Abstract: The present invention relates to a process for the synthesis of overbased additives obtained by carbonation under constant pressure of carbon dioxide, the process consisting of carbonating a reaction mixture comprising a derivative of an alkaline-earth metal and at least one surfactant in a diluent oil and a hydrocarbon solvent in the presence of an oxygeneous accelerator and a nitrogeneous accelerator, while maintaining a constant pressure of carbon dioxide above the reaction mixture, the carbon dioxide is thus progressively introduced as it is consumed, thereby allowing its concentration in the liquid medium not to become too high which could thereafter provoke the formation of insoluble over-carbonated products, the reaction to be self-controlled and to obtain excellent yields of overbased products having very high alkaline values and alkaline-earth contents, while however remaining fluid and stable.

Abstract: Process for inhibition of microorganisms in liquid hydrocarbons by the introduction of one or more biocidal agents into these hydrocarbons, which also include a small quantity of water and a surface-active compound.This treatment is particularly useful for preserving liquid hydrocarbons such as petrol, kerosene, gasoline or domestic fuel while being stored.

Abstract: Process for producing a hydrocarbon cut of high octane number by etherification of an olefin-containing hydrocarbon cut.The olefinic cut, to which methanol is added, passes into an etherification reactor (1) wherefrom are separated (3) a bottom product (15) containing ethers, and a top product (14) containing residual methanol and unreacted light olefins. This top product passes into an etherification reactor (2) and then is washed with water (8).The top product is finally admixed with the bottom product.The so-obtained motor-fuel has a higher octane number than that of the initial hydrocarbon cut.

Abstract: The present invention concerns novel lubricating compositions effective in reducing friction, for use, particularly, in turning machines and remarkable in that the additive comprises by at least one mono- or di-substituted carboxylic acid substituted in the .alpha. or .beta. position with respect to the acid function.

Abstract: A process for the preparation of beta-disubstituted monocarboxylic acids derived from tertiary acyclic, monocyclic or bicyclic hydrocarbons. The process consists in reacting said hydrocarbons with vinylidene chloride and either a functional compound where the molecule includes a tertiary carbon atom bonded to the heteroatom of a functional group such as a tertiary alcohol, an ether, or a tertiary halide or an alkene, in the presence of a concentrated protonic acid. The reaction can be carried out in the presence of a catalyst of the Lewis acid type and particularly BF.sub.3. These acids are useful as synthesis intermediates and as additives for oils and lubricants.

Abstract: A new surface-active agent of the formula: ##STR1## wherein R and R' are hydrocarbon groups, M being a cation it is particularly suitable for the production of micro-emulsions in the presence of aqueous saline solutions.One important application thereof is in the assisted recovery of crude oil.

Abstract: This process consists in adding to gas oil from 100 to 5000 ppm of water in the form of a micellar clear and limped solution, which is stable for long times, obtained by the addition of one or more surfactants, associated with one or more auxiliary surface-active agents (co-surfactants). This invention substantially improves the combustion of gas oils.

Abstract: Oil and water microemulsions having a high salt content and intended for assisted petroleum recovery are prepared from a concentrate containing:a mixture of at least three surfactants constituted respectively by a salt of an alkylsulphuric acid, a salt of an alkylaryl sulphonic acid and a salt of a carboxylic acid derivative selected from the group comprising sulphosuccinic acid and sulphosuccinamic acid,at least one cosurfactant constituted by a compound which is capable of forming hydrogen bonds with water.

Abstract: The method for the inhibition of corrosion of ferrous metals in an aqueous medium consists in adding to the aqueous medium 10 to 2000 ppm of a mixture constituted by a water-soluble complex salt of a metal of groups II to VIII of the periodic table and of a hydroxycarboxylic acid and by a phosphoric ester of alkanolamine.