Enichem Synthesis S.p.a

Enichem S.p.a

Versalis S.p.a.

Polimeri Europa S.p.a.

Maurizio Ghirardini

Franco Rivetti

Gianni Donati

Laura De Nardo

Ugo Romano

Marcello Notari

Sergio Francantonio Lombardini

Giancarlo Paret

Guido Garone

Elena Novello

A process for producing a high-purity dimethyl carbonate, which includes: (I) cooling a commercial grade dimethyl carbonate containing 1 ppm or more of chlorine to a temperature from +6&#xb0; C. to &#x2212;5&#xb0; C. at a rate from 0.5-2&#xb0; C./hour, to obtain a first solid dimethyl carbonate; (II) heating the first solid dimethyl carbonate to a temperature from &#x2212;5&#xb0; C. to +6&#xb0; C. at a rate of 1-5&#xb0; C./hour, to obtain a mixture comprising a second solid dimethyl carbonate and a predetermined amount of a first liquid dimethyl carbonate; (III) separating the first liquid dimethyl carbonate from the mixture, to obtain the second solid dimethyl carbonate; (IV) heating the second solid dimethyl carbonate to a temperature from 20&#xb0; C. to 40&#xb0; C., to obtain a second liquid dimethyl carbonate, wherein the second liquid dimethyl carbonate has a purity degree higher than 99.99% and a chlorine content lower than or equal to 1 ppm.

Process for the production of high-purity dimethyl carbonate

The invention relates to an enhanced process for the recycling of expanded polystyrene. Said process essentially comprises the reduction in volume of expanded polystyrene by means of dissolution in a solvent, separation of the insoluble components, selective precipitation of the polystyrene with an anti-solvent, separation, drying and extrusion of the precipitated polystyrene, recovery by distillation and recycling of the solvent. The process is characterized in that the anti-solvent is a butanol selected form n-butanol, iso-butanol or sec-butanol and the solvent is dimethyl carbonate, alone or in a mixture containing up to 25% by weight of butanol.

Process for the recycling of expanded polystyrene

The reaction between methanol, carbon monoxide and oxygen for preparing dimethyl carbonate, in the presence of cuprous chloride as the catalyst, is carried out in a special reactor constituted by two parallel, vertical tubes, at the base of one of which the fresh gas and the recycle gas are fed; the reaction products are separated by partially condensing the recirculate vapors.

Process for producing dimethyl carbonate and apparatus suitable for such

A method is described enabling HCl and possible entrained CuCl particulate to be removed from a gas-vapor stream leaving a dimethylcarbonate synthesis reactor. The contaminant removal is effected by one of the process fluids used in a small quantity.

Method for removing acid and saline contaminants from a gaseous stream

Process for the preparation of dimethylcarbonate which consists in feeding oxygen and a mixture of methanol and carbon monoxide to the reactor, with a molar ratio methanol/carbon monoxide of between 1 and 2, this mixture coming directly from the non catalytic direct oxidation of methane with oxygen characterized in that the above molar ratio between methanol and carbon monoxide, with fixed temperature and pressure values, is obtained by maintaining the ratio between methane and oxygen between 1 and 100, by injections of fresh oxygen into a tubular reactor, during the above oxidation reaction.

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Milan, Italy

Maurizio Ghirardini