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1.
Abstract

The effectiveness of different catalysts were compared in coal liquefaction experiments using a 250 ml stirred autoclave, 10 g of a Spanish Subbituminous A coal, 1 hour reaction time, 17 MPa operating pressure, 400 rpm stirring speed, at 425 and 450 °C with 2/1 and 3/1 tetralin/coal ratio. The liquefaction products were fractionated into oils, asphaltenes, preasphaltenes and solid residue using pentane, toluene and THF as extractive solvents. Three iron-oxide containing catalysts: red mud, an Fe2O3 aerosol and Cottrell ash (by-product of the aluminium industry); and three alumina supported catalysts: CMA, which is a conventional CoMo/Al2O3 catalyst, CZMA which in addition contains Zn as a second promoter, and CZMFA which has the alumina acidified with fluorine and also contains Zn, were compared. It has been reported that the addition of Zn and of F enhances the HDS, cracking, hydrocracking or hydrogenating activities of CoMo/Al2O3 catalysts in experiments with pure compounds. The objective of this study was to determine if the addition of Zn and of F has also a beneficial effect in the catalyst activities in coal liquefaction, and also to compare cheap iron containing catalysts with the more sophisticated and expensive alumina supported ones.

The results showed that 1) Catalysts effects depend on the operating conditions used, and that with tetralin, a strong H-donor solvent, they never are very pronounced. 2) The supported catalysts have higher activities in coal liquefaction than the iron ones, but there are no significant differences among the catalysts within each group. 3) Zn, which is a cheaper metal than Co, can substitute succesfully for half the amount of Co and retain the activity of the CoMo/Al2O3 catalyst in coal liquefaction. 4) The addition of F to the CoMo/Al2O3 catalyst does not show a benefecial effect  相似文献   

2.
制备了孔分布集中的氧化铝载体,并以饱和浸渍法制备了CoMo/Al2O3催化剂,考察了Co/(Co+Mo)原子比和助剂对催化剂加氢脱硫活性及表面性质的影响。结果表明:当Co/(Co+Mo)原子比为0.3左右时,催化剂的加氢脱硫活性最好;催化剂中引入适量的助剂,可以提高CoMo/Al2O3催化剂的活性。在此基础上研制出具有高加氢脱硫活性的RMS-30催化剂。中型装置评价及工业应用结果表明,与上一代渣油加氢脱硫催化剂相比,RMS-30催化剂具有更好的脱硫和脱残炭性能。  相似文献   

3.
采用液相反应沉积法合成MoS3/Al2O3复合材料,考察了不同反应温度、反应物浓度、反应时间、体系pH值及不同类型分散剂对MoS3在γ Al2O3载体表面沉积量的影响,并采用MoS3/Al2O3复合材料为助剂Co的第2载体制备了CoMo硫化态加氢脱硫催化剂;采用XRF、XRD、XPS、TEM、BET等分析手段对MoS3/Al2O3复合材料及CoMo硫化态和氧化态催化剂进行了表征。结果表明,采用乙醇为分散剂,钼酸钠摩尔浓度为01~1 mol/L、在反应温度85~120℃、体系pH值1~2、反应8~24 h条件下,可以合成MoS3沉积量为628%~868%(以MoO3质量分数计)的MoS3/Al2O3复合材料;与常规氧化态催化剂相比,所制备的CoMo硫化态催化剂具有更高的加氢脱硫活性。  相似文献   

4.
以氢氧化铝干胶和偏钛酸为主要原料制备了Al2O3-TiO2载体,采用等体积浸渍法制备出一系列不同TiO2含量及不同配体改性的CoMo/Al2O3-TiO2催化剂;采用BET,XRD,TPR,HRTEM等方法对所制备的催化剂进行了表征,在10 mL固定床评价装置上对所制备的两个系列催化剂进行了FCC汽油选择加氢脱硫活性评价。结果表明,载体中TiO2的质量分数为10%、浸渍液中添加乙二醇和磷酸改性的催化剂具有较高的加氢脱硫活性和选择性。  相似文献   

5.
菲在不同加氢催化剂上的转化   总被引:1,自引:0,他引:1  
 采用孔饱和共浸渍法制备了CoMo/Al2O3、NiMo/Al2O3和 NiW/Al2O3加氢催化剂。采用 H2-TPR 表征了其还原性能,并与Co/Al2O3、Ni/Al2O3、Mo/Al2O3和 W/Al2O3进行对比。在连续流动固定床加氢微反装置上,考察了菲在不同催化剂上加氢反应的转化率和选择性。结果表明,CoMo/Al2O3、NiMo/Al2O3和NiW/Al2O33个催化剂中,NiMo/Al2O3比 CoMo/Al2O3容易还原,NiW/Al2O3最难以还原。其原因主要是由于Mo与Al2O3相互作用比W弱,相对更容易还原;以及 Ni 比 Co 对促进 Mo(W)还原的效果更显著。在相同的加氢反应条件下,NiMo/Al2O3和 NiW/Al2O3均比 CoMo/Al2O3表现出更好的菲加氢饱和性能,NiMo/Al2O3比 NiW/Al2O3具有更高的低温加氢活性。在菲转化率相当时,NiMo/Al2O3和 NiW/Al2O3表现出更高的八氢菲和全氢菲选择性,而 CoMo/Al2O3则表现出较高的二氢菲选择性,这主要是由于Ni 和Co 助剂对Mo(W)作用效果不同。  相似文献   

6.
采用三苯基砷和三乙基砷作为砷化物配制高砷模拟油,用于对CoMo/Al2O3加氢脱硫催化剂进行强制积砷中毒处理,采用BET,XRD,XRF,Py-IR等分析手段对砷中毒前后催化剂的物化性质进行表征,对中毒前后催化剂的加氢活性进行评价,并对砷中毒催化剂的失活温度进行考察。结果表明,砷化物使加氢催化剂的强酸位消失,B酸位和L酸位总量明显降低,催化剂活性位减少,造成催化剂加氢活性降低。  相似文献   

7.
In order to evaluate the role of vanadium in the hydrogenation (HYD) reaction, a series of alumina supported vanadium catalysts were prepared and characterized by SEM, XRD, Raman spectrometry, 51V NMR, XPS, as well as TPR analyses. The catalytic performance of vanadium in HYD of model molecules (naphthalene) and real feedstock (Kuwait atmospheric residue) was studied after sulfidation of the catalysts. It can be concluded that the HYD capabilities of V/Al2O3 catalysts are lower than that of conventional NiMo/Al2O3 catalyst (RefNiMo). The V/Al2O3 catalysts can only facilitate hydrogenation of the first ring of naphthalene, but have little effect on the further hydrogenation of tetralin. Owing to the different forms of metals and sulfur compounds in residue, the weak HYD activity of V/Al2O3 catalysts is able to facilitate the HDM reaction of the residue, albeit with a slight effect on HDS activity.  相似文献   

8.
以硫化态CoMo/γ-Al2O3,NiW/γ-Al2O3,NiMo/γ-Al2O3,NiMoW/γ-Al2O3为催化剂,1-甲基萘为加氢反应的模型化合物,利用高压加氢微型反应器考察在不同类型催化剂体系上1-甲基萘的加氢饱和反应规律。结果表明:对1-甲基萘的芳烃饱和性能,Ni-Mo-W型最优,Ni-Mo型、Ni-W型次之,Co-Mo型最低;催化剂的活性越高则1-甲基萘的芳烃饱和越容易达到热力学平衡,对压力的变化越不敏感;1-甲基萘的加氢饱和优先发生在不带甲基的芳环上,产物中5-甲基四氢萘的质量分数约为1-甲基四氢萘的2倍。  相似文献   

9.
采用尿素螯合剂法制备了不同MgO含量的Co-Mo/Al2O3-MgO催化剂,采用N2吸附-脱附法、TPR、HRTEM等技术对催化剂进行了表征,在管式固定床反应器中以二苯并噻吩(DBT)的二甲苯溶液为模型化合物对催化剂的加氢脱硫活性进行了评价。实验结果表明,添加MgO可显著改善Co-Mo/Al2O3催化剂的结构和性能,Co-Mo/Al2O3-MgO催化剂呈现出多孔径中心的特点;随MgO添加量的增加,Co-Mo/Al2O3-MgO催化剂中的Co-O-Mo物相增多,硫化后易形成更多高活性Co-Mo-S物相。与Co-Mo/Al2O3和Co-Mo/Al2O3-TiO2催化剂相比,Co-Mo/Al2O3-MgO-0.8(载体中MgO的质量分数为0.8)催化剂在氢烃体积比为300时即呈现出很高的DBT脱除率(97.0%),具有低氢烃比下即可实现高加氢脱硫活性的优点。  相似文献   

10.
以含钛氢氧化铝干胶和不含钛氢氧化铝干胶作为前驱物获得载体,采用浸渍法制备出Pt/Al_2O_3-TiO_2催化剂和Pt/Al_2O_3催化剂;采用BET、XRD、TPR、TEM、氢氧滴定等方法对所制备的催化剂进行表征,以重整抽余油为原料进行烯烃和芳烃的加氢活性评价。结果表明,TiO_2在载体中以锐钛矿形式存在,Pt/Al_2O_3-TiO_2催化剂的孔体积、比表面积和强度均略小于Pt/Al_2O_3催化剂,前者更易还原,Pt的分散度更大,而且有更高的烯烃和芳烃加氢活性。  相似文献   

11.
When a Co/Mo catalyst is used for processing vanadium-containing heavy oils, vanadium deposits on the catalyst. As the amount of vanadium on the CoMo catalyst increases, the catalytic effects of CoMo decline and the presence of vanadium starts to influence the hydroprocessing products. Model feeds have been used to explore the changes in the catalytic activity of CoMo, aged CoMo, and VSx on alumina. Desulfurization, denitrogenation, deoxygenation, aromatics hydrogenation, and metals removal were monitored. Upon the addition of hydrogen sulfide to hydrogen, improvements in the catalysts for aromatics hydrogenation, denitrogenation and metals removal were observed.  相似文献   

12.
铝盐加入方式对CuO/ZnO/Al_2O_3系催化剂性能的影响   总被引:4,自引:2,他引:2  
用XRD,TD-DTG,TPR,N2吸附及N2O滴定法考察了铝盐的加入方式对CuO/znO/A12O3系催化剂前体及催化剂物相组成的影响;用加压微反评价装置考察了其对合成甲醇反应性能的影响。实验结果表明,铝盐的加入方式对催化剂前体物相组成及催化剂的反应活性有明显影响。Cu-Zn和Zn-Al分别沉淀有利于提高催化剂的低温活性;而Cu-Zn-Al三元共沉淀由于形成较多的类尖晶石相(Cu,Zn)Al2O4,降低了催化剂的低温反应活性,但提高了催化剂的热稳定性。保持催化剂中(Cu,Zn)Al2O4含量在适当水平对提高催化剂的整体性能至关重要。  相似文献   

13.
采用共沸蒸馏-均匀沉淀法辅以超声波分散技术制备了纳米γ-Al2O3(γ-Al2O3(Ⅰ)),并以γ-Al2O3(Ⅰ)与商品γ-Al2O3(γ-Al2O3(Ⅱ))为载体,采用等体积浸渍法制得了Co与Mo负载量(分别以CoO与MoO3的质量分数计)分别为6%和16%的CoMo/γ-Al2O3(Ⅰ)与CoMo/γ-A12O3(Ⅱ)催化剂,采用间歇搅拌釜考察了催化剂的苯酚加氢脱氧性能。BET,SEM,XRD,H2-TPR,NH3-TPD表征结果表明,γ-Al2O3(Ⅰ)载体呈纤维介孔状,具有较大的比表面积、孔体积及适宜的孔分布。相对于CoMo/γ-A12O3(Ⅱ)催化剂,CoMo/γ-Al2O3(Ⅰ)催化剂的活性组分高度分散于γ-Al2O3(Ⅰ)载体表面,还原性能较高,酸中心较多。苯酚加氢脱氧反应结果表明,CoMo/γ-A12O3(Ⅰ)催化剂具有较高的加氢脱氧活性,苯酚转化率为79.2%,苯选择性为89.3%。  相似文献   

14.
以铝乳液的形式引入Al,采用反加共沉淀法制备了一系列Cu与Zn的原子比(简称Cu/Zn原子比)不同的CuO-ZnO/Al2O3催化剂;以合成气为原料,在固定床微型连续流动反应器中评价了CuO-ZnO/Al2O3催化剂合成甲醇的性能;采用XRD、H2-TPR和BET等方法对催化剂进行了表征,考察了Cu/Zn原子比对CuO-ZnO/Al2O3催化剂合成甲醇性能的影响。实验结果表明,Cu/Zn原子比的变化对催化剂前体的物相组成和催化剂的活性有明显影响;当Cu/Zn原子比为3时,催化剂的初活性和耐热后活性最高,其前体中含有较多的锌-孔雀石相((Cu,Zn)2CO3(OH)2),该物相分解时生成还原温度较低的CuO-ZnO固溶体,使Cu与Zn的相互作用增强,提高了催化剂的活性。  相似文献   

15.
以MgO为载体,采用等体积浸渍法制备了MgO负载的CoMo硫化物催化剂(CoMo/MgO);作为比较,制备了γ-Al2O3负载的CoMo硫化物催化剂(CoMo/γ-Al2O3)。在反应条件:反应温度260℃、氢分压为3.0 MPa、氢气流量为50 mL/min、质量空速(WHSV)为19 h-1的情况下,CoMo/MgO催化剂对DBT的转化率为88.3%,高于CoMo/γ-Al2O3催化剂的65.5%。经XRD、UV-vis、XPS分析:与CoMo/γ-Al2O3催化剂相比,CoMo/MgO催化剂上形成了更多的八面体钼物种,通过硫化,可以形成更多的CoMoS活性相。  相似文献   

16.
Conventional HDS-catalysts consist of Co and Mo supported on Y-Al2O3. The addition of Zn as a second promoter or the alumina acidification with F increase the catalitye activity in HDS of commercial feeds (Fierro et al., 1984; Boorman et al., 1984). In this paper the combined effect of both Zn and F incorporation is discussed. A series of Zn-Co-Mo catalysts supported on fluorinated alumina (0.0 -2.0 wt% F) was prepared and tested for HDS activity using a commercial gas-oil. The data gathered showed a decrease in HDS activity for intermediate F contents (0.4 - 1.0 wt%). This result could be tentatively explained through alumina surface deterioration during impregnation with NH4HF2 solutions al low pH.  相似文献   

17.
在一系列不同体相原子比[n(Co)/ n (Co+Mo)]的CoMo/Al2O3催化剂制备过程中引入柠檬酸,考察了柠檬酸对CoMo催化剂中助剂作用的影响,并采用BET,XRD,XPS,HRTEM等手段进行表征。结果表明:柠檬酸可以提高助剂Co和主剂Mo在载体表面的分散性,使Co对MoS2的助剂作用增强,这种促进作用在较高体相原子比时更加明显;在4,6-二甲基二苯并噻吩加氢脱硫反应中,催化剂的加氢脱硫活性均随助剂含量的增加表现出先增后减的趋势,且在体相原子比为0.3时达到最高;添加柠檬酸后催化剂的脱硫活性提高,且在较高体相原子比时活性提高更为明显。  相似文献   

18.
用非传统方法制备了Rh2Co2/Al2O3、Co2/Al2O3、Rh4/Al2O3和用传统方法制备了(Rh+Co)/Al2O3催化剂。用连续流动微反装置研究了上述催化剂的CO加氢活性及选择性,并系统地研究了H2/CO比值和温度对反应活性及选择性的影响。结果表明,Rh2Co2/Al2O3的活性不仅高于Rh4/Al2O3和Co2/Al2O3,而且也高于(Rh+Co)/Al2O3,在选择性方面与上述样品也有明显差异。当H2/CO比值从6:1变到1:1时,其它催化剂的反应活性大为降低,而Rh2Co2/Al2O3仍保持高活性。  相似文献   

19.
Abstract

When a Co/Mo catalyst is used for processing vanadium-containing heavy oils, vanadium deposits on the catalyst. As the amount of vanadium on the CoMo catalyst increases, the catalytic effects of CoMo decline and the presence of vanadium starts to influence the hydroprocessing products. Model feeds have been used to explore the changes in the catalytic activity of CoMo, aged CoMo, and VSx on alumina. Desulfurization, denitrogenation, deoxygenation, aromatics hydrogenation, and metals removal were monitored. Upon the addition of hydrogen sulfide to hydrogen, improvements in the catalysts for aromatics hydrogenation, denitrogenation and metals removal were observed.  相似文献   

20.
The effect of solvent pretreatment, temperature, a CoMo/Al2O3 catalyst and pressure on coal liquefaction with anthracene oil has been evaluated. The experiments were conducted in a 500 ml autoclave with 10 g of a Spanish subbituminous A coal. 30 g of solvent, 1 hour reaction time and 400 rpm stirring speed. The liquefaction products were fractionated into oils, asphaltenes and preasphaltenes using pentane, toluene and THF as extractive solvents. The behaviour of anthracene oil as coal liquefaction solvent is very much enhanced by prehydrogenating it and by the addition ot an active catalyst. The influence of temperature depends on the operating conditions such as solvent pretreatment, catalyst, pressure etc. The addition of an active catalyst greatly improves conversion and the quality of the liquefaction products and diminishes repotimerization reactions. Hydrogen pressure is essential for coal liquefaction with anthracene oil, although over 16 MPa no further increase in coal conversion is observed.  相似文献   

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