Technology Types of Continuous Hydrogenation Units
The gas-phase hydrogenation method is only suitable for the reduction of nitro compounds with low boiling point and easy gasification; the liquid-phase hydrogenation method is not limited by the boiling point of nitro compounds, and has a wider application range.
The liquid-phase hydrogenation reaction is a heterogeneous reaction, which is controlled by diffusion. Therefore, in order to strengthen the hydrogenation reduction process, it is necessary to start with the hydrogenation equipment to strengthen the mass transfer between the gas-solid-liquid three-phase.
Types of continuous hydrogenation unit:
1. Kettle type continuous hydrogenation unit
The kettle-type continuous hydrogenation device is an operation method that realizes continuous production with a kettle-type reactor. Compared with the batch-type kettle type, it has the advantages of high production efficiency, low labor intensity, low operating cost, stable product quality, and easy self-control.
The material flows in and out as it enters and flows continuously. After the raw material enters the reactor, it is immediately diluted to reduce the concentration of the reactant. The rapidly exothermic reaction proceeded smoothly.
2. Loop Continuous Hydrogenation Unit
The characteristics of the loop continuous hydrogenation device are: the gas-solid-liquid phase is in the state of emulsified foam, the mass transfer process is enhanced, the production capacity is large, and the equipment structure is complex, the operation requirements are strict, and it is suitable for continuous operation.
This kind of reactor is a forced circulation structure. Generally, the mass transfer area is 2 to 3 times that of the stirred reactor, which shortens the reaction time. A heat exchanger is installed outside, which can be heated and cooled, and the heat transfer effect is good. It is airtight. The performance is better than that of the stirred reactor, and it is suitable for continuous operation.
3. Horizontal continuous hydrogenation unit
The main reactor of the horizontal continuous liquid phase hydrogenation unit is a multi-stage tank horizontal reactor with three baffles and four reaction zones. This reactor is a bubbling gas-liquid-solid three-phase reactor. The lower the mass transfer rate, the lower the production capacity of the reactor.
4. Fluidized bed continuous hydrogenation unit
In the fluidized bed, a large number of catalyst solid particles are suspended in the moving fluid, so that the particles have some apparent characteristics of the fluid. This fluid-solid contact state is called solid fluidization.
The granular material in the fluidized bed can be continuously fed in and out like a fluid, the particles are fully mixed, the bed temperature and concentration are uniform, the contact surface is large, the heat and mass transfer efficiency is high, and the space-time yield is high, so that the bed has unique advantages. Wide range of applications.
5. Fixed bed continuous hydrogenation unit
The fixed bed reactor is a widely used heterogeneous catalytic reactor. The reactor is filled with fixed solid particles, which can be solid catalysts or solid reactants.
For example, in a tubular fixed-bed reactor, the catalyst is installed in the tube, and the reaction materials pass through the bed from top to bottom, and the required temperature conditions are maintained by electric heating or material heat transfer in the tube. In addition, fixed bed reactors can also be used for gas-solid and liquid-solid non-catalytic reactions. The advantage of the fixed bed hydrogenation reactor is that it is easy to operate and has a large production capacity.
