POLYMER SOLUBILITY THEORY PREDICTS EFFICIENCY OF RESIDUAL OIL EXTRACTION BY POLAR SOLVENTS

Light paraffinic solvents (C2 to C7) have traditionally been utilized by the petroleum refining industry to extract oils from crude distillation residua. Extracted oils constitute feedstock to lubricants manufacture and, to a lesser extent, additional cracking stock. More recent literature reveals a growing interest in polar, non-hydrocarbon partially oil-soluble solvents such as alcohols, ketones, and esters of lower carboxylic acids. In this work, articles and patents which report the separation of residua into asphalt and extracted oil by means of polar solvents are briefly reviewed, and the separation performance of same of those solvents is correlated to the solute-solvent interaction parameter (ϰ) in the Flory-Huggins theory of polymer solubility. The three dimensional solubility parameter (δ) approach is followed to estimate ϰ for the solvents of interest at the appropriate operating conditions. The saturate, aromatic, and polar compounds fractions of a bitumen are characterized by solubility parameters equal to the values of δ of the solvents or mixtures thereof used by the standard ASTM D-2007 chromatographic fractionation of the deasphaltenated oil (DAO). A mean value of ϰ is found for every DAO-solvent pair, treatment ratio and temperature. For each solvent considered, yields of extracted oil at varying operating conditions (temperature, pressure, solvent /feed ratio) are found to be well correlated to ϰ, in according with theoretical predictions that the lower a value of ϰ a solvent has for a given solute, the better it dissolves the solute and the higher the yield.

It is suggested that this type of approach could supply criteria to select solvents and operating conditions for applications requiring high yields (to produce additional cracking stock) or lower yields but high rejection of metals and heteroatoms (e.g. for lube oil bases extraction).     

DISSOLUTION OF COALS NEAR CRITICAL CONDITIONS

Two lignites and one bituminous coal were extracted with benzene, toluene and pyridine at both sub and overcritical conditions in a specially designed experimental system which enabled easy solid-liquid separation. Extract yields increased somewhat at overcritical conditions due to more thermal decomposition. The differences between the power of the solvents were not apparent for the lignites, whereas the solubility in pyridine of the bituminous coal was very much higher than those in benzene and toluene. The amounts of oils, asphaltenes and preasphaltenes in the extracts depended on the type of coal and the solvent.     

DISSOLUTION OF COALS NEAR CRITICAL CONDITIONS

ABSTRACT

Two lignites and one bituminous coal were extracted with benzene, toluene and pyridine at both sub and overcritical conditions in a specially designed experimental system which enabled easy solid-liquid separation. Extract yields increased somewhat at overcritical conditions due to more thermal decomposition. The differences between the power of the solvents were not apparent for the lignites, whereas the solubility in pyridine of the bituminous coal was very much higher than those in benzene and toluene. The amounts of oils, asphaltenes and preasphaltenes in the extracts depended on the type of coal and the solvent.     

Deasphalting of crude oils using supercritical fluids

A crude oil has four main SARA constituents: saturates, aromatics, resins, and asphaltenes. The asphaltenes in crude oil are the most complex and heavy organic compounds. The asphaltenes contain highly polar substituents and are insoluble in an excess of n-heptane (or n-pentane). The classic definition of asphaltenes is based on the solution properties of petroleum residuum in various solvents. Asphaltenes are a solubility range that is soluble in light aromatics such as benzene and toluene, but is insoluble in lighter paraffins. The particular paraffins, such as n-pentane and n-heptane, are used to precipitate asphaltenes from crude oil. The effects of four different solvents (water, carbon dioxide, propane, and ethanol) on the deasphalting process under the supercritical conditions were reviewed. Supercritical water is an excellent solvent for removing of high molecular weight organic compounds such as asphaltenes from crude oils under the supercritical conditions.     

采用组合工艺提高辽河减压渣油轻油收率

以辽河减压渣油为原料,采用C5为溶剂,在压力4.0~7.0 MPa、剂油质量比4:1及温度160/180 ℃的条件下进行深度溶剂脱沥青试验,残炭降低率50%左右,90%以上的沥青质得到脱除,并富集到脱油沥青中。采用溶剂脱沥青-脱沥青油催化裂化-沥青残渣焦化组合工艺加工辽河减压渣油的研究结果表明：随溶剂脱沥青压力的提高,脱沥青油的收率增加,压力为7.0 MPa时,总脱沥青油收率达到74.22%,沥青残渣收率明显降低;轻、重脱沥青油催化裂化的平均液化气＋轻油收率分别为25.74%及12.72%,沥青残渣焦化的液化气＋轻油收率均值为7.17%。采用组合工艺技术,辽河减压渣油的液化气＋轻油收率较减压渣油直接焦化提高了4.06 百分点。     

TWO-DIMENSIONAL SOLUBILITY PARAMETER MAPPING OF HEAVY OILS

ABSTRACT

The solubility and insolubility of heavy oils and their fractions in dilute mixtures with various solvents were used to characterize heavy oil interactions. A two-dimensional solubility parameter, developed for the selection of solvents for organic polymers, was found to group all the solvents for each heavy oil fraction in polygon areas when the complexing solubility parameter component was plotted against the field force solubility parameter component. All fractions of Cold Lake vacuum residua, except for the saturate fraction, form concentric solubility areas. Therefore, in going in the direction of decreasing aromaticity from coke to asphaltenes to resins to aromatics, all solvents for the previous fraction in the series are also solvents for all subsequent fractions in the series. As a result, asphaltenes can be precipitated, but not extracted, from heavy oils. This is attributed to the interaction among polynuclear aromatics being the dominate interaction in petroleum that causes insolubility in hydrocarbon liquids. However, the paraffinic chains on the same petroleum molecules limit their solubility in highly complexing liquids. In contrast, even vacuum gas oils from the Exxon Donor Solvent coal liquefaction process are insoluble in aromatic liquids but soluble in moderately complexing liquids because of hydrogen bonding, resulting from oxygen functionality. Hydrotreating of these coal derived vacuum. gas oils reduces their oxygen functionality and increases their solubility areas so that they become compatible with petroleum liquids.     

TWO-DIMENSIONAL SOLUBILITY PARAMETER MAPPING OF HEAVY OILS

The solubility and insolubility of heavy oils and their fractions in dilute mixtures with various solvents were used to characterize heavy oil interactions. A two-dimensional solubility parameter, developed for the selection of solvents for organic polymers, was found to group all the solvents for each heavy oil fraction in polygon areas when the complexing solubility parameter component was plotted against the field force solubility parameter component. All fractions of Cold Lake vacuum residua, except for the saturate fraction, form concentric solubility areas. Therefore, in going in the direction of decreasing aromaticity from coke to asphaltenes to resins to aromatics, all solvents for the previous fraction in the series are also solvents for all subsequent fractions in the series. As a result, asphaltenes can be precipitated, but not extracted, from heavy oils. This is attributed to the interaction among polynuclear aromatics being the dominate interaction in petroleum that causes insolubility in hydrocarbon liquids. However, the paraffinic chains on the same petroleum molecules limit their solubility in highly complexing liquids. In contrast, even vacuum gas oils from the Exxon Donor Solvent coal liquefaction process are insoluble in aromatic liquids but soluble in moderately complexing liquids because of hydrogen bonding, resulting from oxygen functionality. Hydrotreating of these coal derived vacuum. gas oils reduces their oxygen functionality and increases their solubility areas so that they become compatible with petroleum liquids.     

二元溶剂萃取分离重油中芳烃的机理

石油重质馏分油中含有多种烃结构组分,如链烷烃、环烷烃以及不同环数芳烃,采用极性溶剂萃取分离工艺可以实现不同组分的分离,但一元溶剂萃取的精制油收率低、芳烃萃取选择性较差。以减压馏分油为原料,糠醛为主溶剂,含羟基的极性调节剂PR1为副溶剂,开展一元溶剂、二元溶剂单段萃取实验,通过对主溶剂溶解度参数的调配,提升溶剂萃取分离不同烃组分的效果。结果表明,与一元溶剂相比,二元溶剂对三环及以上的芳烃萃取选择性提升率超过100%,用一种新的基团贡献法计算了6种模型分子的溶解度参数,发现各芳烃的萃取选择性随芳烃溶解度参数的增大而增大。考察了不同PR1加入量的二元溶剂萃取效果,结合二元溶剂溶解度参数变化与溶剂核磁共振氢谱(¹H-NMR)化学位移变化,发现溶剂体系氢键作用的变化是溶剂萃取效果产生差异的根本原因。     

FCC油浆中饱和烃的抽提方法研究

以糠醛为抽提溶剂、正辛烷为第二溶剂,采用双溶剂抽提法对中国石化九江分公司和广州分公司FCC油浆进行抽提分离,得到饱和烃和芳烃,考察双溶剂抽提的操作条件及抽余油（富含饱和烃）的组成和裂化性能。结果表明,最佳的抽提条件为：温度50～70 ℃;第一阶段剂油比m（糠醛）:m（油浆）:m（正辛烷）＝2.0:1.0:1.5,第二阶段剂油比m（糠醛）:m（抽余相）＝0.67:1.00,第三阶段剂油比m（糠醛）: m（抽余相）＝1.20:1.00;抽提次数8次,第四次和第五次抽提之间进行一次抽余相溶剂提浓。在该条件下,九江分公司和广州分公司FCC油浆抽提分离得到的抽余油中饱和烃质量分数分别为77%和74%,饱和烃收率分别为95.23%和91.58%,分离效果良好,且得到的抽余油具有良好的裂化性能,是优质的催化裂化原料。     

SOLVENT REFINING OF WASTE LOCOMOTIVE OIL

The potential of ten solvent in the refining of waste locomotive oil have been examined and evaluated The solvents studied were butanone, methyl-isobutyl ketone (MIBK), methyl normal - propyl ketone (MNPK), methyl ethyl ketone (MEK), butyl alcohol, sec-butyl alcohol, pentanol, hexanol, hexane and n-heptane. The solvents were evaluated on the basis of the percent sludge removal, sludge settling rate, oil recovery (yield) and their physico - chemical properties. The optimum settling time and solvent to waste oil ratio were determined to be 24 hours and 5:1 respectively. On the basis of sludge removal potential butyl alcohol ranks first followed by sec-butyl alcohol, butanone, pentanol, hexanol, MEK, MNPK, MIBK, hexane and n-heptane in that order. All the solvents gave very high yields of the refined oils. The physico-chemical properties of the re-refined oils are within acceptable limits. Generally, the properties remained approximately constant regardless of the solvent used for extraction.     

吸附富集裂解原料中的正构烷烃蒸汽裂解制乙烯效果研究

研究了直馏石脑油、加氢焦化石脑油和天然气凝析油三种裂解制乙烯原料及其通过分子筛吸附分离后相应的富含正构烷烃脱附油的裂解乙烯收率,并考察了裂解反应条件对不同裂解原料的裂解性能的影响。在工业装置典型操作条件下,直馏石脑油及其吸附分离吸余油和脱附油的乙烯收率分别为29.9%,23.0%,41.1%,脱附油的乙烯收率比直馏石脑油增加11.2个百分点,脱附油的三烯总收率比石脑油增加8.6个百分点;对于加氢焦化石脑油和凝析油,其相应脱附油的裂解乙烯收率分别提高11.1和6.5个百分点。石脑油和脱附油裂解乙烯收率和丁二烯收率均随裂解出口温度的升高而增加,丙烯收率基本不随裂解出口温度的变化而改变。     

脱沥青油及其糠醛抽余油的催化裂化性能研究

采用提升管催化裂化装置,考察脱沥青油（DAO）以及抽提条件分别为剂油质量比2:1、抽提温度80℃;剂油质量比2:1、抽提温度85℃两种工况下对DAO进行糠醛抽提所得到的抽余油A与B等三种催化裂化原料的裂化性能。实验结果表明：DAO经过糠醛抽提后所得抽余油的催化裂化转化率较高,轻质油收率较高,重油和焦炭产率较低,其催化裂化性能和裂化产品的性质均优于DAO。     

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%.     

蜡下油资源在润滑油加氢装置的应用

蜡下油是溶剂脱蜡工艺生产润滑油基础油的副产物,一般用作催化裂化原料。文章介绍了如何通过在润滑油加氢装置原料中掺入一定比例的蜡下油,来优化原料性质、提高产品质量,并重点对基础油质量、收率的变化及装置能耗等的影响进行了分析。结果表明:通过对掺炼量、反应温度等操作条件的调整,生产出了高品质的APIⅢ类基础油产品。     

Process for Separation of Petroleum Acids from Crude Oil

A new technique for separation of petroleum acids from crude oil was proposed. The method relates to processes for treating acidic oils or fractions thereof to reduce or eliminate their acidity by addition of effective amounts of crosslinked polymeric amines such as polypropylene amine and anionic exchange resins having amino-groups. Petroleum acids contained in the mixture can be extracted by a complex solvent. The results indicate that more than 80 % of the petroleum acids are removed and the process does not cause environmental pollution because all the solvents are recovered and reused in the test.     

催化裂化轻循环油萃取脱芳烃的溶剂选择

通过分析催化裂化轻循环油（LCO）中烃类的组成筛选合适的模型化合物,考察了溶剂对LCO中芳烃组分的萃取分离效果,探讨了溶剂萃取性能与溶剂物性参数之间的关系。结果表明: 溶剂对芳烃的选择性系数从大到小的顺序为环丁砜＞二甲亚砜＞糠醛＞N,N-二甲基甲酰胺（DMF）＞N-甲基吡咯烷酮＞N,N-二甲基乙酰胺;溶剂的偶极矩和介电常数与LCO中烃类的这两个参数要有足够大的差异才能有效分离LCO中的芳烃;溶剂对芳烃的选择性系数可与其溶解度参数进行关联,对于与芳烃色散力参数δD相近的溶剂,其极性力δP越大,对芳烃的选择性系数越大;在40 ℃、剂油质量比1:1的条件下,DMF单次萃取LCO得到的抽出油中芳烃质量分数仅为87.2%,而环丁砜单次萃取时为97.3%;通过向DMF中引入助溶剂提高δP,在相同条件下萃取得到的抽出油中芳烃质量分数可达96.5%,抽出油收率为29.9%,萃取性能优于单一溶剂。     

Separating group compositions in naphtha by adsorption and solvent extraction to improve olefin yields of steam cracking process

In order to improve the steam cracking feeds, several model compounds including normal paraffins, iso-paraffins, cyclanes and aromatics were selected as the feeds of steam cracking process and the olefin yields were investigated. In the typical reaction conditions, the normal paraffins in the naphtha contribute most to the ethylene in the products; the iso-paraffins are the main sources of the propylene; the cyclanes mainly produce the butadiene and the aromatics can hardly produce olefins. According to this, the adsorption process and solvent extraction process were adopted to separate the group compositions in naphtha properly to optimize the cracking feeds. The n-paraffins in naphtha were gathered through adsorption process using 5A molecular sieves. The ethylene yield improved by 13% using the desorption oil rich in n-paraffins as the cracking feed. The aromatics and the cyclanes were extracted from the naphtha. Compared with the naphtha, the ethylene and propylene yields of the extraction raffinate oil were 3.0 and 1.5% higher respectively.     

炼油厂重质馏分油作蒸汽裂解装置原料的研究

应用小型蒸汽裂解模拟试验装置对加氢尾油、常二线油、常三线油、减一线油、减二线油等重质馏分油的裂解性能进行评价，考察水油质量比为0.8时裂解温度对产品收率的影响。结果表明：随着裂解温度的升高，乙烯收率逐渐增大，丙烯收率逐渐减小，双烯（乙烯+丙烯）收率和三烯（乙烯+丙烯+丁二烯）收率先增大后减小，在810 ℃时达到最大；加氢尾油的目的产物（乙烯、丙烯、丁二烯）收率最高，裂解性能最好，常二线油、常三线油次之，减一线油和减二线油最差。     

炼油厂重质馏分油作蒸汽裂解装置原料的研究

应用小型蒸汽裂解模拟试验装置对加氢尾油、常二线油、常三线油、减一线油、减二线油等重质馏分油的裂解性能进行评价,考察水油质量比为0.8时裂解温度对产品收率的影响。结果表明：随着裂解温度的升高,乙烯收率逐渐增大,丙烯收率逐渐减小,双烯（乙烯+丙烯）收率和三烯（乙烯+丙烯+丁二烯）收率先增大后减小,在810 ℃时达到最大;加氢尾油的目的产物（乙烯、丙烯、丁二烯）收率最高,裂解性能最好,常二线油、常三线油次之,减一线油和减二线油最差。     

四碳醇溶剂精制再生废润滑油的研究

针对溶剂精制再生废润滑油环保、经济、高效的特点,应用四碳醇极性溶剂为萃取剂、聚丙烯酰胺为絮凝剂进行再生废润滑油研究,采用单因素实验方法考察工艺条件的影响,得到的最佳工艺条件为：萃取溶剂为异丁醇、精制时间15 min、精制温度25 ℃（室温）、剂油质量比5/1、絮凝剂用量1.0%。该工艺下再生油产率达82.1%,再生油理化指标得到明显改善,黏温指数达130以上、闪点超过200 ℃、酸值为0.01 mg KOH/g、残炭含量降低到0.01%以下,表明采用该精制工艺再生废润滑油是可行的,有广阔的应用前景。