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Abstract Three regimes of combustion are discussed, the thermal reaction of fuels and oxidant and the propagation of deflagration and detonation waves from an ignition source. An explanation is given of the chain character of all combustion reactions, and the complex chemical mechanism that has been developed to explain the oxidation of the simplest fuel, hydrogen, is presented as an illustration. Similar mechanisms exist for the oxidation of hydrocarbons but these are not detailed. It is pointed out that certain important chemicals are formed as transient molecules during such oxidation processes which under suitable conditions may be recovered. The winning of valuable chemicals from combustion reactions is stressed in terms of future utilization of coal and oil reserves, extending the usefulness of flame from that of generating energy. In the last two decades the physical aspects of combustion have been studied in great detail. Technical heat-release is profoundly affected by physical processes and of the latter the most important is turbulence. An explanation is given of what constitutes turbulence and how it behaves. The structure of the combustion or deflagration wave is detailed. The interaction of turbulence with a propagating combustion wave is illustrated. It is pointed out that turbulence can be beneficial for technical combustion processes but if overdone it can be harmful and result in loss of combustion efficiency or even extinction of flame. The concept of flame stretch is introduced to explain a number of important phenomena such as minimum ignition energy, flame stabilization, required strength of pilot flames and maximum permissible turbulence intensity which affects the maximum possible heat release rate in technical combustion systems. A characteristic dimensionless number is introduced, a critical value of which controls limiting conditions with respect to minimum ignition energy, the propagation of a flame from an ignition source, flame stabilization, onset of inefficient combustion and extinction of flame. The critical value of this number has been by BERNARD LEWIS, Combustion and Explosives Research Inc., Pittsburgh, Pennsylvania measured. It turns out to be of the order of unity for all of the above-mentioned phenomena. This is a very useful criterion and it constitutes the basis of the art of flame design-to know how much turbulence is required and how and where to provide it in a practical system. It is suggested that the general validity of the physical considerations discussed in this paper leads one to believe that it will be possible to control the combustion process in the automobile engine to a degree as to make unnecessary the use of antiknock additives. Résumé Trois régimes de combustion sont traités: la réaction thermique entre combustible et comburant et la transmission des ondes de déflagration et de détonation à partir d'une source d'allum
Abstract Résumé Criteria were developed for operating scaled models On a élaboré les règles de mise en service de to evaluate the effect of process and reservoir variables modèles réduits pour l'étude des effets des paramètres on in-situ combustion. These scaling criteria were du gisement et du mode opératoire sur la combustion tested in two cylindrical models, one having a volume "in situ". Les règles de similitude ont été étudiées sur 325 times greater than the other. The results demon- deux modèles cylindriques, dont les volumes sont dans strate the validity of the scaled-model approach, le rapport de 1 à 325. Les résultats obtenus montrent especially for reservoirs in which heat generation is la validité de la méthode d'étude par modèle réduit, controlled by mass transfer of oxygen. spécialement pour les gisements OU la production de Process and reservoir variables were studied in seven- chaleur est régie par le transfert de masse de l'oxyspot pattern models initially saturated with connate gène. water and 2100-CP oil. At practical injection rates, Le mode opératoire et l'influence des paramètres recoveries from 60-70 percent pore volume were du gisement ont été étudiés sur un modèle à sept puits, achieved at reasonable air-oil ratios from a relatively saturé initialement avec de l'eau et une huile de visthick, shale-free sand. Either reduced sand thickness cosité de 2100 cp. Aux débits d'injection conformes à or interbedded shale in the models increased require- la pratique normale, on arrive à une récupération de ments for injected air or oxygen to get equivalent 60 à 70% du volume des pores avec un rapport air/ recoveries. huile raisonnable, po, ur un horizon relativement To test the usefulness of redistributing heat in the épais de sable propre. S'il ya réduction d'épaisseur de reservoir, water and oxygen were injected. At a water- l'horizon sableux ou intercalation de bancs argileux, les to-oxygen mass ratio of about 5, oil recovery was in- besoins en air ou en oxygène injecté se trouvent augcreased and equivalent air-oil ratios were sharply mentés pour atteindre une même récupération. reduced. Pour améliorer la répartition de la chaleur dans le Direct comparison of model results with results of réservoir, on a injecté à la fois de l'eau et de l'oxygène. unconfined field burning tests are not possible. Le maximum de récupération d'huile est atteint pour However, qualitative comparisons indicate results are un rapport massique eau/oxygène de 5, et le rapport compatible. Hence, the scaled-model approach to air/huile est ainsi fortement réduit. study in-situ combustion seems practicable. I1 n'est pas possible de comparer directement les résultats obtenus sur modèle réduit avec ceux d'essais sur champ o ù les limites de l'aire de combustion ne sont pas définies. Cependant, les comparaiso
Abstract Résumé Basic in situ combustion technology is reviewed with L'auteur passe en revue les principes fondamentaux emphasis on light oil reservoirs. The stoichiometry and de la combustion "in situ", notamment pour le cas des the propagation of the combustion zone through the gisements à huile légère. L'étude de la stoichiométrie porous rock of a reservoir are discussed in funda- et de la propagation de la zone de combustion à mental terns. The most distinguishing fact of in situ travers l'espace poreux d'un gisement est étudiée du combustion is air consumption which is related point de vue fondamental. La considération majeure, directly to fuel consumption. The economics, in turn, pour la combustion "in situ", est la consommation are determined by air requirements, air injection costs, d'air qui est directement liée à la quantité d'huile oil-in-place, volumetric conformance, and sale price brûlée. L'économie du procédé est, d'autre part, régie of the crude oil. par la consommation d'air, le coût d'injection de Yair, In evaluating a prospect for combustion, a know- la quantité d'huile en place, le rendement volumétrique ledge of the geologic characteristics of the reservoir is et le prix de vente de l'huile brute. vital to the understanding of performance and diag- Pour l'estimation d'un projet de combustion "in nosis of operating problems. Fuel content is another situ", la connaissance des caractéristiques géologiques most important variable. This property is best deter- du gisement est essentielle. La quantité d'huile brûlée mined experimentally in the laboratory. However, it is est par ailleurs un paramètre primordial, que l'on important to sample the different lithologies of a given détermine de préférence par des essais de laboratoire. column in order to arrive at an average fuel content for Cependant, il importe d'échantillonner les divers the reservoir. niveaux lithologiques du réservoir pour évaluer une The Fry In Situ Combustion Test is cited as an teneur en huile brûlée moyenne pour le gisement. example of the application of these principles to light L'essai de combustion "in situ" du gisement de oil reservoirs. The selection of a reservoir for conduct- "Fry" est choisi comme exemple d'application de ces ing a successful in situ combustion operation requires principes aux gisements d'huile légère. Le choix d'un much greater geologic understanding and engineering réservoir et la préparation d'une opération de combusskill and competence than is necessary in applying the tion "in situ" exigent, pour arriver à un succès, une older methods of secondary recovery. connaissance extrêmement approfondie du cadre géologique, ainsi qu'une compétence et une habileté technique plus grandes que pour tout autre procédé de récupération secondaire. BASIC IN SITU COMBUSTION TECHNOLOGY energy into a rese
- Geology > Mineral (1.00)
- Geology > Geological Subdiscipline > Economic Geology > Petroleum Geology (0.81)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.70)
Chairman's summary sary duplication of research efforts in various countries; indeed between different organizations in the same The theme of the panel as expressed in its title was so country. Frequently, this duplication is the result of an all embracing that it was deliberately narrowed. The imperfect understanding of the status of a problem; of papers give primary attention to those aspects of fluid the factors which can be regarded as being established; flow in porous media which are both economically and of those which require elucidation. important and technically controversial. In particular, The papers by FAROUK ALI, DONOHUE and an evaluation is sought of the usefulness of models of STAHL; by CRAIG; and by BLACKWELL and various types: physical, analog and mathematical, as KOONCE, all examine the same problem: the factors tools for predicting reservoir behaviour. No apology involved in relating the performance of a model to the is necessary for limiting discussion to this problem. The performance of an actual reservoir. All these authors oil industry does not study fluid flow phenomena as an agree that three types of models are of prime imporacademic exercise; it does so because such studies are tance: the physical or scaled model, the electrical intimately related to the recovery of gas and oil in their analog model, and the mathematical model. All primary, secondary and indeed, tertiary stage. authors, both in the papers themselves and in their Three of the papers (all of them American) critically subsequent discussion cf them, place heavy emphasis examine the limitations inherent in studying reservoir on the scale model with secondary emphasis given to problems by means of models. Two French papers mathematical models. The network analog model dwell in some detail on phenomena which, as the now appears to be generally regarded as passé. Americans seem also to agree, but be better defined if Dr. CRAIG amplified in discussion that it is necesthe role of models in forecasting reservoir behaviour sary to separate model experiment into two broad is to be fully understood. Taken together the five categories: mechanistic and dimensionally scaled. All papers have increased appreciation of the pros and panelists agreed that the advent of powerful digital cons of the newer systems of petroleum recovery. computers has made the mathematical model a true Unfortunately, if not unnaturally, neither the panelists rival to the physical model. Nevertheless, Messrs. nor those participating in discussion from the floor, CRAIG, FAROUK ALI and MARLE, agreed that have succeeded in answering all the questions which in the case of both mathematical and physical models, need to be resolved. In the papers themselves and in it was necessary to understand fully the nature of the the discussion
- North America > United States (0.29)
- South America > Venezuela (0.28)
- South America > Brazil (0.28)
Abstract Résumé For more than twenty years the petroleum industry Depuis plus de vingt ans l'industrie pétrolière has studied reservoir oil recovery performance by étudiat le comportement des gisements de pétrole en laboratory fluid flow experiments. Early studies were faisant au laboratoire des expériences d'écoulement. designed to investigate the mechanism of oil displace- En premier lieu le but des essais était d'étudier le ment by water, gas, or solvent injection as well as by mécanisme du déplacement de pétrole brut par l'eau, application of thermal methods including underground le gas, ou les solvants, et par des méthodes thermiques, combustion and the injection of hot water or steam. en incluyant la combustion subterranée ainsi que Within about the past ten years increasing emphasis l'injection d'eau chaude ou de vapeur. Pendant les has been applied to scaled model studies, primarily in derniers dix ans environ, on a noté un intérêt croissant an attempt to obtain quantitative information on the dans les études faites sur modèles dimensionnels, portion of the reservoir which could be swept by principalement pour obtenir de données quantitatives injected fluids. Model studies have also provided infor- pour la portion du gisement qui est balayée par les mation on the effect of dispersion in miscible flooding. fluides injectés. On a également etudié dans les mo-The problems involved in applying laboratory model dèles les effets de la dispersion sur la recupération par flow experiments to field operations are critically des fluides misciples. reviewed. It is concluded that for a model experiment L'auteur a fait une reviue critique des problèmes to yield results directly applicable to specific field qu'on rencontre en utilisant, dans la production d'un operations, three requirements need be met. These are gisement, les expériences d'écoulement faites authe mechanism of the recovery process must be laboratoire. On a conclu que, pour obtenir des understood both qualitatively and quantitatively, résultats qui soient directement utilisables dans la the anatomy of the reservoir must be known in production d'un gisement donné, il ya trois conditions detail, and the model tests must properly consider requises :il faut comprendre aussi qualitativement both the process mechanism and the reservoir ana- comme quantitativement, le mécanisme de récupératomy. Examples of successful application of model tion; il faut connaître en détail les caractéristiques test results to actual field operations are presented. géometriques et physiques du gisement; il faut que les expériences faites sur le modèle prennent en considération le mécanisme de récupération ainsi que les caractéristiques du gisement. La communication comprend des exemples de résultats réussis d'utilisation de telles expériences dans la produ
Résumé Les tonnages importants de gaz carbonique issus de la combustion de produits ptroliers et jusqu'alors non valoriss peuvent tre utiliss en photosynthse dans la culture synthtique d'une algue bleue: Spirulina maxima. Originaire du Tchad, cette algue alimentaire n'a jusqu' prsent jamais t tudie. L'algue sche est trs riche en protines (63%) et en vitamines. La culture en milieu basique est aise et la technologie grande chelle en plein air est tablie. Le rendement est lev (40 45 tonnes/an/ha de matire sche), et le prix de revient est assez bas. L'utilisation des rgions improductives est envisage pour fournir en abondance une substance vgtale riche, utilisable dans l'alimentation animale et humaine. Devant l'expansion dmographique croissante la ncessit de rechercher des solutions au problme de la sous-alimentation et de la malnutrition de nombreuses populations du globe devient de plus en plus imprieuse. La malnutrition se manifeste surtout par une carence specifique en protines, et des organismes spcialiss comme le FAO rvlent que 17 % seulement de la population mondiale parviennent consommer une ration de protines suffisante. Les protines couramment utilises dans l'alimentation humaine proviennent de quelques espces animales et vgtales. Bien que les protines animales soient d'excellente qualit puisqu'elles fournissent tous les acides amins indispensables la vie, elles demeurent lentes produire et onreuses. Malgr les possibilits d'augmentation de leur production il est exclu qu'elles puissent elles seules subvenir aux besoins des populations. Tout en poursuivant l'amlioration des rendements en protines fournies par les vgtaux suprieurs il importe ds maintenant de rechercher de nouvelles sources de protines pour faire face aux besoins actuels et futurs. Aussi, la culture des microorganismes est-elle envis Par Mlle G. CLMENT, MM. M. REBELLERet P. TRAM BOUZE, Institut Franais du Ptrole, France. Abstract Carbon dioxide in large amounts derived from petroleum products combustion which normally is lost, can be used in photosynthesis for synthetic culture of the blue-green alga "Spirulina Maxima". Coming from Tchad, this food alga has never been studied before. Dry alga has a high protein (63%) and vitamin content. It easily grows in a basic medium and its large scale open air technology is now achieved. High yield (40 to 45/tons/year/ha of dry matter) and rather low cost are obtainable. Development in unproductive areas is being planned with a large rich vegetal substance production for food and feed in view. age, et en particulier certaines algues microscopiques qui sont des vgtaux chlorophylliens peuvent constituer une matire alimentaire de haute valeur nutritive. On sait que la photosynthse est le mcanisme physiologique grce auquel ces algues utilisent l'nergie solaire pour labore
- Energy > Oil & Gas (1.00)
- Health & Medicine > Consumer Health (0.74)
INTRODUCTION When greenhouse atmospheres have been enriched with carbon dioxide (CO2) from the normal ambient air level of approximately 0.03 per cent to 0.1 per cent, increased yields, better quality and earlier crops have been produced. CO2 produced by burning a suitable fuel, such as LPG or kerosine, is advantageous and economical; although pure CO2 can be introduced from cylinders or as dry ice. The commercial advantages of introducing CO2 into greenhouse atmospheres was quickly realized by growers in Europe. It was accepted as commercial practice following very little research effort and in fact research has not kept pace with commercial development. Whilst a great deal of data is available on photosynthesis covering many varieties of plants, the part played by CO2 is perhaps the least understood. The concentration required for maximum photosynthesis depends upon the levels of many other factors, such as light, temperature, humidity and water and nutrient supply. Some basic research to study the interaction of these factors has been carried out but the picture is far from complete. Most research is now directed to field application to find the most economical levels of applying CO2 to obtain maximum yields under the different growing conditions. A great deal of practical knowledge is now becoming available. Crops are sensitive to sulphur dioxide and incomplete combustion products, fuel quality and complete combustion is therefore important. There is now available a wide range of testing apparatus and these are examined. HISTORICAL For many years the importance of carbon dioxide as the basic material for photosynthesis, has been known. Early experiments, dating from the nineteenth by G. HEYS, Shell, Great Britain century, proved that when the natural CO2 level of air was increased, plants responded and greater weights and yields were obtained. It was thought possible to commercialize these results on a field scale. Various products were burnt, charcoal, special "fuels", coal, gas and paraffin. In some instances increased yields were obtained but too often the plants died due to toxic products produced during combustion. This was either due to inherent impurities in the fuel, or incomplete combustion products. Work has continued sporadically over the last half century but it was not until the early 1960's in Holland that a real commercial interest was awakened. In 1959 Gaastral at Wageningen, in Holland, studied the relationship of photosynthesis to carbon dioxide, light, temperature and stomatal diffusion resistance. He studied the way in which individual leaves of tomatoes and cucumbers, enclosed in special chambers but attached to the plant, responded to CO2 when the above mentioned factors were varied. At about the same time, Klougart2 in Denmark was working on a semi-commercial scale to find the best conditions for growth, of various economic glasshouse crops. Daunicht3 was working
- Europe > United Kingdom (0.34)
- Europe > Denmark (0.24)
- Materials > Chemicals (1.00)
- Energy > Oil & Gas > Downstream (1.00)
Résumé L'examen des problèmes qui se posent en matière de conversion d'énergie par magnétohydrodynamique met en évidence l'importance considérable de la conductivité électrique du fluide de conversion. Les auteurs examinent les perspectives d'améliorer cette caractéristique qu'offrent certaines voies de recherche actuellement à l'étude: utilisation de la chimi-ionisation et utilisation de veines striées. Ils concluent que malgré les difficultés qui restent à vaincre, les études de chimi-ionisation laissent un certain espoir de réduire considérablement la quantité de semence à utiliser. En ce qui concerne les veines striées, leur emploi permettrait d'améliorer le rendement et de réduire la longueur et le prix du générateur MHD. Abstract A brief survey of the problems to be solved in the field of energy conversion by magnetohydrodynamics shows the prime importance of the electric conductivity properties of the conversion fluid. The authors examine the prospects for improving this feature that are offered by the main processes now being studied: the chemi-ionisation process and the striated flow process. They conclude that in spite of many remaining difficulties there is some hope of reducing the amount of seed by using the chemi-ionisation process; the striated flow process could be able to improve the efficiency of the plant and to reduce the length and the price of the MHD generator. Introduction En cycle ouvert, le fluide de conversion, constitué de produits de combustion de combustibles fossiles convenablement ensemencés assume deux fonctions différentes: une fonction de fluide moteur dont la détente fournit le travail mécanique nécessaire pour vaincre les forces de Lorentz et engendrer le travail électrique, une fonction de conducteur électrique permettant la circulation de courants sous l'effet de la force électromotrice engendrée par le déplacement de ce conducteur dans le champ magnétique. Si la première fonction se retrouve dans toutes les utilisations énergétiques des produits pétroliers et n'appelle pas de commentaire particulier, le second point est propre à la conversion M.H.D. et fait intervenir la conductivité du fluide de conversion pétrolier comme une caractéristique d'une importance determinante. La conductivité est en effet l'un des facteurs de la puissance volumique: W = K (K-Z)CTV~B~ où K est le facteur de charge, o la conductivité, V la vitesse d'écoulement, B l'induction magnétique. A ce titre, elle n'intervient pas seulement pour contribuer à fixer le prix d'investissement, mais aussi pur B. SALE, C. MARLE, F. Le BOUC, Znstitur Français du Pétrole (Frunce). comme l'un des facteurs essentiels déterminant les pertes de générateur et la température de sortie c'est- à-dire en définitive le rende
Abstract of energy. Use as (1) raw ma PROBLEMS IN THE UTILIZATION OF FOSSIL FUELS erials (2) sources of heat (3) sources Résumé de chaleur, (3) source d'énergie. Utilisation comme (1) matières premières, (2) sou Problems for (2) contained in (3). Only degraded reaction products or remainders from (1) or (3) ought to be burned. Adequate kinetic guidance of reactions. Exothermal steps in (i) should be directed toward simultaneous energy gain. For (3) low-temperature oxidation in fuel cells will continue in importance. Development of catalytically efficient electrodes. In processes involving air, formation and either utilization or destruction of nitric oxide provides kinetic problems. Removal or prevention of formation of soot, of carcinogenic substances. Hydromagnetic generators pose kinetic problems of fast combustion, high temperature, high ionization. re Problèmes pour (2) contenus en (3) Seulement des produits dégradés ou des résidus de (2) ou (3) devraient être brûlés. Direction adéquate de la cinétique. Utilisation des pas exothermes pour gain d'énergie. Pour (3) l'oxidation á température basse dans des piles électriques. Développement d'électrodes d'activité catalytique. Problèmes dûs à la formation et i'utilisation ou la déstruction de l'oxyde de l'azote. Formation du noir de carbone et des substances carcinogéniques. Génerateurs magnetohydrodynamiques, problèmes cinétiques de combustion vite, des températures élévées, d'ionisation. Kinetic problems in the utilization of fossil fuels are possibly fuel cells) combustion involves a chain especially interesting where there is a possibility or a reaction, normally a branching chain reaction. This hope of influencing a process in a favorable sense. involves usually chain initiating reactions, chain The classical example, probably, is the suppression propagating steps, chain branching and finally chain of knock in Otto engines by "anti-knocks". Here the breaking reactions. practical application preceded theoretical work and kinetic experiments: the problem, however, was extremely stimulating for a wide field. Even if one supposes that the Otto engine will disappear from many fields in the not too distant future, the problem engines are being used, especially in motor cars, the to a replacement of lead by other additives. Further- H~ i- Oz + 20H chaininitiation more, the branching chain processes, initiating the -+ H~O -i- chain propagation knocking reaction, are similar, or partly identical with 3- Oz -+ OH + O chain branching those leading to normal ignition. Consequently, the 4* o Hz + H + OH chain branching general results may be useful for efficient ignition on the 5- + Oz + Hoz + chain breaking under one hand, for instance in case of diesel engines, and for special conditions burning chambers of gas turbine, of rockets, etc., on 6. f OH f -+ Hzo -t- chain breaking the other hand.
Prepared discussion read by C. M. Stendhal (U.S.A.). The results of the various phases of the API Oil Burner research program described by the authors were not intended to be finished burners ready for commercial application. Considerable development is still required to reach this stage. It is being done, and is there progress along these lines which can be discussed? Which of these approaches studied by the API shows the most promise? Do the authors know whether consideration is being given to combining the different phases of the API work? Are combination vaporizing-recirculation or recirculation-ultrasonic burners being investigated; and what advantages might be gained by making such combinations ? Also, what attributes must a new burner possess if it is to displace a considerable fraction of the high pressure burners now in use ? In the area of residual fuel combustion, we expect to see a number of improved burners applying the Ijmuiden studies, despite the slightly higher combustion air pressure they require. These burners should reduce considerably the volume required for combustion and will be most valuable in package boilers. In very large boilers, the limitation on size is more apt to be the heat transfer surface requirement. Regarding the use of low excess air combustion, the major remaining problem is that no readily applicable means has been developed for achieving satisfactory combustion at 1 per cent excess air in existing boilers. Where this level has been reached, it has usually been the result of intensive effort and revised instrumentation. As a result, there has been a growing trend toward the combination of operating at moderately low excess air levels, around 5 per cent, and using a small amount of alkaline earth additives. With regard to air pollution, we feel that it will be necessary to find ways to burn petroleum fuels with no emission of pollutants in the future. Currently, the emphasis is on reducing emission of SOp. We can count on increasing pressure to reduce particulates, nitrogen aromatics. If we are unable to solve these problems, the almost inevitable result will be a premature switch to nuclear power generation. J. A. BOLT (U.S.A.): Regarding further development from the API program, at least three manufacturers in the U.S.A. are working on recirculating burners, and interest is very high. Battelle has developed small ultrasonic burners for U.S. military applications, and more are being ordered. There is also an ultrasonic atomizer burner, developed in Germany by Dr. Pohlmann which appears promising, in which the atomizer is used in both, to lift the fuel
- Energy > Oil & Gas > Downstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.34)
- Energy > Power Industry > Utilities > Nuclear (0.34)