毛细管气相色谱法测定三苯基膦的含量

采用１０ｍ×０．２５ｍｍｉｄＯＶ－１０１石英毛细管柱，氢火焰检测器（ＦＩＤ），蒽酮作内标物，建立了毛细管气相色谱法分析三苯基膦的方法。该法快速、准确，其回收率为９９．２％—１００．３％。     

Modeling of Coke Formation and Catalyst Deactivation in Propane Dehydrogenation Over a Commercial Pt-Sn/γ-Al2O3 Catalyst

Propane dehydrogenation was carried over a commercial Pt-Sn/γ-Al₂O₃ catalyst at atmospheric pressure and reaction temperatures of 580, 600, and 620°C and WHSV of 11 h^?1 in an experimental tubular quartz reactor. Propane conversions were measured for catalyst time on stream of up to nine days. The amounts of coke deposited on the catalyst were measured after one, three, six, and nine days on stream using a thermogravimetric differential thermal analyzer (TG-DTA) for each reaction temperature. The coke formation kinetics was successfully described by a coke formation model based on a monolayer-multilayer mechanism. In addition, catalyst deactivation was presented by a time-dependant deactivation function. The kinetic order for monolayer coke formation was found to be two, which would support a coke formation step involving two active sites. The kinetic order for multilayer coke formation was found to be zero. The activation energy for monolayer coke formation was found to be 29.1 kJ/mol, which was lower than the activation energy of about 265.1 kJ/mol for multilayer coke formation indicating that the presence of metals can promote coke formation on the catalyst surface.     

A Study on the Coke Behaviors During Alkylation of Benzene with Ethanol Over Different HZSM-5 Catalysts

Abstract

Four different kinds of HZSM-5 zeolites with different acid properties and crystal size were used as catalysts in alkylation of benzene with ethanol to produce ethylbenzene and the coke behaviors were studied. The catalysts were characterized by X-ray diffraction (XRD), Brunacr-Emmett-Teller (BET), scanning electron microscopy (SEM), wet chemical analysis, NH₃-temperature programmed desorption (TPD), and Py-infrared (IR). The coke amount was measured by thermal gravity (TG) and the nature of the coke deposition was characterized by ultraviolet-visible (UV-Vis) and C/H analysis. The results showed that besides acid property, the crystal size could also affect the catalytic performance, coke content, and the nature of the coke deposition. The effect of reaction conditions including temperature, weight hourly space velocity, and time on stream on the catalytic performance and coke behaviors were also discussed over S-4.     

THE INFLUENCE OF NATURE OF COKE ON KINETICS OF CATALYST REGENERATION

ABSTRACT

Experiments have been carried out to study the effects of coke composition on combustion parameters and burn-off time in the regeneration of coke-deactivated supported alumina catalyst. At high temperatures, results showed that the combustion behaviour is dependent on coke type as oxidizable and reduceable coke profiles versus time showed different trends. The curves of coke burn-off profiles were found to depend on the initial amount of coke deposited and on the oxygen concentration in the regenerating gas mixture. The higher the oxygen concentration, the shorter the time it takes to burn the same amount of coke. The high temperature combustion was assumed to follow the unreacted core model on the basis of which a model relating various parameters in coke deactivation was derived and the various dependencies demonstrated graphically for the different coke types. Oxidizable coke data fitted the linear model equation adequately while reducible coke data did not—another evidence of the difference in the kinetics of removal. Results further show a direct proportionality relationship between amount of coke accumulated under the same conditions and amount removed, confirming that the type of coke deposited is a function of accumulation conditions.     

Hydrotreating of Maya Crude Oil: I. Effect of Support Composition and Its Pore-diameter on Asphaltene Conversion

Abstract

A systematic study for a concept governing support effect in heavy oil hydrotreating (HDT) catalysts is performed. Different Al₂O₃ and its mixed oxides supports were prepared and CoMo supported catalysts were tested for Maya heavy crude oil hydrotreating. Fresh and spent catalysts are characterized with N₂ adsorption-desorption, element analysis, and scanning electron microscopy-energy dispersion analysis by x-ray (SEM-EDAX), which confirms that coke and metals deposition on the surface of catalyst is most probably near the pore mouth. It is also demonstrated from these results that asphaltene conversion depends on the pore diameter of the catalyst, while other hydrotreating conversions (hydrodesulfurization (HDS), hydrodenitogenation (HDN), and in some extent hydrodemetallization (HDM)) are more likely affected by the nature of active metal distribution. The evaluation of alumina mixed oxide (TiO₂, ZrO₂, B₂O₃, and MgO) supported catalysts indicates that supports with basic nature have better stability than the acid ones.     

An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Abstract

Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.     

RFCC沉降器内油浆重组分结焦反应过程实验模拟

 利用自制的热转化生焦实验装置和热重分析仪,考察了反应条件和油浆的性质对油浆重馏分热转化生焦的影响。结果表明,n(H)/n(C)原子比、残炭值、结构族组成等性质对其生焦率的影响要远大于反应时间、反应温度和油浆中催化剂含量等反应条件的影响。油浆中重组分馏分沸点的高低不能有效反映其生焦倾向,而重组分中的沥青质和胶质是生焦的主要前驱物,其芳碳率与生焦率有较好的线性对应关系。改变沉降器的操作条件可以缓解沉降器的结焦程度,但防止结焦的根本途径是通过调节主提升管的反应条件,从而减少进入沉降器内的油气中的结焦前驱物和沥青质的含量。     

Influence of coker-derived liquids on coking performance of Venezuelan heavy oil residue

Coking technological improvements are required to effectively upgrade/refine extra-heavy oil residues. The influence of types and blending ratios of coker-derived liquids on the coking performance of Venezuelan residue was studied in terms of product distribution and coke morphology. Blending of the coker diesel distillates (200–350?°C) with the residues was not suggested, given the negative interactions at all blending ratios (0–0.6) as concluded from coke yield analysis. Blending of the coker gas oil improved the coke quality and inhibited the coke formation. The recycle of heavy coker gas oil (430?°C+) at a blending ratio of 0.3 was most favorable.     

Composition of the Products of Thermolysis of Heavy Oil with the Addition of Light Hydrocracked Naphtha

Abstract

A series of experiments has been carried out on the thermolysis of heavy oil using 2.5–10.0% light hydrocarbon naphtha additive of vacuum gasoil prepared from conventional oil. It has been shown that the employment of the additive increases the conversion of heavy oil, avoids coke formation in the products of thermolysis as compared to the basic process without additive, and does not prevent the decrease in the viscosity of the products during thermolysis. It has been revealed on the example of the heavy oil of Ashal’chinskoe deposit (Russia) that the thermolysis with the addition of light naphtha gives a liquid product with the yield higher than 97% and the viscosity of less than 80?mm²/s.     

非碱性氮化物催化裂化生焦研究

采用小型固定流化床实验装置,在减压蜡油体系下,研究了非碱性氮化物吲哚的催化裂化反应网络,结合Py-FTIR和XPS等表征技术探究了吲哚的生焦行为。研究表明,吲哚在催化裂化条件下易于转化,主要发生烷基转移、开环裂化和脱氢缩合反应,导致汽油和柴油的氮传递系数（NTC）增加;吲哚生焦造成催化剂反应性能降低,汽油烯烃含量升高;吲哚优先作用于催化剂Lewis酸中心,使中、强Lewis酸中心数量降低60%;吲哚导致的生焦主要位于催化剂表面,发生在转化率较低时;随着转化深度提高,烃类的生焦逐渐占优势。     

接触剂上焦炭的气化反应性能

采用XPS、TGA-DTA、TEM-EDX、SEM-EDX技术对挂焦接触剂、气化一部分焦炭后的挂焦接触剂上的焦炭进行了物化分析。结果表明,接触剂表面的碳可以划分为无定型碳、烃类碳和羰基碳3种,并且以无定型碳为主。焦炭主要分布在接触剂颗粒表面,而且分布不均匀。接触剂颗粒体相微区内金属对焦炭的气化反应具有催化作用,金属含量越高,碳含量越少,而接触剂颗粒表面微区内金属未能体现出明显的催化气化性能。焦炭层阻碍了气化剂在金属上的吸附,接触剂上的烧焦过程或焦炭气化过程主要为非催化反应。     

Effects of five ashes on the stability of petroleum coke water slurry

The effects of five main ingredients (i.e. SiO₂, Al₂O₃, Fe₂O₃, CaO and MgO) of coal ash on the stability of petroleum coke water slurry (PCWS) were investigated in this paper. The results showed that the stability of PCWS could be improved tremendously by the appearance of a small quantity of CaO in the PCWS, while the other 4 ashes had little impact. When the apparent viscosity was 1000 mPa·s, the PCWS with CaO dosage of 0.3 wt% would possess the solid concentration of 68.0%, the flow characteristic exponent of 0.78, and the water separation rate of 3.4%.     

乙烯氢甲酰化反应动力学的研究——Ⅰ.以丙醛为反应介质

以丙醛为反应介质、铑膦络合物为催化剂,对乙烯氢甲酰化反应的动力学进行了研究。通过对试验数据的关联,提出了丙醛生成速度的经验模型:r=649exp(-30400/RT)C_(Rh)~(0.949)C_T~(-0.076)P_E~(0.641)P_(H2)~(0.586)P_(CO)~(0.293)exp(0.044C_T~(-0.156)P_(CO))结果表明,C_(Rh)、T、P_(E)和 P(H2)是影响反应速度的主要因素,C_T 的影响很小,而 P_(CO)的影响在1.88bar 时有极大值,反应的表观活化能为30.4kJ/mol·K。     

RFCC沉降器内油浆重组分结焦反应过程的实验模拟

利用自制的热转化生焦实验装置和热量分析仪,考察了反应条件和油浆的性质对油浆重馏分热转化生焦的影响.结果表明,油浆的n(H)/n(C)、残炭值、结构族组成等性质对其牛焦率的影响要远大于反应时间、反应温度和油浆中催化剂含量等反应条件的影响.油浆中重组分馏分沸点的高低不能有效反映其生焦倾向,而重组分中的沥青质和胶质是生焦的主要前驱物,其芳碳率与生焦率有较好的线性对应关系.改变沉降器的操作条件可以缓解沉降器的结焦程度,但防止结焦的根本途径是通过调节主提升管的反应条件,从而减少进入沉降器的油气中的结焦前驱物胶质和沥青质的含量.     

Catalytic co-cracking of waste polypropylene and residual fuel oil

Abstract

Industrial waste polypropylene (PP) homopolymer and residual fuel oil (RFO) were pyrolyzed together in presence of catalyst ZSM-5 under the atmospheric pressure with different mixing ratios of the feedstocks. The experiments were carried out in a batch reactor at two different temperatures of 500?°C and 600?°C with the blended mixture (PP/RFO) to catalyst (ZSM-5) ratio of 4:1. The effects of blending ratios between the two feedstocks and temperature with respect to the yield of the products oil, gas, and residual coke were determined. The optimum blending ratio of PP and RFO with respect the higher quantity yield of liquid product was found to be 1:1 at 500?°C. The percentages of liquid fuel, gas, and coke were observed to be 74.8%, 10.2%, and 15% at 500?°C.     

硫代磷酸苯酯缓蚀剂的合成

针对高温环烷酸腐蚀,以五硫化二磷和苯酚为原料,合成了硫代磷酸苯酯缓蚀剂。通过正交试验确定硫代磷酸苯酯合成工艺条件;采用红外光谱对合成产物进行了结构表征。研究表明,硫代磷酸苯酯最适宜合成条件为:苯酚和五硫化二磷摩尔比3∶1,反应温度180℃,反应时间8 h,在此条件下合成的硫代磷酸苯酯缓蚀剂缓蚀率达到91.3%;红外光谱法(IR)分析产物均出现了硫代磷酸苯酯的主要官能团——-P=S-,-SH及-PO,其吸收峰的位置几乎完全一致,确定硫代磷酸苯酯的生成。     

辽河超稠原油延迟焦化不产生弹丸焦工艺条件探索

中国石油天然气股份有限公司辽河石化分公司1．0Mt／a延迟焦化装置加工辽河超稠原油。由于辽河超稠原油密度大、盐含量高,焦炭塔焦炭中经常出现大量的弹丸焦,导致焦炭塔放水不畅,严重时堵塞放水管道。为此,通过工业试验考察了加热炉出口温度、进料金属含量、循环比、焦炭塔操作压力对弹丸焦形成的影响,得到了基于辽河超稠原油的适合该装置特点的不产生弹丸焦与黏焦的合适工艺条件,并绘制出了寻找合适加热炉出口温度、循环比及焦炭塔塔顶压力的工作曲线。工业试验数据表明,弹丸焦的形成不仅与工艺条件和进料的沥青质含量有关,进料的金属含量过高同样会加速弹丸焦的生成。与一般实验室结果不同的是,工业试验数据表明,降低循环比反而有利于减少弹丸焦的生成,这一发现应引起同行重视。     

THE EFFECT OF LOW TEMPERATURE OXIDATION ON THE CHEMICAL AND PHYSICAL PROPERTIES OF MALTENES AND ASPHALTENES DERIVED FROM HEAVY OIL

Abstract

The chemical changes that occur when the maltene and asphaltene fractions (separated from heavy oil) are subjected to low temperature oxidation (LTO) in the presence and absence of water have been investigated by a combination of classical separation techniques and analytical pyrolysis. In general, it is observed that water has a mitigating effect on the destructive nature of LTO. A detailed analysis of the pyrolytic products suggests that the presence of water reduces the ease with which oxygen reacts with sulfides to give sulfones and thereby supresses the formation of coke. An analysis of the data indicates that most of the coke produced results from LTO of the asphaltenes; only a small portion originates in the maltenes.     

Simulation analysis of steam gasification of petroleum coke with CaO

Abstract

The work deals with the effect of calcium oxide adsorption on the production of hydrogen and methane in steam gasification of petroleum coke using Aspen Plus process simulator. The prediction accuracy of the proposed model is verified by comparing with the existing experimental results. The effects of water vapor flux, the mass ratio of calcium oxide to petroleum coke, pressure, temperature on hydrogen or methane gasification from petroleum coke steam are studied. The production of hydrogen from petroleum coke gasification requires a low temperature and low pressure environment, while increasing the flow of water vapor is beneficial to the production of hydrogen. Maximum H₂ volume fraction of 87.3% is obtained at a temperature of 600?°C, a pressure of 0.1?MPa, the mass of steam to petroleum coke is 1, and the mass of CaO to petroleum coke is 3. The H₂ and CO₂ volume fractions are found to be increased and decreased by 20% and 27.8% respectively, when compared with the corresponding non-CaO case. The production of methane from petroleum coke gasification requires a low temperature and high pressure environment, while decreasing the flow of water vapor is beneficial to the production of methane. Maximum CH₄ volume fraction of 63% is obtained at a temperature of 600?°C, a pressure of 1?MPa, the mass of steam to petroleum coke is 1, and the mass of CaO to petroleum coke is 1. The CH₄ and CO₂ volume fractions are found to be increased and decreased by 14.4% and 21% respectively, when compared with the corresponding non-CaO case.     

Analysis of petroleum coke from low grade oily sludge of refinery

Petroleum coke is often shortened as pet coke. Petroleum coke or pet coke is a product obtained from oil of all kinds during the oil refining process. Petroleum coke is a carbon-rich solid originating from petroleum refining and is obtained by cracking process. Petroleum coke is a byproduct of the coking unit, a residual fuel upgrader. The coke quality depends on the crude oil processed in refinery. The mixture of oil, solids and water deposited at the bottom of the storage deposit is known as waste oil sludge. Oil sludge is one of the solid wastes produced in petroleum refinery and it is a complex emulsion composed of various petroleum hydrocarbons, heavy metals, solid particles, and water. As a result of the refining process of crude oil, the contaminated sludge is biodegraded and converted into waste products that damage the environment and human health. In the coke processing, the assessment of oil sludge fraction is based on the principle of heating to high temperatures and the removal of light fractions from the breakdown. If the oil sludge initially contains low levels of sulfur and metal, the resulting petroleum coke is then calcined before use. The high quality needle type coke produced on convenient conditions in the coking unit.