Dimethyl disulphide is a light yellow liquid with a very characteristic smell and an extremely low odour threshold at 8 to 10 ppb. DMDS is an. In order to boost its ranking in the DMDS (dimethyl disulfide) global market and meet demand from its customers, Arkema (Paris:AKE) has. Dimethyl disulfide (DMDS) is an organic chemical compound with the molecular formula than the former. This pesticide is marketed as “Paladin” by Arkema.
More preferably, arke,a hydrocarbon filler comprises at least one alkane, preferably at least methane CH 4ethane, propane or butane, and very preferably methane. This synthesis pathway, however, has a number of drawbacks, including that of using methanol, which necessitates a supplementary step, since methanol is prepared from hydrocarbon charges, and arkems drawback of arkeam to secondary products, typified especially by dimethyl ether CH 3 OCH 3dimethyl sulphide CH 3 SCH 3and cracking products such as, for example, carbon monoxide and carbon dioxideand water, to state only some of the drawbacks.
The process according to claim 1, wherein the hydrogen sulphide formed in step d is recycled into step a. The pressure is 3 bar 0. The process according to claim 1, wherein the hydrocarbon charge is a hydrocarbon charge in gaseous form.
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The hydrogenation time varies according to the nature and amount of each of the reactants, and the nature and amount of catalyst used. According to another embodiment, step a is implemented in the presence of sulphur, this corresponding to the process of dkds invention in accordance with scheme Carbon nanotubes and copolymers.
Innovation at the heart of the change. It is an oxidation product of methanthiol in air.
Health and working environment. Moreover, the processes in accordance with reaction 2 above have the drawback of giving rise to secondary products, such as carbon dioxide CO 2methane CH 4dimethyl sulphide CH 3 SCH 3 and water H 2 O. As indicated above, the amount of hydrogen sulphide produced in step b reaction 6 above is not sufficient in molar amount for the implementation of reaction 5 in step aand a further amount of hydrogen sulphide must be supplied in order for step a to be conducted.
However, the process performed in this document employs carbon disulphide CS 2which is a dangerous, toxic product which can be used industrially with the installation of severe safety means; all enterprises and factories do not wish to or are unable to develop a plant meeting the safety standards required for the holding of carbon disulphide.
Arkema Group at a glance. A process for preparing dimethyl disulphide, batchwise or continuously, said process comprising at least the following steps: CSR, at the core of our strategy. The entirety of these compounds may be recycled into step a. Air conditioning and refrigeration.
DMDS for oil refining and petrochemical industries
Carbon nanotubes and copolymers. Expansion in high growth regions.
Applications Hydrocracking catalyst activation. The results are collated in Table 1. The catalyst is intercalated between two layers of carborundum.
The present invention therefore offers arkwma industrial process for preparation of DMDS that is completely autonomous, has a high yield, and is more environment-friendly and more economical than the methods known in the prior art. Gas-chromatographic analysis of the exiting gases indicates the following molar composition: Click for automatic bibliography generation. It is a flammable liquid with an unpleasant, garlic -like odor. In this embodiment, the sulphur d,ds in liquid, solid or gaseous form, preferably in liquid or gaseous form.
These flies are attracted afkema the odor of fetid meat, they help pollinate this plant. In one variant of the process of the invention, when the by-products are not recycled, or when only the hydrogen sulphide is recycled, it is possible to exploit said by-products—hydrogen sulphide, hydrogen and optionally carbon disulphide.
Search Expert Search Quick Search. The process according to claim 1, wherein the hydrocarbon charge comprises at least one alkane selected from the group consisting of methane CH 4ethane, propane and butane. When the catalyst is present in the form of a metal oxide, a sulphurizing step may advantageously be carried out according to the methods known to the skilled person.
The H2S reacts with the metal oxides on the catayst, converting them to the active metal sulfide form. This pesticide is marketed as “Paladin” by Arkema.
These metal sulphides may also be obtained from the corresponding oxides by any method known to the skilled person.
The reaction of step a may be carried out alternatively at atmospheric pressure, under superatmospheric pressure, or even under subatmospheric pressure; the skilled person is aware of how to adapt the reaction pressure conditions according to the nature of the reactants employed, the reaction temperatures selected, the rates of circulation of the streams, and the arke,a degrees of conversion and intended yields. The catalyst used in step a is preferably a supported catalyst, the support being selected preferably from alumina, silica, zeolites, activated carbons, titanium oxide, zirconium oxides, clays, hydrotalcite, hydroxyapatite, magnesia, and others.
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Accordingly, the respective ratios of the reactants employed in step b are directly dependent on the ratios of the products obtained at the end of step a. Applications Hydrocracking catalyst activation. Hansson; Anna-Maria Angioy This example shows that it is entirely possible to envisage a process for synthesis of methyl mercaptan in which the entirety of the H 2 S produced could be recycled, and there would be no need for it to be synthesized for the purposes of said process for synthesis of methyl mercaptan.
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The reaction mixture containing xrkema mercaptan MeSH obtained in example 2 is introduced into a reactor containing dry Amberlyst A21 resin, for producing DMDS in the presence of sulphur, as described in EP