High-temperature pyrolysis of plastics to monomers with high gas velocity

Patent metadata

Field	Value
Publication number	US-2022010218-A1
Application number	US-202117365546-A
Country	US
Kind code	A1
Filing date	Jul 1, 2021
Priority date	Jul 11, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A high-temperature plastic pyrolysis process that can produce high yields of ethylene, propylene and other light olefins from waste plastics is disclosed. The plastic feed is pyrolyzed at a high temperature of about 600 to about 900° C. directly to monomers, such as ethylene and propylene. The pyrolysis reaction can be conducted in a fluidized manner which requires separation of heat carrier particles from pyrolysis gases.

First claim

1 . A process for converting plastics to monomers comprising:
contacting a plastic feed stream with a stream of hot heat carrier particles in a reactor; heating the plastic feed stream to an elevated temperature of about 600 to about 1100° C.; lifting the plastic feed stream and the stream of hot heat carrier particles together; pyrolyzing the plastic in the plastic feed stream to gaseous products including monomers; separating the gaseous products from the heat carrier particles; and recovering said monomers from said gaseous products.

2 . The process of claim 1 further comprising lifting the plastic feed stream and the stream of hot heat carrier particles by use of a diluent gas stream.

3 . The process of claim 2 further comprising lifting the stream of hot heat carrier particles into the plastic feed stream with the diluent gas stream.

4 . The process of claim 1 further comprising feeding the stream of hot heat carrier particles through a heat carrier particle inlet into the reactor and separating the gaseous products from the heat carrier particles above the heat carrier particle inlet.

5 . The process of claim 2 wherein the heat carrier particles are spherical.

6 . The process of claim 5 further comprising reheating the separated heat carrier particles in a reheater and recycling a stream of the hot heat carrier particles from the reheater to the reactor.

7 . The process of claim 5 further comprising combusting fuel gas in the reheater to reheat the hot heat carrier particles.

8 . The process of claim 1 further comprising quenching the gaseous products with a cooling liquid to terminate the pyrolysis reaction.

9 . The process of claim 1 further comprising discharging the gaseous products and the heat carrier particles from the reactor before separating the gaseous products from the heat carrier particles.

10 . The process of claim 1 further comprising separating said gaseous products from said heat carrier particles in a cyclonic separator.

11 . A process for converting plastics to monomers comprising:
feeding a stream of hot heat carrier particles to a reactor; feeding a plastic feed stream to the reactor; lifting the hot heat carrier particles with a diluent gas into contact with the plastic feed stream; heating the plastic feed stream to an elevated temperature of about 600 to about 1100° C.; pyrolyzing the plastic in the plastic feed stream to gaseous products including monomers; separating the gaseous products from the heat carrier particles; and recovering said monomers from said gaseous products.

12 . The process of claim 11 further comprising lifting the plastic feed stream and the stream of hot heat carrier particles together by use of a diluent gas stream.

13 . The process of claim 11 further comprising feeding the stream of hot heat carrier particles through a heat carrier particle inlet into the reactor and separating the gaseous products from the heat carrier particles above the heat carrier particle inlet.

14 . The process of claim 11 further comprising reheating the separated heat carrier particles in a reheater and recycling a stream of the hot heat carrier particles from the reheater to the reactor.

15 . The process of claim 11 further comprising quenching the gaseous products to terminate the pyrolysis reaction.

16 . The process of claim 1 further comprising discharging the gaseous products and the heat carrier particles from the reactor before separating the gaseous products from the heat carrier particles.

17 . The process of claim 1 further comprising separating said gaseous products from said heat carrier particles in a cyclonic separator.

18 . A process for converting plastics to monomers comprising:
feeding a stream of hot heat carrier particles into a reactor through a particle inlet; contacting a plastic feed stream with a stream of hot heat carrier particles in a reactor; heating the plastic feed stream to an elevated temperature of about 600 to about 1100° C.; pyrolyzing the plastic in the plastic feed stream to gaseous products including monomers; moving the plastic feed stream and the stream of hot heat carrier particles together toward a reactor outlet; separating the gaseous products from the heat carrier particles; and recovering said monomers from said gaseous products.

19 . The process of claim 18 wherein the reactor outlet is above the particle inlet.

20 . The process of claim 18 further comprising:
discharging the heat carrier particles and the gaseous products from the reactor outlet; and
separating the heat carrier particles from the gaseous products.

Assignees

• Uop Llc

Inventors

• Davydov Lev

Classifications

• C08J2323/06

  Polyethene · CPC title

• C10B53/07

  {of solid raw materials consisting} of synthetic polymeric materials, e.g. tyres (recovery or working-up of waste materials of organic macromolecular compounds or compositions based thereon by dry-heat treatment for obtaining partially depolymerised materials C08J11/10; production of liquid hydrocarbon mixtures from rubber or rubber waste C10G1/10) · CPC title

• C10B49/22

  according to the "fluidised bed" technique · CPC title

• C08J11/12

  by dry-heat treatment only · CPC title

• C10G2400/20

  C2-C4 olefins · CPC title