Snamprogetti S.p.a.

Alessandro Ginnasi

Carlo Rescalli

Luigi Gazzi

Alessandro Vetere

Giancarlo Cotone

Gianfraco Soldati

Pierantonio Martera

Giovanni Passoni

Maria A Scaramucci

Gianfranco Soldati

There is disclosed a process for selectively separating hydrogen sulfide from gaseous mixtures which also contain carbon dioxide by chemical absorption with a substantially anhydrous solution of a tertiary amine, such as methyl diethanolamine, and an auxiliary organic solvent, such as sulfolane.

Process of selective separation of hydrogen sulfide from gaseous

A process is described for stripping acidic gases, mainly hydrogen sulphide and carbon dioxide, from natural gas or synthesis gas, especially when the percentages of such acidic gases are high and the conventional processes become economically objectionable. The process is based on the use of a number of selective solvents, generally belonging to the class of esters, ethers, mixed ester-ethers and lactones, in combination with sequential absorbing cycles which start from the stripping of hydrogen sulphide, and comprise the regeneration of the solvents used by several expansion cycles: H.sub.2 S and CO.sub.2 are recovered and the regenerated solvents recycled.

Cryogenic process for fractionally removing acidic gases from gas

Low temperature treatments are combined with solvent treatments using particularly selective solvents for stripping acidic gases such as carbon dioxide and hydrogen sulphide from natural gas or from synthetic gases. The preferred solvents are a wide range of compounds having an esteric or an etheric function in their molecule, but there are also examples of compounds which have the two functions simultaneously. The stripping process is comparatively simple, is efficient, especially for high contents of acidic gases in the raw gas streams, and is economically acceptable.

Cryogenic process for removing acidic gases from gas mixtures

The present invention is directed to a process for the separation of butadiene from a stream-cracked C.sub.4 hydrocarbon stream by a sequential etherification of isobutylene and the acetylenic compounds that is followed by a distillation step.

Process for separating butadiene from C.sub.4 hydrocarbons streams

Dimethyl carbonate is separated from a mixture thereof with methyl alcohol and water through an extractive distillation process wherein water is utilized as the solvent.

Extractive distillation of a dimethyl carbonate feed with water

Styrene of exceptional purity is separated from a mixture of hydrocarbons including it, xylenes, saturated and olefinic hydrocarbons and ethyl benzene by means of a two-step extractive distillation process through the use of a high boiling polar solvent such as N-formyl morpholine in admixture with an amount of water in the range of from 1% to 30% by weight.

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San Donato Milanese, Italy

Alessandro Ginnasi