Abstract: The invention concerns a rejuvenation process for a solid catalyst for the alkylation of at least one isoparaffin by at least one olefin. The process is characterised in that the catalyst is rejuvenated in the reaction zone by circulating an isoparaffin-rich liquid fraction over the bed, said fraction originating from a zone for separating the reaction effluent extracted from the reaction zone.

Abstract: The invention concerns a catalyst comprising:(a) a carrier containing at least 20% by weight of a fluorinated bridged clay of the smectite group,(b) an amorphous matrix containing at least 10% by weight of alumina, and(c) at least one group VIII metal or metal compound or an association of at least one group VI B metal or metal compound with at least one metal or compound of a metal selected from group VIII non-noble metal. The metals amount, calculated as oxide(s), in proportion to the final catalyst weight, is from 0.01 to 5% for the group VIII noble metals, from 0.01 to 20% for group VIII non-noble metals and from 5 to 40% for the association of group VI B metals with group VII non-noble metals.The carrier amount is such that the florinated bridged clay content of the final catalyst is at least 12% by weight; the matrix amount forms the complement to 100% by weight of the catalyst.

Abstract: A hollow flexible tubular body which comprises at least one tubular layer. The layer is formed by adjacent helical windings having hooked edges and substantially flat sections. The turns of the helix do not show any spontaneous tendency to increase in diameter.

Abstract: An electrode E.sub.1 having the design function of an ion source is placed in a gas stream and emits by corona discharge effect ions which are collected on two electrodes E.sub.2 and E.sub.3. These electrodes consist of grids placed at right angles to the direction of the gas stream on each side of the electrode E.sub.1 at approximately equal distances from this latter. The device comprises electronic means for amplifying the currents collected at the electrodes E.sub.2 and E.sub.3 as well as for calculating the difference and the sum of the currents collected at the electrodes after amplification.

Abstract: New catalyst, particularly suitable for dehydrogenating saturated hydrocarbons, which contains alumina, at least one metal selected from molybdenum, tungsten and rhenium and at least one metal selected from gallium, indium, thallium, germanium, tin, lead, antimony and bismuth, said catalyst having a specific surface from 20 to 150 m.sup.2 /g and a neutralization heat by ammonia absorption at 320.degree.C under 300 mm Hg lower than 10 calories per gram.

Abstract: A sulfur dioxide containing gas is purified by successive contact with an ammonia solution and then a dilute ammonium sulfite solution; the latter solution is regenerated by electrodialysis while the ammonia solution, after SO.sub.2 absorption, is vaporized in order to recover ammonia and sulfur dioxide.

Abstract: A solution of sodium sulfite or sulfide is reacted with ammonium sulfate, so as to produce a gas containing SO.sub.2 or H.sub.2 S, NH.sub.3 and H.sub.2 O, which is thereafter treated for sulfur production and NH.sub.3 recovery, and a liquid outflow containing sodium sulfate which is reacted with CO.sub.2 and NH.sub.3, in order to produce NaHCO.sub.3 and regenerate the ammonium sulfate. NaHCO.sub.3 may be converted to sodium carbonate and CO.sub.2, the latter being re-used in the process.

Abstract: Process for hydrodealkylating an alkylaromatic hydrocarbon charge at a temperature from 400.degree. to 650.degree.C under a pressure from 1 to 30 kg/cm.sup.2 at a space velocity from 1 to 10 by reacting said charge with hydrogen in a molar proportion with respect to the effluent of the reactor in the range from 1 to 10, in the presence of a catalyst containing alumina and at least one metal selected from ruthenium, osmium, palladium, rhodium, iridium, platinum and manganese in an amount from 0.05 to 5 % of the catalyst, said catalyst having a specific surface from 1 to 100 m.sup.2 /g., a total pore volume of 0.2-0.8 g/cc and a heat of neutralization lower than 10 calories per gram are measured by ammonia adsorption at 320.degree. C. under 300 mm Hg.

Abstract: This device comprises in combination means for passive compensation of the alternating movements of the installation, comprising at least one articulated jack connected to a source of pressurized fluid, and complementary means for fine compensation, these complementary means activating the passive compensating means in response to the variation of a parameter which characterizes the movements of the installation.

Abstract: The present invention relates to an apparatus or device for storing elongated flexible elements, such as drilling pipe, in a coiled form. This apparatus includes an inner cylindrical framework supported about a vertical axis, an outer cylindrical framework concentrically separated from the inner framework and connected thereto by an annular base plate closing the bottom of the apparatus. The space between the inner and outer frameworks is open at the top to receive the elongated elements, and the annular base plate is formed of a plurality of annular sector elements connected together in such a manner as to allow a vertical displacement of respective adjacent elements with respect to one another. Various means for connecting adjacent elements are provided. Moreover, various driving and supporting members are provided for rotating the apparatus about the vertical axis.

Abstract: This apparatus comprises a main jack for supporting elements from the installation and a regulating device which includes at least one pivoting jack and makes use of a source of pressurized fluid in communication with a chamber of variable volume in which the pressure of the fluid varies in inverse proportion with respect to the volume of the chamber. The main jack and the regulating device are connected in parallel to the source of pressurized fluid and the regulating device supplies a pressurized auxiliary fluid to means for adjusting the force exerted by the main jack.

Abstract: Organic compounds of the formula:[(H.sub.3.sub.-n X.sub.n)C -- CO.sub.2 M (CO).sub.m (R).sub.p (L).sub.q ].sub.rIn which X is a halogen atom, at least one X being fluorine, M is molybdenum or tungsten, R is a hydride ion or a hydrocarbon group, L is a Lewis base and m, n, p, q and r are integers, are manufactured from fluoracetic esters and molybdenum or tungsten carbonyl compounds, They are useful as catalysts for polymerizing or co-polymerising unsaturated compounds such as butadiene.

Abstract: A process for the preparation of a stable diploid of Candida lipolytica which comprises (a) in a first stage, separately cultivating two haploid strains of Candida lipolytica of opposed sign in a medium rich in assimilable carbon nutrient; (b) in a second stage, cultivating the two resultant strains together in a medium poor in assimilable carbon nutrient; and (c) in a third stage, after the appearance of diploid colonies, treating them with a mutagenic agent to stabilize them. The invention also comprises a process for the preparation of .alpha.-ketoglutaric acid which comprises cultivating a diploid strain obtained by crossing two Candida lipolytica haploid strains of opposite sign in a medium containing, as source of assimilable carbon, at least one hydrocarbon.