【作者】 张龙；

【导师】 张继炎；

【作者基本信息】 天津大学 ， 工业催化， 2003， 博士

【摘要】 本文首次较详细地探讨了炭化树脂负载HPW12催化异丁烷与丁烯烷基化的反应过程。以粒状大孔阳离子交换树脂DKC为母体，经高温炭化及水蒸汽活化制备出了具有适宜比表面积、孔结构及良好机械强度的球状炭化树脂载体。实验确定了适宜的制备条件为：炭化温度873K，炭化时间3h，水蒸汽活化时间1.5h，N2流量30ml/min，制得的载体的比表面积为638.9m2.g-1，平均孔径33.5?，以此载体以HPW12为活性组分制备了炭化树脂负载型催化剂。吸附实验确定了HPW12在载体上的吸附平衡时间及吸附等温线方程。对载体进行预处理影响活性组分的负载。实验研究确定了回流浸渍法制备催化剂的适宜工艺条件为：浸渍液为30%HPW12甲醇溶液，浸渍时间为12h，活化温度为473K。催化剂40h的强制溶脱实验数据表明：活性组分在载体上吸附较牢，并对目标反应的催化活性好于其它同类负载杂多酸催化剂。利用IR、TPD—NH3、XRD、SEM及N2低温吸附等对催化剂进行了表征，结果表明负载过程未使活性组分的结构受到破坏；随着负载量的增大，催化剂的酸强度保持不变，而酸量随着负载量的增加而增大。而活性并不呈现相同的趋势，故负载量应有一适当值。SEM分析表明HPW12均匀分布在载体上。利用加压间歇反应装置和常压连续流动反应装置对催化剂进行了活性评价，找出了反应温度、压力、烷烯比、丁烯空速及加料方式对活性影响的规律，并分别确定了适宜的工艺条件。相应的活性分别为丁烯的转化率100%，TMP的选择性90.8%（加压过程）和丁烯的转化率50%，TMP的选择性65.8%（常压过程），反应前后的碳平衡率大于98.5%。反应后催化剂的IR、孔结构参数及能谱的分析结果表明：催化剂活性降低的原因主要是由于副反应所生成的结焦前驱物对催化剂表面覆盖造成的，结焦前驱物为C10以上的长链烷烃。分别采用有机溶剂萃取法和H2O2氧化法对失活催化剂进行了再生实验，并确定了适宜的再生条件。对溶剂萃取法为：采用二氯甲烷与石油醚为萃取剂，萃取时间10h；对H2O2氧化法为：氧化时间20h，氧化温度353~363K。经再生的催化剂的活性可恢复到初始活性的85%以上。更多还原

【Abstract】 Alkylation of isobutane with butene to produce clean-burning gasoline component is an important reaction in petrochemical industry. The development of new solid catalysts to substitute traditionally used liquid acids has became one of the world-widely attracted subjects, in order to overcome the shortcomings of liquid acid catalysis. Although there exist still some problems about catalyst longlife and regeneration of catalyst to be solved, some achievements in this field have been obtained. Exploration of the new type of solid acid catalyst for the alkylation is theoretically and practically valuable. This thesis deals with the study on the alkylation of isobutane with butene over heteropolyacid HPW12 catalyst supported on carbonized resin in details. Globular carbonized resin carrier is prepared by the calcination and vapor activation of DKC large pore cation exchange resin. It has proper specific surface area、pore structure and better mechanical strength. Its preparation conditions are determined as follows: carbonization temperature 873K, carbonization time 3h, vapor activation time 1.5h, N2 flow rate 30ml/min, and its specific surface area 638.9m2.g-1 and average pore diameter 33.5?. The prepared resin is used to prepare the supported HPA catalyst, in which HPW12 is selected as active component for its stronger acidity. The balance time and isotherm equation for the adsorption of HPW12 on the carrier are determined. Pretreatment of the carrier has an effect on the supportation of HPW12 on it. Suitable conditions for preparation of the catalyst are: reflux impregnation with 30% HPW12 methanol solution; impregnation time 12h; activation temperature 473K. After 40h forced dissolution experiments of the catalyst, it is showed that the HPW12 is tightly binded on the carrier, and it demonstrates better activity for the alkylation than that of other similar supported catalysts. Characterization of the catalyst was carried out by means of IR、TPD-NH3、XRD、SEM and N2 adsorption. Results show that supportation doesn’t damage the structure of HPW12 microstructure and the acidic amount of catalyst increases with the increasing of supported HPA amount. But the acidic strength remains constant. It is <WP=5>concluded that a proper supported amount is enough for the alkylation. SEM analysis shows that HPW12 is uniformly distributed on the carrier. The discontinuously operated autoclave under pressure and the atmospheric continuous flow tubular reactor are employed for the evaluation of alkylation activity. Effects of alkylation temperature, pressure, paraffin/olefin molar ratio, butene WHSV and reactant input ways on the activity of catalyst are investigated and the suitable alkylation conditions have been determined. The corresponding results are as follows: butene conversion 100%, TMP selectivity 90.8% for the alkylation under pressure, and butene conversion 50%, TMP selectivity 65.8% for the atmospheric alkylation. Characterization results for the used catalyst by means of IR, N2-adsorption and SEM show that the deactivation of catalyst is mainly caused by the covery of coke precursor formed from the side-reactions during alkylation. The coke precursor could be mainly the long-chain paraffins with more than ten carbons. Regeneration of the used catalyst is carried out, using the extraction by organic solvent and the H2O2 oxidation at lower temperature. Proper conditions of regeneration of catalyst are determined for the two methods respectively. For solvent extraction, the mixture of dichloromethane with petroether as the solvent, and extraction time is 10h; and as for H2O2 oxidation, oxidation time is 20h, oxidation temperature is 353~363K. After regeneration by these two methods, the activity of the used catalyst can be recovered to above 85% of its initial value. Process flow sheet of alkylation catalyzed by the heteropolyacid HPW12 supported on carbonized resin catalyst is subjected, which employs the riser-type reactor and combination of the alkylation and regeneration of catalyst.更多还原