Process for the thermo-catalytic conversion of polymeric materials
A continuous process for the cracking of a polymeric material, includes the continuous introduction of the polymeric material in a stream or bath of molten catalyst. A plant for the cracking of a polymeric material is also related and includes a closed circuit/environment containing a molten catalyst, and an element adapted to keep the molten catalyst in continuous motion.
1. A continuous process for the cracking of a polymeric material, the process comprising the continuous introduction of said polymeric material in a stream of molten catalyst, wherein said molten catalyst stream flows continuously inside a pipe and said molten catalyst stream conveys said polymeric material through said pipe into a reactor.
2. The process according to claim 1 , further comprising the continuous cleaning of the molten catalyst, eliminating from the molten catalyst solid products that result from cracking of said polymeric material, and any non-polymeric contaminants that are present together with said polymeric material.
3. The process according to claim 1 , wherein said catalyst is kept at a temperature of 300-550° C.
4. The process according to claim 1 , wherein said catalyst melts at a temperature of 330° C. or less.
5. The process according to claim 1 , wherein said catalyst is a metal or a mixture of metals.
6. The process according to claim 1 , wherein said catalyst is selected from the group consisting of lead, tin, zinc, antimony, cadmium and magnesium and mixtures thereof.
7. The process according to claim 6 , wherein said catalyst is selected from the group consisting of lead, a lead-zinc mixture, a lead-tin mixture, a lead-zinc-tin mixture, a zinc-antimony mixture, a lead-copper mixture, a lead-antimony mixture, a lead-cadmium mixture, and a lead-magnesium mixture.
8. The process according to claim 7 , wherein said catalyst is lead.
9. The process according to claim 7 , wherein said catalyst is a mixture of metals selected from the group consisting of:
a lead-tin mixture in which tin is present in a quantity comprised between 5% and 35% by weight on the total weight of the mixture;
a lead-antimony mixture, in which antimony is present in a quantity comprised between 2% and 20% by weight on the total weight of the mixture;
a lead-tin-zinc mixture, in which tin is present in a quantity comprised between 25% and 40% and zinc is present in a quantity comprised between 1% and 5% by weight on the total weight of the mixture;
a lead-cadmium mixture, in which cadmium is present in a quantity comprised between 10% and 40% by weight on the total weight of the mixture; and
a lead-magnesium mixture, in which magnesium is present in a quantity comprised between 1% and 5% by weight on the total weight of the mixture.
10. The process according to claim 5 , wherein said catalyst is mixed with an acid component selected from metallic silicates, metallic carbonates, and mixtures thereof.
11. The process according to claim 10 , wherein said catalyst is mixed with an acid component selected from an aluminum silicate and a lead carbonate.
12. The process according to claim 1 , wherein said polymeric material is selected from the group consisting of:
a linear chain plastic or a mixture of linear chain plastics;
a halogenated plastic, for example PVC, or a mixture of halogenated plastics;
a branched chain plastic or a mixture of branched chain plastics;
a mixture of linear chain plastics and branched chain plastics;
a mixture of linear chain plastics and halogenated plastics;
a mixture of halogenated plastics and branched chain plastics; and
a mixture of halogenated plastics, branched chain plastics, and linear chain plastics.
13. The process according to claim 1 , wherein said polymeric material is contaminated by other non-polymeric materials.
14. The process according to claim 1 , wherein said polymeric material is a mixture of polymeric materials that originate from the management of waste selected from the group consisting of municipal solid waste and special waste.