Casale Chemicals Sa

Casale Sa

Floriall Holdings Limited

Other

Oronzio Denora Impianti Elettrochimici S.p.a.

Urea Casale Sa

Snia Viscosa Societa Nazionale Industria Applicazioni Viscosa S.p.a.

Panclor S.a.

Fondazione Denora

Metkon S.a.

Giancarlo Sioli

Luigi Giuffre

Placido M Spaziante

Placido Spaziante

Giancarlo Matera

Mirco Fornaroli

Franco Righi

Aldo Castoldi

Giacomo Cavuoti

The present invention concerns process for obtaining melamine at high purity characterized by comprising the steps of:&#x2014;quenching a melamine melt, deprived of off-gases of the melamine synthesis and containing melamine impurities such as ammeline, ammelide and polycondensates, with an aqueous solution comprising ammonia under conditions such to substantially convert polycondensates into melamine, obtaining a melamine solution substantially free of polycondensates, recovering melamine from said melamine solution by melamine crystallization, obtaining melamine crystals and a melamine crystallization mother liquor,&#x2014;treating said crystallization melamine mother liquor under conditions such to convert at least a portion of its ammeline content into ammelide and melammine, obtaining a treated mother liquid having at least a reduced ammeline content. The invention also concerns a high-pressure non-catalytic plant for the production of high-purity melamine implementing the above process and apparatuses suitable to be used in this plant.

Process for the production of high purity melamine from urea

A process for high-pressure, liquid phase conversion of urea into melamine is disclosed, where molten urea is fed to a first reaction zone (S) where the melamine melt is under mechanical agitation, and a heat input (Q) is provided to maintain the endothermic reaction, and the liquid is then passed to a second reaction zone (S) kept at a lower temperature and where further agitation is provided. Embodiments of plants adapted to carry out the process are also disclosed, including multiple stirred reactors in cascade and a single reactor with multiple internal compartments defining said first and second reaction zones.

Process for producing high-quality melamine from urea

An electrolyser () comprising an electrolysis cell stack () inside a pressure vessel (), wherein the first terminal end plate () of the cell stack is integral with one a closed ends of the pressure vessel, thus forming a stationary head () of the cell stack equipped with the fluid and electric connections, and the second terminal end plate () of the cell stack is inside the vessel and is free to move in a longitudinal direction in response to thermal expansion or contraction, thus forming a floating head () of the stack. The pressure vessel () is preferably pressurized using a gaseous product obtained in the process of electrolysis.

High pressure electrolyser

A method for formaldehyde production through catalytic oxidation of methanol, comprising the steps of feeding to a first oxidation catalytic bed () a gas flow comprising methanol and oxygen at a predetermined crossing linear flow rate, obtaining at the outlet of said first catalytic bed () a flow of gaseous reaction products comprising unreacted methanol, and feeding the flow of gaseous products to a second oxidation catalytic bed () is distinguished by the fact that the flow of gaseous reaction products comprising unreacted methanol is fed to the second catalytic bed () with a crossing linear flow rate substantially equal to said predetermined first catalytic bed () feeding flow rate.

Method for the production of formaldehyde

A structural component for electrolytic cells of an electrochemical reactor of the filter-press type, comprising a frame () supporting its corresponding functional element (), a bipolar sheet or a diaphragm, respectively.

Structure for an electrochemical reactor of the filter-press type

A method of storage and redistribution of electrical energy comprising the steps of: producing hydrogen and oxygen through water electrolysis in an electrolyzer () operating under pressure; collecting the hydrogen and oxygen so obtained in respective pressurized tanks (); reconverting into water and electrical energy hydrogen and oxygen, through an electrochemical reaction of the latter in a fuel cell () fed from the tanks (), distinguishes itself by the fact that in the electrolyzer () and in the fuel cell () a same liquid phase is used and by the fact that the water produced in the fuel cell () by the hydrogen and oxygen reconversion step, is collected in the respective liquid phase and transferred together with the liquid phase to the electrolyzer () in order to undergo electrolysis.

Method and apparatus for the storage and redistribution of electrical energy

A Kit of modular components for the manufacture of an electrochemical reactor () of the so-called filter-press type having a substantially tubular body (), closed at the opposite ends by end plates () and in which is defined a sequence of electrolyte cells () in fluid with pipes (to) extended in said body (), in a direction parallel to its axis (AA), for the collection and distribution of process fluids, distinguishes itself in that it comprises: a plurality of electrochemically functional flat elements () selected from bipolar elements and separation elements, a plurality of frames (), all identical to each other, realized with an electrically non-conducting material and structured to enclose and support inside them, in a per se known way, respective pre-selected electrochemically functional flat elements (), each of the frames () being equipped with an equal plurality of through-holes () parallel to the axis of the respective frame () and equally angularly arranged between consecutive frames, each through-hole () being in fluid communication with the inside of the frame () through at least one passage (to) extended in the respective frame () in a substantially radial direction; a plurality of cylindrical bush inserts (), obtained with an electrically non-conducting material, capable of being coaxially engaged in each of the through-holes () in a pressurized fluid-tight arrangement, to hermetically close such at least one fluid communication passage (to) between the hole and the inside of the respective frame ().

Filter-press type electrochemical reactor with bush inserts

Process and reactor for heterogeneous exothermic synthesis of

Process for heterogeneous exothermic synthesis of formaldehyde

Apparatus for the electrolysis of solutions. The apparatus comprises bipolar elements formed of a conductive plate peripherally surrounded by an insulating frame provided with feeding and discharging channels along peripheral zones of the frame. A cavity is formed with the conductive plate as the bottom and the frame as wall. Separating elements can be inserted between the bipolar elements. The separating elements consist of a porous diaphragm and an insulating frame also having feeding and discharging channels. Electrodic structures, consisting of cut and expanded metal sheets, nets or other material having high internal porosity may fill up the remaining space between two lateral bipolar elements and a central separating element.

Apparatus for the electrolysis of solutions

A novel process for the preparation of alkyl isocyanates comprising reacting COX.sub.2 and an alkyl amine hydrohalide of the formula

Preparation of alkyl isocyanates

A horizontal diaphragmless bipolar electrolyzer comprising a horizontal housing made of electrically insulated material, an anodic or (cathodic) plate at one end of the housing provided with a plurality of blade shaped electrodes vertically arranged along the housing axis, a cathodic (or anodic) plate at the opposite end of the housing provided with a plurality of blade shaped electrodes vertically arranged along the housing axis, at least one bipolar electrode element with blade shaped anodes and cathodes vertically arranged on opposite sides thereof on the housing axis to interleaf with the electrodes of the next unit, means for introducing fresh electrolyte at one end of the housing, means for removing treated electrolyte at the opposite end, a space above the electrode assembly for gas disengagement and removal, a space below the electrode assembly for solid particles collection and means for impressing an electrolysis current thereon.

Novel horizontal diaphragmless electrolyzer

Production of monochloroacetic acid with a minimum of polychlorinated derivatives in a two stage process by reaction of acetic anhydride and hydrogen chloride at a low temperature to produce a solution of acetyl chloride in acetic acid and chlorinating the said solution at a higher temperature which may be effected in a continuous manner.

Growing community of inventors

Cernobbio, Italy

Giancarlo Sioli