437 results about "Dimethyl sulfide" patented technology

The present invention relates to flavor oils including mint-, fruit- and spice-type flavors that are specially processed to substantially eliminate low-molecular weight sulfur compounds, in particular dimethyl sulfoxide (DMSO), which has been found to be the main precursor of malodorous species such as dimethyl sulfide and methyl mercaptan. These malodorous species are produced via oxidation-reduction reactions involving such sulfur-containing compounds present in flavor oils. A preferred processing method is an aqueous-washing process, which has advantages of being simple, inexpensive and easy to implement while importantly avoiding the problems of typical processes including non-selective removal of desirable components and subjecting the flavor oils to extreme conditions that may destroy other components and result in undesirable changes in flavor or odor character. Other processing methods to selectively remove non-desired components include (1) distillation to remove polar low boiling point components, (2) filtration through adsorbents selective for sulfur compounds, (3) countercurrent extraction and (4) column chromatography. The processing methods may optionally be followed by reengineering to add back desired components that may have been removed or altered during the processing. The specially processed flavor oils are particularly useful in oral care compositions comprising components with chemical reducing capability such as stannous ions, which react with the sulfur-containing compounds to produce malodorous products.

The invention provides a method for preparing dimethyl sulfoxide. The method comprises the following step of contacting dimethyl sulfide and at least one oxidant with at least one tin silicate molecular sieve under an oxidation condition. According to the method, especially when peroxide is used as an oxidant, the conversion rate of dimethyl sulfide and the effective utilization rate of the oxidant are high, the selectivity of dimethyl sulfoxide is good, the using amount of dimethyl sulfide and the oxidant can be effectively reduced, and the production cost of dimethyl sulfoxide can be reduced. Furthermore, by adopting the method, the catalyst has good activity stability, and high dimethyl sulfide conversion rate, oxidant effective utilization rate and dimethyl sulfoxide selectivity can stilled be obtained even the catalyst runs continuously for a long time or is recycled for multiple times. Furthermore, the method is mild in reacting condition and easy to control, and is suitable for large-scale production.

The invention discloses a gas purification method for treating low-concentration organic compounds, in particular to a gas purification method aiming at the following malodorous compounds such as sulfides of dimethyl sulfide (DMS), dimethyl disulfide (DMDS), sulfurated hydrogen (H2S) and the like as well as formaldehyde, acetic acid, isopropyl alcohol, acetone and the like. The method comprises: at least one catalyst adsorption unit in parallel connection and / or in series connection; and / or an ozone generating unit which can provide ozone to the catalyst adsorption unit to serve as a component that can strengthen the adsorption function of catalyst and is easy to be treated or is harmless after low temperature oxidation reduction or decomposition reaction, so as to greatly improve the treatment efficiency and extend the service life of the catalyst adsorption material.

Gas streams containing non-condensible gases (NCG's) including reduced sulfur compounds, such as hydrogen sulfide, dimethyl sulfide, dimethyl disulfide and mercaptans, are treated to remove the NCG's from the gas stream. Following an optional initial gas-liquid contact to cool the gas stream to its adiabatic dewpoint and to remove particulates, the gas stream is subjected to an intimate gas-liquid contact with aqueous chlorine dioxide, in one or more contact stages, to oxidize the reduced sulfur compounds and other oxidizable compounds present in the gas stream, and then the gas stream is passed through an entrainment separator to remove entrained liquid droplets. Acidic gases produced in the oxidization stage and residual chlorine dioxide generally are removed from the gas steam by intimate gas-liquid contact of the gas stream with an aqueous neutralizing and reducing solution, in one or more contact stages, and ten the gas stream is passed through an entrainment separator to remove entrained liquid droplets.

The invention discloses a catalyst for synthesizing methyl mercaptan and a preparation method of the catalyst. The catalyst comprises a carrier, an active component and an assistant, wherein the carrier is gamma-Al2O3, the active component is one or more of Fe2O3, MoO3, ZnO and NiO, and the assistant is alkali metal oxide or alkaline earth metal oxide. The catalyst is prepared as follows: impregnating a precursor of the assistant on the carrier by using a secondary equivalent-volume impregnation method, loading the precursor containing the active component by using the impregnation method again after roasting for one time, and obtaining a target product namely the catalyst for synthesizing the methyl mercaptan after the secondary roasting. According to the catalyst provided by the invention, methyl alcohol and sulfuretted hydrogen are used as raw materials to synthesize the methyl mercaptan, the selectivity of the catalyst is good, the active temperature of the catalyst is lower than that of the prior art, the reaction temperature is between 230-260 DEG C, the yield of the methyl mercaptan is more than 90%, in addition, no dimethyl sulfide is produced in the target product, so that subsequent separation is not needed.

The invention relates to composite biological deodorization spray for pets and a preparation method thereof. The spray is suitable for solving the problems of halitosis, body odor, feces odor and thelike of dogs and cats. The deodorization spray comprises, by mass, 5-8% of a Spanish bayonet extract, 4-5% of a green tea extract, 6-8% of an origanum oil extract, 4-5% of a persimmon extract, 4-5% ofa horseradish extract, 3-4% of zinc diricinoleate, 5-6% of an emulsifier, 1-2% of a stabilizing agent, 1-2% of a pH value regulator and the balance purified water. It is proved through deodorizationeffect identification that the deodorization performance of the spray is good, and the spray can quickly eliminate ammonia gas, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfideand various common odor molecules of the pets within 5 minutes. Meanwhile, pathogenic microorganisms can be effectively inhibited and killed, and generation of odor can be inhibited from the source.

The invention discloses a synthesis method of taxane drug 7, 10-methoxy-docetaxel. The synthesis method includes using 7, 10-trichloro-ethoxycarbonyl-10-deacetylbaccatin III (compound 1, CAS (chemical abstracts service) number 95603-44-4) as starting material, using triethyl silicon substrate for protection, and performing reactions of removal of protecting group of trichloro-ethoxycarbonyl, dimethyl sulfide etherification, hydrogenation reduction, removal of protecting group of the triethyl silicon substrate, side chain condensation and side chain deprotection to obtain the 7, 10-methoxy-docetaxelf with more than 99% purity. Reaction conditions are simple and mild. The synthesis method has the advantages that the required equipment is simple and is easy to operate, and methylate reagents such as highly toxic methyl iodide or dimethyl sulfate is not needed. The synthesis method is applicable to industrial production.

The invention discloses a method for oxidizing dimethyl sulfide, which comprises the step of contacting dimethyl sulfide with an oxidizing agent under oxidation reaction conditions and is characterized in that the oxidizing agent is gas containing ozone. The method disclosed by the invention is free from any inhibitor or initiator in feed gas and has high selectivity and higher effective ozone utilization rate; particularly, the effective ozone utilization rate is greatly increased in the presence of a titanium-containing catalyst; furthermore, the method disclosed by the invention is simple in process and easy for control and is beneficial to industrial production and application; in addition, compared with the traditional method, the problems of being complex in traditional production process, corrosive in equipment, harmful for discharging and the like are overcome.

The invention relates to a method for co-producing sodium methyl mercaptide and dimethyl sulfide, which essentially comprises the following steps of: under a negative pressure condition, filling methane chloride gas into a sodium hydrosulfide solution; implementing a four-stage cascade reaction, absorbing by a sodium hydroxide solution to obtain a sodium methyl mercaptide solution; and making the reaction liquid obtained from the four-stage cascade reaction standing and layering to obtain the dimethyl sulfide. The method for co-producing the sodium methyl mercaptide and the dimethyl sulfide is low in toxicity of the adopted raw materials, short in reaction duration, moderate in required reaction condition, simple in operation, high in product yield and simple in post-treatment; and the method can be massively adopted in the industrial production, and has a great economic value.

The invention relates to lithium-sulfur battery electrolyte capable of improving battery capacity and a preparation method thereof. The electrolyte is prepared from organic solvents, a lithium salt and an additive and is characterized in that the organic solvents include a first solvent, a second solvent and a third solvent; the first solvent is one or more of 1,3-dioxolane, 1,4-dioxane and 1,1-dimethoxyethane; the second solvent is one or more of glycol dimethyl ether and diglyme; the third solvent is one or more of dimethyl sulfide organics; the volume ratio of the first solvent to the second solvent is (0.5 to 2) : 1, and the volume fraction of the third solvent in the organic solvents is 10 to 40%. Dimethyl ether organics are reduced into methyl lithium sulfur and can contribute capacity except positive active materials. By means of the unique work principle, lithium sulfur batteries prepared from the electrolyte have the characteristics of achieving and even exceeding the theoretical capacity of the lithium sulfur batteries.