Hydrogenation reactor for liquid catalytic hydrogenation
Technological processes of liquid catalytic hydrogenation include hydrogenation system, catalyst filtration system and supporting system for other hydrogen source, sampling, cooling and product purification, etc. Different technology needs different process and device. Reaction system normally will be designed as batch production and continuous production is available for special requirements.
Hydrogenation reactor is composed of driving mechanism, hallow shaft, shaft seal, self-suction impeller and high efficient axial flow paddle. The high speed operating self-suction type hollow impeller can have plenty of liquid to circulate inside and outside of impeller. According to the Venturi jet principle, gas above liquid level will pass through hollow mixing shaft and being discharged with high speed moving liquid; thus gas in the reactor will be pumped into deep liquid continuously, mixed and dispersed; again and again an uniform gas liquid mixing system will be generated. It can realize high efficient gas liquid contact, strengthen the gas-liquid mass transfer process and shorten the gas liquid reaction time. Function of the bottom high efficient axial flow paddle is suspending catalyst uniformly and dispersing gas sprayed from self-suction impeller into reactor uniformly, including the bottom of reactor.
As hydrogenation is a strong exothermic reaction, the reaction heat need to be transferred by built-in coiler and external jacket with cooling water. According to the different reaction heat, reaction temperature and reaction rate, it can be designed with different cooling medium, cooling process and cooling medium. Internal coiler of reactor in industrial device can be of multilayer setting; cooling area can be 8~12m2/m3 and heat exchanger can be external built for special heat transferring requirements.
Hydrogenation belongs to middle-high pressure reaction normally and direct sampling is very dangerous. Technological process designed by we factory includes safe sampling system with pressure, which can ensure getting sample without catalyst safely and conveniently.
Normally catalyst will be added at one time. The special technological requirement is that we can design catalyst replenishing system with pressure, which can replenish catalyst during the reaction safely.
Filter on catalyst is also very important. Different type of catalyst need different filtering system, for example: sedimentation in tank, sedimentation out of tank, micro porous filtration and filter press, etc. Some filtering systems need to be designed with safe filter and catalyst deactivation system.
Design of catalytic hydrogenation reactor need to note:
1. Flammable and combustible hydrogen and solvent.
2. Medium feeding and filtering of high-active catalyst.
3. Middle-high pressure operation.
4. Temperature controllability reduction caused by reaction heat.
5. Medium containing catalyst return to hydrogen pipeline and system through gas inlet pipe, which may lead hidden dangers.
6. Safety of sampling with pressure.