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.     

Development of correlation for extension of the true boiling point (TBP) and molar mass

The true boiling point curve (TBP) is an important tool for the petroleum industry; it is used to obtain the behavior of petroleum during distillation. This work developed a correlation for the extension of the TBP curve by means of molecular distillation. TBP curve is well established for a temperature of 565°C in a conventional distillation. With the correlation developed, it is possible to reach values near 1,000°C. A second correlation was also developed for predicting the values of molar mass of waste petroleum. Both correlations demonstrated to be valid and represent a great advancement for the petroleum industry.     

Recovery and Characterization of Petroleum Residues Through the Molecular Distillation Process

Molecular distillation process is an efficient way to separate complex residues to obtain improvement and a more complete characterization of crude oils. It presents advantages such as to generate distillation products that can be experimentally characterized, and the operation conditions of this process generate distillate cuts with an atmospheric equivalent boiling point (AEBP) above 650°C without risks of thermal degradation. The aim of this work is to carry out the separation of two vacuum residues (VR) within the process temperature range from 550 to 670°C, using the Brazilian Molecular Distillation equipment. As a result, five distillate cuts and five residues from molecular distillation processing were generated. The molecular distillation (MD) technique provided a gain in distillate yield of about 10% over the conventional methods. The efficiency of the technique was verified through the vapor pressure osmometry experiments and the extension of true boiling point (TBP) curves of petroleum. The extended TBP curves by the molecular distillation process demonstrated that this alternative method is appropriate to extend the TBP curves to temperatures above those of the conventional methods.     

COMPOSITIONAL ANALYSIS OF NORTH SEA OILS

ABSTRACT

The molar fluid composition of either the reservoir fluid or the well stream is determined by combining the true boiling point (TBP’) distillation data with gas chromatographic (GC) analysis of the light ends. For the purpose of thermodynamic simulation of phase behavior of petroleum reservoir fluids, in addition to the compositional data, physical properties of the pseudo fractions, i.e. density and molecular weight are required. A major drawback of the TBP distillation is the fact that the fractions contain typically 20 -30 % of the material outside the defined boiling range. Another significant issue is the use of generalized density and molecular weight data in the absence of experimentally determined values. This can introduce major inaccuracies in the phase behavior calculations because the generalized value of density and molecular weight significantly differ in each oil based on the paraffin-naphthene-aromatic distribution and its geographic origin.

In this work we have performed the true TBP distillation of 7 stabilized North Sea oil samples. All the oils were distilled from carbon number 6 to 19 and the distillation was terminated at C₂₀₊, which was termed as the residue. We have performed analysis of the Cm fraction of each oil by gas chromatography. Subsequently, the specific gravity and molecular weights of the TBP fractions were determined and compared with the generalized values, which indicated major differences. In addition, the superiority of the PVT calculations for a volatile oil and a gas condensate using the experimentally determined specific gravity and molecular weight of the pseudo fractions against the generalized properties is also demonstrated.     

Extending the true boiling point curve of a heavy crude oil by means of molecular distillation and characterization of the products obtained

Petroleum is evaluated by means of the true boiling point (TBP) curve, making possible to investigate the yields of the products that will be obtained in refineries, as well as establishing operating strategies and process optimization. Refineries determine TBP curves until 838 K. With molecular distillation the TBP can reach values up to 973 K. Molecular distillation shows potential in the separation, purification, and concentration of products. Eta residue is fractioned and the TBP of the whole crude oil is extended. Products of the distillation were characterized by density, SimDis (simulated distillation), and molar mass. Results showed that density and molar mass of the cuts obtained increase as the process temperature increases. These analyses confirm the efficiency of the separation method by molecular distillation.     

COMPOSITIONAL ANALYSIS OF NORTH SEA OILS

The molar fluid composition of either the reservoir fluid or the well stream is determined by combining the true boiling point (TBP') distillation data with gas chromatographic (GC) analysis of the light ends. For the purpose of thermodynamic simulation of phase behavior of petroleum reservoir fluids, in addition to the compositional data, physical properties of the pseudo fractions, i.e. density and molecular weight are required. A major drawback of the TBP distillation is the fact that the fractions contain typically 20 -30 % of the material outside the defined boiling range. Another significant issue is the use of generalized density and molecular weight data in the absence of experimentally determined values. This can introduce major inaccuracies in the phase behavior calculations because the generalized value of density and molecular weight significantly differ in each oil based on the paraffin-naphthene-aromatic distribution and its geographic origin.

In this work we have performed the true TBP distillation of 7 stabilized North Sea oil samples. All the oils were distilled from carbon number 6 to 19 and the distillation was terminated at C₂₀₊, which was termed as the residue. We have performed analysis of the Cm fraction of each oil by gas chromatography. Subsequently, the specific gravity and molecular weights of the TBP fractions were determined and compared with the generalized values, which indicated major differences. In addition, the superiority of the PVT calculations for a volatile oil and a gas condensate using the experimentally determined specific gravity and molecular weight of the pseudo fractions against the generalized properties is also demonstrated.     

常减压蒸馏装置减压炉进料结焦倾向研究

采用甲苯不溶物的生成量来表征油品的结焦倾向,考察了不同温度和不同停留时间对油品中甲苯不溶物生成量的影响,得到了不同性质油品的临界结焦曲线;分析了油品性质对结焦倾向的影响。结果表明：随着反应温度的升高和反应时间的延长,不同性质油品的结焦趋势均加剧,且有独立的临界结焦界线;在临界结焦界线的下方不会结焦,而在上方会有结焦前体物的生成,且远离后更为明显;环烷基原油的结焦倾向严重,不宜进行减压蒸馏,更不宜进行减压深拔操作。通过安全操作曲线模拟计算可知,生产重油D的中间基原油深拔到565 ℃左右时离安全操作曲线还有约40 ℃的空间,显示该原油还有进一步深拔的潜力。     

全馏程实沸点蒸馏曲线数学模型

根据原油的实沸点（ＴＢＰ）蒸馏数据和超临界萃取分馏方法得到的常压渣油ＴＢＰ蒸馏数据,开发了获得全馏程ＴＢＰ蒸馏数据的方法。针对大庆原油建立了描述原油ＴＢＰ蒸馏曲线、相对分子质量曲线和密度曲线的数学模型,为工艺设计提供了可靠的基础数据计算方法。     

实沸点蒸馏前后高酸重质原油的石油酸分布表征

The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）. The acid class （heteroatom number）, type （z numbers） and carbon number distributions were positively characterized. It was found out that the total acid number （TAN） of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposedmore significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction ofTAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.     

减压渣油特征化参数的研究

在对多种渣油进行超临界流体萃取分馏及窄馏分性质分析的基础上，计算了三种减压渣油超临界流体萃取分馏窄馏分的Ｗａｔｓｏｎ Ｋ值，发现适用于原油及其轻馏分的ａｔｓｏｎＫ值不能表达渣油及其馏分的特性和分类。首次提出了以Ｈ／Ｃ原子比、分子量及密度三因素来表征减压渣油的特征参数ＫＨ。利用文献数据，以ＫＨ为依据对渣油的物性、热裂化、催化裂化及高温热解的结果进行了分析研究，表明ＫＨ值可以较好地体现渣油或其馏分的整     

快速蒸馏法及其在原油酸值分布规律研究中的应用

原油和馏分的酸值(TAN)是反映其加工过程中腐蚀性的重要指标。传统的实沸点蒸馏(TBP)方法未考虑石油酸在原油蒸馏过程中的分解,得到的馏分酸值严重偏低,影响了对馏分腐蚀性的判断以及相应防腐措施的制订。为此开发了一种原油快速蒸馏(RD)仪,采用短分馏柱、高真空度、高蒸馏速率对原油进行分段蒸馏切割,有效避免了原油中石油酸的分解,使各馏分酸值的加权值达到了原油酸值的90%以上。在此基础上,研究了几种典型高酸原油酸值的分布规律,发现原油可馏出部分的酸值基本上都是随着沸点的升高而增高。另外,通过傅里叶变换离子回旋共振质谱(FT-ICR MS)分析表明,实沸点蒸馏过程中酸值降低的主要原因是大分子石油酸的分解,而与石油酸的类型相关性较小。     

石油馏分三种蒸馏曲线换算软件的设计与开发

以石油馏分的恩式蒸馏曲线作为基础,根据文献中提供的模型进行其他蒸馏曲线的关联和换算。以VB6．0作为开发用户操作界面为平台,设计了一个能分别对石油馏分恩式蒸馏曲线与实沸点蒸馏曲线、恩式蒸馏曲线与平衡汽化曲线和不同压力下平衡汽化曲线换算的软件,大大提高了蒸馏数据换算的效率和准确性。通过对文献提供的实例进行测试表明,该软件针对3种蒸馏曲线的换算均有很好的准确性和吻合性。     

用沙特阿拉伯中质原油经减压蒸馏研制70号高等级道路沥青

用沙特阿拉伯中质原油经常规实沸点蒸馏及燃料型减压分馏直接生产的70号沥青不能满足中国石化集团公司的1号高等级道路沥青AH－70标准。采用二次减压蒸馏工艺可以直馏生产70号高等级道路沥青,分析了残留低相对分子质量组分对高等级道路沥青性能的影响,沥青中蜡油残留得多,针入度比低。第一次减压蒸馏的深度不能过大,切割温度以不超过500℃为宜;第二次减压蒸馏需提高真空度,进料温度以不超过360℃为好。     

Soil Microbial Degradation of Vacuum Residue

Abstract

The effect of microbial consortia on the alteration of petroleum residual structure and portions was studied, which can propose an alternative or complementary method for stringent upgrading heavy crude oil methods, which consist of heavy and complex hydrocarbons. Biological processing of petroleum heavy fractions and residua may provide an alternative or complementary process in refining heavy crudes—the dominant refinery feed in the future—with less severe process conditions and higher selectivity to upgrade heavy fractions of crude oil. The primary objective was to observe the ability of an indigenous bacterial consortium taken from a soil bellow the vacuum column contaminated with vacuum residue (VR) for several decades from the Tehran refinery distillation unit, in degradation of residua components. Enrichment with VR, as sole source of carbon and energy, is the selected biosurfactant-producing microbial consortium. The biodegradation of net VR using indigenous consortia from this specific ecosystem was studied. The considered period of biodegradation of these heavy hydrocarbons was remarkably shorter than usual studies. Bacterial growth and VR biodegradation ability of this consortium analyzed with SARA test in 20 days. Studying the inoculum size and aeration effect revealed the significance of oxygen for this consortia activity and the similarity of 7% and 5% inoculation on alteration percentage of alkane, aromatic, and asphaltene and resin in VR. Results study revealed a 30.4%, 6.9%, and 9.4% decrease in the asphaltene, aromatics, and saturated aliphatic contents of VR, respectively, in only 20 days in 30°C at 150 rpm.     

减压渣油中钙赋存状态的研究

利用酸解的方法将低凝稠油减压渣油和超稠油减压渣油中的石油酸钙变为有机酸,采用醇碱溶液抽提的方法将石油酸抽提出来,通过红外光谱表征,证明是支化度较高、侧链较短的环烷酸。根据抽提物的模拟蒸馏数据对2种原油脱钙后柴油馏分和润滑油馏分酸值的增加情况进行了估算。     

Controlling the Oil Rectification Process in a Primary Oil Refining Unit Using a Dynamic Model

The composition of Devonian oil has been simulated using an experimental true-boiling-point (TBP) curve, and the physicochemical properties (density, molecular weight, enthalpy, etc.) of the feedstock arriving at the plant have been calculated. The optimization criterion proposed is the calculation of the yield of light fractions. The optimization problem with constraints on variables (initial and final boiling points of light fractions) and constraints in the form of inequalities (overlapping neighboring fractions) using the function fmincon has been solved and implemented in the programming environment Matlab. A nonlinear dynamic model of the oil rectification process has been developed and implemented. The Matlab ode 15s solver and the explicit second-order Euler method have been used to develop the model. The model in the form of a system of algebraic–differential equations has been applied to the distillation column control system of an atmospheric pipe still at a small oil refinery. In the case of controlling according to the model, the column profile temperatures are maintained at optimal (preset) values and the quality of the petroleum products is also maintained. A comparison has been made between two operating modes of the distillation column in the processing unit. The results of the study suggest the following. The method of controlling in accordance with the model provides an increase in the recovery of light products through the use of optimization and the dynamic model, shortening of the overlap intervals of the temperatures of the gasoline and diesel fractions, and a decrease in deviations of the boiling points of petroleum products.     

超临界流体萃取分馏法分离石油重质油

石油渣油的分离和评价，对重质油加工技术水平的提高具有重要的指导作用。根据超临界流体萃取的基本原理，开发了一种以Ｃ３、Ｃ４、ｎ－Ｃ５或它们的混合物为溶剂的超临界流体萃取分馏方法和仪器，采取恒定温差线性升压的操作模式将石油重质油按性质的差异分离成窄馏分进行深入的研究，从而为石油重质油的合理有效地加工利用提供基础数据和信息。着重介绍该分离方法的原理、仪器、分离条件的研究及其在重质油分离中的应用。本方法可     

低成本船用燃料油生产方案研究

船用燃料油主要由减压渣油、加氢渣油、催化油浆、催化裂化柴油等组分通过调合手段生产;通过对高黏调合组分进行热改质以降低其倾点和黏度,可减少轻调合组分的用量,优化生产配方,降低船用燃料油的生产成本.W炼油厂原计划将通过直馏工艺生产的常压渣油作为低硫船用燃料油销售,采用常减压蒸馏-热改质组合工艺小试研究表明:优选合适切割点的...     

KINEMATIC VISCOSITY-TEMPERATURE CORRELATION FOR UNDEFINED PETROLEUM FRACTION OF A WIDE BOILING RANGE

A new correlation was developed to predict the effect of temperature on Kinematic Viscosity of petroleum fractions of all boiling ranges including 455^-°C. This correlation covers a wide boiling ranges of petroleum fractions. This correlation has been developed to represent the data for a wide range of temperature from 30 to 200°C. The correlation is based on experimental kinematic viscosity data for twenty TBP fractions of Arab heavy, Arab medium and Arab light and Arab extra-light crude oils. The proposed correlation has been found to fit all the experimental data consisting of 248 measurements of the kinematic viscosity with an over all average absolute deviation of 7.2% compared to 9.1% given by Amin (1994) et al. method.     

KINEMATIC VISCOSITY-TEMPERATURE CORRELATION FOR UNDEFINED PETROLEUM FRACTION OF A WIDE BOILING RANGE

A new correlation was developed to predict the effect of temperature on Kinematic Viscosity of petroleum fractions of all boiling ranges including 455^?°C. This correlation covers a wide boiling ranges of petroleum fractions. This correlation has been developed to represent the data for a wide range of temperature from 30 to 200°C. The correlation is based on experimental kinematic viscosity data for twenty TBP fractions of Arab heavy, Arab medium and Arab light and Arab extra-light crude oils. The proposed correlation has been found to fit all the experimental data consisting of 248 measurements of the kinematic viscosity with an over all average absolute deviation of 7.2% compared to 9.1% given by Amin (1994) et al. method.