On bitumen liberation from oil sands

Laboratory experiments were performed to investigate the effect of pH on (a) bitumen film thinning and film rupture process (b) bitumen/water contact line displacement and (c) the static contact angle of bitumen on a glass surface in the presence of an aqueous medium. A coated bitumen film on a glass surface was found to thin down and rupture spontaneously when a few drops of water having a pH of 11 was placed on it. In another experiment, a bitumen coated glass plate was submerged in water. The contact line of an initially circular bitumen film on the glass surface displaced in the inward direction to take the shape of a droplet. Measurement of the dynamic contact angle of bitumen with time showed that the bitumen/water contact line displacement was faster at a pH of 3 than at a pH of 11. However, the static contact angle of bitumen on the glass surface was found to be large at the high pH of 11, a condition conducive to easy detachment of bitumen droplet from the glass surface. The above observations suggest that a pH cycle might be desirable in bitumen liberation from oil sands.     

The production of synthetic crude oil from oil sand by application of the lurgi-ruhrgas-process

Synthetic crude oil can be produced from oil sand by application of the Lurgi-Ruhrgas process which is characterized by the circulation of fine-grained heat carriers. The process is described and information given on its commercial application to date, which relates to the cracking of hydrocarbons to olefins and the carbonization of fine-grained coal. Reference is made to distillation tests on approx. 45 tons of raw oil sand. The yield of oil in commercial plants is expected to be approx. 95% by weight. Studies and computations show that beneficiated oil sand used as feedstock has advantages over raw oil sand. It is suggested that in a commercial plant beneficiation and LR distillation should be combined. Based on the present state of Technology LR units for an output of about 8,000 - 12,000 bbl/day of crude oil could be built. The approximate capital and operating costs of such a unit are indicated. In closing, reference is made to further possible applications of the LR process.     

水辅助溶剂法提取油砂中的沥青

开发了一种水辅助溶剂法从油砂中提取沥青的技术。该方法通过在油砂固相与有机溶剂间介入水层提取油砂中的沥青。以内蒙古扎赉特旗油砂矿为研究对象,考察了温度、剂砂质量比、提取时间、甲苯在复合溶剂中的含量及溶剂的种类与性质对沥青回收率高低的影响,结果表明：最佳提取条件为提取温度50℃,剂砂质量比1∶1,提取时间25min。沥青回收率与提取溶剂的性质紧密相关,水层介入有效降低了固体微粒组分在有机相中的含量,且便于后续的有机相与泥砂相的分离。通过对各种溶剂提取的沥青进行组分分析,发现各种溶剂对沥青提取能力的差异性源于溶剂的化学组成和结构不同。本文相关研究结果对溶剂法提取油砂中沥青技术及溶剂种类的选择具有指导作用。     

Recovery of residual bitumen from oil sand sludges

Factorial experiments were conducted to examine the effects of dilution, caustic addition and lime addition on the recovery of residual bitumen by flotation from oil sands tailings sludges. Dilution was found to be the most significant variable, and it was established that close to 100% recovery of the substantial quantity of residual bitumen could be achieved by flotation, after diluting 1 volume of sludge with 2 volumes of water. These results indicate that physical and chemical changes in the sludges may have occurred, during the storage period, to place the residual bitumen in a more accessible form. Atomic absorption analysis and infra-red data on the sludge fractions indicate that the changes could have resulted from the interaction between calcium ion, present in the system in low concentrations, and surface active materials responsible for stabilizing the bitumen dispersed in the tailings.     

Preparation of bitumen from oil sand by ultracentrifugation

Ultracentrifugation was investigated as a means to obtain solvent-free bitumen from oil sand. The bitumen from three oil sands of varying grades was separated by placing the sands in specially designed tubes and centrifuging for 2 h at 198 000 at 20 °C. For all grades of oil sand, approximately 70% of the bitumen was recovered. The recovered bitumen was compared to the residual remaining on the sand, and to that extracted by the conventional Soxhlet technique. The ultracentrifuged bitumen contained some emulsified water and a small amount of fine solids. The solvent-extracted material was water-free, but contained a small amount of residual solvent and fine solids. The ultracentrifuge caused some fractionation of the bitumen, resulting in a product slightly enriched in asphaltene components compared to the solvent-extracted material. The residual bitumen remaining on the sand was correspondingly slightly depleted in asphaltenes. However, as evidenced by gas Chromatographic simulated distillation data, ultracentrifugation did retain the light (180–220 °C) components of the bitumen which were lost during the solvent removal step following solvent extraction. Other analyses such as density, viscosity and elemental composition verified that ultracentrifugation resulted in some fractionation of bitumen components.     

Preparation of bitumen from oil sand by centrifugation

Centrifugation was shown to have certain advantages over solvent extraction for the separation of bitumen from oil sand for research purposes. No fractionation of the bitumen during centrifugation was detected by chemical analysis. Some limitations of the method are pointed out.     

Sunflower oil processing from crude to salad oil

World-wide use of sunflower oil is second only to soybean oil. Interest in domestic use as a premium salad oil is very recent. The high ratio of polyunsaturated-to-saturated fatty acids makes sunflower oil a premium salad oil. Sunflower oil, however, contains a small amount of high melting wax which must be removed to avoid settling problems. It is possible to produce a brilliant, dewaxed, deodorized sunflower oil with over a 100-hr cold test at 0 C. This quality oil can be produced by conventional caustic refining, dewaxing, bleaching and deodorization. A quality finished oil may also be produced by dewaxing and steam refining. This paper reviews various methods for processing sunflower oil from the crude state through the finished, dewaxed, deodorized salad oil. Presented at the ISF/AOCS Meeting, New York, April, 1980.     

新型原油三嗪基类脱硫剂的合成研究

从井下采出的原油中常含有硫化氢,硫化氢对于采出原油的分离、储运设备会产生腐蚀,严重的会引起泄露,加入油溶性三嗪基类脱硫剂可有效地去除硫化氢。本文以正丁胺、环己胺和二正丁胺为原料分别与多聚甲醛反应合成三嗪基类脱硫剂,合成产物分别与硫化氢反应来测定其硫容量和使用性能,结果表明:环己胺三嗪基脱硫剂会生成沉淀,正丁胺和二正丁胺类三嗪基脱硫剂不生成沉淀,但正丁胺三嗪基脱硫剂的硫容量较低。环己胺和正丁胺均不适合用作合成油溶性三嗪基脱硫剂的原料。当二正丁胺与多聚甲醛的物质的量比为1.05∶1时,合成的三嗪脱硫剂硫容量较高,最高可达180.32g/kg。此外,在环己胺三嗪脱硫剂合成中加入甲苯可降低脱硫剂的凝固点,提高该类脱硫剂的防冻结能力。     

Separation and characterization of bitumen from Athabasca oil sand

Separation and chemical analysis was investigated using bitumen samples from Athabasca oil sand in Alberta. Fractionation according to solubility and polarity has been used to separate bitumen into its fractions. The solvent de-asphaltening was performed by n-pentane solvent (solubility fractionation), and the polarity fractionation using Fuller’s earth allows maltene to separate into SARA components (saturates, aromatics, resins and asphaltenes). The SARA components are analyzed comprehensively using elemental analysis (EA), Fourier-transformed infrared (FTIR), ultraviolet-visible spectroscopy (UV-vis), high performance chromatography (HPLC) and thermogravimetric analysis (TGA). EA (C, H, N, S), heavy metals (Ni, V) concentrations, FT-IR and UV-vis tests provided the explanation of chemical composition. From IR spectra, maltene and saturates/aromatics (sat/aro) contained more aliphatic compounds than resin or asphaltene. Also, IR spectrum of sat/aro was similar to crude oil and VGO (vacuum gas oil). Different UV signal data clearly indicates the contribution of aromatic constituents in the fractions. Using optimized analysis conditions of HPLC, we successfully separated the peaks for bitumen and its fractions. The characteristic peak pattern of SARA (saturates, aromatics, resins, asphaltenes) fractions was observed, and also the peak pattern of sat/aro was similar to that of crude oil and VGO. However, TGA results revealed that thermal behavior for sat/aro was similar to that of crude oil but different from that of VGO. Also, from the comparison between decomposition temperature of TGA and boiling point, their correspondence was found.     

Modern techniques for the production of crude tall oil

A short background of the methods for the production of crude tall oil is given. A simplified flow sheet of the continuous acidulation proces is shown and a new type centrifuge is introduced for the continuous separation of the various components of the acidulated sulfate reaction mixture. The separation section of the process is described with particular emphasis given to the operation of the centrifuge. Performance of the process is discussed with respect to yield and quality of the crude tall oil.     

水基提取技术用于油砂分离的研究进展

油砂作为一种重要的非常规油气资源,其分离技术的研究近些年来引起了国内科研工作人员的重视。介绍了目前世界上最重要的油砂分离技术--水基提取技术的基本原理及影响油砂分离的重要影响因素,阐述了油砂结构、特性与水基提取分离的重要关系及分离条件对沥青回收率的重要影响作用,同时探讨了原子力显微镜用于油砂水基分离过程中相关微观机理研究的重要应用,最后对水基提取技术用于油砂工业生产的流程进行了简单介绍。     

Kinetics of methyl ester production from mixed crude palm oil by using acid-alkali catalyst

The production of biodiesel from high free fatty acid mixed crude palm oil using a two-stage process was investigated. The kinetics of the reactions was determined in a batch reactor at various reaction temperatures. It was found that the optimum conditions for reducing high free fatty acid (FFA) in MCPO (8-12 wt.%/wt oil) using esterification was a 10:1 molar ratio of methanol to FFA and using 10 wt.%/wt of sulfuric acid (based on FFA) as catalyst. The subsequent transesterification reaction to convert triglycerides to the methyl ester was found to be optimal using 6:1 molar ratio of methanol to the triglyceride (TG) in MCPO and using 0.6 wt.%/vol_TG sodium hydroxide as catalyst. Both reactions were carried out in a stirred batch reactor over a period of 20 min at 55, 60 and 65 °C. The concentration of compounds in each sample was analyzed by Thin Layer Chromatography/Flame Ionization Detector (TLC/FID), Karl Fischer, and titration techniques. The results were used for calculating the rate coefficients by using the curve-fitting tool of MATLAB. Optimal reaction rate coefficients for the forward and reverse esterification reactions of FFA were 1.340 and 0.682 l mol⁻¹ min⁻¹, respectively. The corresponding optimal transesterification, rate coefficients for the forward reactions of TG, diglyceride (DG), and monoglyceride (MG) of transesterification were 2.600, 1.186, and 2.303 l mol⁻¹ min⁻¹, and for the reverse reactions were 0.248, 0.227, and 0.022 l mol⁻¹ min⁻¹, respectively.     

Displacement of bitumen from reconstituted oil sands by aqueous solutions

A simple method has been developed for modelling the recovery of bitumen from packed beds of oil sand by water or caustic solution displacement. Batches of reconstituted oil sand were prepared by intimately mixing predetermined amounts of sand, water, and bitumen, thereby permitting the composition of the oil sand to be controlled and varied within a wide range. Dilution of the bitumen with hexadecane facilitated the mixing process and allowed experiments to be performed at low temperatures while maintaining oil-water viscosity ratios comparable to those prevailing at the higher temperatures encountered during hot water or steam displacements in the field. The effects of a wide range of compositional and operational variables were studied using a two-level fractional factorial design technique and the findings are discussed. Of particular interest are the observations that the density and initial connate water saturation of the oil sand exert significantly more effect on bitumen recovery efficiency for the case of water displacement than for caustic solution displacement.     

Studies on bitumen: Part 2. Changes in bitumen during weathering

Changes which occurred during exposure of a 200 penetration straight reduced bitumen to climatic conditions, to illumination under a light source, and to a soil cover in a green-house were studied. The rheological properties of the bitumen were altered more by illumination than by either of the other treatments. Acid-, alkali-, water-, and dioxansoluble products of weathering treatments were brown, fluorescent, low-molecular-weight compounds. The equivalent weight values of the water-soluble acidic components were compared with the results from gel filtration, paper electrophoresis, and mass spectrometry studies.     

Kinetics of bitumen extraction from oil sands using organic solvents

The kinetic study of bitumen extraction from oil sands is significant for efficiency improvement and reactor design in industrial applications. Here, an improved pseudo-first-order kinetic model was established with the assumption of a constant Sherwood number, which took into account the mass transfer area. Five organic solvents were used for the extraction kinetics of the prepared bitumen microbeads. The improved pseudo-first-order kinetic model exhibited excellent fitting effects. Petroleum ether/dichloromethane was proved to be the best solvent. The results also showed an exponential decrease in the diameter of the bitumen microbeads and a linear increase in mass transfer coefficients with time for all the solvents. The kinetics of bitumen extraction from oil sands using different solvents were predicted according to the corresponding average mass transfer coefficients. The experimental results confirmed that the improved kinetic model was capable of describing the mass transfer process of bitumen extraction from oil sands.     

Supercritical fluid extraction of a crude oil, bitumen-derived liquid and bitumen by carbon dioxide and propane

Extractions of a crude oil, a bitumen-derived liquid and bitumen were conducted at several temperatures and pressures with carbon dioxide and propane in order to assess the effect of the size and type of compounds in the feedstocks on the extraction process. The pure-solvent density at the extraction conditions was not the only variable governing extraction, and the proximity of the extraction conditions to the pure-solvent critical temperature affected the extraction yields and the compositions of the extract phases. Higher oil yields were obtained at lower solvent reduced densities when the extraction temperatures were in the vicinity of the pure solvent critical temperature. In the crude oil and native bitumen extractions, as the extraction time and/or the extraction pressure increased, heavier compounds were found in the extract phases. This preferential extraction was not observed with the bitumen-derived liquid. The non-discriminatory extraction behaviour of the bitumen-derived liquid was attributed to its thermal history and to the presence of olefins and significant amounts of aromatics. Phase behaviour calculations using the Peng-Robinson equation of state and component lumping procedures provided reasonable agreement between calculated and experimental results for the crude oil and bitumen extractions, but failed to predict the bitumen-derived liquid extractions.     

SAGD采出水净水剂的研究

针对辽河油田超稠油SAGD采出水含油量高的特点,以多元醇、环氧氯丙烷、二甲胺和乙二胺为原料,合成了一种适用于处理超稠油SAGD采出水的净水剂GBEDE-08;并考察了药剂加量、沉降时间和水温对GBEDE-08除油效果的影响.实验结果表明:GBEDE-08不仅除油性能良好,而且除油速度快;在水温90℃、沉降时间90 min和投加质量浓度为300 mg/L的条件下,可将采出水含油质量浓度从62 517 mg/L降低到145 mg/L,除油率达到99%以上,是一种高效的净水剂.     

油砂沥青水溶液与溶剂抽提及分离

采用热碱水法对内蒙油砂进行了沥青抽提及分离实验,并对产物沥青进行了性质分析.实验表明,热碱水抽提适宜条件为:碱浓度0.25%、反应温度95℃、搅拌速度80r·min-1、固液比S/L=1:1.5、反应时间15min,沥青收率可达92%.本研究为油砂资源的研究和开发利用提供了理论和基础实验参数.     

某油田原油污水处理工艺与改造

重点介绍了某油田原油污水不达标问题,系统分析了原油污水处理工艺、生产分离器、电脱水器、浮选器等污水处理设备的性能,从根本上改变了原设计的原油污水处理工艺,并对部分原设备进行内部改造,用水力旋流器替换了浮选器,使油田的原油污水达标排放,满足了国家对环保的要求,同时为油田稳产创造了条件.