【作者】 崔晓静；

【导师】 马静红；

【作者基本信息】 太原理工大学 ， 工业催化， 2007， 硕士

【摘要】 石油烃类溶剂油在日常生活及工业生产中有着广泛的用途。目前国内生产的溶剂油均不同程度的含有芳烃，这严重限制其应用范围。因此溶剂油脱芳是油品精制工业的重要内容。催化加氢是应用最为广泛的方法，包括气相及液相两种加氢方式。目前，国内大部分厂家均采用气相加氢的方式，操作条件苛刻，能耗较高。本文是采用间歇式液相催化加氢技术，在低温低压下即可实现溶剂油的深度脱芳。以往研究发现，具有适宜表面酸性的沸石载体可提高贵金属催化剂的加氢活性及抗硫性。因而本文通过利用改性的Beta作为金属催化剂的载体，以改善沸石的酸性为目的；以及在沸石负载金属催化剂中添加沸石助剂，研究催化剂中沸石的载体效应和氢溢流效应，以获得具有良好加氢活性及抗硫性催化剂，研究内容主要包括：1)采用NaAlO₂对HBeta改性，在85℃、HBeta与NaAlO₂的固液比为1∶60g／mL条件下，分别制备了时间（4h，6h，8h和12h）及母液浓度（0.03mol／L，0.06mol／L，0.15mol／L，0.30mol／L）不同的改性HBeta，使用IR，Pyridine-IR及NH₃-TPD考察了改性条件对HBeta酸性的影响。并以其为载体，采用浸渍法制备负载Ru催化剂，研究其在0.06wt．％苯／正己烷模型反应物中的加氢活性；考察了载体酸性变化对催化剂加氢活性的影响。结果表明，以0.03mol／L NaAlO₂对HBeta改性时，随着改性时间增加，HBeta的酸量增大，并在8h酸量增大最明显。这可能因为8h前NaAlO₂主要对沸石起补铝作用，使得酸总量不断增大；而之后母液对沸石的溶硅作用导致骨架部分坍塌，造成铝含量的部分损失。相比HBeta而言，改性时间≥12h时更有利于沸石的酸强度增强。4h时以不同浓度的碱性NaAlO₂对HBeta改性时，当NaAlO₂溶液浓度范围为0.03～0.06mol／L时，与HBeta相比改性沸石HBeta的总酸量增加，而其酸强度先变弱后变强。浓度不超过0.06mol／L的母液对沸石改性时，更有利于沸石补铝的进行，且母液浓度为0.06 mol／L时，HBeta酸强度明显增强；浓度在0.06～0.15mol／L时，HBeta的B酸量大幅下降，而L酸基本不变；而当浓度超过0.30mol／L时，偏铝酸钠母液可能通过对沸石强烈的溶硅作用导致沸石结构的破坏和总酸量的锐减，也使得HBeta的酸强度减弱。以经过不同时间补铝后的HBeta为载体的金属钌催化剂的加氢活性均有提高，其中，以Ru／HBeta-0.03-6h提高得最为明显。这可能是载体的酸量与扩散效应共同作用的结果。以经不同母液浓度处理的HBeta为载体时得到类似的结果：Ru／HBeta-0.06-4h＞Ru／HBeta-0.03-4h＞Ru／HBeta-0.30-4h＞Ru／HBeta-0.15-4h＞Ru／HBeta。其活性提高的具体原因有待于进一步的研究。2)选用抗硫性最好的Ru／HUSY作为催化剂主体，再加入钠型（NaY，USY，Si-MCM-41）及氢型沸石分子筛（HY，HUSY，HBeta）作为助剂，制备了一系列（Ru％=1.0，2.5wt.％）的混合型催化剂，并研究了分子筛助剂类型及加入的质量比例对催化剂Ru／HUSY在有／无硫存在时加氢活性的影响。结果表明，氢型沸石，尤其是HUSY的加入可有效提高催化剂的加氢活性，其原因是由于氢溢流现象的存在；而抗硫性的提高则可能是由于氢型沸石的加入吸附了溶剂油中的硫，减小了硫中毒的影响。这也是钠型沸石助剂提高催化剂抗硫性的原因。且随着HUSY加入比例的增加，催化剂的加氢活性与抗硫性不断增加，并在两者的质量比例为1∶5（HUSY∶Ru／HUSY）时达到最大，且最终可将溶剂油中的苯含量脱至5ppm以下，而硫含量减少至1ppm以下。更多还原

【Abstract】 Nowadays, Solvent-oils are widely used in daily life and industrial field, however, All of solvent-oils in the country contain certain amount of aromatics, and this has seriously limited their application fields. Therefore, dearomatization of solvent-oils is very necessary for oil refining. There are many dearomatization methods, and among them, catalytic hydrogenation method including gas- and liquid-phase hydrogenation is a method widely used. Gas-phase hydrogenation is popular in most factories, but it asks for high reaction temperature and pressure, this would cost more energy resources. So, in this research, liquid-phase hydrogenation with low reaction pressure and temperature was used to dearomatize the trace amount of aromatics in 6^# solvent-oil. In our previous study, it was found that zeolite support obtaining proper surface acidity can improve the hydrogenation activity and sulfur tolerance of noble metal catalysts. Thereby, zeolite HBeta and HUSY with proper acidity were chose as the support and additional agent of Ru supported catalyst, and their acidity was further improved by modification and ion-exchanging method. It was hoped that Ru catalyst supported on modified HBeta and Ru/HUSY mixed with additional agent HUSY could exhibit better hydrogenation activity and sulfur tolerance.Firstly, Under the condition of 85℃and 1:60g/mL （HBeta/mother liquor of NaAlO₂）, HBeta was modified by NaAlO₂ solution with different concentration （0.03mol/L, 0.06mol/L, 0.15mol/L, 0.30mol/L） in a given time （4h） and by 0.03mol/L NaAlO₂ solution in different modifying time（4h, 6h, 8h, 12h）, respectively. The effect of time and concentration of NaAlO₂ on acidity of HBeta were studied by IR, Pyridine-IR and NH₃-TPD techniques. Then, Ru catalyst supported on modified HBeta was prepared by impregnation and characterd by Pyridine-IR. Further, its hydrogenation activity was studied in 0.06wt% benzene/hexane model reactant. The result showed that the acid amount of HBeta modified by 0.03mol/L NaAlO₂ solution increased with the increase of modifying time and reached highest at 8h. This was mainly resulted from realumination and silicon-soluting effect of NaAlO₂ solution before and after 8 hour. The realumination effect increased the acid amount of HBeta, while the silicon-soluting effect caused part loss of Al in the structure of HBeta. It was also showed that the acid strength of HBeta modified by 12h was only stronger than HBeta. Under the given time （4h）, with the concentration of NaAlO₂ solution increasing from 0.03 to 0.06mol/L, the acid amount of modified HBeta increased, while the acid strength of modified HBeta was firstly weaker and then became stronger than HBeta. NaAlO₂ with concentration no more than 0.06mol/L is favor for realumination of HBeta, while the acid strength of HBeta modified by 0.06mol/L NaAlO₂ improved remarkablely. When modified with liquor concentration between 0.06-0.15mol/L, B acid and L acid sites of HBeta decreased and increased, respectively. The structure and acid amount of HBeta were destroyed and decreased sharply with concentration above 0.3mol/L, This may be due to the solving of Si atoms from zeolite framework into liquor. The hydrogenation activity of Ru catalyst supported on HBeta modified by different time improved and the activity of Ru/HBeta-0.03-6h is the highest among them, this may be resulted from the co-effect of acid amount and diffusion effect of the support. The same result was found in metal catalysts supported on HBetas realuminated with various concentration of mother liquor and their hydrogenation follows: Ru/HBeta-0.06-4h > Ru/HBeta-0.03-4h > Ru/HBeta-0.30-4h>Ru/HBeta-0.15-4h>Ru/HBeta, and the reason for this is still needed to find.Secondly, Mixed catalysts were prepared by mixing additional molecule sieves agents （NaY, USY, Si-MCM-41 HY, HUSY, HBeta） with Ru/HUSY （Ru%=1.0 or 2.5wt. %）. The influence of additional agents and their additional proportion on the hydrogenation activity of Ru/HUSY with/without sulfur were studied. The result showed that the addition of H-zeolite, especially HUSY, can improve effectively the hydrogenation, this was due to hydrogen spillover phenomenon between active metal sites and acid sites of the support. Also, the addition of H-zeolite improved sulfur tolerance of catalyst, this may be due to sulfur adsorption of additional agent which could decrease the sulfur poisoning of the catalyst. Similarly, the improvement of sulfur-tolerant of Ru catalysts supported on Na-zeolite was because the Na-zeolite can adsorb part amount of sulfur in solvent-oil. With amount of additional zeolite agents increasing, the hydrogenation activity and sulfur tolerance of mixed catalyst increased and reaches the highest when the proportion of HUSY: Ru/HUSY is 5. After the hydrogenation, Benzene and sulfur containing in solvent-oil can be reduced below 5 and 1ppm, respectively.更多还原