C~+_8重整混合芳烃精制催化剂TCDTO-1的研制

研究了采用大孔小晶粒分子筛作为活性组分,非贵金属改性以提高反应的稳定性的脱烯烃TCDTO-1催化剂。由小晶粒分子筛制备的脱烯烃TCDTO-1催化剂具有良好的扩散性能、脱烯烃活性和稳定性,在原料溴指数、温度、压力、空速等反应条件一致前提下,其单程寿命为白土的10倍以上。催化剂再生2次后脱烯烃活性略有下降,但是单程寿命有所提高。催化剂精制后产物分布和白土相比无明显变化。     

丝光沸石择形催化合成甲胺反应的性能研究

制备了经阳离子改性的合成丝光沸石催化剂 ;以氨和甲醇为原料 ,在常压固定床上进行了合成甲胺反应研究 ,考察了工艺条件对催化剂催化性能的影响 ,并通过正交试验筛选出最佳工艺条件。结果表明 :经钙、镁离子交换的丝光沸石催化剂具有较高活性和良好选择性 ,甲醇转化率 >90 % ,对二甲胺的单程选择性 >40 %。自制的这种钙离子改性丝光沸石催化剂(CaHM)的催化性能优于目前国内工业化的甲胺生产催化剂 ,而且CaHM是经添加粘接剂焙烧成型的样品 ,可直接供产品的中试放大。     

无机物负载体的制备和表征及其催化苯酚羟基化的研究

研究了低硅铝比沸石分子筛及天然矿土硅铝酸盐负载无机盐或氧化物为催化剂,催化氧化苯酚制取邻、对位二元酚。用化学常量法分析了负载离子的含量,采用XRD、IR、DRS、Mossbauer谱等手段,对催化剂进行表征。研究了不同金属离子无机盐的各种载体催化剂的催化活性,证明了热稳定性差的沸石及矿土负载改性为六配位非骨架杂原子的无孔道致密相,对苯酚羟化反应有较好的催化活性,n沸石1作催化剂,溶剂用水,苯酚与H2O2摩尔比为3：1,pH值为1．5(Fe改性),4(Cu改性),温度为60℃(Fe改性)、80℃(Cu改性),时间为1h,催化剂的量为苯酚的1／10,催化剂有一定再生能力,重复3次使用效果较好。     

改性HY分子筛催化剂催化甲基叔丁基醚与苯酚合成叔丁基苯酚的研究

甲基叔丁基醚(MTBE)作为烷基化剂,以改性HY分子筛为催化剂,在常压连续流动固定床反应器上,对苯酚烷基化合成对叔丁基和2,4 二叔丁基苯酚(2,4 DTBP)的反应规律进行了较为系统的研究。以不同改性物及其含量改性HY分子筛,可调节其表面酸量、酸分布及孔道尺寸,从而改变催化剂的反应活性及产物选择性。苯酚与MTBE烷基化反应主要在中等强度和弱的B酸中心上进行。催化剂表面的酸量和酸分布不但影响活性,同时影响2,4 DTBP的选择性。对单组分氧化物改性的HY分子筛催化剂研究表明,每种改性物均存在一个最佳含量,P2O5改性后HY催化剂的性能最优越。苯酚的转化率达99.60%,2,4 DTBP选择性达63.90%。这一结果是目前分子筛作催化剂合成2,4 DTBP的最好结果,具有潜在的应用前景。     

在改性HY分子筛催化剂上甲基叔丁基醚与苯酚合成步丁基苯酚的研究

甲基叔丁基醚(MTBE)作为烷基化剂,以改性HY分子筛为催化剂,在常压连续流动固定床反应器上,对苯酚烷基化合成对叔丁基和2,4-二叔丁基苯酚(2,4-DTBP)的反应规律进行了较为系统的研究.以不同改性物及其含量改性HY分子筛可调变其表面酸量、酸分布及孔道尺寸,从而改变催化剂的反应活性及产物选择性.苯酚与MTBE烷基化反应主要在中等强度和弱的B酸中心上进行.催化剂表面的酸量和酸分布不但影响活性,同时影响2,4-DTBP的选择性.对10种单组分氧化物改性的HY分子筛催化剂研究表明,每种改性物均存在一个最佳含量,P2O5改性后HY催化剂的性能最优越.苯酚的转化率达99.60%,2,4-DTBP选择性达63.90%.这一结果是目前分子筛用催化剂合成2,4-DTBP的最好结果,具有潜在的应用前景.     

碱改性HZSM-5催化热解木质素催化剂失活分析

对0.3 mol·L^-1 NaOH改性后的HZSM-5以及未改性HZSM-5催化剂进行循环和再生评价实验以考察催化剂的寿命。对反应后和再生的催化剂进行N₂吸脱附以及NH₃-TPD表征,并通过对反应后的催化剂进行SEM、TGA、FTIR、UV-Vis等表征分析催化剂积炭。两种催化剂的活性均随着循环实验次数的增加而逐渐降低,经4次循环实验的改性HZSM-5催化剂的催化活性远高于4次循环实验的未改性HZSM-5催化剂。反应过的催化剂经高温煅烧再生后其活性都有所恢复,再生后的改性HZSM-5的催化活性仍高于未改性催化剂。对两种不同催化剂积炭分析,改性后催化剂的积炭量少于未改性的催化剂,其积炭组分中高聚芳烃的含量相对较多。     

新发明

苯酚的提纯方法 中国专利CN1111607A报道了一项发明,涉及苯酚的提纯方法及用异丙苯法联产苯酚和丙酮的工艺中得到苯酚的提纯方法。目的是开发一种适于从苯酚中提纯去掉微量有机杂质具有高活性、能够再生并具有长催化寿命以及具有高机械强度及稳定性的催化剂。用非均质沸石催化剂提纯苯酚得到此结果。用丁烷裂解法测得催化     

再生对烯烃转化反应催化剂活性影响的探究

以某厂11.7万t/a烯烃转化装置反应器运行数据为基础,研究催化剂活性随运行时间延长的减弱情况,并分析再生对催化剂初期活性及减弱速率的影响。结果表明：每次再生后,催化剂最高活性平均下降5.59个百分点,运行周期内催化剂活性平均减弱速率减少0.042%/d;与原反应运行至丁烯单程转化率下降至70%左右再生相比,在单程转化率下降5.59个百分点时进行再生可以始终保持催化剂的最大活性,丁烯平均单程转化率提高3.02个百分点,装置丙烯产量增加约0.4万t/a。     

碱改性HZSM-5催化热解木质素催化剂失活分析

对0.3 mol·L-1 Na OH改性后的HZSM-5以及未改性HZSM-5催化剂进行循环和再生评价实验以考察催化剂的寿命。对反应后和再生的催化剂进行N2吸脱附以及NH3-TPD表征,并通过对反应后的催化剂进行SEM、TGA、FTIR、UV-Vis等表征分析催化剂积炭。两种催化剂的活性均随着循环实验次数的增加而逐渐降低,经4次循环实验的改性HZSM-5催化剂的催化活性远高于4次循环实验的未改性HZSM-5催化剂。反应过的催化剂经高温煅烧再生后其活性都有所恢复,再生后的改性HZSM-5的催化活性仍高于未改性催化剂。对两种不同催化剂积炭分析,改性后催化剂的积炭量少于未改性的催化剂,其积炭组分中高聚芳烃的含量相对较多。     

改性ZSM-5沸石上甲苯-乙醇烷基化催化性能的研究

本文研究了甲苯-乙醇在改性 ZSM-5沸石分子筛上的烷基化反应,并对其进行了单组份磷改性和双组份磷-铁、磷-镁、磷-钙改性实验。实验表明,改性后的催化剂的反应活性均不同程度地降低了,而对位产品的选择性则明显提高了。这归因于加入新的组份改变了沸石的孔道和孔口尺寸,其表面酸性也发生了变化。     

On the activity and stability of platinum/alumina catalyst during multiple deactivation and regeneration

Catalyst surface characterizations have been carried out to investigate the role of dispersion on catalyst activity and to probe the occurrence of oscillations in coking levels with cycle number generally observed during multiple deactivation and regeneration schemes. The titrations were done, cycle by cycle, at 430°C after oxidation and at the same temperature (430°C) after reduction at 500°C. Results show the usually observed trend - that the dispersions after oxidation are higher than those after reduction. The average decline in dispersion from oxidation to reduction was calculated to be 39.25%. It was observed that the cycles with high toxic coke removal were characterised by high deactivation times. The deactivation times were still high even for cycles subsequent to those with low dispersion. At high dispersions the catalyst had short deactivation times, that is the small crystallites deactivate faster than large ones. The nature of reducebale coke and the efficiency of its removal is a much more determinant factor of catalyst activity than the level of metal disperision. Thus prolonged toxic coke reduction at the high temperature of 500°C, though resulting in an apparent lowering of dispersion, does not affect the quality of the catalyst. The dispersion before reduction could be retained on oxidation. Hence reduction at 500°C did not introduce sintering.     

α-甲基苯乙烯加氢工业催化剂失活分析及再生

苯酚丙酮装置副产的α-甲基苯乙烯影响装置物耗,通常采用加氢将其转化为异丙苯作为原料循环使用,可提高装置运行效率、降低单耗,提高技术经济指标。α-甲基苯乙烯具有高度聚合性,易形成低聚物,同时含水、苯酚、碱性物等杂质,从而导致加氢催化剂失活。针对某工业装置运行中α-甲基苯乙烯加氢催化剂出现的失活现象进行剖析,并根据分析结果进行再生试验。结果表明,加氢催化剂失活原因主要是由于钠、铁杂质沉积以及苯酚、苯乙酮的聚合物覆盖所致。基于失活原因,重点比较了不同再生方案对加氢催化剂性能的影响,结果发现,水洗可以去除钠杂质,热异丙苯清洗或焙烧加氢催化剂可以除去表面的聚合物,使加氢催化剂性能完全恢复,产物中α-甲基苯乙烯残余量约500×10^-6,通过再生试验为工业α-甲基苯乙烯加氢催化剂的长周期稳定运行提供技术支撑。     

HDS catalyst regeneration: Coke burning-off by air in a shallow bed

Regeneration of coked HDS catalyst by air in a thin layer was studied experimentally and simulated using a simple model of the reactivation reactor. Using kinetic data on deposited coke oxidation obtained separately, the time course of the catalyst pellet temperature was correctly predicted. Conditions under which safe regeneration takes place were determined and verified experimentally as well as conditions under which coke ignites spontaneously. Under ignition conditions the degree of regeneration can not be controlled, which might result in irreversible catalyst deactivation.     

Kinetics of steam regeneration of SAPO-34 zeolite catalyst in methanol-to-olefins (MTO) process

Methanol-to-olefins(MTO) is industrially applied to produce ethylene and propylene using methanol converted from coal,synthetic gas,and biomass.SAPO-34 zeolites,as the most efficient catalyst in MTO process,are subject to the rapid deactivation due to coke deposition.Recent work shows that steam regeneration can provide advantages such as low carbon dioxide emission and enhanced light olefins yield in MTO process,compared to that by air regeneration.A kinetic study on the steam regeneration of spent SAPO-34 catalyst has been carried out in this work.In doing so,we first investigated the effect of temperature on the regeneration performance by monitoring the crystal structure,acidity,residual coke properties and other structural parameters.The results show that with the increase of regeneration temperature,the compositions of residual coke on the catalyst change from pyrene and phenanthrene to naphthalene,which are normally considered as active hydrocarbon pool species in MTO reaction.However,when the regeneration temperature is too high,nitrogen oxides can be found in the residual coke.Meanwhile,as the regeneration temperature increases,the quantity of residual coke reduces and the acidity,BET surface area and pore structure of the regenerated samples can be better recovered,resulting in prolonging catalyst lifetime.We have further derived the kinetics of steam regeneration,and obtained an activation energy of about 177.8 kJ·mol~(-1).Compared that with air regeneration,the activation energy of steam regeneration is higher,indicating that the steam regeneration process is more difficult to occur.     

钴基费托合成催化剂失活机理及再生研究进展

综述了钴基费托合成催化剂的失活机理、催化剂再生工艺及如何延长催化剂寿命的研究进展,通过分析催化剂失活原因,认为中毒、Co颗粒烧结、积炭、氧化、固相反应、晶相重构、表面阻塞和催化剂磨损等因素造成催化剂不同程度失活,其中积炭和Co颗粒烧结是催化剂失活的最主要原因,延长催化剂寿命的关键是提高催化剂的抗烧结能力和抑制积炭生成。增强活性金属Co和载体间的相互作用,保持Co晶粒分布均一或采用包覆、限域等策略可提高催化剂的抗烧结能力,通过添加助剂、调整氢碳比和空速等工艺参数亦可抑制积炭的生成。采用氢处理、脱蜡-氧化-还原和脱蜡-氧化-溶液处理-还原等工艺可实现催化剂的再生,对催化剂进行再生时要结合催化剂失活的主要原因,选择合适的再生工艺来最大限度地恢复催化剂活性。今后,提高催化剂的稳定性以及开发催化剂再生工艺技术路线是提高钴基费托合成技术竞争力的关键。     

生物质热解催化剂积炭问题的研究进展

生物质催化热解获得生物油等高质产品是最有前途替代传统化石能源的方法之一,但在热解过程中存在着严重的催化剂失活问题,其中积炭是导致催化剂失活的最主要因素。本文对近年来生物质催化热解领域的催化剂积炭问题进行综述,重点介绍催化剂积炭失活原因及表征方法、积炭的影响因素分析（催化剂结构、催化剂酸性与反应温度）、抑制催化剂积炭的方法 （催化剂改性、高压反应条件等）以及积炭催化剂再生方法 （氧化灼烧再生、臭氧低温再生、非热等离子体再生等）,并介绍了近年来新兴的微波催化热解技术对催化剂积炭的抑制和消除作用,然后针对该领域目前所面临的困难和发展方向进行展望,以期为生物质催化热解过程中催化剂积炭问题研究提供理论基础。     

A reactor design simulation with reversible and irreversible catalyst deactivation

In Mobil's Methanol-to-Gasoline (MTG) Process, two types of catalyst deactivation occur. The first type is reversible coking of the zeolite; the coke is burned off during regeneration, restoring activity. The second type is permanent deactivation of the zeolite. We have developed a dynamic simulation of the MTG process to investigate the interaction between these two types of deactivations. In our simulation, the rate of the coking depends on the amount of irreversible deactivation that had previously occurred. Also, the permanent deactivation occurs both during the reaction and catalyst regeneration. With this type of deactivation interaction, we were able to predict experimental observations in our pilot plant studies; in particular, the second cycle on a given catalyst is longer than the first cycle. We have used the model to compare the overall catalyst cycle life for both adiabatic and isothermal reactor simulations.     

Fe2O3催化甲基化合成2，3，5-三甲基苯酚

制备并考察了甲醇甲基化法合成2，3，5-三甲基苯酚的固体酸催化剂，进行了甲基化反应工艺条件的优化研究。实验结果表明，最优工艺条件：反应温度370 ℃、液空速0.2 h^-1、n(3，5-二甲基苯酚)∶n(甲醇)∶n(水)=1∶2∶1；原料3，5-二甲基苯酚的转化率达95.96％，目的产物2，3，5-三甲基苯酚的收率为72.01％。并采用XRD、SEM、DTA和TG等测定方法对催化剂进行了研究，发现催化剂表面上积炭污染是造成催化剂活性下降的主要原因。     

Investigation of coke extraction from zeolite-HY under supercritical and near-critical conditions

In-situ regeneration of deactivated catalysts by dissolving coke or coke precursors with supercritical reaction fluids is of important economical significance. Investigations of coke extraction on zeolite-HY were performed in a gradientless reactor under supercritical and near-critical conditions with ethylbenzene disproportionation as a test reaction and n-butane or n-pentane as inert. Experimental results illustrate the large ability of coke extraction under supercritical conditions. The influences of the experimental conditions on the ethylbenzene disproportionation and the coke extraction are discussed. Under appropriate supercritical conditions the coking and the coke extraction can reach an equilibrium, so that no further deactivation of the catalyst was observed. Several regularities about coke extraction on the surface of the catalyst are proposed.