Abstract: A process for temporarily interrupting a Fischer-Tropsch type reaction carried out on a feed comprising at least carbon monoxide and hydrogen is carried out in a three-phase reaction zone comprising a liquid phase, a gas phase and solid catalyst particles maintained in suspension, said process comprising a step a) for interrupting the reaction and a step b) for restarting said reaction, during which the solid catalyst particles are maintained in suspension in the reaction zone; a) during the step for interrupting the reaction, supply of the feed is stopped, and a blanket of an inhibiting gas comprising less than 1% by volume of hydrogen and at least 5% by volume of at least one inhibiting compound selected from the group formed by carbon monoxide and water is established; and b) during the reaction restart step, in the reaction zone, a blanket of an activating gas with a hydrogen content of at least 20% by volume is established and supply of the feed is restarted.

Abstract: The object of the invention is a catalytic composition comprising titanium and phosphorus and resulting from the contacting of at least one titanate with at least one quaternary "onium" salt of an acid selected from the group consisting of phosphoric acid and the phosphonic acids of formula R.sup.7 H.sub.2 PO.sub.3 in which R.sup.7 is a hydrocarbon group having 1 to 38 atoms of carbon and the "onium" remainder is a remainder of formula (R.sup.8 R.sup.9 R.sup.10 R.sup.11 M).sup.+ in which M is an element from the group VA of the periodic table of elements, preferably nitrogen or phosphorous, and R.sup.8, R.sup.9, R.sup.10 and R.sup.11, identical or different, represent each an atom of hydrogen or a hydrocarbon group having 1 to 38 atoms of carbon.This catalytic composition is utilizable for producing asters and polyesters from epoxides and carboxylic acid anhydrides.

Abstract: A method and device are provided for producing synthetic gas by combustion of a fuel in a combustive agent deficient atmosphere, said combustive agent being gaseous, said device including first means for feeding the fuel and a part of the combustive gas into the reactor, and second means for feeding a second part of the combustive gas into the reactor, said second means including a porous wall defining at least a part of said reactor.

Abstract: A new class of antiwear and extreme-pressure additives consisting of thiophosphoretted compounds obtained by reactin gphosphorus sulfieds, especially phosphorus decasulfide P.sub.4 S.sub.10, with surbasic detergent additives, is described. The reaction product can be optionally treated by at least one active hydrogen compound: water, alcohol, phenol, acid, ammonia, amine, amide and/or mercaptan.

Abstract: Disclosed is a process for selective hydrogenation in liquid phase of an effluent originating from an ethane steam cracker in which said effluent is contacted with a catalyst consisting of at least supported palladium characterized in that it is carried out in the presence of a liquid phase containing at least part of the hydrogenated gasoline cut, condensed and recycled, of said effluent.Said effluent (1), said liquid phase (8) and possibly hydrogen (13) pass through the hydrogenation reactor (4). The product obtained is fractionated (5) into a gaseous cut at the top (7) containing ethylene and a liquid gasoline cut at the bottom which is partially recycled (8).The process may be used for production of ethylene and for production of gasoline.

Abstract: New compositions, useful as viscosity additives, having dispersing properties in various hydrocarbon oils, are disclosed, which comprise:recurrent units derived from one or more acrylic or methacrylic esters (e.g. 55-99.8% by weight),recurrent units derived from one or more nitrogenous vinyl monomers obtained by reacting triallylcyanurate with aliphatic amines or polyamines (e.g. 0.2-10% by weight), and optionallyrecurrent units derived from one or more vinyl aromatic monomers (e.g. 0-35% by weight).These copolymer compositions generally have a weight average molecular weight from 30,000 to 800,000 and a polydispersity generally lower than 5. They can be prepared by any radical copolymerization process using for example azoic or peroxydic initiators.The copolymer compositions considered are used as additives for improving the rheological properties of hydrocarbon oils. In addition, they exhibit good dispersing properties.

Abstract: An aluminosilicate type catalyst and its use in the aromatization of a C.sub.2 -C.sub.4 light-gas cut in the presence or not of olefins is described.The catalyst is characterized by the following composition expressed by weight:a) 0.01 to 10% by weight of galliumb) 0.1 to 99.49% of a matrixc) 0.5 to 99.99% of a zeolite having the following approximate chemical formula:M.sub.2/n O, Al.sub.2 O.sub.3, xSiO.sub.2whereinM represents a proton and/or a metallic cation,n is the valency of said cation,x is a number ranging from 12 to 1000,said zeolite having a MFI structure being synthesized, moreover, in a fluoride medium and having a fluorine content ranging from 0.02 to 1.5% by weight incorporated during synthesis.

Abstract: A method and device for introducing a carburetted mixture into a first cylinder of an internal combustion engine under pressure, this engine comprising at least one other cylinder with a pump crankcase, further comprising a connecting duct between the crankcase and the first cylinder, with an angular non zero shift between the cycle of each of the cylinders, and at least one of the gas transfer ports of said other cylinder is positioned so that a back-flow occurs therein during a part of the cycle.

Abstract: The invention relates to compositions which contain a chlorofluorinated ether and at least one solvent, and their use in thermal absorption apparatus for the generation of heat or cold.In the compositions according to the invention, the chlorofluorinated ether is 1-difluoromethoxy-1,1,2-trifluoro-2-chloroethane (enflurane: CF.sub.2 H-O-CF.sub.2 CHFCl) and the solvent is selected among aromatic esters and .omega.,.omega.'-dialkylated polyoxyethylene glycols.The present invention can be particularly applied in the heating and refrigeration areas using absorption systems such as, for example, heat pumps.

Abstract: An acquisition device for digitizing highly dynamic signals. After amplification in a fixed gain amplifier, the signals are applied to a sample and hold unit, the output of which is connected to an analog-to-digital converter to which a variable reference voltage is applied. This reference voltage is available at the output of a multiplexer to the inputs of which voltages are applied derived from sub-divisions of a calibrated voltage. The choice of the reference voltage is effected by a logic assembly as a function of the comparisons made by comparators between the sampled voltage and the derived voltages. The digitized signals are represented by a digital word from the converter and a digital word of gain G from the logic assembly.

Abstract: A centering device for an assembly, particularly for drilling, having at least one centering device relative to which the assembly rotates. A driving arrangement is provided for rotationally driving the centering device, with the driving arrangement including a friction clutch in the form of, for example, a disk clutch, cone clutch, or drum clutch.

Abstract: The present invention relates to a device and method for using a logging probe of small diameter with resect to a well in which it is to operate. The device of the invention is characterized in that it includes a widener for widening the diameter of said probe.

Abstract: Compositions of copolymers are disclosed containing 10 to 35% by weight of units derived from at least one vinylaromatic monomer, 5 to 15% by weight of units derived from at least one linear or branched alkyl methacrylate with 1 to 4 carbon atoms, 20 to 50% by weight of units derived from at least one linear alkyl methacrylate with 8 to 14 carbon atoms and 15 to 50% by weight of units derived from at least one linear alkyl methacrylate with 16 to 22 carbon atoms. The copolymer compositions have a weight average molecular weight of 100,000 to 400,000 and a polydispersity index in general of less than 5.They are prepared by any free-radical copolymerization method using for example azo or peroxide initiators.These compositions have the advantage of providing a better compromise between the characteristics required of a viscosity additive for lubricating oils.

Abstract: A hydrotreatment method, for example, hydroviscoreduction or hydrodesulfurization in which the charge of hydrocarbons is reacted with hydrogen in contact with a catalyst finely dispersed in the liquid phase. To separate the product from the catalyst, the effluent freed from its accompanying free gas is passed along, and in contact with the upstream wall of a porous inorganic membrane. The oil that has not been filtered contains a concentrate of catalyst and is recycled to the hydrotreatment reactor. The filtered oil constitutes the product of the method.

Abstract: The invention concerns a process for manufacturing a composition of fatty acid esters useful as gas oil substitute motor fuel, said composition containing at least one hydrated ethyl alcohol.The process comprises:(A) A first acid transesterification step in the presence of at least one aliphatic, linear or branched monoalcohol of 1 to 5 carbon atoms, consisting at least partly of hydrated ethyl alcohol containing 1 to 60% by weight of water, said step leading to the formation of a phase mainly containing ethyl esters after removal of the produced glycerol phase,(B) A second step wherein the initial free acidity or that formed during the first step in the phase containing the esters is decreased to a value at most equal to about 2%; and(C) A third step of basic transesterification of the phase resulting from step B, in the presence of at least one aliphatic, linear or branched monoalcohol of 1 to 5 carbon atoms, with the recovery of the so-formed ester composition.

Abstract: Process for manufacturing a mixture of methanol and higher alcohols by reacting carbon oxides with hydrogen in the presence of a catalyst containing simultaneously copper, cobalt, aluminum and at least one alkali or alkaline-earth metal A selected from lithium, sodium, potassium, rubidium, caesium, beryllium, magnesium, calcium, strontium and barium, in respective atomic ratios of Cu/Co=0.1-5, Al/co=0.7-4, A metals/Co=0.05-3.5, the proportion by weight of each metal to the total metals weight being respectively: copper: 10-65%, cobalt: 5-50%, aluminum: 5-40%, metal A: 0.1-15%, the homogeneity of the catalyst being such that the atomic ratio cobalt/aluminum does not vary by more than 15% with respect to its average value, on a scale of 5 nanometers.

Abstract: A device for generating sound pulses in a well by a mobile mass striking against a target element integral with an elongate body anchored in a well by retractable shoes actuated by hydraulic cylinders. The mobile mass which slides in a first chamber in the body is moved away by a piston moving in a second chamber of the body and intermittently locked in the moved away position by a valve. The piston, the valve and also the hydraulic cylinders acting on the anchorage shoes are actuated by a hydraulic system which may be remote controlled from the surface.

Abstract: A method for amplifying multiplexed signals including the steps of amplifying each signal in different amplifiers, each having different amplification gains, selecting the amplified signal of optimum amplitude and digitizing the selected amplified signal wherein the selection is operated by a previous measuring of the digitized value of the signal, without amplification, considered as a reference signal.

Abstract: Liquid and gas materials are reacted in the presence of a catalyst in a reactor of the dispersed bed type which comprises a plurality of superposed chambers through which the catalyst progressively drops, its rate of transfer from one chamber to another being controlled by injecting an auxiliary fluid into downcomers through which the catalyst is forced to pass.

Abstract: A method of preparing a yeast enriched in L-lysine and capable of excreting an organic acid, such as citric acid, and possibly also isocitric and glutamic acids, when cultivated on a hydrocarbon-containing medium comprises subjecting a yeast of the species Candida lipolytica to the action of a mutagenic agent, such as a chemical agent or radiation, cultivating the thus-treated yeast in a culture medium containing a lysine analogue, preferably that to which the original yeast is most sensitive, in a concentration which is about 50 to 100 times greater than that to which the cells of the original yeast are most sensitive, and cultivating the resultant mutated resistant yeast on a medium containing at least one hydrocarbon such as a C.sub.10 -C.sub.20 normal paraffin as well as conventional nutrients, the cultivation preferably being effected in an agitated aerated medium at a pH of 3 to 6 and a temperature of 25.degree. to 30.degree. C..