Abstract: The present invention relates to a method for preparing dimethyl disulphide, in batches or continuously, preferably continuously, said method including at least the following steps: a) reacting at least one hydrocarbon feedstock in the presence of hydrogen sulphide (H2S) and optionally sulphur (S) such as to form carbon disulphide (CS2) and hydrogen (H2); b) reacting said carbon disulphide (CS2) by hydrogenation in the presence of said hydrogen (H2) obtained in step a), such as to form methyl mercaptan (CH3SH), hydrogen sulphide (H2S) and optionally hydrogen (H2); c) optionally, but preferably, recirculating said hydrogen sulphide (H2S) formed in step b) to step a); d) reacting the methyl mercaptan formed in step b) with sulphur such as to form dimethyl disulphide and hydrogen sulphide; e) optionally recirculating the hydrogen sulphide formed during step d) to step a); and f) recovering the dimethyl disulphide.

Abstract: The invention relates to a process for the preparation of symmetrical or asymmetrical dialkyl disulphides by involving at least one mixture of symmetrical and/or asymmetrical dialkyl disulphides in a basic and/or photochemical catalytic reaction, with joint extraction, preferably continuously, of the symmetrical and/or asymmetrical disulphide(s) which it is desired to obtain. The process of the invention is particularly suited to the preparation of dimethyl disulphide or diethyl disulphide from a mixture of symmetrical and/or asymmetrical dialkyl disulphides.

Abstract: The invention relates to a catalyst comprising an active component based on molybdenum and on potassium and a support based on hydroxyapatite, and also to a process for preparing said catalyst and a process for producing methyl mercaptan in a catalytic process by reaction of carbon monoxide, sulphur and/or hydrogen sulphide and hydrogen, comprising the use of said catalyst.

Abstract: The present invention concerns a method for preparing an alkali metal sulfide, from at least one oxygenated alkali metal compound comprising at least one step a) involving reacting said oxygenated alkali compound(s) with at least one sulfur compound of formula (I): in which: R represents a linear or branched alkyl or alkenyl radical, containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms; n is equal to 0, 1 or 2; x is equal to 0 or to a whole number having a value of between 1 and 10, preferably x is a whole number equal to 1, 2, 3 or 4; R? represents a linear or branched alkyl or alkenyl radical, containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms or, only if n=x=0, a hydrogen atom; or indeed R and R? can form, together and with the sulfur atom(s) bearing them, a sulfur heterocycle containing 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, and optionally one or a plurality of heteroatoms chosen from oxygen, nitrogen and sulfur.

Abstract: The present invention relates to the use of (poly)-oxymethylene dialkyl ethers as agents for capturing carbon oxides, CO and/or CO2. The invention also relates to the process for capturing carbon oxides using at least one absorption agent chosen from said (poly)oxymethylene dialkyl ethers.

Abstract: The present invention relates to a method for producing L-methionine using a bio-synthesis process and a specific enzymatic process. More particularly, the present invention relates to a method for producing L-methionine with high yield by enzyme conversion reaction from L-methionine precursor in the presence of methyl mercaptan (CH3SH). The process of the present invention enables selective production of L-methionine which may be used in various fields of industry, such as feed- and food-additives, as raw material for medical supplies, pharmaceutical drugs, and the like.

Abstract: The present invention relates to a sulphiding agent for a hydrotreating catalyst which makes possible faster sulphiding of the catalyst but which also makes possible to very significantly limit solid deposits, in particular of sulphur. The sulphiding agent according to the invention is essentially composed of diethyl disulphide (DEDS) or dipropyl disulphide(s) (DPDS) or dibutyl disulphide(s) (DBDS) and can be employed in “in situ” and “ex situ” presulphidation processes.

Abstract: The invention relates to a hydrocarbon hydroprocessing catalyst comprising a support based on at least one refractory oxide, at least one metal from group VIII and at least one metal from group VIB. The inventive catalyst is characterized in that it also comprises at least one organic compound having formula (I) or (II): in which each R1 represents independently an alkyl group at C1-18, an alkenyl group at C2-18, an aryl group at C6-18, a cycloalkyl group at C3-8, an alkylaryl or arylalkyl group at C7-20, or the two R1 groups together form a divalent group at C2-18, and R2 represents an alkylene group at C1-18, an arylene group at C6-18, a cycloalkylene group at C3-7, or a combination of same. The invention also relates to a method of preparing one such catalyst and to the use thereof for hydroprocessing or hydrocracking.

Abstract: The invention relates to a hydrocarbon hydroprocessing catalyst comprising a support based on at least one refractory oxide, at least one metal from group VIII and at least one metal from group VIB. The inventive catalyst is characterized in that it also comprises at least one organic compound having formula (I) or (II) in which each R1 represents independently an alkyl group at C1-18, an alkenyl group at C2-18, an aryl group at C6-18, a cycloalkyl group at C3-8, an alkylaryl or arylalkyl group at C7-20, or the two R1 groups together form a divalent group at C2-18, and R2 represents an alkylene group at C1-18, an arylene group at C6-18, a cycloalkylene group at C3-7, or a combination of same. The invention also relates to a method of preparing one such catalyst and to the use thereof for hydroprocessing or hydrocracking.

Abstract: Disclosed herein is a chain transfer agent in a free-radical emulsion polymerization process, of at least one mercapto-methyl ester, and also relates to the free-radical emulsion (co)polymerization process comprising at least one such mercapto-methyl ester and uses thereof. Also disclosed herein are mercapto-methyl diesters.

Abstract: The present invention concerns a method for preparing an alkali metal sulfide, from at least one oxygenated alkali metal compound comprising at least one step a) involving reacting said oxygenated alkali compound(s) with at least one sulfur compound of formula (I): in which: R represents a linear or branched alkyl or alkenyl radical, containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms; n is equal to 0, 1 or 2; x is equal to 0 or to a whole number having a value of between 1 and 10, preferably x is a whole number equal to 1, 2, 3 or 4; R? represents a linear or branched alkyl or alkenyl radical, containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms or, only if n=x=0, a hydrogen atom; or indeed R and R? can form, together and with the sulfur atom(s) bearing them, a sulfur heterocycle containing 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, and optionally one or a plurality of heteroatoms chosen from oxygen, nitrogen and sulfur.

Abstract: The invention relates to a process for the preparation of symmetrical or asymmetrical dialkyl disulphides by involving at least one mixture of symmetrical and/or asymmetrical dialkyl disulphides in a basic and/or photochemical catalytic reaction, with joint extraction, preferably continuously, of the symmetrical and/or asymmetrical disulphide(s) which it is desired to obtain. The process of the invention is particularly suited to the preparation of dimethyl disulphide or diethyl disulphide from a mixture of symmetrical and/or asymmetrical dialkyl disulphides.

Abstract: The present disclosure relates to a process for obtaining dialkyl disulphides from alkyl mercaptan and from sulphur, in which a reaction intermediate present in the final disulphide is decomposed at the end of synthesis. This operation makes it possible to avoid the degradation of said reaction intermediate over time, which is responsible for the decrease in purity of the dialkyl disulphide.

Abstract: Disclosed herein is a chain transfer agent in a free-radical emulsion polymerization process, of at least one mercapto-methyl ester, and also relates to the free-radical emulsion (co)polymerization process comprising at least one such mercapto-methyl ester and uses thereof. Also disclosed herein are mercapto-methyl diesters.

Abstract: The present invention relates to a method for producing L-methionine using a bio-synthesis process and a specific enzymatic process. More particularly, the present invention relates to a method for producing L-methionine with high yield by enzyme conversion reaction from L-methionine precursor in the presence of methyl mercaptan (CH3SH). The process of the present invention enables selective production of L-methionine which may be used in various fields of industry, such as feed- and food-additives, as raw material for medical supplies, pharmaceutical drugs, and the like.

Abstract: The present invention concerns an additive for reducing the formation of coke and/or carbon monoxide in thermal hydrocarbon cracking units and/or of other organic compounds in heat exchangers. The additive according to the invention is essentially composed of diethyl disulphide (DEDS) or dipropyl disulphide(s) (DPDS) or dibutyl disulphide(s) (DBDS) and can be used on the metal walls of a cracking reactor and on the metal walls of a heat exchanger placed downstream from the cracking reactor, and during the process of cracking hydrocarbons and/or other organic compounds.

Abstract: One subject of the invention is a dimethyl disulphide in which the content of biocarbon is at least 1%. Another subject of the invention is processes for preparing this dimethyl disulphide. Yet another subject of the invention is the use of such a dimethyl disulphide for the manufacture of methanesulphonic acid.

Abstract: The present invention relates to the use of (poly)-oxymethylene dialkyl ethers as agents for capturing carbon oxides, CO and/or CO2. The invention also relates to the process for capturing carbon oxides using at least one absorption agent chosen from said (poly)oxymethylene dialkyl ethers.

Abstract: The present disclosure relates to a process for obtaining dialkyl disulphides from alkyl mercaptan and from sulphur, in which a reaction intermediate present in the final disulphide is decomposed at the end of synthesis. This operation makes it possible to avoid the degradation of said reaction intermediate over time, which is responsible for the decrease in purity of the dialkyl disulphide.

Abstract: The present invention relates to a hydrogenation catalyst, particularly useful for the hydrogenation of carbon disulphide (CS2) to form methyl mercaptan (CH3SH), and to a preparation method thereof. The present invention also relates to a method for continuously preparing methyl mercaptan by the catalytic hydrogenation of carbon disulphide, with a carbon disulphide conversion rate of 100%, and a methyl mercaptan selectivity of 100%.