Eniricerche S.p.a.

Snamprogetti

Enichem Sintesi S.p.a.

Agip S.p.a. - Snam S.p.a.

Luigi Rivola

Bruno Notari

Sebastiano Di Liberto

Franco Rivetti

Ugo Romano

Arnaldo Roggero

Franco Mizia

Giuseppe Civardi

Alberto Gandini

Margherita Corbellini

Agostino Balducci

Marco Cesari

Yean Demertzis

Viviana De Malde

Lucio Di Biase

Giacomo Capitelli

Vittorio Mormino

A method for monitoring the state of, and for locating any detachment of, the protective covering of immersed or buried pipelines or other metal structures subjected to cathodic protection with constant current, on the basis of the overall electrical resistance offered by the pipeline/covering/ground system, consisting of applying local sinusoidal wave excitation currents of different frequencies to the pipeline and measuring the corresponding voltage responses, then comparing the measured responses of the system to determine, on the basis of response differences or coincidences at the various frequencies, whether within the portion under consideration there is detachment with corrosion underway or whether there is simple covering decay.

Device and method for monitoring and locating defects in, and detachment

Compounds of general formula ##STR1## wherein: R is a linear or branched C.sub.1 -C.sub.20 alkyl radical, m is either 0 or 1; n has a value of from 1 to 10, are corrosion inhibitors, suitable for inhibiting the general corrosion and the stress brittlening caused by hydrogen sulfide (SSC), in an acidic environment, in the presence, or absence of carbon dioxide, of medium-and high-strength manganese steels and low-alloy steels, commonly used in petrochemical facilities and in bore drilling, transport and processing systems for natural gas or petroleum.

Inhibition of steel corrosion

A method for monitoring the soundness of the protective covering on underground metal structures subjected to cathodic protection, based on the electrical resistance offered by said covering, and consisting of modulating the imposed cathodic protection current and measuring the corresponding variation in potential due to the ohmic drop, said resistance being obtained from the ratio of the variation in potential to the modulation current.

Method for continuously monitoring the soundness of the protective

A method for monitoring damage to the protective covering of immersed or underground metal structures subjected to cathodic protection, based on the electrical resistance offered by said covering, and consisting of modulating the cathodic protection feed current and measuring the corresponding potential variation due to the ohmic loss, said resistance being obtained from the ratio of potential variation to modulation current, to activate an alarm system on sudden fall and rise in ohmic resistance due to accidental events.

Device and method for real-time monitoring of accidental damage to the

A method is disclosed for the inhibition of general corrosion, and of stress corrosion by hydrogen sulfide in manganese and low-alloy, medium-strength and high strength steels, obtained by means of the use of compounds of formula:

Inhibitors of corrosion in high-strength and medium-strength steels

A composition of matter for inhibition of stress corrosion stainless steels in contact with aqueous and/or polar organic solutions which contain chloride ions and optionally cuprous ions, comprising an aqueous or polar organic solution of a member selected from the group consisting of quaternary ammonium alkylcarbonates and quaternary ammonium benzylcarbonates having the general formula: ##STR1##

Stainless steels stress corrosion inhibitors

A composition of matter for inhibition of stress corrosion of stainless steels in contact with aqueous and/or polar organic solutions which contain chloride ions and optionally cuprous ions, comprising an aqueous or polar organic solution of a member selected from the group consisting of quaternary ammonium alkylcarbonates and quaternary ammonium benzylcarbonates having the general formula: ##STR1##

Process for the purification of olefins by removing oxygen and acetylene from them which comprises passing the olefins over a contact material consisting essentially of a metallic element from the first B group of the period system which element is homogeneously and finely dispersed on a carrier selected from zeolites, spheroidal alumina, silica gel, Kieselghur or colloidal silica stabilized in an aqueous suspension. The purification process is carried out at temperatures of from -50 to 50.degree. C. under pressures of from 0.01 to 60 atmospheres. The contact material is prepared by mixing a suitable compound of the metallic element such as a carbonate or ammonia complex with the selected carrier, thereafter atomizing the mixture to obtain microspheroids, granulating the spheroids into the desired shape and size and finally subjecting the carrier material to a reducing treatment to obtain the metallic element thereon. The contact material for the purification preferably utilizes the element copper with the contact material having the size of 1-250.mu. and is most suitably used in the purification of ethylene.

Preparation of copper and silver particles for ethylene purification

Aluminum chlorohydroxide represented by the formula Al.sub.2 (OH).sub.x Cl.sub.y in which x and y range from 1 to 4 and 5 to 2, respectively, is produced by reacting hydrochloric acid with an amount of aluminum oxide or hydroxide which is equal to or slightly greater than the stoichiometric amount for obtaining aluminum trichloride, in the temperature range of from 160.degree. to 270.degree. C, and in the pressure range of from 0.1 to 50 kg/cm.sup.2.

Process for the production of aluminum chlorohydroxides

A process is described whereby aluminum chlorohydroxide having a controlled chlorine content is prepared by subjecting a mineral containing aluminum oxide or hydroxide (e.g. bayerite, gibbsite, diaspore, boehmite or alumina bayer) is subjected to a preliminary etching with hydrochloric acid at a temperature in the range from 110.degree. to 150.degree. C, the solution so obtained is neutralized with ammonia and the desired aluminum chlorohydroxide (e.g. Al.sub.2 (OH).sub.5 Cl) is crystallized out.

Process for the production of aluminum chlorohydroxides having a

An ammonium organic salt is recovered from an aqueous solution in which it is contained at a concentration in the range from 0.2% to the salt solubility limit by atomizing the solution in hot air at a temperature in the range of 100.degree. to 150.degree.C.

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San Donato Milanese, Italy

Luigi Rivola