such as the application of metallic carriers and supercritical fluids are also described.  相似文献   

19.
The catalytic activity of ceria-supported Pd for selective hydrogenation of CO is well preserved in the presence of 30 ppm H2S due to the parallel oxidation of sulfur by CeO2 under standard methanol synthesis conditions. The bifunctional nature of this catalyst opens a route for the conversion of sulfur-contaminated gas streams such as the integrated gasification combined cycle syngas or biogas into liquid fuels if desulfurization by conventional means is not practical.  相似文献   

20.
The catalytic activity of cefia-supported Pd for selective hydrogenation of CO is well preserved in the presence of 30 ppm H2S due to the parallel oxidation of sulfur by CeO2 under standard methanol synthesis conditions. The bifunctional nature of this catalyst opens a route for the conversion of sulfur-contaminated gas streams such as the integrated gasification combined cycle syngas or biogas into liquid fuels if desulfurization by conventional means is not practical.  相似文献   

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