Process for the preparation of polymers from waste plastic feedstocks

Abstract

A process for the production of polymers from waste plastics feedstocks includes: providing a hydrocarbon stream A obtained by treatment of a waste plastics feedstock; optionally providing a hydrocarbon stream B; supplying a feed C comprising a fraction of the hydrocarbon stream A and a fraction of the hydrocarbon stream B to a thermal cracker furnace comprising cracking coil(s); performing a thermal cracking operation in the presence of steam to obtain a cracked hydrocarbon stream D; supplying the cracked hydrocarbon stream D to a separation unit; performing a separation operation in the separation unit to obtain a product stream E comprising a monomer; supplying the product stream E to a polymerisation reactor; and performing a polymerisation reaction to obtain an polymer. The process allows for optimisation of the quantity of waste plastic material that finds its way back into a polymer that is produced as outcome of the process.

1 . A process for the production of polymers from waste plastics feedstocks comprising the steps in this order of:
 (a) providing a hydrocarbon stream A obtained by treatment of a waste plastics feedstock;   (b) providing a hydrocarbon stream B;   (c) supplying a feed C comprising a fraction of the hydrocarbon stream A and a fraction of the hydrocarbon stream B to a thermal cracker furnace comprising cracking coil(s);   (d) performing a thermal cracking operation in the presence of steam to obtain a cracked hydrocarbon stream D;   (e) supplying the cracked hydrocarbon stream D to a separation unit;   (f) performing a separation operation in the separation unit to obtain a product stream E comprising a monomer;   (g) supplying the product stream E to a polymerisation reactor; and   (h) performing a polymerisation reaction in the polymerisation reactor to obtain an polymer,   wherein the hydrocarbon stream A comprises:
 ≥25.0 and ≤50.0 wt %, of n-paraffins; and/or 
 ≥5.0 and ≤20.0 wt %, of iso-paraffins; and/or 
 ≥25.0 and ≤50.0 wt %, of olefins; and/or 
 ≥5.0 and ≤20.0 wt %, of napthenes; and/or 
 ≥5.0 and ≤15.0 wt %, of aromatics 
   with regard to the total weight of the hydrocarbon stream A.   
     
     
         2 . The process according to  claim 1 , wherein the hydrocarbon stream A has an initial boiling point >25° C. and a final boiling point of <350° C., wherein the initial boiling point and the final boiling point are determined in accordance with ASTM D86 (2012). 
     
     
         3 . The process according to  claim 1 , wherein the hydrocarbon stream A has an atomic chlorine content of <800 ppm by weight as determined in accordance with ASTM UOP 779-08. 
     
     
         4 . The process according to  claim 1 , wherein the hydrocarbon stream A has an atomic nitrogen content of <1600 ppm by weight as determined in accordance with ASTM D5762 (2012). 
     
     
         5 . The process according to  claim 1  wherein the hydrocarbon stream A has a bromine number of <100 as determined in accordance with ASTM D1159-07 (2012). 
     
     
         6 . The process according to  claim 1 , wherein in step (c), the feed C comprises ≤50.0 wt %, of hydrocarbon stream A. 
     
     
         7 . The process according to  claim 1 , wherein the treatment of the waste plastics feedstock to obtain hydrocarbon stream A involves a pyrolysis treatment. 
     
     
         8 . The process according to  claim 1 , wherein the waste plastics feedstock comprises 90.0 wt % of polymeric material, with regard to the total weight of the waste plastics feedstock. 
     
     
         9 . The process according to  claim 1 , wherein the waste plastics feedstock comprises
 <20.0 wt % of polyesters; and/or   <20.0 wt % of polyamides; and/or   <2.0 wt % of polyvinyl chloride   
       with regard to the total weight of polymeric material in the waste plastics feedstock. 
     
     
         10 . The process according to  claim 1 , wherein the waste plastics feedstock comprises ≤10.0 wt % of ingredients being the sum of the content of glass, paper, metal, cardboard, compostable waste, wood, stone, textiles, rubber materials and superabsorbent hygiene products, with regard to the total weight of the waste plastics feedstock. 
     
     
         11 . The process according to  claim 1 , wherein the hydrocarbon stream A comprises:
 ≥25.0 and ≤40.0 wt %, of n-paraffins; and/or   ≥5.0 and ≤15.0 wt %, of iso-paraffins; and/or   ≥25.0 and ≤40.0 wt %, of olefins; and/or   ≥5.0 and ≤15.0 wt %, of napthenes; and/or   ≥5.0 and ≤12.5 wt %, of aromatics   
       with regard to the total weight of the hydrocarbon stream A. 
     
     
         12 . The process according to  claim 1 , wherein the hydrocarbon stream B comprises:
 25.0 and ≤80.0 wt %, of n-paraffins; and/or   ≥5.0 and ≤40.0 wt %, of iso-paraffins; and/or   ≥0.01 and ≤2.0 wt %, of olefins; and/or   ≥5.0 and ≤40.0 wt %, of napthenes; and/or   ≥5.0 and ≤15.0 wt %, of aromatics   
       with regard to the total weight of the hydrocarbon stream B. 
     
     
         13 . The process according to  claim 1 , wherein the feed C comprises a fraction of olefins F O,C  of ≤2.0, with regard to the total weight of feed C.