Cracking process
AssigneeUnion Carbide Corporation
InventorsCharles W. Albright, George E. Keller, II
Life of this patent
Estimating the term…
Abstract
A process for cracking thermoplastic polymers to valuable products, primarily their monomers, comprising the following steps: A. converting the polymer into a liquid or fluidized stage; B. introducing the polymer from step (a) in droplet or particulate form into a reaction zone and admixing said polymer with a hot inert gas or mixture of hot inert gases in the reaction zone Wherein the weight ratio of gas to polymer is about 1 to about 8 parts of gas per part of polymer; the temperature of the gas is such as to heat the polymer to a temperature in the range of about 800.degree.C. to about 1050.degree.C.; and the residence time in the reaction zone is about 10 to about 100 milliseconds; and C. quenching the recovering product.
Claims20
A process for cracking polyethylene or polypropylene to monomer comprising the following steps:
- a. converting the polymer into a fluidized particulate state;
- b. introducing to a reaction zone a cracking gas comprising steam and the polymer from step (a) and admixing said polymer with the cracking gas in said reaction zone
- wherein the weight ratio of cracking gas to polymer is about 1 to about 8 parts of gas per part of polymer, the temperature of the cracking gas is such as to heat the polymer to a temperature in the range of about 800.degree. C. to about 1050.degree. C., and the residence time of the polymer and the products derived from the cracking thereof in the reaction zone is about 10 to about 100 milliseconds;
- and
- c. quenching effluent from the reaction zone and recovering the monomer.
A process for cracking polyethylene or polypropylene to monomer comprising the following steps:
- a. converting the polymer into liquid droplet form;
- b. introducing to a reaction zone a cracking gas comprising steam and the polymer from step (a) and admixng said polymer with the cracking gas in said reaction zone
- wherein the weight ratio of cracking gas to polymer is about 1 to about 8 parts of gas per part of polymer, the temperature of the cracking gas is such as to heat the polymer to a temperature in the range of about 800.degree. C. to about 1050.degree. C., and the residence time of the polymer and the products derived from the cracking thereof in the reaction zone is about 10 to about 100 milliseconds;
- and
- c. quenching effluent from the reaction zone and recovering the monomer.
A process for cracking polyethylene to ethylene monomer which comprises the following steps:
- a. converting polyethylene into a fluidized particulate state;
- b. introducing into a reaction zone a cracking gas comprising a mixture of combustion gases produced from the essentially complete combustion of a fuel gas and oxygen mixed together with steam, at an inlet temperature of about 950.degree. to about 2000.degree. C.;
- c. introducing the polyethylene from step (a) into the reaction zone and admixing the polyethylene with the cracking gas therein
- wherein the weight ratio of cracking gas to polyethylene is about 1 to about 8 parts of gas per part of polyethylene, the outlet temperature of the reaction zone is in the range of about 800.degree. C. to about 1050.degree. C., the pressure in the reaction zone is in the range of about 5 psig to about 30 psig, and the residence time in the reaction zone of the polyethylene and the products derived from the cracking thereof is about 10 to about 100 milliseconds;
- and
- d. quenching the effluent from the reaction zone and recovering product comprising ethylene monomer.
Dependencies are inferred from the claim text.