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.
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The process of the invention also makes it possible to obtain a high yield and a high selectivity in terms of DMDS. It is also possible to consider not using H 2 S in the first step, and generating the required H 2 S in situ by reacting the hydrocarbon charge with sulphur according to reaction 3 defined above.
Methyl mercaptan may itself be produced from methanol CH 3 OH and hydrogen sulphide H 2 S in accordance with the following reaction 1: Select the topic you are interested in: Accordingly, the hydrocarbon charge reacted with hydrogen sulphide H 2 S in step a may be any type of charge known to the skilled person, and is generally a hydrocarbon charge in gaseous, liquid or solid form, preferably in gaseous or liquid form, more preferably in gaseous form, and comprises at least one hydrocarbon having a hydrocarbon chain in saturated or unsaturated linear, branched or cyclic form.
A process for preparing dimethyl disulphide, batchwise or continuously, said process comprising at least the following steps: According to another embodiment, step b is carried out without catalyst. CSR, at the core of our strategy. Vision of HR VP. 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 intended degrees of conversion and intended yields.
Food industry and agrochemicals. According to one embodiment, step a is carried out in the presence of a catalyst. Finance Media Products Human resources. The present invention therefore offers an 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.
Like most sulphur arekma, DMDS has a strong, unpleasant odor although one positive upshot of this is to make leak detection easier.
Fuel desulfurization, the final step in refining, employs a process called hydrotreating.
Arkema introduces DMDS Evolution® E2, a new DMDS grade with optimized odor
DMDS also works as an effective product for operators in the petrochemicals industry arkems must protect their steam-cracking coils against the formation of coke and carbon monoxide.
Liquid sulphur is introduced into this reactor.
Douglass and Richard V. The process is optimized in this way, since each carbon atom present in the initial hydrocarbon charge is converted into half a mol of methyl mercaptan.
Dimethyl disulfide – Wikipedia
Disulphides, and especially dimethyl disulphide, are of great industrial interest and are nowadays very widely used in industry, for example and non-limitatively as an additive for sulphurizing catalysts, especially for hydrotreating petroleum fractions, or else as a soil fumigation agent aroema agriculture. The results are collated in Table 1 below:. With further advantage the hydrocarbon charge is pure, meaning that it contains a single compound, for example an alkane, and preferably methane CH 4ethane, propane or butane, and very preferably methane.
This registration as a normal substance is fully in line with European Chemicals Agency ECHA requirements since DMDS cannot be handled as an intermediate in such petrochemical and refining applications. These metal sulphides may also be obtained from the corresponding oxides by any method known to the skilled person.
The catalyst from the first step in example 1 was replaced by 60 cm of platinum wire with a diameter of 0. The results are collated in Table 1 below: Lethal dose or concentration LDLC:.
This succession of two reaction steps is notable in that the dmss of mols of methyl mercaptan formed is identical to the number of mols of methane consumed, and that step a reaction 5 xmds twice as many mols of hydrogen sulphide as formed in step b reaction 6. More preferably, the hydrocarbon filler comprises at least one alkane, preferably at least methane CH 4ethane, propane or butane, and very preferably methane.
A particularly advantageous form of exploitation for the hydrogen formed is its combustion with oxygen to provide the thermal energy required for the various steps in the process of the invention, particularly for the heating for the reaction of step awhich requires high temperatures for industrially acceptable performance levels.
Accordingly, in a first aspect, the present invention provides a process for preparing dimethyl disulphide, batchwise or continuously, preferably continuously, said process comprising at least the following steps: The balanced reaction may then be written in accordance with scheme 9 below:. According to another embodiment, step a is implemented in the presence of sulphur, ddms corresponding to the process of the invention in accordance with scheme DMDS and chlorine are reacted with borontriflouride phenolate to produce 4- methylthio phenol.
For example, the reaction varies between several seconds and several minutes. It has been shown accordingly that the process for synthesis of dimethyl disulphide according to the present invention offers a very great number of advantages over the known processes of the prior art, more particularly the advantage of not requiring the use of methanol, thereby resulting in lower production costs.
Process for oxidation of alcohols.