双环戊二烯连续加氢用镍基催化剂研究

制备了用于双环戊二烯(DCPD)固定床连续式加氢合成桥式四氢双环戊二烯的负载型Ni基催化剂。利用低温氮气吸附(BET)、X射线晶体衍射(XRD)以及程序升温还原(H2–TPR)等手段对催化剂进行表征。结果表明,Ni–Cu/γ–Al2O3催化剂具有更好的加氢活性和稳定性,Cu的加入可降低Ni O的还原温度,促进Ni O在载体表面的分散,有利于加氢活性的提高。此工作为筛选更适合DCPD固定床连续加氢催化剂提供理论和实验依据。     

骨架铜催化对氯硝基苯选择性加氢制备对氯苯胺

以骨架铜(S-Cu)为催化剂,研究了对氯硝基苯(p-CNB)选择性加氢制备对氯苯胺(p-CAN)的反应规律。采用XRD、BET和SEM表征手段对S-Cu催化剂的微观结构进行了表征,考察了溶剂、反应温度、压力和底物初始浓度等因素对反应物转化率和目标产物选择性的影响。结果表明,在20 mL甲醇溶剂中,p-CNB初始用量7mmol,S-Cu催化剂0.5 g,60℃和氢气压力1.0 MPa的条件下反应120 min,p-CNB的转化率达100%,p-CAN的选择性达97.9%。     

Continuous hydrogenation of soybean oil in a trickle-bed reactor with copper catalyst

Continuous hydrogenation of soybean oil with a stationary copper catalyst bed was performed at 110–180 C, 30–75 psig hydrogen and Iiquid hourly spaced velocities (LHSV) of 0.25–0.6 cc/hr/cc catalyst. In contrast to batch, continuous hydrogenation was achieved at a lower temperature with no need to postfilter the product. The soybean oil products from the continuous and batch processes hydrogenated to 0% triene were similar in fatty acid composition,trans content of 29% and linolenate selectivity of 5. Biometrician, North Central Region, Agricultural Research Service, U.S. Department of Agriculture, stationed at the Northern Regional Research Center, Peoria, IL 61604.     

Vapor-Phase hydrogenation of methyl linoleate in the presence of a supported copper catalyst

Methyl linoleate was hydrogenated in the vapor phase in the presence of a copper-on-alpha alumina catalyst. The kinetics of the reaction could be formulated with a Eley-Rideal mechanism including the reaction between chemisorbed methyl ester and hydrogen in the gas phase. The absorption coefficients in the rate equation were based on separately performed adsorption studies recently reported.     

Raney铜催化糠醛选择性加氢制备环戊酮和环戊醇

以Raney铜催化糠醛加氢制备环戊酮和环戊醇。考察了溶剂类型、溶剂比例、溶剂与糠醛的比例、反应温度、氢气压力及反应时间等参数对糠醛转化率和选择性的影响。结果表明,以体积比4∶1的甲醇和水作为溶剂,糠醛与溶剂体积比1∶10,温度180℃,氢气压力3 MPa,反应时间4 h时,Raney铜催化糠醛加氢对于环戊酮和环戊醇表现出良好的活性和选择性,糠醛转化率达98.9%,环戊酮和环戊醇的选择性分别为52.9%和19.3%。采用XRD、BET和SEM对Raney铜催化剂的微观结构进行了表征。     

Laboratory-scale continuous hydrogenation

Data required for modeling and simulation of continuous hydrogenation kinetics have been obtained in an isothernal, cocurrent flow-type reactor. A preheated suspension of catalyst in oil, mixed with hydrogen, is passed cocurrently through 10 m length of 0.12 cm ID Teflon tubing at flow rates varying from 1.5 to 4.5 ml/min, gas flow rates from 100 to 700 ml/min, and temperatures from 150 to 190 C. The hydrogenations are run using nickel catalyst at outlet pressures of one atmosphere. Samples are removed at equal intervals along the length of the reactor and analyzed by gas chromatography. The kinetics of the continuous reactor are satisfactorily modeled by the simple scheme Ln→Lo→01→S using first order kinetics. Reaction rates, calculated by a digital computer, are shown to be related to temperature by the Arrhenius equation.trans Content and degree of hydrogenation are increased with temperature are decreased as oil flow increases. Hydrogen flow rate has little or no effect over the range studied.     

Influence of chlorine poisoning of copper/alumina catalyst on the selective hydrogenation of crotonaldehyde

The effect of the presence of chlorine on the activity and selectivity of a Cu/Al₂O₃ catalyst has been examined for the selective hydrogenation of an unsaturated aldehyde, crotonaldehyde. Cu/Al₂O₃ in the absence of chlorine poisons produced 1-butanol almost exclusively, whereas catalysts pre-dosed with a suitable amount of chlorine compound (CCl₄, CHCl₃ and CH₂Cl₂) shifted the product distribution towards formation of butanal. The poisoning effectiveness increased in the order CCl₄32Cl₂CH₃Cl and methyl chloride was found to totally deactivate the catalyst. The most significant enhancement in butanal selectivity was observed with CCl₄ and CH₂Cl₂. The effect of chlorine as a poison is in contrast to the effect of sulphur which enhances formation of crotyl alcohol and the origins of these effects are discussed.     

Evaluation of hydrogenation catalyst activity

The AOCS Recommended Practice for testing activity of hydroge-nation catalysts was used to compare activity and properties of a number of commercial catalysts with the AOCS standard catalyst. Four of five commercial catalysts tested were similar to the standard but one commercial catalyst was markedly more active and more selective. It also was very difficult to filter after hydrogenation. Selectivity of the catalysts in hydrogenation of soybean oil was determined from change in fatty acid composition. The most selective catalyst produced the highest level oftrans isomers and the highest dropping point. Solid fat contents measured after 30 and 40 min of hydrogenation time were determined by wide-line nuclear magnetic resonance. The Recommended Practice and standard catalyst were useful tools in evaluating activity and selectivity of hydrogenation catalysts.     

镍系SBS加氢反应机理及加氢催化剂制备研究

对镍系SBS催化加氢机理进行了探讨,对催化剂制备工艺进行了优化。当催化剂组分质量浓度为2～4 g/L,陈化温度为50～70℃,n(Al)/n(Ni)为3～6时催化剂活性最高。向待加氢胶液中加入一定量破杂剂A可使催化剂活性及稳定性有一定程度提高。用该法制备的催化剂有较好的稳定性,常温下放置一个月其催化活性几乎没有变化。     

Catalytic hydrogenation of vegetable oils: II. The activity of the prereduced copper chromite catalyst

The prereduction of copper chromite with hydrogen produces a strong deactivation of catalyst in soybean oil hydrogenation at 200 C and 6 atm. ESCA studies and kinetic data show that the decrement of the activity is correlated to the disappearance of Cu″ and Cu′ species and to the decrement of Cu/Cr ratio on the catalyst surface. The comparison of activity between original and prereduced catalysts allows a better elucidation of the role of Cu′ in promoting the double bond conjugation and of Cu° in catalyzing the conjugated double bond hydrogenation. For part I, see ref. 23.     

固相加氢催化剂在苯加氢新装置上的工业应用

介绍了SCB-1固相加氢催化剂在苯加氢新装置副反应器上的工业应用。经过对催化剂性能指标对比评价,SCB-1固相加氢催化剂在活性组成、尺寸、比表面积参数上与进口催化剂的参数接近,堆密度和强度指标又优于进口催化剂。通过优化工艺参数,产品质量不断得到优化,并能保证SCB-1固相加氢催化剂活性持久,延长该催化剂的运行周期至9年。通过在苯加氢装置生产中的使用,表明SCB-1固相加氢催化剂是一种机械强度高、活性好的苯加氢催化剂,该催化剂性能优于国外的同类产品,完全可以替代国外的进口催化剂。产品纯度达到99.96%,产品中苯质量分数小于10 mg/kg。     

国内清洁柴油加氢催化剂研究进展

综述了国内清洁柴油国Ⅴ标准加氢催化剂研究进展情况,目前,国内多家研究机构在柴油清洁生产方面都有自己独特的加氢催化剂及工艺,且达到了国际先进水平。中科院大连化物所的最新柴油加氢催化剂从性能到制备技术达到了国际领先水平。     

Selective hydrogenation of soybean oil: V. A Novel copper catalyst with excellent re-use properties

A procedure for the preparation of highly active copper catalyst by chemisorption of copper-ammonia complex on silica gel is described. This catalyst was highly selective towards the reduction of linolenate in soybean oil. The catalyst was re-used four times with no loss in activity.     

加氢催化剂预硫化技术研究进展

加氢催化剂的活性组分大多是由Mo、Co、Ni、W等金属元素组成,并且催化加氢过程在石油炼制工业具有广泛的应用。为了获取高性能的加氢催化剂,对于加氢催化剂的预硫化研究一直是石油工业的研究热点之一。本文从加氢催化剂硫化后的活性相的结构及其催化活性两个方面阐述了加氢催化剂预硫化的研究进展,并对其进一步的研究方向进行了分析。     

Monitoring of hydrogenation with various catalyst ratios

Soybean oil was hydrogenated using two different nickel-based commercial catalysts (Nysosel 222 and SP-10) at various ratios in 4-L reactors under constant conditions (165°C, 2 bar hydrogen pressure, and 500 rpm stirring rate). Trans isomer formation, reaction rates, selectivity (S) ratios, and melting behaviors of the samples were monitored during the reactions. When Nysosel 222 was used at 0.02, 0.03, and 0.04%, iodine values (IV) were reduced from 130.1 to 70.6, 50.9, and 44.7 and total trans isomers increased from 0 to 34.2, 43.3, and 40.5%, respectively, after 100 min of hydrogenation. However, SP-10 reduced IV from 130.1 to 77.2, 75.7, and 71.3 after 100 min when used at 0.1, 0.15, and 0.2%, respectively, whereas total trans isomers were 58.6, 70.4, and 70.7%. Reaction rates increased with catalyst ratio and time but were higher for Nysosel 222 than for SP-10 although 5–10 times less Nyosel 22 was used than SP-10. Linoleate selectivity (S ₃₂) was almost constant for Nysosel 222, whereas it was higher but fell with time for SP-10. Increasing the catalyst ratio decreased the time needed to reach the highest oleate selectivity (S ₂₁) ratios, and the IV values where the highest S ₂₁ were attained were different for the catalysts. Increases in m.p. of SP-10 samples were slower after IV values of 80 were attained, where S ₂₁ ratios reached to higher values. Solid fat contents (SFC) of these samples fell markedly above 21.1°C, and steeped SFC curves were obtained.     

植物油加氢催化剂的研究进展

综述了植物油加氢催化剂的研究现状,介绍了植物油的基本特点以及影响其加氢的因素,表明催化剂是植物油加氢的关键,介绍了不同体系催化剂在植物油加氢中的研究现状,其中重点介绍了Ni基催化剂、Cu基催化剂、Pd基催化剂和Pt基催化剂在植物油加氢行业的研究状况及发展,以及影响催化剂催化活性的因素,催化剂的材料、催化剂载体等。指出植物油加氢催化剂是由贱金属向贵金属、单元体金属向多元体金属以及加强对载体和活性组分负载技术研究的发展趋势。     

碳二加氢催化剂的工业应用

在对进口G-58 C和国产LY-C2-02催化剂在兰州石化乙烯装置碳二加氢单元二段反应器的工业应用数据进行分析和比较的基础上,考察了改进型LY-C2-02催化剂的工业应用性能。结果表明:与G-58C催化剂相比,改进型LY-C2-02催化剂具有活性和选择性比较高、操作弹性范围宽、操作稳定等特点,完全适应6000 h-1空速的工艺条件,综合性能与G-58C催化剂水平相当;LY-C2-02催化剂具备替代进口G-58C型催化剂的能力,对实现碳二加氢催化剂国产化、降低乙烯装置成本、增加效益有一定的现实意义。     

JT-8型焦炉煤气加氢催化剂失活样品剖析

焦炉煤气深度净化是焦炉煤气综合利用的关键技术。采用XRF、颗粒抗压碎力、烧失重、压汞法孔结构、XRD和XPS等对JT-8型加氢催化剂新鲜样、使用样和焙烧样进行表征。加氢催化剂失活的主要原因是催化剂表面结焦积炭,形成致密板结层,隔绝了气体与催化活性位的有效接触,同时引起床层阻力降不断上涨。加氢催化剂使用样中含有大量的碳元素,质量分数从6.6%到29.4%均有分布;催化剂颗粒表面的碳原子百分数占76.23%~79.74%,其形态是类石墨炭形态(C—C、C—H)和高度聚合的有机碳形态(C—O、C=O),且以类石墨炭为主。使用样的微孔被堵塞,导致孔容和比表面积均大幅减少,平均孔径变大;焙烧后,一些小孔径的微孔结构可能被破坏,导致比表面积下降,平均孔径变大;结焦积炭严重的样品恢复率较差。