PROCESS FOR THE PREPARATION OF A LUBRICANT BASE STOCK COMPRISING THE SELECTIVE THERMAL DECOMPOSITION OF PLASTIC POLYOLEFIN POLYMER

The present invention relates to a process for the preparation of a lubricant base stock from the thermal decomposition of plastic polymer. The present invention provides a process for preparing a lubricant base stock from the thermal decomposition of plastic polyolefin polymer, the method comprising the steps of: i) introducing plastic polyolefin polymer into a thermal reaction zone of a vacuum pyrolysis reactor; ii) heating the plastic polyolefin polymer at sub-atmospheric pressure, wherein the temperature in the thermal reaction zone of the reactor is from 500° C. to 750° C., to induce thermal decomposition of the plastic polyolefin polymer and to form a thermal decomposition product effluent which comprises a major portion by weight of a C20 to C60 wax fraction; iii) condensing a vapour component of the thermal decomposition product effluent from the vacuum pyrolysis reactor in a multistage condensation comprising a plurality of condensation stages connected in series; and iv) subjecting the C20 to C60 wax fraction of the thermal decomposition product to catalytic hydroisomerization in a hydroisomerization reactor in the presence of hydrogen to form the lubricant base stock.