Catalyst and a benzene hydrogenation process using said catalyst

A process for the production of cyclohexane by hydrogenation of benzene, comprising at least two steps, as follows:

• a) gradually introducing the feed of benzene for hydrogenation and a hydrogen-rich gas into a reaction zone containing a cyclohexane-rich liquid phase and a nickel-based catalyst in suspension in said phase, said reaction zone being maintained at a temperature of about 100.degree. C. to about 250.degree. C., at an absolute pressure of about 0.5 MPa to about 10 MPa, and recovering a gaseous phase containing cyclohexane, hydrogen and benzene,
• b) introducing the gaseous phase obtained from step a) into a reactor containing at least one fixed bed of a solid nickel-based hydrogenation catalyst, said reactor being maintained at a temperature of about 100.degree. C. to about 300.degree. C., at an absolute pressure of about 0.5 MPa to about 10 MPa, the hourly space velocity being between 1 h.sup.-1 and 10 h.sup.-1, and recovering substantially pure cyclohexane after depressurizing and cooling,
• said process being characterised in that the nickel-based catalyst in suspension used in step a) is produced using at least one trialkylaluminium with formula AlR.sup.1 R.sup.2 R.sup.3 where R.sup.1, R.sup.2 and R.sup.3 each independently represent a linear or branched alkyl group containing 1 to 12 carbon atoms, to reduce a solution, in a hydrocarbon or hydrocarbon mixture, of at least one nickel carboxylate with formula R.sup.4 COONi, where R.sup.4 is a hydrocarbon residue containing 1 to 24 carbon atoms, and at least one sodium carboxylate with formula R.sup.5 COONa where R.sup.5 is a hydrocarbon residue containing 1 to 24 carbon atoms, the Ni:Na molar ratio being between 2:1 and 1000:1.