固体超强酸SO_4~(2-)/ZrO_2催化正烷烃异构化和裂解反应机理的研究

本文利用脉冲微反装置初步考察了有机溶剂处理对催化剂SO_4~(2-)/ZrO_2的活性及选择性的影响,同时通过考察催化剂活化温度及吸附水对催化活性的影响、吡啶中毒试验、TPD分析等,对催化剂催化烷烃反应的活性中心以及烷烃在催化剂上进行异构化和裂解反应的机理进行了探讨。认为主要活性中心是超强B酸中心;串连裂解反应并不是裂解反应的唯一途径。     

Effects of UV light irradiation on propane in an argon plasma

It has been shown that propane conversion into acetylene, by propane cracking in an argon plasma, is increased when the reaction site is irradiated with UV light in the range 220–400 nm. The reactions were carried out between 4500 and 6400 K. A model is outlined following which the propane conversion increase at 6400 K (40%) is tied up to energy absorption by acetylene in the lower wavelengths range (220–250 nm). Also, a combined adsorption-photochemical process, related to precursors and submicron carbon particles, could be responsible for the yield increase observed at 5400 K (45%), around 365.0 nm.     

催化裂化待生剂上有机吸附物种的鉴别分析

为了鉴别分析催化裂化待生剂上分子筛孔道内、外的有机吸附物种，提出了超声萃取提取待生剂上外表面的有机吸附物种方法，优化了萃取条件；对分子筛孔道内的有机吸附物种。采用HF处理待生剂，溶解催化剂分子筛骨架以释放孔内积炭，并用二氯甲烷作溶剂萃取。采用GC-MS分离并鉴别分子筛孔道内、外的有机吸附物种，实验结果显示：在催化剂外表面主要是二环和三环芳烃，而在分子筛孔道内解吸的则是从双环到七元环的多环芳烃。这些结果对研究催化裂化催化剂的性能和结炭的机理提供了重要信息。     

渣油重组分沥青质结构分析及其对临氢热反应过程生焦的影响

以塔河常压渣油(THAR)为原料,正己烷为溶剂分离获得重组分C6-沥青质及其脱沥青油,并将所得沥青质回调至脱沥青油中配制成不同沥青质含量的渣油,以此为原料进行了高压釜临氢热反应实验。首先利用元素分析、1H-NM R及13CNM R、GPC分子量测定、FT-IR、XRD及SEM对沥青质的分子结构参数、官能团、晶体结构及表面形貌进行了分析研究。结果表明,该沥青质芳环侧链中长链部分较少且支链化程度较高,并以甲基、乙基、丙基结构为主,其芳香度fA高达0.57,芳环缩合程度及芳香片层结构较大,且芳香环系同时存在迫位缩合和渺位缩合的结构,已经形成连接致密的高芳香度结构。鉴于沥青质结构的复杂性,考察了其含量对临氢热反应过程的影响,结果表明,随着沥青质含量的增加,渣油的转化率逐渐增加,当沥青质含量超过5.12%时,其转化率的增加以快速生成焦炭为代价。另外,渣油中长链脂碳含量f3C与轻质油收率存在一定规律性,即随着f3C增加,轻质油收率先增加后趋于平缓,而残炭值、芳香度fA与焦炭收率表现出良好的线性关系。     

Determination of sulphur in liquids obtained by thermal cracking of waste polymers and commercial fuels with different analytical methods

Low sulphur concentration in hydrocarbon products as fuels or lubricants is an important requirement for the high quality standards of refineries. A non-polarised energy dispersive X-ray fluorescence spectroscopy (EDXRFS) and sample combustion technique (ASTM D6428-99) was compared. A new application of energy dispersive X-ray spectrometry as analytical method for the determination of sulphur in fuels and fuel-like fractions was investigated. Low sulphur containing fuels and hydrocarbon mixtures obtained by thermal cracking of waste polymers were measured and the influence of C/H ratio on accuracy was studied. The concentration of sulphur in samples was measured with calibration graphs of different hydrocarbon matrices (commercial gasoline, diesel oil and white oil were used). Good correlation was observed between the different methods, but the correlation was depending on the characteristics of the matrices. Detection limits of 1.0 ppm, 1.1 ppm and 0.9 ppm were obtained for S in gasoline, diesel oil and white oil, respectively.     

A correlation between Hammett acidity of catalysts and their activity in temperature-programmed reaction of cumene dealkylation

On the basis of TPR spectra of cumene adsorbed on oxide catalysts, the relationship between Hammett acidity and reciprocal benzene formation temperature (H₀ = 32.50 – 18.37 10³/T_m) has been found. Using this relationship, it is possible to estimate a value of H₀ for oxide materials in an interval of –5.6 < H₀ < –16. The correlation between acidic strength of B-sites and rate constants of heterogeneous catalytic reactions is discussed.This revised version was published online in December 2005 with corrections to the Cover Date.     

重油催化裂化装置提升管内反应历程研究

利用自行研制的工业提升管在线取样系统对胜利石油化工总厂重油催化裂化装置提升管中下部进行在线取样，将取得的液体和催化剂榈进行处理分析，从而得到了重油催化装置提升管反应器中下部液体产品分布、催化剂活性、碳含量和焦炭H／C的变化规律。认为重油催化裂化的主要反应发生在提升管的中下部区域，并对提升管油剂混合处的渣油雾化、汽化和油剂接触状况进行了讨论。     

XPS study of nickel deposited on USY zeolites

Nickel-deposited USY zeolite samples were prepared by a method of impregnation with a solution of nickel naphthenate in benzene followed by drying and calcination. The interaction between nickel and zeolite was investigated by XPS after calcination, steaming and hydrogen reduction.     

压力对USY催化甲苯裂解结焦及其前驱体的影响

研究了压力对USY催化剂催化甲苯裂解结焦及其前驱体的影响。采用热重、红外、13C固体核磁、元素分析、色质联用、程序升温氧化法等手段对催化剂上的焦炭和液相产物中的焦炭前驱体进行了考察。结果表明，沉积在催化剂上的焦炭主要为缩合度较高的多环芳烃，随着压力的升高，总的结焦量减少，液相产物中多环芳烃的环数和质量分数呈增加趋势，证明了超临界流体对焦炭前驱体有萃取效果。并探讨了超临界条件下甲苯催化裂解结焦的机理。     

水热法合成Ni(OH)2/SiO2催化剂制备碳纳米管:镍含量对碳纳米管管径和产率的影响

以硝酸镍和正硅酸乙酯为主要原料，采用前驱物水热法制得不同镍含量的纳米Ni(0H)2／SiO2复合粉体，用复合粉体做催化剂催化裂解C2H2制得多壁碳纳米管粗产物。研究表明：在复合粉体Ni(OH)2／SiO2催化剂中，硅镍比在一定范围内(1：2～1：14)，随着镍含量增加，粒径增大，结晶程度提高，催化剂活性先提高后下降，制得的碳纳米管纯度及产量先增后降，碳管的管径分布范围先窄后宽。催化剂硅镍比为1：12时，制得的碳纳米管纯度高，管径细而均匀(10～18nm)，且粗产物数量较多(1g催化剂合成3．3g碳纳米管粗产物)。