77results about How to "Improve one-way yield" patented technology

The invention discloses a coproduction method of methyl benzoic acid, methyl benzaldehyde, and methyl benzyl alcohol. The method comprises the following steps: (1) primary oxidation: continuously introducing xylene, a catalyst and oxygen-containing gas into a primary oxidation reactor to carry out reactions to obtain a primary oxidation reaction liquid; (2) secondary oxidation: continuously introducing the primary oxidation reaction liquid into a secondary oxidation reactor, and continuously introducing water and oxygen-containing gas into the secondary oxidation reactor to carry out reactions to obtain a secondary oxidation reaction mixture; (3) liquid-liquid layering: introducing the secondary oxidation reaction mixture into a liquid-liquid layering device to carry out layering to obtain an oil phase in the upper layer and a water phase in the lower layer, and returning the oil phase to the primary oxidation reactor; (4) water phase separation: separating and purifying the water phase to obtain methyl benzoic acid, methyl benzaldehyde, and methyl benzyl alcohol. The method has the advantages of high raw material conversion rate, high product yield, good selectivity of target product, and environment-friendliness.

The invention discloses a coproduction method of methyl benzyl alcohol, methyl benzaldehyde, and methyl benzoic acid. The coproduction method comprises the following steps: mixing xylene, a co-oxidization agent (a C8 oxygen-containing compound), and a catalyst, and continuously introducing oxygen-containing gas to carry out reactions. By controlling the amount of the added oxygen-containing gas, the content of oxygen gas in tail gas is not more than 5%. The mass ratio of the co-oxidization agent (a C8 oxygen-containing compound) to xylene is 0.003-0.2:1, and the using amount of the catalyst is 10-10000 ppm of the weight of the xylene. The reaction temperature is 105 to 200 DEG C, the reaction pressure is 0.2 to 2.5 MPa, the reaction time is 0.4 to 5 hours, and the xylene is oxidized into a mixture of methyl benzyl alcohol, methyl benzaldehyde, and methyl benzoic acid in one step. The method has the advantages of mild reaction conditions, high product yield, good selectivity, green, and environment-friendliness.

The invention discloses a method for synthesizing PODE through condensation, oxidation, polycondensation and etherification of methyl alcohol. The method includes the steps that firstly, methylal with the mass purity of 85%-99.9% is prepared through a reaction of the methyl alcohol and diluted methanal; secondly, the methylal and air are catalyzed and oxidized by iron-molybdenum catalysts to prepare methanal with the mass purity of not less than 70%; thirdly, the methanal is subjected to polycondensation and then is refined to obtain triformol with the mass purity of not less than 99.9%; fourthly, the methylal and the triformol are subjected to etherification, reactive distillation and dehydration and are refined to obtain PODE3-8 with the mass purity of over 99%. By the adoption of the method, the single-pass yield of the PODE is increased from 40%-50% to 95%, the yield of the PODE3-8 is increased from 20% to 90%, product distribution is more reasonable, and the product purity is improved from 50% to 99%. The PODE is wide in application prospect and remarkable in economic, social and environmental benefit.