Summary Systems optimized for micellar flooding are not all equivalent in terms of solubilization, interfacial tensions (IFT's), and oil recovery efficiency. The basic conditions that promote high solubilization into microemulsions, a property correlated to the values of IFT'S, were established in a previous paper. Changes in oil type, for example, have to be compensated for by adjustment of the lipophile of the surfactant; however, this is not always sufficient to guarantee a high solubilization. The purpose of this paper is to investigate the influence on solubilization of the relationship between the oil type to be solubilized and the surfactant lipophile. We found that this relationship is a determining factor for solubilization at a given temperature and salinity. For example, we observed that for the alkane series, solubilization is not affected by the alkane carbon number (ACN), provided that the compensation be achieved by adjustment of the surfactant lipophile length. For other oils or mixture of oils, like crudes, however, this is not necessarily the case; the solubilization may be found to be more or less different from that of alkanes, depending on the structure of the surfactant lipophile. A particularly interesting case of oil mixtures is mixtures of hydrocarbons and methane (under pressure), because this gas is often dissolved in substantial amounts in live crudes. The incidence of the presence of methane is shown to be a function of the amount of gas presence of methane is shown to be a function of the amount of gas dissolved and of the nature of the dissolving hydrocarbon. An interpretation of the results is proposed, based on the oil/lipophile, oil/oil, and lipophile/lipophile interaction energies, which are involved in Winsor's R-theory. Introduction The design of the micellar or microemulsion slug for surfactant flooding requires careful attention to attain the low IFT's essential for mobilizing the residual oil trapped in the reservoir. Ultralow IFT's have been shown to occur when a surfactant-rich phase-called middle phase-is in equilibrium with both excess oil and water phases. 2 The IFT values were found to correlate to the amount of oil and water solubilized in the middle phase: the higher the solubilization, the lower the tensions. It is then convenient to compare various systems through their solubilizing power. For meaning comparison, however, a reference state has to be chosen, generally the three-phase system in the middle phase of which equal volumes of oil and water have been solubilized. Such systems are commonly said to be "at optimum" and can be obtained by scanning any formulation variable. Comparison of optimized systems through their solubilizing power will reveal that they are not all equivalent. This raises the problem of finding the best surfactants from the solubilization and IFT standpoints. A corollary question is whether a meaningful comparison of surfactants, though taken at optimum, can be achieved, whatever the composition of the system. This question has been addressed in a previous paper, which showed that a key factor was the level of the interaction energies of the surfactant with oil and water. At optimum, the compensation for the change in a formulation variable that has affected one side of the water/oil interface (where the surfactant is adsorbed) has to be carried out on the same side so as not to decrease the solubilization. For example, a shortening of the surfactant tail compensated for by an increase in salinity entails a decrease in solubilization. In the same way, an augmentation in the hydrophobicity of the oil-e.g., through its ACN-decreases the solubilization if the compensation is achieved through an increase in salinity. On the other hand, a variation of normal ACN can be compensated for by adjustment of the surfactant tail length at constant salinity without serious damage to solubilization. Regarding the effect of oil on solubilization, however, some difficulties have appeared in some cases when hydrocarbons different from the normal alkane series were used, even though the compensation had been carried out through the surfactant tail length. The purpose of this paper is to investigate in detail the relationship between paper is to investigate in detail the relationship between the surfactant lipophile and the oil to be solubilized. The results obtained when the oil change is compensated for by adjustment of the surfactant tail length will be presented first. Compensation by changing the surfactant hydrophile will be discussed next. Oils of various natures and molecular weights will be used, as well as mixtures. The effect of the presence of dissolved methane in the oil will be seen as an interesting particular case of mixture. SPERE P. 41

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This paper sets out to demonstrate, at lab scale, the feasibility of the twomain phases of the process, namely the emulsification of a heavy Venezuelanacidic crude oil (ZUATA), and the subsequent breaking of the oil-in-wateremulsion. The heavy ZUATA crude can be emulsified directly by making use of thesurfactants naturally present in this rich acid oil. These potentialsurfactants, mainly represented by naphthenic acids, become effectiveemulsifiers when salified into naphthenate anions by the addition of bases(soda, ammonia). Stable oil-in-water emulsions, typically with 60 to 65% oil, are obtained byusing these two bases. There are a number of advantages to be gained in usingammonia to form the oil-in-water emulsions as opposed to other bases (soda forexample) for emulsion breaking and phase separation. The paper demonstrates that it suffices to heat the emulsion to break it. Itdescribes the conditions required for ammonia removal and recovery, and theresulting emulsion breaking. An industrial process for achieving the separation is then proposed. Introduction Extra heavy oils (viscosity >10,000 cP, 7<°API<12) can betransported1–3 by heated pipelines, or regular heating of the crude, or dilution with a lighter crude or a naphtha. Of all these different transportmeans, dilution is the most economical and currently the most widely used. The dilution ratio varies between 30 and 40% depending on the transportationspecifications of the pipelines (19°API and crude viscosity<350 cP forCanada, 400 cP for Venezuela). Using the diluent affects the capacity of thepipeline, which is reduced from 30 to 40% and this entails the necessity ofeither having a second pipeline for diluent return, or purchasing more diluenton the production site. Moreover, as the diluent is extracted from the crudeduring atmospheric distillation in the upgrader unit or in the customer'srefinery, the crude desalting, heating and atmospheric distillation units areover-sized by 30 to 40%. The transportation of heavy crude oil by emulsification in water4can be made economically attractive, in comparison with other means such asdilution, provided the surfactant stabilizing the emulsion can be recovered.The lower viscosity of the oil-in-water emulsion significantly increases thetransportation capability. Using water instead of diluent simplifies the crudetreatment process. This paper sets out to demonstrate, at lab scale, the feasibility of the twomain phases of the process, firstly, emulsification of a heavy Venezuelanacidic crude oil (ZUATA) and, secondly, the subsequent breaking of theoil-in-water emulsion. Emulsification of heavy ZUATA oil The ZUATA oil can be emulsified directly, without any added externalsurfactant, owing to the surfactants naturally present in this rich acid heavyoil (°API: 7.8, Total Acidity: 4.3 mg KOH/g). The relevant "potential"surfactants are chiefly represented by naphthenic acids, which become"effective" surfactants when transformed into naphthenate anions by addition ofa base (NaOH, NH4OH)5.These naphthenate salts assume therole of "effective" surfactants, enabling oil-in-water emulsions to be obtainedat various oil-to-water ratios.

2014 Le cyclone, bien connu comme séparateur centrifuge peut être valablement utilisé comme réacteur chimique gaz-solide. Des premières expériences faites sur un cyclone du type standard chauffé à 1 323 K au foyer d'un four à image soulignent la bonne efficacité du transfert de chaleur entre ses parois et le gaz qui le traverse.On montre, dans un deuxième temps, que les informations recueillies à la suite de la mise en 0153uvre en continu de la pyrolyse flash de sciure de bois à 1 143 K sont tout à fait en accord avec celles issues d'autres expériences effectuées dans des conditions fort différentes. Cette réaction ainsi que toute autre réaction gaz-solide endothermique pourraient être mises en 0153uvre à une plus large échelle dans ce nouveau type de réacteur grâce à l'utilisation de l'énergie solaire concentrée.Abstract. 2014 Cyclones, known as centrifugal separators, can be also used as gas-solid chemical reactors. Preliminary experiments made on a cyclone of a conventional type heated at 1323 K at the focus of an image furnace show the good efficiency of heat transfer between the walls and the gas. We have then studied the continuous flash pyrolysis of wood sawdust at 1 143 K. The results obtained agree with others issued from experiments made in quite different conditions. Such a reaction or any other endothermic gas-solid reaction could be carried out on a large scale in such a new type of reactor by use of concentrated solar energy.