Hydrothermal treatment of electron-beam irradiated pine sawdust in a mixture with vacuum tower bottoms

Hydrothermal processing of electron-beam irradiated pine sawdust in a mixture with vacuum tower bottoms (VTB) in an autoclave with continuous removal of the vapor phase at a hydrogen pressure of 7.0 MPa has been investigated. It has been found that as the sawdust irradiation dose increases to 1.0 MGy, the degree of VTB conversion during the hydrothermal treatment of the mixture increases and the amount of the hydrocarbon fraction in the resulting liquid product grows to reach a yield of 38.0 wt %. At a temperature of 430°C, the conversion of biomass for two hours is 83–84 wt % and the yields of liquid and gaseous products are 49.0 and 35.0 wt %, respectively.     

Characteristic features of liquid-phase oxidation of vacuum tower bottoms in the presence of modifiers

The influence of modifiers affecting the structural organization of a petroleum system and the kinetics of oxidation of vacuum distillation bottoms have been studied. It has been shown that the introduction of modifiers into the petroleum feedstock alters the ratio of the dispersed phase to the dispersion medium, thereby affecting the rate of the oxidation process. It has been found that the main factor determining the performance of modifiers affecting the structure of the petroleum system is the modifier nature. The maximum concentration of modifiers in the vacuum tower bottoms (VTB) was 5.0 wt %. The dependence of the oxidation rate upon the duration of oxidation has been determined for the modifiers. It has been shown that brown-coal pyrolysis tar introduced into VTB has an inhibitory effect, and oil shale pyrolysis tar and a diamond blend initiate the oxidation process. For blown asphalts produced from modified and unmodified VTB, expressions relating the softening point and penetration have been obtained. The properties of different blown asphalts obtained from the feedstock modified with the test additives at optimal concentrations have been compared.     

Chemical Reaction Engineering Studies on Cocracking of Petroleum Vacuum Residue with Coal, Plastics, and Biomass (Bagasse and Petrocrop)

In our previous article, Ahmaruzzaman and Sharma (2007), the cracking of petroleum vacuum residue (XVR) and its coprocessing with thermoplastic and biomass (Calotropis procera) has been discussed. This article deals with the studies on cocracking of XVR with thermosetting plastic, i.e., bakelite (BL), Samla coal (SC), biomass, i.e., bagasse (BG) or C. procera (CL) and their binary, ternary, and quaternary mixtures in a thermogravimetric analyzer (TGA). The kinetic studies were performed using the Coats and Redfern kinetic modeling equation. The overall activation energies obtained were 25 kJ/mole for petroleum vacuum residue, 99 kJ/mole for polypropylene, 21 kJ/mole for coal, 23 kJ/mole for Calotropis procera, and 25 kJ/mole for the combination of these four materials. However, other models, such as van Krevelan et al. and Horowitz and Metzger have also been used in some cases to compare the results with those obtained by the Coats and Redfern kinetic models. In the present work, the effect of catalysts on the cracking of Basra vacuum residue (BVR) has also been reported.     

Simulation of the temperature-driven pervaporation of dilute 1-butanol aqueous mixtures through a PTMSP membrane in a cross-flow module

The selective thermal pervaporation (TPV) of dilute aqueous mixtures of 1-butanol through a hydrophobic poly(1-trimethylsilyl-1-propyne) (PTMSP) membrane in plate-and-frame modules with an air gap has been investigated experimentally and theoretically for the first time. The dependences of the composition and the permeate flow on the temperature and initial concentration of the mixture, the liquid coolant temperature, and the membrane thickness have been measured. It has been shown that a permeate flow across the PTMSP membrane can be achieved in the TPV mode that is not inferior to that of vacuum pervaporation at condensation temperatures of 0.5–15.0°C. The permeation and diffusion activation energies have been estimated from the measured temperature dependences of the partial fluxes. Equations for the TPV process have been derived in terms of the one-dimensional resistance model. The temperature dependences of the diffusion coefficients of 1-butanol and water in the membrane have been determined, and the linear temperature and concentration fields of the components in the module for membranes of different thickness have been calculated from the experimental data using these equations.     

Kinetic Studies on Cocracking of Petroleum Vacuum Residue with Thermoplastics and Biomass (Petrocrop)

Cracking of petroleum vacuum residue (XVR) and its cocracking with plastics (PP or PS), Calotropis procera (CL) as a binary, ternary, and quaternary mixture of these individual plastics, and CL with XVR was carried out in a Perkin-Elmer thermogravimetric analyzer (TGA) for the purpose of comparing the process of the mixture with those of the individual components. Experiments were conducted at a heating rate of 40 K/min, in the temperature range of 30-900°C. Based on the results obtained, three temperature regimes were selected for studying the nonisothermal kinetics of TGA of individual XVR, plastics, and biomass as well as of the cocracking of these with XVR, i.e., below 400°C, between 400-500°C, and above 500°C. The kinetic studies were performed using the Coats and Redfern kinetic modeling equation. The overall activation energies obtained were 25 kJ/mole for petroleum vacuum residue, 99 kJ/mole for polypropylene, 21 kJ/mole for coal, and 35 kJ/mole for the mixture of all these materials. Thus, it has been found that there exists an overall synergy when three materials were coprocessed together. The overall orders and activation energies change during coprocessing of two or three different macromolecules, including mixed vacuum residue as presently observed. The detailed results that were obtained will be reported.     

Evaluation of Atmospheric and Vacuum Residues Using Molecular Distillation and Optimization

The term atmospheric residue describes the material at the bottom of the atmospheric distillation tower having a lower boiling point limit of about 340°C; the term vacuum residue (heavy petroleum fractions) refers to the bottom of the vacuum distillation, which has an atmospheric equivalent boiling point (AEBP) above 540°C. In this work, the objective is to evaluate the behavior of different kinds of Brazilian atmospheric and vacuum residues using molecular distillation. The Falling Film Molecular Distillator was used. For the results obtained through this process, a significant range of temperature can be explored avoiding the thermal decomposition of the material. So these results are very important to the refinery decisions and improvements. The Experimental Factorial Design results showed that the temperature has more influence on the process than the feed flow rate, when a higher percentage of distillate is required.     

Kinetics of thermal degradation of macromolecular petroleum compounds in the presence of fatty acid triglycerides

The kinetics of thermal degradation of high-molecular-mass fractions of crude oil mixed with rapeseed oil has been studied by dynamic thermogravimetry. The structural parameters of the average molecule of vacuum residues of crude oils processed at Naftan and the Mozyr refinery and hydrocarbon oils, resins, and asphaltenes isolated from the residues have been first determined by NMR and IR spectroscopy. It has been shown that the addition of rapeseed oil can increase the rate of thermal degradation of heavy petroleum residues, with the character of the effect of the vegetable oil on the kinetics of the process being determined by structural features of macromolecular petroleum compounds, namely, the relative amount of aromatic units and the length of alkyl chains.     

常减压蒸馏装置长周期运行的技术措施

中国石油大庆分公司炼油厂二套常减压蒸馏装置采用先进控制技术，机泵的电动机采用变领调速技术，减压塔顶抽真空系统采用新型高效真空喷射泵等措施，使装置操作平稳串提高，设备故障串降低；原油电脱盐装置在注破乳剂的基础上加注脱盐剂，高温减压渣油系统加注防垢剂，使换热网络高效平稳运行，装置能耗降低；采用新型环保型燃烧器，将减压塔顶释放气引入加热炉燃烧，改造污水隔油池，在加热炉内壁喷涂高铝纤维等措施，使生产、生活环境得到改善，使装置实现了连续安全、平稳、高效运行1165天的长周期运行记录。     

降低常减压装置重蜡油残炭的可行性探讨

针对常减压装置重蜡油(减四线)残炭、Ni,V等含量居高不下、难以作催化原料的问题,确认常压塔塔内雾沫夹带严重,使柴油拔出能力降低、操作稳定性变差,是造成减压拔出率降低的主要原因;优化常压塔拔出率、实现减压深拔是解决问题的关键。根据模拟计算,可将常压重油中低于350℃馏分油质量分数操作值由目前的12.5%降低到6%,减一线馏分的柴油量可比原操作值降低90%。调整常压拔出率,使减压塔分离效果大幅改善,雾沫夹带和减顶缩径段压力降降低,减四线残炭及金属含量可大幅度减少。     

LANET—35重油催化裂化催化剂的工业应用

ＬＡＮＥＴ－３５新型重油催化剂，经大连石化公司１．４０Ｍｔ／ａ催化裂化装置半年多的工业应用，表明该催化剂的筛分组成分布合理，堆积密度适中，在装置中流化正常。原料掺大庆减压渣油可由５２％提高到６０％，表现出较强的重油转化能力和抗重金属污染的能力，对焦炭的选择性好，可直接生产９０号汽油。     

委内瑞拉减压渣油的热解特性及其动力学研究

采用热重 质谱(TG-MS)联用对委内瑞拉减压渣油在不同升温速率下进行热解实验,研究其热解反应特性,并采用3种等转化率法和分布活化能模型(DEAM)求取减压渣油热解反应的动力学参数。实验结果表明,委内瑞拉减压渣油的热解主要反应温度区间为179~490 ℃,总质量损失率为77.54%,质量损失峰值在446 ℃达到最大,最大质量损失速率为317.38μg/min。Flynn-Wall-Ozawa(FWO)法比其他2种等转化率法能更好地描述减压渣油的热解过程,由其计算得到的热解活化能为56.77~178.91 kJ/mol。进一步采用DEAM模型将减压渣油分为4个假定组分,对升温速率为10 ℃/min条件下的热重分析(TG-DTG)数据进行分峰拟合,求得饱和分、芳香分、胶质和沥青质四组分动力学参数,并据此获得减压渣油总活化能分布曲线。结果表明,委内瑞拉减压渣油活化能主要集中在100~250 kJ/mol范围内,通过加权求和获得平均活化能为190.11 kJ/mol。     

An investigation on the effect of SBS+Vacuum bottoms residue modification on rheological characteristics of asphalt binder

In this research, the effect of adding SBS and vacuum bottoms residue on 60/70 neat asphalt binder have been carried out using classic and superpave testing methods. Adding SBS led to increase of softening point, elastic recovery and viscosity of asphalt binder. Besides, SBS reduced the penetration and ductility of specimens. Results of dynamic shear rheometer indicated that G^* and G^*sinδ reduced by adding the SBS content before and after aging while δ and G^*/sinδ parameters increased. Therefore, adding SBS improves the permanent deformation and fatigue resistance of neat asphalt binder.     

Hydrotreating of vacuum gas oil on modified Ni–Mo/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts

The effect of the introduction of P₂O₅ into Ni–Mo/Al₂O₃ catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-Al₂O₃ prepared from aluminum hydroxide AlOOH powder of the TH-100 brand (Sasol) has been used. The catalytic properties of the catalysts obtained have been examined in the hydrotreating of vacuum gas oil in a continuous-flow unit under hydrogen pressure. The amounts of sulfur and polycyclic aromatic hydrocarbons, the hydrocarbon group composition, and the carbon residue of the feedstock and the hydrotreating product have been determined. The catalysts after testing have been studied using differential thermal analysis in combination with thermogravimetry (DTA–TGA); the influence of the amount of the modifier on the catalytic activity and coking of the catalysts has been shown.     

渣油催化裂化生焦反应集总动力学模型的研究

在柴油馏分和重馏分油催化裂化生焦反应集总动力学模型研究的基础，通过生焦反应试验和动力学参数估计，建立渣油催化裂化生焦反应十集总动力学模型。结果表明，反应系统气相和液相均符合催化生焦机理的动力学模型，具有较好的拟合试验数据能力和良好的外推性，并符合催化裂化生焦反应规律。     

Kinetic Study on the Hydrocracking Reaction of Vacuum Residue Using a Lumping Model

Abstract

Based on the experimental hydrocracking of vacuum residue, a kinetic study using a lumping model was carried out to gain insight into the characteristics of catalytic reactions. The lumped species were the saturates, aromatics, resins, and asphaltenes (SARA) constituents in the residue (798 K⁺) fraction and gas, naphtha, kerosene, gas oil, vacuum gas oil, and coke in the products. The pyrite reaction favoring hydrocracking to lighter products was more temperature-dependent than that using a mixture of pyrite and active carbon. The kinetic study showed that the addition of active carbon to pyrite limited the transformation of resins to asphaltenes.     

Optimization of vacuum resid solvent deasphalting to produce bright stock and hard asphalt

To prepare bright stock (BS) and 30# hard asphalt simultaneously, propane solvent deasphalting (SDA) of Oman vacuum residue was optimized. Result showed the optimal process conditions were as follows: extraction tower top temperature of 64°C, settling tower top temperature of 74°C, extraction pressure of 3.35 MPa, solvent ratio of 5. Compared with SDA of Oman VR to prepare bright stock and 70# asphalt, the yields of light deasphalted oil (LDAO) and heavy deasphalted oil (HDAO) were 26.8% and 24.7%, and increased by 1.7% and 5.2% respectively; carbon residue of LDAO was less than 1.2%, conformed to the feed requirement of furfural refining to produce bright stock. The yield of DOA was 48.5%, and DOA could be directly used to produce 30# hard asphalt. The PG grade of 30# asphalt was PG 76–22 and the 30# asphalt mixture had high rut dynamic stability and water resistant stability. HDAO could be used as feedstock of catalytic cracking and light yield oil (gasoline and diesel) was 65.99%.     

Dibenzo-18-crown-6 as a catalyst for <Emphasis Type="Italic">tert</Emphasis>-butyl hydroperoxide decomposition

Degradation of tert-butyl hydroperoxide in chlorobenzene in the presence of dibenzo-18-crown-6 ether has been studied. It has been established and kinetically proven that the degradation is preceded by the formation of an intermediate complex of the hydroperoxide with the crown ether. The composition of the complex and thermodynamic and kinetic parameters of its formation and decomposition have been determined.     

Effect of organic eutectic on nitrocellulose stability during artificial aging

ABSTRACT

Recently, the eutectic composition of organic binary mixtures MENA+DPA has been found to be an efficient stabilizer of nitrocellulose. However, the behavior of such new stabilizer must be further investigated, especially after a long period of storage of the energetic composition. In this study, the stabilizing effect of the eutectic MENA+DPA on NC stability during artificial aging (at 338.65 K for 120 days), compared to its pure components, has been investigated by conventional stability tests and kinetic modeling. According to Bergmann & Junk (T = 405.15 K) results and over the entire period of aging, the eutectic MENA+DPA exhibits the best stabilizing effect on NC. The vacuum stability test (T = 353.15, 363.15, 373.15, and 383.15 K) results revealed that the amount of the evolved gas of NC containing this eutectic composition is very close to that of DPA, known as the conventional stabilizer. Furthermore, the kinetic modeling on VST data, obtained at four isothermal temperatures, was performed by two different methodologies, viz, fitting and free models to determine the kinetic triplets, which have been subsequently used to predict the storage lifetime for the studied systems. It was found that the NC stabilized by the eutectic MENA+DPA presents the highest value of the activation energy and has the longest storage lifetime during the entire heating period corroborating the stability tests results and affirming the excellent stabilizing effect of this mixture with respect to its pure component even if a long storage period is expected.     

常减压蒸馏装置减压深拔技术改造及工艺优化

针对中国石油化工股份有限公司广州分公司加工能力为8Mt／a的Ⅲ套常减压蒸馏装置存在的常压塔操作压力高、减压塔塔底渣油泵容易抽空等影响常、减压深拔的现状,采取了降低常压塔塔顶系统压力降、增加减压急冷油系统等措施。结果表明：减压渣油500℃馏出率从改造前的3．20％降低至2．67％,常压塔塔底油350℃馏出率从改造前的9．0％降低至4．3％,高价值蜡油收率提高了2．95个百分点。     

扬子石化公司炼油厂减压塔技术改造

简要介绍扬子石油化工股份有限公司炼油厂常减压蒸馏装置减压塔改造情况。标定结果表明，通过对减压塔内填料、分布器、集油箱等内件改造，满足了装置3．5Mt/a扩能设计要求，装置负荷提至3．8Mt/a时，减压塔运行正常。减压拔出率提高1．15个百分点，减压侧线产品质量得到改善。