43 results about "Chemical reaction engineering" patented technology

The invention discloses a novel Beckmann rearrangement method for preparing caprolactam from cyclohexanone oxime, and belongs to the technical field of chemical reaction engineering. The method comprises the following steps of: by using high-efficiency mixing and excellent mass transfer and heat transfer properties of a microreactor, using fuming sulphuric acid as a dispersed phase in a first microreactor, dissolving the cyclohexanone oxime in an inert solvent to serve as a continuous phase, mixing the two phases and initiating an rearrangement reaction; taking the cured reaction mixture as acontinuous phase, introducing the continuous phase into a second microreactor, mixing with the introduced water serving as the dispersed phase, performing hydrolysis reaction to obtain caprolactam-containing aqueous solution, and circulating the inert solvent back to the system. The method only needs the reaction time of 10 to 40 seconds in a large acid oxime ratio of 0.8 to 3.0, namely can achieve high conversion rate of over 99.9 percent and high selectivity of over 99.9 percent, and has the advantages of high operational flexibility, low operating cost, high safety and controllability, high production efficiency, and capacity of greatly reducing the yield of a byproduct ammonium sulfate.

The invention discloses a method for preparing epoxy chloropropane by cyclizing dichloropropanol in a microreactor, belonging to the technical field of chemical reaction engineering. The method comprises the following steps: quickly mixing a dichloropropanol water solution with a sodium hydroxide water solution in the microreactor; controlling the temperature of the cyclization reaction to be 40-100 DEG C; finishing reaction in a delay tube; and finally separating in a rectifying tower to obtain epoxy chloropropane. According to the method, the reaction material solutions are quickly mixed in the microreactor, so that the cyclization reaction is fully finished while side reactions caused by non-uniformly mixing are prevented and the usage amount of alkali liquor is guaranteed to be closer to the theoretical value. Compared with the traditional cyclization tower and the reactive distillation coupling technology, the method for preparing epoxy chloropropane by cyclizing dichloropropanol in the microreactor has the advantages of short material retention time, high conversion rate, high selectivity and the like, so that the production cost can be saved, the material consumption can be reduced and the byproduct amount can be decreased.

The invention belongs to the technical field of chemical reaction engineering, and relates to a method and a device for continuously feeding low-boiling point materials to high-pressure devices. The specific steps are: transport the low-boiling point material to the pressure-resistant buffer tank through the material storage tank; add a certain pressure of protective gas to the pressure-resistant buffer tank; the low-boiling point material enters the high-pressure reaction system from the pressure-resistant buffer tank through the metering pump ; When the material reserve in the pressure-resistant buffer tank decreases, repeat the steps to achieve continuous, stable and uniform feeding. The invention realizes the liquid feeding of low-boiling materials, and ensures the continuity, stability and uniformity of the feeding, effectively reduces the problem of stopping the pump caused by the bubbles caused by the vaporization of the materials, and ensures the stability of the reaction in the reactor .

The invention relates to the technical field of chemical reaction engineering, and especially relates to a method and an apparatus for rapid hydrothermal synthesis. The apparatus comprises a power mechanism, a plurality of liquid storage devices and a reactor, the liquid storage devices are connected with the reactor through a channel transition mechanism, and the channel transition mechanism is provided with a flow rate control device; and the reactor includes a channel distribution structure and a multiple heat exchange assembly, the multiple heat exchange component uses a high temperature and high pressure hot liquid as a heat source, the multiple heat exchange assembly is composed of a plurality of pinch plates which can be vertically buckled up and down, grooves are arranged at two sides of the middle pinch plate, the grooves of the adjacent pinch plate are buckled to form a plurality of closed channels, and the channel distribution structure is communicated with the closed channels of the multiple heat exchange assembly. The apparatus has a strong heat exchange function, and can prepare nano-composite particles with various crystal phases and a complicated structure under hydrothermal conditions, and the obtained nano-composite particles can be directly used without hydrothermal aging treatment, so the process flow is obviously shortened, and the process cost of the product is reduced.

The invention discloses a system and a method for synthesizing cyclohexanone oxime with a microreactor, belonging to the field of chemical reaction engineering. The system is composed of a first micro-mixer, a second micro-mixer, a reaction pipeline with a heat exchange jacket and a back pressure valve connected in series. First, use the first micro-mixer to mix the slurry containing titanium-silicon molecular sieve and ammonia with hydrogen peroxide solution, and then use the second micro-mixer to disperse cyclohexanone into the mixed slurry to initiate the ammoximation reaction, and finally in the reaction The reaction process is completed in the pipeline. The system can achieve high conversion rate (>99%) and high selectivity (>99%) within a reaction time of 0.5min to 20min. The amount of stagnation of materials in the micro-reaction system is small, which improves the controllability and safety of the ammoximation reaction.

The invention discloses a method for inhibiting chloroform acidifying during separation of N-methylpyrolidone (NMP) and chloroform by adding a stabilizing agent, and belongs to the technical field of chemical reaction engineering. According to the method, a high-boiling-point alcohols and phenols stabilizing agent is added into the NMP / chloroform system, and gives play to effect of inhibiting acidifying during separation of NMP / chloroform. The method is capable of effectively inhibiting acidifying phenomenon during separation of NMP / chloroform and improving NMP recovery utilization efficiency, and possesses the advantages of simple operation, low cost, high safety and the like.