[dominiccheuk]

I am a 4th year chemical engineering student currently doing my final year design project in which my part is to design a continuous stir tank hydrogenator (340L with 250L nominal working volume), nitile is reduce to produce 50 tonnes of primary amine by hydrogenation in the present of raney nickel per year. Operation temperature and pressure is roughly 50 degree celcius and 6 bar gauge.

From literature it shows that the reduction of nitrile to primary amine will form imine as an intermediate. R-CN (nitrile) to RCH=NH (imine intermediate) to RCH2NH2 (primary amine), which is a desire process. But, secondary and tertiary amines will also form as a secondary by-product. The reaction of imine and primary amine will form secondary amine and so on to form tertiary amine. Anyone know where i can find the experimental data for the chemoselectivity for these related reaction? Ammonia or acetic anhydride or alkali could be use to interfere chemical equilibrium to protect the primary amine to get a better yield, any recommendation to these reagent in the design?

One other problems exists is how to filter, reactivate and recycle the catalyst (raney nickel) in slurry form, please suggest any recommendation for configuration. Also, would anyone know how to find out the deactivation rate for the catalyst, with or without experimental data and how can i identify and discard spent catalyst?

Please comment anything about continuous hydrogenation in CSTR and suggestion for mixing and heat transfer will be highly appreciate as well.

Many thanks,
Dominic