This PhD thesis describes the Ni-catalysed alkylation of ammonia with alcohols to achieve high selectivity to primary amines. This work was broadly divided into two parts: (i) developing and understanding reaction conditions through batch reactions; and (ii) deploying the system into a flow reactor and understanding how the system works and fails.
Extensive screening of heterogeneous catalysts in the alkylation of ammonia with alcohols was carried out in batch reactors. It was found that a commercial 65 wt% Ni/Al2O3/SiO2 catalyst yielded the highest selectivity towards the primary amine. High selectivities of 99% with 7 different alcohols to their corresponding amines were achieved with moderate alcohol conversions, under the reaction conditions of 160 °C, 72 hours, 30 mL of 0.1 M alcohol in o-xylene, alcohol/Ni = 10 and anhydrous ammonia/alcohol = 7. An extruded version of this catalyst was created for the application in flow.
A flow reactor was then designed and constructed. Competitive formation of the nitrile side-product was suppressed when the catalyst was pre-reduced. Higher alcohol conversions and selectivities to the primary amines were achieved at 51 – 100% and 99% respectively. This improvement in performances is attributed to the minimisation of water accumulation. Over an extended continuous run for 78 hours, it was found that the carbon deposition on the catalyst resulted in the deactivation of the catalyst in flow.