US 12,742,123 B2 · Light olefin recovery from plastic waste pyrolysis

Abstract

Systems and methods are provided for integration of a reactor for polyolefin pyrolysis with the effluent processing train for a steam cracker. The polyolefins can correspond to, for example, polyolefins in plastic waste. Integrating a process for polyolefin pyrolysis with a steam cracker processing train can allow a mixture of polymers to be converted to monomer units while reducing or minimizing costs and/or equipment footprint. This can allow for direct conversion of polyolefins to the light olefin monomers in high yield while significantly lowering capital and energy usage due to integration with a steam cracking process train. The integration can be enabled in part by selecting feeds with appropriate mixtures of various polymer types and/or by limiting the volume of the plastic waste pyrolysis product relative to the volume from the steam cracker(s) in the steam cracking process train. By selecting plastic waste and/or other polyolefin sources with an appropriate mixture of polyolefins as the feedstock, the resulting polyolefin pyrolysis product can be separated in a steam cracking process train to produce separate fractions for various polymer grade small olefin products.

Claims10

Dependent claims

A method for pyrolyzing a mixed polyolefin feed, comprising:

exposing a feedstock comprising a mixture of polyolefins comprising two or more types of monomers to polyolefin pyrolysis conditions to form a pyrolysis effluent;
separating the pyrolysis effluent to form at least a pyrolysis product fraction and a fraction comprising solid particles;
performing steam cracking on a steam cracker feed to form a steam cracker reactor effluent, wherein the steam cracker feed comprises one or more of whole and partial crudes, naphtha boiling feeds, distillate boiling range feeds, atmospheric resid boiling range feeds, or vacuum resid boiling range feeds, the steam cracker feed being separate from the feedstock;
separating the steam cracker reactor effluent to form at least a first fractionator product and one or more additional fractionator products having a higher boiling range than the first fractionator product;
passing at least a portion of the first fractionator product and at least a portion of the pyrolysis product fraction into a process gas compressor to form a compressed olefin product fraction;
and
separating at least a first product stream comprising ethylene and a second product stream comprising propylene from the compressed olefin product fraction.

4 more elements

An integrated system for performing polyolefin pyrolysis and steam cracking, comprising:

a feedstock source containing a feedstock comprising a mixture of polyolefins comprising two or more types of monomers;
a pyrolysis reactor configured to subject the feedstock to polyolefin pyrolysis conditions to form a pyrolysis effluent;
a first separation stage configured to separate the pyrolysis effluent to form at least a pyrolysis product fraction and a fraction comprising solid particles;
a stream cracker feed source containing a steam cracker feed comprising one or more of whole and partial crudes, naphtha boiling feeds, distillate boiling range feeds, atmospheric resid boiling range feeds, or vacuum resid boiling range feeds, the steam crack feed being different from the feedstock,
a steam cracking reactor configured to crack the steam cracker feed to form a steam cracker reactor effluent,
a second separation stage configured to separate the steam cracker reactor effluent to form at least a first fractionator product and one or more additional fractionator products having a higher boiling range than the first fractionator product;
a process gas compressor configured to form a compressed olefin product fraction from the at least a portion of the first fractionator product and at least a portion of the pyrolysis product fraction;
and
a plurality of olefin separation stages configured to separate a first product stream including ethylene and a second product stream comprising propylene from the compressed olefin product fraction.

6 more elements

Dependencies are inferred from the claim text.

Light olefin recovery from plastic waste pyrolysis

Life of this patent

Light olefin recovery from plastic waste pyrolysis

Life of this patent

Abstract

Claims10