A fluidized bed retort for oil sands

Fluid bed retorting of oil sands is a viable method of extracting oil from mined oil sands. The process is based on a direct heating concept in which one vessel is utilized for the pyrolysis and vaporization of the bitumen contained in the oil sand and for the burning of the residuals which remain with the sand. Experimental results show that a significantly upgraded liquid hydrocarbon product can be obtained. Oil yields can exceed eighty per cent of the bitumen present in the feed material. The sulfur content of the produced oil is reduced. Gas produced can have a significant heating value and contains sulfur mainly in the form of hydrogen sulfide. Refluxing of the overhead product increases liquid yields and reduces the sulfur content of the oil. Water injection and the use of enriched air has a beneficial effect on the process. Thermal efficiencies in excess of eighty per cent can be achieved without recovering the heat from the expended sand.     

N.m.r. line shape-relaxation correlation analysis of bitumen and oil sands

The first results of the analysis of bitumen and oil sands using the recently developed n.m.r. spingrouping technique are presented. The n.m.r. relaxation experiments were carried out on bitumen, and on natural and dried oil sands samples. The results indicate that the spin-grouping can resolve and quantify several components of the samples studied. The bitumen and bitumen fraction of the oil sands are resolved according to their spin-spin relaxation times into three major groups: solid-like (rigid), solid-like (mobile) and semi-liquid. The water in the oil sands exists in two different environments. Tentatively one environment is assigned to be the bridges between the sand grains, while the other is assigned to be the clay surface. One can conclude that with spin grouping of complex mixtures the decomposition (in which components are resolved according to their dynamic state) is possible. The accuracy of such resolution is of the order of a few per cent.     

不同有机溶剂对新疆油砂沥青的组成性质影响

油砂作为一种非常规石油资源,越来越受到人们的重视。油砂沥青的含量和性质对其开发有着重要的影响。有机溶剂抽提可以测定油砂沥青的含量。本文研究了3种溶剂对新疆油砂的抽提能力,并对不同溶剂抽提得到的新疆油砂沥青进行了性质分析。结果表明,新疆油砂含油率（甲苯测）为11.75%,属于中品位油砂矿;甲苯、氯仿和石油醚3种不同溶剂对新疆油砂沥青进行抽提,发现3种溶剂抽提能力的大小关系为氯仿＞甲苯＞石油醚;抽提过程中,氯仿表现出对胶质和沥青质较强的萃取能力,而石油醚对沥青质的萃取能力几乎为0,采用氯仿可以更准确地测定油砂沥青的含量。氯仿抽提得到新疆油砂沥青及其组分的杂原子含量和分子量高于甲苯和石油醚抽提的。由红外谱图发现,氯仿抽提得到的油砂沥青的含氧、含硫官能团的吸收峰强度大于甲苯和石油醚抽提的,表明氯仿对油砂沥青中极性物质的抽提能力更强。     

Water‐Based Bitumen Recovery from Diluent‐Conditioned Oil Sands

Important process development aspects leading to more efficient bitumen recovery from diluent‐conditioned oil sands by water‐based methods are discussed. Bitumen viscosity of 0.5–2 Pa·s is required at the processing temperature and can be reduced to this level by bitumen dilution with an organic solvent. Oil sand porosity, however, poses a restriction on the amount of diluent that can be accepted by the oil sand. Also oil sand‐diluent conditioning time is an important process parameter and can vary from a few minutes for oil sands with low‐viscosity bitumen to several hours if viscosity of the bitumen is high. Additionally, the bitumen separation efficiency during digestion and flotation can be enhanced by reducing the bitumen/water interfacial tension through addition, for example, of tripolyphosphate to the aqueous phase.     

Use of heavy oils (and derivatives) to process coal

Oil sands bitumen from the Athabasca and Cold Lake deposits, Lloydminster heavy oil and various liquid derivatives from oil sands bitumen can be successfully employed to solubilize an Alberta high-volatile C bituminous coal. In the presence of hydrogen, the degree of coal solvation is increased; catalytic hydrogenation is even more effective and gives higher yields of soluble products.     

Effect of Operating Temperature on Water‐Based Oil Sands Processing

Operating temperature is one of the most important controlling parameters in oil sands processing. Considering the massive energy consumption and green house gas emission, lowering the processing temperature is highly desirable. To achieve such an ambitious goal requires a comprehensive understanding on the role of temperature in oil sands processing. This paper provides an overview of major findings from existing studies related to oil sands processing temperature. The relation between temperature and bitumen recovery is discussed. The effect of temperature on the physiochemical properties of oil sand components, such as bitumen viscosity, bitumen surface tension and surface potentials of bitumen and solids, is analyzed. The interactions between bitumen and solids and between bitumen and gas bubbles as a function of temperature are recounted. Also discussed is the role of chemical additives in oil sand processing. It has been found that temperature affects nearly all properties of oil sands among which bitumen viscosity and bitumen‐solids adhesion impose a prominent impact on bitumen recovery. The use of selected chemical additives can reduce bitumen viscosity and/or the bitumen‐solids adhesion, and thus provide a possible way to process oil sands at a low temperature while maintaining a high bitumen recovery.     

离子液体促进溶剂萃取油砂沥青

传统水洗法和溶剂萃取法萃取油砂沥青时,存在沥青中含有沙土和残沙中含有油等缺点。为解决上述缺点,本文采用不同比例的乙酸甲酯/正庚烷复合溶剂萃取油砂沥青,研究了离子液体（1-丁基-3-甲基咪唑四氟硼酸盐,[Emim]BF4）对该溶剂萃取体系的萃取率和分离洁净程度的影响。采用红外光谱仪和扫描电镜对萃取后的残沙和沥青的洁净程度进行了定性分析,并结合元素分析仪和电感耦合等离子体发射光谱仪获得萃取后残沙和沥青的洁净程度的定量结果。实验结果表明：当复合溶剂体积比为2∶3时,[Emim]BF4促使沥青回收率达到最大值94.20%,比单纯复合溶剂萃取体系的最大萃取率高7.92%;通过上述测试方法的定性和定量分析,证明了[Emim]BF4能有效解决沥青夹带沙土和残沙中含油的问题。     

Conical filtering centrifuge for separation of solvent-diluted bitumen from oil sand mineral particles

The development of a continuous process for the separation of solvent-diluted bitumen from mineral particles is an important step for the development of solvent-based extraction technology of bitumen from mined oil sands. In this work, a custom-made conical filtering centrifuge is used to separate toluene-diluted bitumen from oil sand mineral particles. Compositions of wet granular samples are analyzed before and after centrifugation for three different oil sand ores. Results suggest that conical filtering centrifuges could be used for continuous separation of solvent-diluted bitumen from oil sand ores with relatively coarse particles.     

Fines/Water Interactions and Consequences of the Presence of Degraded Illite on Oil Sands Extractability

The chemical composition of the aqueous phase in oil sand slurries influences bitumen recovery from oil sands, especially those containing greater than 10% fines. The composition is controlled by a combination of mixing and dilution, ion exchange with clay surfaces and precipitation of divalent ions as carbonate minerals. Elevated levels of soluble potassium in the oil sand, which appear to be a marker for degraded illite or smectitic clays, are associated with depressed bitumen recovery. These clays have a swelling character and can contribute divalent ions to the slurry by ion exchange between the clay mineral surfaces and the process water.     

Understanding Water‐Based Bitumen Extraction from Athabasca Oil Sands

The current state of knowledge on the fundamentals of bitumen recovery from Athabasca oil sands using water‐based extraction methods is reviewed. Instead of investigating bitumen extraction as a black box, the bitumen extraction process has been discussed and analyzed as individual steps: Oil sand lump size reduction, bitumen liberation, aeration, flotation and interactions among the different components that make up an oil sand slurry. With the development and adoption of advanced analytical instrumentations, our understanding of bitumen extraction at each individual step has been extended from the macroscopic scale down to the molecular level. How to improve bitumen recovery and bitumen froth quality from poor processing ores is still a future challenge in oil sands processing.     

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.     

A comparison of fluidized bed pyrolysis of oil sand from Utah,USA, and Alberta,Canada

Characterization and thermal pyrolysis of oil sand was conducted. The experiment was performed on Circle Cliffs, Utah, U.S.A. and the results were compared with the data from Alberta, Canada. The reaction character identified by TGA was dual mode of vaporization of light hydrocarbon and thermal cracking of high molecular hydrocarbon. The pyrolysis experiment was performed in a 2 kg/h capacity fluidized bed externally heated by electricity. The process variables investigated were a temperature range of 723-923 K, fluidization gas velocity of 1.5-2 times of the minimum fluidization velocity, solid retention time of 15-30 minutes, and average particle size of 435 microns. The results of TGA and elemental analysis of bitumen provided necessary information regarding maximum liquid yield from the pyrolysis prior to pyrolysis experiment. The oil yield was maximum at 823 K. The yield of liquid was not exceeding the weight percent of maltenes in original bitumen. The optimum reaction condition should be fast vaporization of light hydrocarbon and minimizing thermal cracking of high molecular hydrocarbon. To maximize the liquid yield, fast heating and vaporization of oil sand bitumen and then the rapid removal of the vaporized product from the heating zone is recommended, i.e., operation in a fluidized bed reactor.     

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 the pyrolysis of utah tar sands

Utah tar sands have been pyrolyzed experimentally in a tubular furnace into a stream of nitrogen. Various condensate products have been collected and analyzed, and the pyrolyzed sands have been analyzed for coke and unreacted bitumen. The kinetics of the pyrolysis appeared to be second order under conditions of approximately constant temperature and in experiments with continuously changing temperatures. A lighter product with less sulfur, nitrogen, and arsenic was produced when more rapid heating rates were used. Other characteristics of the reaction and products are presented.     

有机溶剂萃取加拿大油砂应用研究

介绍了溶剂作为萃取剂分离油砂的技术,溶剂萃取油砂过程包含两个阶段:沥青相向溶剂的溶解过程和沥青、溶剂与砂粒的分离过程。考察了单一溶剂甲苯、丙酮、乙酸乙酯和甲苯/正庚烷、丙酮/正庚烷、乙酸乙酯/正庚烷组成的复合溶剂体系在相同条件下对油砂沥青的萃取率,在此基础上进一步对比了不同溶剂体系对沥青四组分饱和分、芳香分、胶质和沥青质的萃取效果,同时考察了不同浓度的沥青-溶剂溶液的表面张力,结果表明在油砂萃取过程中沥青-溶剂体系的表面张力主要取决于所选溶剂的种类,而沥青的浓度对溶液表面张力的影响不大。混合溶剂体系甲苯/正庚烷、丙酮/正庚烷、乙酸乙酯/正庚烷相比纯溶剂萃取率较高,其沥青溶液表面张力较低,是良好的分离油砂溶剂体系。     

Microwave applications to oil sands and petroleum: A review

This review provides a general overview of microwave applications in oil sands bitumen or shale oil production in petroleum upgrading. The vast oil reserves in the oil sands of Alberta will become a major source of petroleum products in the near future and a number of alternative technologies have been explored for the production and upgrading of oil sands and heavy oil. This study is based primarily on the unique selective heating capacity associated with exposure of materials to microwaves. Of particular interest are applications of microwaves for bitumen extraction, upgrading heavy oils, removing heteroatoms, and the underground heating of oil sands to reduce bitumen viscosity and allow it to be pumped to the surface. The fundamentally different method of transferring energy from the source to the sample is the main advantage of utilizing microwave energy. By directly delivering energy to microwave-absorbing materials, conventional issues such as long heating periods and energy loses can be minimized. Microwave energy was shown to be effective in some applications; however, it is not used commercially at the present time.     

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands—II. Flotation hydrodynamics of water-based oil sand extraction

Bitumen flotation hydrodynamics in water-based oil sand extraction is critically reviewed by comparing aeration of oil sand slurries with mineral flotation. The role of the two-stage particle-bubble attachment model in flotation is emphasized as a means to accelerate bitumen flotation recovery. It involves the generation of micro/nanobubbles and their frosting on hydrophobic bitumen droplets, followed by their attachment to a flotation-size bubble via its coalescence with the nanobubbles frosted on the bitumen. Nanobubble generation by hydrodynamic cavitation demonstrates that the size of nanobubbles can be reduced, and the number of nanobubbles increased by fast liquid flow, intensified agitation, high dissolved gas content and surfactant concentration. The mechanism of pre-existing gas nuclei in enhancing nanobubble generation by cavitation is utilized to produce a large volume of stabilized nanobubbles for practical flotation, by continuously recirculating the stream through a gas saturation tank or a cavitation tube. The aeration of oil sand slurries in hydrotransport pipelines is analyzed based on its similarity to dissolved air flotation. Bitumen extraction recovery increased significantly with the presence of nanobubbles in the system. The role of improved flotation hydrodynamics in bitumen recovery is briefly discussed in terms of the Suncor operation using flotation columns to process oil sand middling streams. Future research should be directed at understanding bitumen flotation kinetics, optimizing size ranges of nanobubbles for maximized flotation recovery, minimizing wearing of cavitation tubes in industrial operations, and intensifying the role of in-situ nanobubble nucleation on hydrophobic particles/bitumen droplets in flotation, especially for bitumen extraction from underperforming oil sands.     

Fundamentals of Mechanical Upgrading of Athabasca Oil Sands: Mechanisms of Sand and Bitumen Separation

Abstract

Sand and bitumen were separated mechanically from Athabasca oil sands using cold water in a plate mill. Sand extraction was found to be a function of the product of rotational frequency, oil sands charge weight, and the inverse fourth power of the distance between the rotating plate and the bottom of the mill. Ranges of testing were 20–150 rpm, 10–100 g, and 1.3–27 mm for rotational frequency, oil sand charge, and clearance, respectively. Sand extractions were primarily the result of particle-vessel collisions resulting in brittle failure of the bitumen layer. Extractions reached a limit for each set of experimental conditions after approximately 5 min. The maximum concentration of bitumen in the oil sand fraction was 27% by weight or 50% by volume. A dimensional analysis showed extraction to be a function of Reynolds number, volume fraction of oil sands, and the ratio of clearance to mill radius.     

Understanding bitumen partial upgrading through process modelling and simulation

Partial upgrading is an emerging direction in the processing of Canadian oil sands bitumen in response to the economic and environmental challenges in the oil sands industry. Partial upgrading aims to improve bitumen quality only to the level at which pipeline specifications are met without use of diluent. Given that partial upgrading technologies have not yet reached commercial deployment, there is a lack of technical data to assess the expected benefits in terms of energy input and greenhouse gas emissions reduction. In this study, we present an assessment of a partial upgrading scheme using detailed process simulation. We developed a conceptual process scheme considering visbreaking, solvent deasphalting, and naphtha hydrotreating as the core partial upgrading processes. Reactor models were assembled using experimental data from CanmetENERGY's pilot plant facilities and from the literature and integrated into a plant‐wide simulation model. Simulations allowed the examination of trends in partial upgrader product yields and quality and enabled a comparison with traditional bitumen upgrading.     

The continuous flash pyrolysis of biomass

A continuous atmospheric pressure flash pyrolysis process for the production of organic liquids from cellulosic biomass has been demonstrated at a scale of 1–3 kg/hr of dry feed. Organic liquid yields as high as 65–70% of the dry feed can be obtained from hardwood waste material, and 45–50% from wheat straw. The fluidized sand bed pyrolysis reactor operates on a unique principle so that char does not accumulate in the bed and treatment of the sand is not necessary. The product gas, about 15% of the yield, has a medium heating value. The liquid product is an acidic fluid, which pours easily and appears to be stable. A preliminary economic analysis suggests that if the pyrolysis oil can be used directly as a fuel, its production cost from wood waste is probably competitive with conventional fuel oil at the present time.