载体及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响

研究了γ-Al_2O_3或SiO_2载体,以及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响。发现经过碱化或负载Sn的γ-Al_2O_3作为载体,能够较好地保持该催化剂在正己烷芳构化反应中的高活性和高选择性,并有益于改善Pt/BaKL沸石催化剂的抗硫性能。     

载铂L分子筛对铂铼或铂锡重整催化剂的改性研究

本文采用机混方式将Pt/KL 以1∶1质量比分别混入铂铼及铂锡等催化剂内,在加压连续微反及常压脉冲微反中进行多种纯烃反应,考察其芳构化活性和选择性的变化。实验结果表明,PtKL 混入铂铼催化剂内,以正庚烷反应时,其芳构化活性和选择性并没改变。PtKL 能对链烷具有较强1-6环化能力,主要在于金属功能,而当PtKL 与PtRe/Al_2O_3相混时,催化剂中大量的Al_2O_3担体并未影响其金属功能,但经预硫化的PtRe/Al_2O_3中,所含微量硫(约0.03m%)却造成单功能PtKL 催化剂中毒失活,因此对于铂铼这类需预硫化的催化剂,不适宜引入PtKL 分子筛进行改性。由于铂锡催化剂使用中不需预硫化,在无硫的干扰情况下,PtKL 混入PtSn/Al_2O_3内能较好地改善正庚烷芳构化活性和选择性,但其失活速率略有增加。     

Re／Pt比对Pt—Re／Al2O3重整催化剂性能的影响

利用纯烃反应,TPR、AEM等手段考察了Pt-Re/Al_2O_3催化剂的不同铼铂比对反应性能、硫吸附量,以及铂和铼组元的还原状态及相互作用诸因素的影响。实验结果表明,催化剂不经硫化,铼铂比的提高主要使氢解和开环裂解活性增加;预硫化后,氢解和开环裂解活性受到抑制,MCP芳构化活性增加,n-C_7芳构化活性降低。随着铼铂比的提高,催化剂积炭量减少,稳定性提高,但对硫中毒更敏感。铼铂比的提高,还使催化剂的不可逆吸附硫量增加,而S/Re比为一定值。高铼铂比催化剂的优异稳定性,主要由于其抗积炭能力的提高,而铼铂比的提高并不能改善催化剂抗金属聚结和抗中毒能力。     

工业连续重整催化剂的Pt聚集与再分散研究

通过对一些连续重整工业装置上催化剂性能下降情况的研究发现,催化剂中Pt的聚集是引起催化剂性能下降的主要原因之一。通过对聚集Pt的再分散研究发现,对于Pt聚集程度较轻的催化剂,可以通过调整操作,使聚集的铂晶粒得到再分散,催化剂的性能得到恢复;但在Pt聚集颗粒较大或重整催化剂结构发生改变时,聚集的铂晶粒就很难被再分散。     

Pt/KL芳构化催化剂中载体酸碱性的作用

采用水热脱铝法提高硅铝比使L分子筛的酸性增强,采用离子交换法脱除KL分子筛上部分的K使分子筛的碱性降低。并担载Pt制成芳构化催化剂,考察了具有不同酸碱性的载体及其催化剂的物化性质和催化性能,发现载体的酸碱性对Pt的电子状态及Pt在分子筛孔道内的分散有明显的影响,从而产生不同的芳构化反应活性和选择性;随着载体酸性增强和碱性减弱,催化剂的活性降低,芳构化反应选择性下降。     

改性丝光沸石用于半再生重整催化剂的研究

将改性的丝光沸石用于固定床半再生重整催化剂的研究结果表明：在重整催化剂中引入适当量、适当硅铝比的丝光沸石，可以改善催化剂的性能；丝光沸石上引入适量的磷，可以调变丝光沸石的酸分布，使丝光沸石的强酸中心向中强酸和弱酸转化；引入上述改性的丝光沸石，可以为催化剂提供部分配性，减少反应过程的补氮量，而催化剂的比表面积和金属分散度没有明显改变，但对孔径分布有一定的影响。     

各种含镓沸石的芳构化性能和表面酸性的研究

通过离子交换制得Ｇａ改性ＺＳＭ－５，利用迅速晶化法合成了铝镓双金属硅酸盐沸石，以正己烷的转化为探针反应研究了它们的芳构化性能，对其活性和选择性进行了考察。结果表明，在Ｇａ含量较高时，铝镓双金属硅酸盐沸石具有比Ｇａ改性ＺＳＭ－５更好的活性和芳烃选择性。还用ＮＨ３－ＴＰＤ法研究了几种含镓合成沸石的酸性质，发现由于引入Ｇａ的方法不同使得酸性质产生差异，并对反应结果产生影响。     

分子筛孔结构和酸性对正癸烷加氢裂化反应性能的影响

采用XRD,BET,NH3-TPD方法对不同孔结构的Beta、ZSM-5分子筛和两种不同介孔体积的Y 型分子筛Y1、Y2进行表征,以正癸烷为模型化合物考察四种分子筛制备的加氢裂化催化剂的反应性能。结果表明,Beta分子筛的活性和异构选择性最高,Y型分子筛次之,ZSM-5分子筛的活性和异构选择性最低。对于Y 型分子筛,介孔体积较大的Y2分子筛的异构癸烷选择性较高。在Beta和Y型分子筛上,正癸烷主要按照三支链叔碳正离子β-裂化机理生成较多的支链产物;在ZSM-5分子筛上,正癸烷主要按照单支链仲碳正离子β-裂化机理生成较多的直链产物。     

甲苯甲醇侧链烷基化催化反应的研究

从催化剂、反应机理、研究手段等方面对最近几年甲苯甲醇侧链烷基化反应的研究进展进行了述评,提出了该课题目前须解决的几个问题,就催化剂的研究方向提出了一些建议。     

不同分子筛载体制备的Pt催化剂对正辛烷加氢异构反应的催化性能

 分别以Y-β复合分子筛、Y和β的机械混合物、Y、β为载体，制备了Pt系加氢异构催化剂Pt/Y-β、Pt/Y+β、Pt/Y、Pt/β，采用XRD、N₂等温吸附-脱附、FT-IR等分析手段进行表征，探讨了其物化性能的差异，并采用固定床反应器考察了上述催化剂对正辛烷加氢异构化反应的催化性能。结果表明，与Pt/Y+β相比，催化剂Pt/Y-β具有较高的相对结晶度、较大的比表面积和孔体积、较高的B酸和L酸，为正碳离子发生骨架异构化和裂化反应提供了条件。230℃时，在Pt系催化剂催化正辛烷加氢异构化反应中，按正辛烷转化率高低排列的催化剂顺序为Pt/Y-β＞Pt/β＞Pt/Y＞Pt/Y+β；按裂解率高低排列的催化剂顺序为Pt/β＞Pt/Y-β＞Pt/Y+β＞Pt/Y；按液体收率高低排列的顺序与裂解率的排列相反；按异辛烷产率高低排列的催化剂顺序为Pt/Y-β＞Pt/Y＞Pt/β＞Pt/Y+β，其中，Pt/Y-β催化剂上单、双支链异辛烷产率分别于230、240℃取得最大值，分别为27.97%、12.54%，明显高于其它催化剂。以双微孔复合分子筛Y-β为载体制备的异构化催化剂Pt/Y-β是具有双重结构的催化剂，具有酸性功能的可调变性、孔道的非单一性，将成为石油加工和石油化学品深加工的新型催化材料。     

KINETIC INVESTIGATION OF METHYLCYCLOPENTANE REFORMING ON FRESH AND DEACTIVATING Pt/Al2O3 CATALYST

The conversion of methylcyclopentane (MCP) in hydrogen on fresh and deactivating Pt/Al₂O₃ catalyst to hydrogenolysis products (2-methylpentane, 3-methylpentane and n-hexane), cyclohexane and benzene was studied in a Berty CSTR at various partial pressures of MCP and H₂, and at a total pressure of 1 atm. For the kinetic studies, temperatures between 370 - 400° and W/F values up to 0.33 g min/cm³ were used. The conversion of MCP was found to increase with increase in temperature at all the MCP partial pressures investigated. The hydrogenolysis products and benzene composition generally increased with increase in temperature and W/F. The mechanism for the reforming of MCP was similar to that proposed by Dartigues et al. (1978) except that the formation of hydrogenolysis products was accounted for in this formulation. Eleven rate models were developed and tested and six satisfied the set criteria. Since hydrogenation/dehydrogenation and desorption steps are relatively rapid, the conversion step to hydrogenolysis products was deemed the only rate determining step with an activation energy of 36.31 kcal/gmol. For the deactivation studies, the model of Corella and Asua (1982) was used for the development of two deactivation models. The only model found to predict the deactivation behavior was the step leading to the formation of the coke precursor as rate controlling.     

REFORMING OF N-OCTANE ON A Pt/Al2O 3 CATALYST. 1. PRODUCT DISTRIBUTION AND KINETIC ANALYSIS.

The conversion of n-octane on Pt/Al₂O₃ catalyst to hydrocracked products, isooctane, ethylbenzene, o-,p-,m-xylene and toluene was investigated in hydrogen in a Berty CSTR at three different partial pressures of n-octane, 101·325 KPa total pressure, temperatures between 400°C-460°C and W/F values up to 0·33gmincm^-3. The hydrocracked products were the most predominant. Of the other products, isooctane was present in the highest yield. A sequence of elementary steps based on the suggested reaction network of Ako and Susu (1986) was found to predict the experimental conversion-W/F data with the conversion of adsorbed isooctane to adsorbed o-xylene as the rate determining step. The activation energies for the forward and backward reactions of this step were determined to be 21·2 and 14·3 Kcal/gmol, respectively.     

REFORMING OF N-OCTANE ON A Pt/Al2O 3 CATALYST. 1. PRODUCT DISTRIBUTION AND KINETIC ANALYSIS.

ABSTRACT

The conversion of n-octane on Pt/Al₂O₃ catalyst to hydrocracked products, isooctane, ethylbenzene, o-,p-,m-xylene and toluene was investigated in hydrogen in a Berty CSTR at three different partial pressures of n-octane, 101·325 KPa total pressure, temperatures between 400°C-460°C and W/F values up to 0·33gmincm^-3. The hydrocracked products were the most predominant. Of the other products, isooctane was present in the highest yield. A sequence of elementary steps based on the suggested reaction network of Ako and Susu (1986) was found to predict the experimental conversion-W/F data with the conversion of adsorbed isooctane to adsorbed o-xylene as the rate determining step. The activation energies for the forward and backward reactions of this step were determined to be 21·2 and 14·3 Kcal/gmol, respectively.     

一种新型闭锁料斗的开发

介绍了一种由洛阳石油化工工程公司开发的新型闭锁料斗 ,重点介绍了其特点、操作步骤、主要数学模型。该闭锁料斗无催化剂磨损并且控制简单。与传统的闭锁料斗相比 ,技术性能更佳 ,投资和操作费用大幅度降低 ,经济效益显著。     

KINETIC INVESTIGATION OF METHYLCYCLOPENTANE REFORMING ON FRESH AND DEACTIVATING Pt/Al2O3 CATALYST

ABSTRACT

The conversion of methylcyclopentane (MCP) in hydrogen on fresh and deactivating Pt/Al₂O₃ catalyst to hydrogenolysis products (2-methylpentane, 3-methylpentane and n-hexane), cyclohexane and benzene was studied in a Berty CSTR at various partial pressures of MCP and H₂, and at a total pressure of 1 atm. For the kinetic studies, temperatures between 370 – 400° and W/F values up to 0.33 g min/cm³ were used. The conversion of MCP was found to increase with increase in temperature at all the MCP partial pressures investigated. The hydrogenolysis products and benzene composition generally increased with increase in temperature and W/F. The mechanism for the reforming of MCP was similar to that proposed by Dartigues et al. (1978) except that the formation of hydrogenolysis products was accounted for in this formulation. Eleven rate models were developed and tested and six satisfied the set criteria. Since hydrogenation/dehydrogenation and desorption steps are relatively rapid, the conversion step to hydrogenolysis products was deemed the only rate determining step with an activation energy of 36.31 kcal/gmol. For the deactivation studies, the model of Corella and Asua (1982) was used for the development of two deactivation models. The only model found to predict the deactivation behavior was the step leading to the formation of the coke precursor as rate controlling.