MINERAL MATTER AND CLAY-ORGANIC COMPLEXES IN OIL SANDS EXTRACTION PROCESSES

ABSTRACT

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the bitumen product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed.

The samples were obtained from Suncor's oil sands extraction plant located in Fort McMurray, Alberta. Samples were obtained from throughout the extraction process from the primary froth through to the final diluted bitumen product. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as well as with other techniques such as interfacial tension measurements. The data indicates that high water content products originate, to a great extent, from the presence of a very hydrophilic organic matrix attached to the surface of the clay and heavy metal minerals.     

CHARACTERIZATION OF OIL SANDS MINERAL COMPONENTS AND CLAY-ORGANIC COMPLEXES

ABSTRACT

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as veil as with other techniques such as interfacial tension measurements.     

CHARACTERIZATION OF OIL SANDS MINERAL COMPONENTS AND CLAY-ORGANIC COMPLEXES

Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailings as well as carry over of water and mineral matter with the product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as veil as with other techniques such as interfacial tension measurements.     

Athabasca oil sands: effect of organic coated solids on bitumen recovery and quality

The Canadian oil sands deposits in northern Alberta contain about 1.3 trillion barrels of crude oil equivalent. The largest of the four major formations is found in the Athabasca region where bitumen is heterogeneously distributed throughout an unconsolidated mineral matrix. About one-tenth of the oil sands in this deposit is economically recoverable by conventional surface mining techniques.The Hot Water Extraction Process (HWEP) is used commercially to recover bitumen from surface mined oil sands ore. The viability of this process relies on the existence of a thin water film around each solid particle in the ore matrix. However, a completely water-wet mineral condition is not generally the case for oil reservoirs, including oil sands deposits. In the latter case, it has been shown that certain solid fractions are associated with significant amounts of toluene insoluble organic matter (TIOM), physically or chemically adsorbed onto particle surfaces. These fractions are generically described as ‘organic rich solids’ (ORS). In bitumen separation processes, the organic matter associated with various ORS fractions represents an impediment to optimum bitumen separation and upgrading. In this sense, these solids are considered to be ‘active’ relative to the ‘inactive’ water wetted quartz particles comprising the bulk of the oil sands ore. Preliminary results indicate that the ORS content of an ore appears to be a better predictor for ore processability than the traditional use of bitumen or fines (−44 μm) contents.Two types of ORS have received particular attention. The first is a coarser fraction, usually less than 44 μm but also occurring as particles greater than 100 μm in diameter. This material typically occurs as aggregates of smaller particles bound together by humic matter and precipitated minerals. During the bitumen separation process, these heavy aggregates carry any associated bitumen into the aqueous tailings, thus reducing overall bitumen recovery. The second important fraction comprises very thin, ultra-fine clay particles with a major dimension of <0.3 μm. These ultra-fine clays, with a surface coating of organic matter, remain with bitumen during the separation process. In bitumen upgrading, these solids may be entrained with volatile overheads and cause problems in downstream operations. This paper summarises the protocols developed to separate and characterise these intractable components from HWEP process streams and discusses their role in determining bitumen recovery and quality.     

13NMR CHARACTERIZATION OF HUMIC MATTER PRESENT IN DIFFERENT OIL SANDS

Insoluble organic matter (humic matter) present in oil sands can alter the wettability of the inorganic matrix and thereby cause serious problems during bitumen recovery.

Using a cold water agitation test, solids rich in organic matter were isolated from various oil sands which were chosen to reflect different behavior in the hot water extraction process.¹³C NMR examination of these separated solids showed significant structural variations between samples isolated from different oil sands. Humic matter from Utah oil sand appeared to be more aliphatic than that derived from Athabasca oil sand.

Humic acids extracted from organic rich solids as a result of prolonged treatment with 2% NaOH show remarkable similarity in their ¹³C NMR spectra. Humins differ substantially in the relative contribution of the terrestrial and marine source material. There was apparent correspondence between poor bitumen separation and the presence of humin with highly paraffinic structures.     

13NMR CHARACTERIZATION OF HUMIC MATTER PRESENT IN DIFFERENT OIL SANDS

ABSTRACT

Insoluble organic matter (humic matter) present in oil sands can alter the wettability of the inorganic matrix and thereby cause serious problems during bitumen recovery.

Using a cold water agitation test, solids rich in organic matter were isolated from various oil sands which were chosen to reflect different behavior in the hot water extraction process.¹³C NMR examination of these separated solids showed significant structural variations between samples isolated from different oil sands. Humic matter from Utah oil sand appeared to be more aliphatic than that derived from Athabasca oil sand.

Humic acids extracted from organic rich solids as a result of prolonged treatment with 2% NaOH show remarkable similarity in their ¹³C NMR spectra. Humins differ substantially in the relative contribution of the terrestrial and marine source material. There was apparent correspondence between poor bitumen separation and the presence of humin with highly paraffinic structures.     

CHARACTERIZATION OF SOLVENT-INSOLUBLE ORGANIC MATTER ASSOCIATED WITH MINERAL MATTER FROM OIL SANDS*

Considerable quantities of insoluble organic matter (IOM) are known to be associated with certain solid fractions found in oil sands. This organic matter is believed to be partly responsible for the intractability of the sludge generated by the hot water process used for the extraction of bitumen from Alberta oil sands. In previous investigations we had attempted to enrich the insoluble organic matter by dissolving the minerals in concentrated HCl/HF mixtures. As a result of this severe acid treatment the inorganic material is decomposed, but the organic constituents are also likely to undergo significant changes. In the present work we have used a milder HCl/HF treatment for mineral dissolution. The results from the current investigation are compared with the results of the previous study to assess the chemical alterations of the organic matter resulting from the two treatments.

The fractions obtained from the mild acid treatment were analyzed using solid state ¹³C NMR spectroscopy and elemental analysis. Latter results have been discussed in terms of a van Krevelen diagram which is derived by plotting the atomic H/C ratios against O/C. The NMR data were used to calculate the aromaticities of the various organic fractions. Based on the elemental compositions and the NMR data, it is suggested that the IOM associated with the sludge solids is derived from terrestrial sources.     

A PHYSICAL CHEMICAL EXPLANATION FOR DETERIORATION IN THE HOT WATER PROCESSABILITY OF ATHABASCA OIL SAND DUE TO AGING

The oxidation of sulphide minerals during storage of Athabasca oil sands causes solubilization of inorganic salts which affect recovery of bitumen during hot water extraction. DLVO and Ionizable Surface Group Model theories accurately predict that the level of soluble salts produced is sufficient to cause coagulation of the fine particles during the process which leads to a deterioration in froth quality and loss of bitumen recovery. The rate of aging is specific to each oil sand but storage of oil sands under an inert atmosphere in air-tight container at sub-zero temperatures will minimize oxidation.     

油砂沥青油的加工利用

利用溶剂抽提分离油砂沥青,比较了油砂沥青油的沸腾床加氢实验和焦化实验,以及油砂的干馏实验。结果表明,以甲苯为溶剂抽提分离油砂沥青,可使沥青油回收超过90%。油砂沥青油具有密度大、灰分高、盐含量高的特点,胶质沥青质质量分数超过90%。采用沸腾床加氢处理脱盐沥青油,可使其硫、残炭、镍、钒的脱除率分别达到7283%、6685%、9616%和9824%,胶质和沥青质的转化率分别为7353%和9863%,加氢产物是优质的深加工原料。采用焦化处理非脱盐沥青油,总液收6164%,焦炭产率2895%,资源相对有效利用率低。油砂直接干馏,沥青油总回收率只有7856%。从油砂沥青油的有效回收和利用上看,沸腾床加氢是最有效的手段。     

CHARACTERIZATION OF SOLVENT-INSOLUBLE ORGANIC MATTER ASSOCIATED WITH MINERAL MATTER FROM OIL SANDS∗

ABSTRACT

Considerable quantities of insoluble organic matter (IOM) are known to be associated with certain solid fractions found in oil sands. This organic matter is believed to be partly responsible for the intractability of the sludge generated by the hot water process used for the extraction of bitumen from Alberta oil sands. In previous investigations we had attempted to enrich the insoluble organic matter by dissolving the minerals in concentrated HCl/HF mixtures. As a result of this severe acid treatment the inorganic material is decomposed, but the organic constituents are also likely to undergo significant changes. In the present work we have used a milder HCl/HF treatment for mineral dissolution. The results from the current investigation are compared with the results of the previous study to assess the chemical alterations of the organic matter resulting from the two treatments.

The fractions obtained from the mild acid treatment were analyzed using solid state ¹³C NMR spectroscopy and elemental analysis. Latter results have been discussed in terms of a van Krevelen diagram which is derived by plotting the atomic H/C ratios against O/C. The NMR data were used to calculate the aromaticities of the various organic fractions. Based on the elemental compositions and the NMR data, it is suggested that the IOM associated with the sludge solids is derived from terrestrial sources.     

A PHYSICAL CHEMICAL EXPLANATION FOR DETERIORATION IN THE HOT WATER PROCESSABILITY OF ATHABASCA OIL SAND DUE TO AGING

ABSTRACT

The oxidation of sulphide minerals during storage of Athabasca oil sands causes solubilization of inorganic salts which affect recovery of bitumen during hot water extraction. DLVO and Ionizable Surface Group Model theories accurately predict that the level of soluble salts produced is sufficient to cause coagulation of the fine particles during the process which leads to a deterioration in froth quality and loss of bitumen recovery. The rate of aging is specific to each oil sand but storage of oil sands under an inert atmosphere in air-tight container at sub-zero temperatures will minimize oxidation.     

MANAGEMENT OF OIL SANDS TAILINGS

In Alberta, oil sands bitumen is utilized for synthetic crude oil (SCO) production by surface mining, bitumen extraction followed by primary (coking) and secondary (catalytic hydrotreating) upgrading processes. SCO is further refined in specially designed or slightly modified conventional refineries into transportation fuels. Oil sands tailings, composed of water, sands, silt, clay and residual bitumen, is produced as a byproduct of the bitumen extraction process. The tailings have poor consolidation and water release characteristics. For twenty years, significant research has been performed to improve the consolidation and water release characteristics of the tailings. Several processes were developed for the management of oil sands tailings, resulting in different recovered water characteristics, consolidation rates and consolidated solid characteristics. These processes may affect the performance of the overall plant operations. Apex Engineering Inc. (AEI) has been developing a process for the same purpose. In this process oil sands tailings are treated with Ca(OH)₂ lime and CO₂ and thickened using a suitable thickener. The combination of chemical treatment and the use of a thickener results in the release of process water in short retention times without accumulation of any ions in the recovered water. This makes it possible to recycle the recovered water, probably after a chemical treatment, as warm as possible, which improves the thermal efficiency of the extraction process. The AEI Process can be applied in many different fashions for the management of different fractions of the tailings effluent, depending on the overall plant operating priorities.     

MANAGEMENT OF OIL SANDS TAILINGS

ABSTRACT

In Alberta, oil sands bitumen is utilized for synthetic crude oil (SCO) production by surface mining, bitumen extraction followed by primary (coking) and secondary (catalytic hydrotreating) upgrading processes. SCO is further refined in specially designed or slightly modified conventional refineries into transportation fuels. Oil sands tailings, composed of water, sands, silt, clay and residual bitumen, is produced as a byproduct of the bitumen extraction process. The tailings have poor consolidation and water release characteristics. For twenty years, significant research has been performed to improve the consolidation and water release characteristics of the tailings. Several processes were developed for the management of oil sands tailings, resulting in different recovered water characteristics, consolidation rates and consolidated solid characteristics. These processes may affect the performance of the overall plant operations. Apex Engineering Inc. (AEI) has been developing a process for the same purpose. In this process oil sands tailings are treated with Ca(OH)₂ lime and CO₂ and thickened using a suitable thickener. The combination of chemical treatment and the use of a thickener results in the release of process water in short retention times without accumulation of any ions in the recovered water. This makes it possible to recycle the recovered water, probably after a chemical treatment, as warm as possible, which improves the thermal efficiency of the extraction process. The AEI Process can be applied in many different fashions for the management of different fractions of the tailings effluent, depending on the overall plant operating priorities.     

CHARACTERIZATION OF VARIOUS BITUMEN SAMPLES FROM TAR SANDS

We have investigated twenty three bitumen samples obtained using different separation methods such as: ultracentrifugation, Dean-Stark extraction, solvent extraction employing vigorous agitation, hot water separation and the Solvent Extraction Spherical Agglomeration technique. These samples were extracted from oil sand feedstocks of different grades, Suncor sludge pond tailings and mineral agglomerates obtained from the Solvent Extraction Spherical Agglomeration process. All of the bitumen samples were examined on a comparative basis using various analytical techniques. These included: fractionation into asphaltenes and maltenes; elemental analyses; molecular weight determination using vapour pressure osmometry and gel permeation chromatography, infrared, proton and 13C nuclear magnetic resonance spectroscopy. Proton and ¹³C n.m.r. spectroscopic data were used to determine the distribution of various types of hydrogens and carbons in the samples. These data were also used to derive various molecular parameters in order to investigate average molecular structures of different bitumen samples and some of their asphaltene fractions.     

CHARACTERIZATION OF VARIOUS BITUMEN SAMPLES FROM TAR SANDS

ABSTRACT

We have investigated twenty three bitumen samples obtained using different separation methods such as: ultracentrifugation, Dean-Stark extraction, solvent extraction employing vigorous agitation, hot water separation and the Solvent Extraction Spherical Agglomeration technique. These samples were extracted from oil sand feedstocks of different grades, Suncor sludge pond tailings and mineral agglomerates obtained from the Solvent Extraction Spherical Agglomeration process. All of the bitumen samples were examined on a comparative basis using various analytical techniques. These included: fractionation into asphaltenes and maltenes; elemental analyses; molecular weight determination using vapour pressure osmometry and gel permeation chromatography, infrared, proton and 13C nuclear magnetic resonance spectroscopy. Proton and ¹³C n.m.r. spectroscopic data were used to determine the distribution of various types of hydrogens and carbons in the samples. These data were also used to derive various molecular parameters in order to investigate average molecular structures of different bitumen samples and some of their asphaltene fractions.     

两种油砂加工方法的对比研究

分别采用溶剂萃取法和流化热转化法对内蒙古图牧吉油砂的加工方法进行了研究。溶剂萃取法可以得到油砂中几乎所有油品,但其液体产品具有高密度、高黏度及高残炭等特点,后续加工难度大;流化热转化法可以得到油砂中82.3%的油品,与溶剂萃取法相比,其液体产品的性质得到了较大程度的改善。对流化热转化得到的液体产品进行分馏和分析,其中汽油、柴油收率之和达到了37.32%,但是需要进一步精制才能达到国家油品标准的质量要求;重油收率达到了62.68%,可以通过进一步掺炼实现其轻质化。     

加拿大油砂溶剂提取分离的实验研究

采用半连续溶剂抽提法对加拿大油砂进行了提取分离试验,应用溶解度参数理论以及实验筛选出最佳抽提溶剂为重整汽油。综合考察了提取温度、溶剂流量、提取时间以及提取压力等工艺操作条件对油砂沥青提取的影响。结果表明,在提取温度80 ℃、溶剂流量60 mL/min、提取时间60 min、提取压力1.0 MPa的条件下,油砂沥青提取率达到92.74%。     

ANALYSIS AND PHYSICO-CHEMICAL CHARACTERIZATION ON CHINESE OIL SAND BITUMENS

The extraction of four Chinese oil sands from Sinjiang and Inner Mongolia Autonomous Regions with Dean-Stark extractor were investigated. The mineral composition and sand grain distribution were determined and the bitumens were separated into saturates, aromatics, resin-I and resin-II, asphaltenes. The structure parameters and molecular model were made for the bitumens. Elemental analysis, molecular weight, FTIR, 1H-NMR were made for the bitumen fractions. The results show that the molecular structure of Mongolia bitumens have more polycyclic aromatics than that of Sinjiang bitumen. It is believed that the extraction of Sinjiang oil sand bitumen by hot alkaline water is much easier than Mongolia oil sand due to the difference of the viscosity of bitumen, the molecular structure and other physico-chemical properties of the bitumens.     

快速溶剂萃取法提取印尼油砂沥青的工艺研究

采用快速溶剂萃取技术提取油砂沥青,通过单因素试验和正交试验得出加压溶剂萃取技术的最佳工艺参数。研究结果表明：在高压条件下,混合适量硅藻土分散剂,快速溶剂萃取法提取油砂沥青比传统索氏抽提与费舍尔试验更有优势。利用正交试验获得快速溶剂萃取法提取油砂沥青的最佳工艺参数为：压力10 MPa,土砂比（硅藻土与油砂的体积比）2∶1,萃取温度160 ℃,循环次数5次,溶剂选择四氢呋喃,单次静态萃取时间12 min。