Abstract: A method of determining or predicting a value P.sub.x of a property of a feed X to a steam cracking process or yield of said process, which method comprises measuring the absorption D.sub.ix of said material at more than one wavelength in the region 600-2600 nm, comparing signals indicative of said adsorptions or a mathematical function thereof with signals indicative of absorptions D.sub.im or mathematical function thereof at the same wavelength for a number of standards S in a bank for which the said property or yield P is known, and choosing from the bank at least one standard S.sub.m with property P.sub.m said standard having the smallest average value of the absolute difference at each wavelength i between the signal for the material and the signal for the standard S.sub.m to obtain P.sub.x, with averaging of said properties or yields P.sub.m when more than one standard S.sub.m is chosen. If desired the method can be used as such to control the steam cracking process by comparison of P.sub.

Abstract: The technical field of the invention is that of manufacturing heat treatment apparatuses such as furnaces for thermally cracking chemical substances, in particular hydrocarbons.

Abstract: An apparatus for on-line measuring physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio, comprising means for providing (N)IR radiation in a predetermined spectral range; means for transmitting light at selected wavelengths in the (N)IR spectral region; means for delivering light from said transmitting means to a hydrocarbon product line; means for allowing an optical path length in the hydrocarbon product line; means for detecting the light transmitted through the said optical path; means for providing the obtained signal to be input to processing equipment for spectral analysis and correlating the spectral data to the physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio.

Abstract: The present invention relates to a method of manufacturing one or more chemical products in which a chemical reaction is performed by causing one or more reagents to flow along the inside of a tube disposed in a radiation zone of a furnace. In the method, at least a portion of the tube is caused to vibrate so as to limit the deposition of reaction by-products on the inside wall of the tube. More particularly, the tube can be vibrated at a frequency lying in the range 50 Hz to 2000 Hz. The invention also provides apparatus for performing the method of the invention, which apparatus comprises a furnace including a radiation thermal enclosure through which at least one tube passes, which tube is provided with at least one excitation means suitable for generating tube vibration.

Abstract: The technical field of the invention is the field of methods and apparatus for thermally cracking chemicals. The present invention provides a method and apparatus for measuring the vibration of a duct in which there flows at least one fluid and which is disposed inside a thermal enclosure at high temperature, wherein a vibration sensor is used that is located inside the enclosure.

Abstract: The present invention relates to a method of manufacturing one or more chemical products in which a chemical reaction is performed by causing one or more reagents to flow along the inside of a tube disposed in a radiation zone of a furnace. In the method, at least a portion of the tube is caused to vibrate so as to limit the deposition of reaction by-products on the inside wall of the tube. More particularly, the tube can be vibrated at a frequency lying in the range 50 Hz to 2000 Hz. The invention also provides apparatus for performing the method of the invention, which apparatus comprises a furnace including a radiation thermal enclosure through which at least one tube passes, which tube is provided with at least one excitation means suitable for generating tube vibration.

Abstract: Apparatus for the cracking of hydrocarbons in the presence of steam for the production of olefins and diolefins which includes a thermal radiation enclosure enclosing at least one cracking tube having an inlet to which the hydrocarbons and steam are supplied and having an outlet for the cracking products. The internal diameter of the tube diminishes continuously or discontinuously from the inlet to the outlet and the ratio between the internal diameters of the tube at the inlet and the outlet is between 1.2 and 3. The ratio of the length of the tube within the enclosure to the mean internal diameter of the tube is between 200 and 600. Heat is supplied to the tube by burners within the enclosure so that the thermal power applied along the length of the tube increases in the direction from the inlet to the outlet and so that the ratio between the thermal power applied to the half of the tube extending from the inlet to the thermal power applied to the remaining half of the tube is between 40/60 and 15/85.

Abstract: The present invention relates to a process for the preparation of olefins by the cracking of hydrocarbons consisting in passing a mixture of hydrocarbons and steam flowing in a cracking tube disposed inside a radiation zone of a furnace. The process is characterized in that an increase of the cracking temperature of the mixture between the inlet and the outlet of the radiation zone is associated to a non-homogeneous distribution of the thermal power of the furnace, greater at the beginning of the cracking tube than at the end, and to a reaction volume which is greater in the second half of the length tube than in the first one. The present invention relates also to a cracking furnace in which between the inlet and the outlet of the radiation zone the diameter of the cracking tube increases and the thermal power of the burners used to heat the cracking tube decreases.

Abstract: The present invention relates to a process for the preparation of olefins by the cracking of hydrocarbons consisting in passing a mixture of hydrocarbons and steam flowing in a cracking tube disposed inside a radiation zone of a furnace. The process is characterized in that an increase of the cracking temperature of the mixture between the inlet and the outlet of the radiation zone is associated to a non-homogeneous distribution of the thermal power of the furnace, greater at the beginning of the cracking tube than at the end, and to a reaction volume which is greater in the second half of the length tube than in the first one.The present invention relates also to a cracking furnace in which between the inlet and the outlet of the radiation zone the diameter of the cracking tube increases and the thermal power of the heating means decreases.

Abstract: The invention concerns a process for the production of copolymers of propylene and but-1-ene which can be used for the production of hollow bodies or heat-sealable films and wherein the proportion by weight of units derived from but-1-ene is from 10 to 40% and wherein the proportion of isolated ethyl branches is at least equal to the square of the proportion of units derived from propylene contained in said polymers. The process is characterized in that a gaseous mixture of propylene and but-1-ene is brought into contact, in the absence of liquid diluent, with a catalytic system which is stereospecific in the polymerization of propylene alone.

Abstract: The invention concerns a process for the production of polyolefins with a wide range of distribution in respect of molecular masses.The process comprises polymerizing ethylene, which is optionally accompanied by one or more other olefins, in contact with a catalytic system comprising:(a) a catalyst comprising a solid compound of titanium, magnesium and a halogen such as chlorine or bormine(b) one or more organometallic compounds of a metal of groups II and III of the periodic table of elements(c) one or more halogenated ethylenic hydrocarbons.The resulting polyolefins are particularly suitable for being shaped by means of extrusion-blowing.

Abstract: PCT No. PCT/FR78/00008 Sec. 371 Date Mar. 22, 1979 Sec. 102(e) Date Mar. 22, 1979 PCT Filed July 10, 1978The invention concerns a process for preventing the formation of deposits on the walls of the heating or cooling circuits of heat exchangers in which an aqueous heat-exchange liquid circulates.This process comprises mixing with the heat-exchange liquids from about 0.3 to about 5% by weight of a product of polyaddition of ethylene oxide and propylene oxide on a monohydric alcohol, water, a diol or a triol, the ethylene oxide representing from 60% to 90% by weight of the fixed alkylene oxides.This process can be used in particular in internal combustion engine cooling circuits.

Abstract: A process for producing titanium-trichloride based catalyst comprising reducing titanium tetrachloride in excess with an organo-aluminum compound in the presence of 2 to 5 mols per mol of organo-aluminum of one or more aliphatic ethers having the formula R'--O--R" in which R' and R" are alkyl groups containing 1 to 5 carbon atoms and maturing the formed precipitate at a temperature within the range of 80.degree.-115.degree. C., said catalyst being useful with an organo-metallic co-catalyst in the polymerization of olefins.

Abstract: A catalyst for use in the polymerization of olefins and a process for its manufacture wherein an excess titanium tetrachloride is reduced by an organoaluminum reducing agent, with the ratio of moles of titanium tetrachloride to the number of gram equivalents of the organoaluminum compound being at least 1.8. The catalyst is prepared in the presence of an aliphatic ether to produce titanium trichloride having regularly-shaped granules and improved catalytic properties suitable for use with an organoaluminum co-catalyst in the polymerization of olefins.

Abstract: Process and apparatus for assembling tubular components of metal or thermoplastic material by frictional welding in which use is made of a short tubular connecting cuff placed between the end surfaces to be assembled of the two tubular members held in alignment with said cuff and which is rotated about an axis perpendicular to the surfaces to be welded while regulating the position of the cuff along the axis until uniform softening by friction is obtained of the contacting surfaces, the rotation of the cuff is then stopped while maintaining a pressure on the tubes until the weld is consolidated upon cooling.The apparatus is characterized by the fact that thrusts independent of one another are exerted between the cuffs and tubes so as to produce pressure contact between the two ends of the cuffs and corresponding ends of the tubes.

Abstract: The dry polymerization of olefins to produce polymers having a molecular weight above 50,000 in the presence of a catalyst system formed of a compound of a transition metal and a co-catalyst of an organo-metallic compound of a metal of Groups II or III of the periodic table, in which the polymerization reaction is carried out in a series of reaction vessels wherein the formed polymer is transferred from one to the other and in which additional co-catalyst is added to reaction vessels beyond the first, the gaseous effluent from each reaction vessel is recycled back to the reaction vessel and in which the co-catalyst is introduced into the first reaction vessel in an amount such that the atomic ratio of the metal of the co-catalyst to the transition metal is within the range of 0.1 to 10, and in which the co-catalyst is introduced into vessels other than the first in an amount such that the atomic ratio of metal of the co-catalyst to the transition metal is within the range of 0.1 to 20.

Abstract: A method for the polymerization of olefins using a catalyst in the form of a solid compound of a transition metal in which the transition metal is at least partially reduced to a valency state lower than the maximum valency state, with the transition metal compound being subjected prior to use to pre-activation by contact with magnesium and one or more halogenated hydrocarbons and one or more organo-metallic compounds of Groups II and III.

Abstract: The polymerization of olefins to form polymers having a molecular weight greater than 50,000 wherein the polymerization is carried out in the presence of a catalyst component formed of a compound of a transition metal of the sub-groups IVa, Va and VIa, and a co-catalyst component of at least one organo-metallic compound of a metal from groups II and III of the periodic table, in which the co-catalyst is in the form of a liquid which is separately introduced into the reaction vessel on a carrier formed of an inert porous powder which is impregnated with the co-catalyst.

Abstract: The method of polymerizing olefins which includes the preparation of a pre-activated compound of a transition metal of IVa, Va and VIa of the periodic table of elements, in which the transition metal is at least partially in a reduced valency state, in which the pre-activation is carried out by contacting the transition metal compound with an organomagnesium compound and then polymerizing the olefins in the presence of the pre-activated transition metal compound and an organo-aluminum compound.

Abstract: A method for producing solid polymers having a molecular weight greater than 50,000 from olefins wherein the olefin is polymerized in the absence of a liquid dispersion agent of a nature different from that of the olefin to be polymerized, and in contact with a prepolymer containing a small amount of transition metal of subgroups IV-b, V-b and VI-b having been produced by the polymerization of an olefin in a dispersion liquid containing a Ziegler-type catalyst.