甲基萘烷基化催化剂上积炭的表征

研究了HZSM—5沸石催化甲基萘与甲醇的烷基化反应。采用热重分析、红外光谱分析、元素分析和色—质联机分析等手段，对甲基萘与甲醇烷基化失活催化剂上积炭的二氯甲烷溶解炭(焦炭前身物)和不溶解炭物进行了表征。实验结果表明：焦炭前身物主要由三环取代芳香化合物组成，并有芳醚类化合物存在。HZSM—5沸石催化剂失活的原因可能是由甲醇自身反应生成的烃类化合物进一步与萘环反应形成多环芳香化合物引起的。     

三氯化铝负载HY沸石催化β-甲基萘转移烷基化反应

通过液相沉积法将无水AlCl3负载到HY沸石上制得负载型催化剂。研究了负载前后HY沸石催化β-甲基萘(β-MN)与均四甲苯(TMB)转移烷基化反应性能。结果表明,随着负载型HY沸石的表面酸性增强,沸石的孔径减小,催化β-MN与TMB转移烷摹化反应的活性提高,2,6-／2,7-二甲基萘(DMN)的选择性得到改善。当反应在β-MN与TMB摩尔比为1:1,反应温度为400℃,空速为6.0 h-1的条件下进行时,β-MN的转化率为46.4％,2,6-DMN／2,7-DMN的选择性为25.6％。     

Mg2+改性β沸石催化甲基萘烷基化反应

在Mg^2 改性Hβ分子筛催化剂上进行了甲基萘与甲醇的烷基化反应。考察了Mg^2 交换量对Hβ分子筛催化剂的比表面程、表面酸中心强度和催化甲基萘与甲醇烷基化效果的影响。通过正交试验，优化了影响Mg^2 改性Hβ催化剂催化效果的原料配比、反应温度及质量空速（WHSV）等反应条件。实验结果表明：随Mg^2 交换量增加，催化剂的比表面积下降，催化剂表面的弱酸中心数增加，烷基化催化效果改善；甲基萘与甲醇烷基化反应的最佳条件为空速0.4-0.6h^-1、反应温度460℃、原料配比MN：ME：TMB为1：0.6：3-1：0.8：3。     

Zn2+改性β沸石催化合成2,6-二甲基萘

在Zn^2 改性邱分子筛催化剂上进行了甲基萘与甲醇的烷基化合成2,6-DMN反应。考察了Zn^2 交换容量对Hβ分子筛催化剂的比表面积、表面弱酸量和催化甲基萘与甲醇烷基化效果的影响。实验结果表明：随Zn^2 交换容量增加,催化剂的比表面积下降,催化剂表面的弱酸量有所增加。经Zn^2 改性后催化剂的反应效果均有提高,同时发现影响甲基萘甲醇烷基化反应的主要因素是催化剂的表面弱酸量。     

2,6-二甲基萘制备技术进展

综述了目前国内外制备2,6-二甲基萘的各种催化剂体系、工艺技术和研发状况,包括煤焦油和石油裂解重质芳烃的直接分离法;萘、甲基萘、甲苯、二甲苯等为原料的化学合成法以及二甲基萘的异构化法。通过比较其工艺特点和催化剂性能,指出以廉价、丰富的萘或甲基萘为原料与甲醇烷基化反应合成2,6-二甲基萘是当前最合理的技术路线;其中,高效催化剂的制备是关键,特别是以改性沸石分子筛为主的催化剂。     

Hβ沸石催化2-甲基萘甲醇烷基化的研究

介绍了以Hβ沸石分子筛为催化剂，2—甲基萘为原料，进行甲醇烷基化反应合成2，6—二甲基萘。主要考察了反应温度、原料配比、空速和载气量等条件对烷基化反应转化率和2，6—二甲基萘选择性的影响。     

苯和乙烯气相烷基化制乙苯ZSM型沸石催化剂的研究

考察了沸石结构类型、模板剂种类、晶粒尺寸和硅铝比对ZSM型沸石催化剂烷基化反应性能的影响。发现以四丙基溴化铵为模板剂合成的适中硅铝比和较小晶粒的ZSM－5沸石催化剂对苯与乙烯气相烷基化反应具有高的活性、选择性和稳定性。     

转移甲基化合成2,6-二甲基萘研究

以β-甲基萘为原料,均四甲基苯为烷基化剂,在催化剂作用下,进行转移甲基化反应合成2,6-二甲基萘,考察了反应的温度,催化剂和烷基化剂的加入量对反应结果的影响。     

2-甲基萘酰基化反应研究

2-甲基-6-酰基萘是聚酯PEN的前体,其合成方法对PEN的发展具有重要的意义。以三氯化铁和氯化锌2种路易斯酸为催化剂,考察反应时间、反应温度对2 甲基萘酰基化催化性能的影响。试验结果表明三氯化铁催化剂对2 甲基萘的酰基化具有较好的催化效果,在反应温度为25 ℃,反应时间为5 h时目的产物的收率可达84%,且过高的温度会导致大量副产物的生成,降低产率,而反应时间的长短对产物的选择性无较大影响。根据试验结果,得出了合成目的产物的适宜操作条件。     

不同硅铝比HZSM-5甲醇制汽油性能比较

考察了不同硅铝比的HZSM-5分子筛催化剂在流化床甲醇制汽油反应中的催化性能。结果表明,催化剂的反应活性随着催化剂硅铝比的增加而增加。     

Optimization of the production of biodiesel from soybean oil by ultrasound assisted methanolysis

This paper evaluates and optimizes the production of biodiesel from soybean oil and methanol using sodium hydroxide as catalyst. The study and optimization was carried out at low catalyst concentration (0.2 to 0.6 w/w). The reaction was carried out with application of low-frequency high-intensity ultrasound under atmospheric pressure and ambient temperature in a batch reactor. Response surface methodology (RSM) was used to evaluate the influence of methanol to oil ratio and catalyst concentration on soybean oil conversion into biodiesel. Analysis of the operating conditions by RSM showed that the most important operating condition affecting the reaction was the methanol to oil ratio, while catalyst amount showed little significance in the transesterification reaction. Total consumption of oil was obtained when alcohol to oil ratio of 9:1 and catalyst concentration of 0.2 w/w were applied.     

超临界氨合成

Ammonia synthesis at supercritical conditions was first studied over iron and active carbonsupported ruthenium catalysts in a fixed-bed reactor. The influences of 15 kinds of different supercritical media, such as alkanes of C7-C13, 1, 2, 3, 4-tetrahydronaphthalene, cis-decalin, o-xylene,ethylbenzene, quinolin, n-hexane and aniline etc. and reaction conditions (catalyst, temperature, space velocity, particial pressure of media) on ammonia at supercritical condition were investigated.Supercritical medium was decomposed under reaction conditions over Fe and Ru/AC catalysts. The decomposition products deactivated the catalysts. Alkane decomposed the least, and the rate of deactivation was the slowest. Therefore alklane was a relatively good medium. The decomposion of supercritical medium was the key for the deactivation of catalysts. Another important reason for the decrease of ammonia concentration was that the effective pressure of syngas decreased because of the presence of supercritical media. The active temperature of catalyst was the decisive factor in supercritical ammonia synthesis. Supercritical catalytic reaction was viable only at a lower temperature. Ammonia ynthesis at supercritical conditions is possible if a catalyst with active temperature lower than 573 K could e developed and the decomposition of supercritical media could be prevented.     

基于Aspen Plus用户模型的甲醇合成模拟及分析

对板间换热式甲醇合成塔建立了一维拟均相数学模型,并用四阶Runge-Kutta法求解其轴向温度与浓度分布。利用Aspen Plus中的User 2模块将其嵌入整个甲醇合成全流程进行模拟,并用取自工厂的实际数据进行验证,结果吻合良好。分析得到了原料气入口温度、操作压力、汽包压力及进料流量对反应器出口甲醇物质的量分数的影响,以及不同时期催化剂的活性分布及粗甲醇的产量分布,提出了在催化剂中后期应采取提高操作压力的措施来保证粗甲醇的产量。     

Methylation of phenol over high-silica beta zeolite: Effect of zeolite acidity and crystal size on catalyst behaviour

A systematic investigation was carried out to elucidate several aspects of the gas/solid methylation of phenol over high Si/Al ratio beta-structured zeolite in protonated form, characterised by various techniques, including XRD, SEM, BET, ICP, FTIR, TGA, microcalorimetry, and modeling by ab initio calculations. Data on the characteristics and the kinetic and mechanistic features of the catalytic reaction, as well as on catalyst deactivation, show that these zeolites, besides being very active for the present reaction, lead to cresols and anisole as primary products. As catalyst deactivation proceeds, the selectivity to cresols and anisole increases substantially, accompanied by a rapid decrease in selectivity to polyalkylated species. Medium- to low-strength silanols are the main contributors to catalyst surface acidity. High-strength Lewis acid sites either are virtually absent (especially when metal cations partially substitute for protons) or play a role essentially in catalyst deactivation. Stacking faults in the zeolite framework, generated by the intergrowth of at least two beta polymorphs, lead to an increased concentration of silanol-based Brønsted acid sites. Deactivation is due to the interaction of phenol and oxygenated products with the silanol-based acid sites and of methanol only with the strong acid sites of both Lewis and Brønsted nature. Self-oligomerisation–cyclisation of methanol to olefins and aromatics, followed by further alkylation to aromatic C atoms, contributes to catalyst deactivation. At any conversion level and at any temperature, the anisole/cresol ratio is systematically lower for the larger-crystal size zeolite, because the secondary transformations of anisole to cresols by both intramolecular rearrangement and intermolecular alkylation of phenol is favoured by the longer residence time of anisole within the zeolite pores.     

甲醇合成铜基催化剂硫化氢中毒研究(Ⅰ)——硫化氢中毒本征失活动力学

研究了甲醇合成C207铜基催化剂硫化氢中毒本征失活动力学.研究表明,硫化氢分压增加,失活速率加快;温度升高,失活速率加快.本征失活速率方程为r_d=-da/dr=0.1474×10~(12)exp(-81128/R_gT)P_(H_2s~a)     

甲醇合成铜基催化剂硫化氢中毒研究(Ⅰ)——硫化氢中毒本征失活动力学

研究了甲醇合成C207铜基催化剂硫化氢中毒本征失活动力学.研究表明,硫化氢分压增加,失活速率加快;温度升高,失活速率加快.本征失活速率方程为r_d=-da/dr=0.1474×10~(12)exp(-81128/R_gT)P_(H_2s~a)     

甲苯甲醇烷基化制对二甲苯催化剂中试反应性能研究

经过多步改性制备了负载二氧化硅（SiO₂）、氧化镁（MgO）、五氧化二磷（P₂O₅）、贵金属铂（Pt）的纳米ZSM-5分子筛催化剂,并在六段固定床反应器上分段装填该催化剂720 g进行甲苯、甲醇烷基化制对二甲苯反应活性评价。实验结果表明,通过调变甲醇和甲苯物质的量比可以使甲苯转化率在22%~30%可调,烷基化液相产物中二甲苯选择性保持在95%以上,二甲苯中对二甲苯选择性保持在95%以上;催化剂单程寿命达到1 300 h,随着反应时间延长催化剂的活性有所下降。通过X射线衍射（XRD）、热重分析（TG-DTG）和氮气吸附-脱附等手段对参加反应前后的催化剂进行了表征,结果表明反应中生成的积炭堵塞了分子筛的孔道或覆盖了催化剂的活性位;经过在反应器内原位再生,催化剂的反应活性基本恢复到新鲜催化剂水平。     

基于超临界流体密度的烷基化内扩散影响动力学

利用烷基化反应实验数据和超临界流体密度计算数据,开展了考虑内扩散影响的烷基化反应动力学研究,采用优化计算方法进行模型参数估值,确定了烷基化反应速率常数、有效扩散系数、催化剂失活速率常数.研究结果表明,基于PengRobinsn(PR)方程计算流体密度的动力学模型在显著性水平α=0.01下有较高的实验数据拟合精度和模型可信度,说明该方法是计算超临界流体密度的较好方法.从有效因子大小可以看出,烷基化反应总体上处于中孔扩散阻力区.