Abstract: Process for the production of synthesis gas, by means of catalytic partial oxidation or autothermal reforming of light hydrocarbons, which comprises partially oxidizing the hydrocarbon with oxygen coming from the reduction of at least one metal oxide selected from hexavalent chromium oxide, supported on an inert carrier and modified with an alkaline and/or earth-alkaline metal, and metal oxides capable of autonomously sustaining the catalytic partial oxidation reaction by means of redox cycles.

Abstract: Improved yield process for urea synthesis by starting from ammonia and carbon dioxide, comprising a reaction zone under high pressure and temperature conditions, a section wherein a portion of unreacted ammonia and carbon dioxide are stripped and recycled to the reactor, which section operates under substantially the same reactor pressure, and a subsequent section, operating under medium and/or low pressure conditions, for urea purification and simultaneous recovery of residual carbon dioxide and a portion of residual ammonia contained in the effluent stream from the stripping section, as an aqueous solution of ammonium carbamate, in which said aqueous ammonium carbamate solution is either totally or partially fed to said stripping section. Said process makes it possible a conversion of carbon dioxide into urea to be obtained in the reactor which is higher than 70%.

Abstract: Improved yield process for urea synthesis by starting from ammonia and carbon dioxide, comprising a reaction zone under high pressure and temperature conditions, a section wherein a portion of unreacted ammonia and carbon dioxide are stripped and recycled to the reactor, which section operates under substantially the same reactor pressure, and a subsequent section, operating under medium and/or low pressure conditions, for urea purification and simultaneous recovery of residual carbon dioxide and a portion of residual ammonia contained in the effluent stream from the stripping section, as an aqueous solution of ammonium carbamate, in which said aqueous ammonium carbamate solution is either totally or partially fed to said stripping section. Said process makes it possible a conversion of carbon dioxide into urea to be obtained in the reactor which is higher than 70%.

Abstract: The process claimed enables three separate streams to be obtained, from mixtures containing methanol, ethanol, n-propanol, isobutanol, water and other both low- and high-boiling compounds, of which one is anhydrous basically consisting of methanol and ethanol (I), one containing most of the n-propanol present in the mixture fed (II), together with small quantities of methanol, ethanol, isobutanol and water, and one containing most of the isobutanol and high-boiling compounds present in the above mixture (III), by the use of three rectifying columns, stream (I) being taken from a lateral point of the first column, stream (II) obtained from the head of the second column, stream (III) obtained from the bottom of the second column.

Abstract: A process for the synthesis of urea starting from ammonia and carbon dioxide, comprising a reaction step carried out in at least two distinct operating zones basically at the same pressure, but having a different operating temperature, the difference being preferably between 5.degree. and 60.degree. C., and subsequent separation steps of the non-converted reagents, wherein a gaseous stream is transferred from the first zone, at a higher temperature, to the second zone, at a lower temperature, and a liquid stream, containing urea and/or ammonium carbamate, is transferred from the second zone to the first, so that said gaseous stream is preferably at least 5% by weight with respect to the stream effluent from the first zone to the subsequent separation steps. This process allows a ratio urea/(urea+carbamate), in the stream leaving said reaction step, of more than 70%, to be obtained.

Abstract: From a mixture containing methanol, ethanol, n-propanol, isobutanol water and other high-boiling and low-boiling compounds, the claimed process enables three separate streams to be obtained, one an anhydrous stream of methanol or methanol and ethanol (I), one containing most of the n-propanol present in the feed mixture (II), and one containing most of the isobutanol present in the feed mixture (III), by using three fractionating columns.

Abstract: A cryogenic process for the removal of acidic gases from natural or synthetic gases comprising preliminary cooling of the gas to condense a portion of the acidic gases contained in the gas, and contacting the cooled gas with a mixture of one or more organic selective solvents such as low molecular weight esters, alcohols and ethers and one or more organic compounds such asheptane,fractions of natural gasoline containing hydrocarbons;monoaromatic compounds;dimethylethers of polyglycols having the glycolic unit CH.sub.2 --CH--O-- repeated three to five times;methoxy- and/or ethoxyalcohols, wherein the alcoholic group is a radical having from 3 to 4 carbon atoms in either linear or branched chain.

Abstract: A process is disclosed for the dehydration of a mixture of methanol and higher alcohols, containing 20 to 80% by weight of methanol, 1 to 60% by weight of at least a higher alcohol selected from those containing from 2 to 10 carbon atoms, 1 to 50% by weight of water and 0.

Abstract: A cryogenic process is disclosed for the selective removal of acidic gases from natural gases or from synthesis gases by adsorption in two towers and cooling of the gas outcoming from the first tower to the purpose of condensing a portion of CO.sub.2 contained in the same gas, which is characterized in that in it a mixture is used constituted by one or more selective solvents selected among low molecular weight esters, alcohols and ethers.

Abstract: Cryogenic process for the removal of acidic gases from natural gases or from synthesis gases essentially comprising the absorption in one or more towers in order to reduce the content of acidic gases, a cooling carried out, in the case of one single absorber tower, upstream the same tower, or, in case of two absorber towers, between the same towers, a regeneration of the solvent or of the solvents used in the absorption, the solvent or the solvents used being selected among low molecular weight esters, alcohols and ethers, characterized in that with the solvent or solvents the gas outcoming from one or more of the absorber towers is mixed once or more times, the mixtures thus formed being then cooled, the solvent being thus separated from the same gas.

Abstract: A process for removing acid gases from natural or synthesis gases by absorption, comprising the following stages:(a) cooling the natural or synthesis gas to be purified to condense part of the CO.sub.2 contained in said gas;(b) feeding the cooled and partly condensed gas to an absorption column in order to reduce the acid gas content to the required value;(c) regenerating the solvent or solvents used in the acid gas absorption, the solvent or solvents used being chosen from esters, alcohols and ethers of low molecular weight.

Abstract: A cryogenic process for removing acid gases from natural or synthesis gases, comprising the following stages:(a) feeding the natural or synthesis gas to a first absorption column in order to absorb the H.sub.2 S;(b) cooling the substantially H.sub.2 S-free gas to condense part of the CO.sub.2 contained in said gas;(c) feeding the cooled and partly condensed gas to a second absorption column in order to reduce the CO.sub.2 content to the required value;(d) regenerating the solvent or solvents used in the acid gas absorption, the solvent or solvents used being chosen from esters, alcohols or ethers, of low molecular weight.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method is disclosed for preparing carbonyl compounds from hydrocarbon streams coming from steam-cracking installations, the improvement consisting in that an alcohol is added to such a stream in a first reaction area and in the presence of an acidic ion-exchange resin the acidic centers of which have totally been exchanged with mercuric ions and with ions of alkali metals or alkaline earth metals, the resultant product being rectified to separate it from the hydrocarbon stream and then hydrolyzed in a second reaction area in the presence of an acidic ion-exchange resin and finally recovered by rectification.

Abstract: The present invention provides a novel process for the separation of acetylenic compounds from saturated, olefinic and dienic hydrocarbons by etherifying the acetylenic compounds with an acyl compound in the presence of an acid ion - exchange resin containing mercuric ions.

Abstract: A method is disclosed for removing the small fractions of acetylenic compounds from a mixed hydrocarbon stream, the improvement consisting in that said stream is treated with an organic acid in the presence of an acidic ion-exchange resin, preferably an --SO.sub.3 H containing resin, the acidic groups of said resin having totally been exchanged with alkali metal ions or alkaline earth metal ions. Acetic acid (glacial, anhydrous) is the preferred acid.

Abstract: The present invention provides a novel process for the separation of acetylenic compounds from saturated, olefinic and dienic hydrocarbons by etherifying the acetylenic compounds with an alcohol or a glycol in the presence of an acid ion-exchange resin containing mercuric ions.

Abstract: 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.