Oil sand processing

The large Canadian oil-sands surface-mining and water-based flotation processing operations involve a number of kinds of emulsions and foams in a variety of process steps. Whereas mineral ore flotation relies on wettability alteration and bubble attachment, oil and bitumen flotation rely more on attachment and filming to create an oleic foam. 

A consequence of the application of flotation technology to oil sands bitumen production is the co-production of tailings suspensions, consisting of fine silica and clays plus some residual emulsified bitumen. This is discussed in somewhat more general terms in Section 10.4. See also Refs. [638,642]. 

Bitumen is separated from the oil sand matrix, in large tumblers, where surfactants play key roles in separating bitumen from mineral particles and then floating the former. As reviewed elsewhere [79, 167], from the bitumen, alkaline conditions are used to produce (saponify) a class of natural surfactants that are predominantly aliphatic carboxylates of chain length typically to and also 

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It will be interesting to see whether the GTL trend started by the SMDS process will continue. The inclusion of lubricating oil production as part of the Pearl GTL design indicates that it may not. In a related field there also seems to be movement. In oil sands processing, where the product traditionally had been a synthetic crude oil that was sold for refining elsewhere, there seems to be increasing interest in adding value to the product.71... 

Canadian oil sand processing plants have been developed by Syncrude and Suncor for extraction and upgrading of tar sand bitumen into fuel. Aboveground surface mining and in-situ methods have been developed to recover raw material. Bitumen recovery from surface mined oil sand requires conditioning in order to free the bitumen from the sand matrix. 

Example. In the primary flotation vessel of an oil sands processing plant, two different process conditions yield the following data for the flotation of bitumen mean bitumen droplet diameter, 0.26 mm, mean droplet density,... 

The coke residue is the result of the hydrogen-deficient stoichiometry of the process. With a proximate analysis (determination of the compounds, moisture, ash, etc., present) of carbon 80%, volatiles 10%, sulfur 6%, and ash 4%, the coke has a fuel value near that of high rank coals. It is burned in the site power plants to provide steam and electrical power for oil sands processing. However, the high sulfur content detracts from its wider utility as a fuel. Any coke in excess of the current fuel requirement is finely powdered and incorporated into the dyke walls to help trap any hydrocarbons present in water seepage through the wall. 

Electrostatic Properties in Nonaqueous Media. Although suspensions most commonly comprise particles dispersed in aqueous media, the petroleum industry contains many examples of particles dispersed in nonaqueous media. Examples include precipitated asphaltenes in oil (see Chapter 8) and mineral solids dispersed in diluted froth in oil sands processing (see Chapter 13). Particles can be electrostatically stabilized in nonaqueous media, although the charging mechanism is different (7, 34). In a recent review Morrison (34) emphasized that many models are... 

The chemical and physical properties of clay suspensions produced during oil production from oil sands are described. With a composition of approximately 70 wt% water (with some unrecovered bitumen) and 30 wt%solids (>90% less than 44 gm in size)9 these clay suspensions consolidate very slowly. Clay aggregate or floe morphology has been shown to be a function of the water chemistry and can be manipulated to produce a tailings suspension that is easier to consolidate and dewater. Commercial oil sands processing has been going on in northeastern Alberta since 1967, and in that time approximately 250 million m3 of this difficult to dewater clay suspension has been produced. The reclamation options for this material (mature fine tailings) on a commercial scale are also outlined. 

The main sources of inorganic ions found in tailings water are (1) oil sand connate water (water in the spaces between the sand grains), (2) makeup water taken from the Athabasca River for use in plant processes, and (3) chemicals added during hot water extraction and other processes. These sources contribute ions that accumulate in the pond water that is recycled to oil sands processing. 

MacKinnon, M. D. Boerger, H. Assessment of a Wet Landscape Option for Disposal of Fine Tails Sludge from Oil Sands Processing Petroleum Society of the Canadian Institute of Mining, Metallurgy, and Petroleum Calgary, Canada, 1991 Vol. 3, pp 124-1-124-15. 

V Homoff, JK Liu. Dynamic interfacial tension effects of oil sands processing. Proceedings of Fourth World Congress, Chemical Engineering, Karlsruhe, 1991. 

Kasiri S, Ulrich A, Prasad V Kinetic modeling and optimization of carbon dioxide fixation using microalgae cultivated in oil-sands process water, Chem EngSci 137 697—711,2015. 

Emulsion drilUng fluids emulsion fracturing, stimulation, acidizing fluids enhanced oil recovery (EOR) in situ emulsions produced (well-head) emulsions bituminous oil sand process and froth emulsions heavy oil pipeUne emulsions fuel oil and tanker emulsions... 

An FTIR method has also been developed for the determination of the naphthenic acids in oil sand process tailings [97]. In this method, a tailings sample is clarified by filtration (0.45 pm nominal pore size) then by ultrafiltration. Acidification to pH 2.5 with sulfuric acid ensures the acid form of all carboxylate functionalities and thus complete dissolution. The sample is then extracted with methylene chloride and evaporated to dryness. The naphthenic acid residue is dissolved in methylene chloride, the carbonyl stretching frequencies at 1708 and 1748 cm are observed and the corresponding absorbance values determined by FTIR. The method determines total organic carboxylates and therefore is sensitive to a broader range of structures than the carboxylate surfactants alone, but is sometimes used as an indicator of relative carboxylate surfactant concentrations, especially in studies of oil sand tailings pond samples. 

The existence of optimum concentrations for separation- and flotation-aid surfactants is qnite common in mineral processing operations. In oil sand processing, reasons for reductions in process efficiency at higher than the optimum concentrations may be due to the formation of different adsorption layer orientations and/or multiple adsorption layers at interfaces. Either or both of these could explain the observed reductions in surface electric charge (Zeta potential) at the bitumen/aqueous and gas/ aqueous interfaces (see Figure 14). 

With guidelines for the critical concentrations and recognizing the preferential adsorption behaviour (dominance) of the carboxylate surfactant, an extremely wide range of oil sand processing behaviours can be nnderstood, as illustrated in a number of papers on the subject [70, 101-104,116],... 

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