Process for recycling composite materials and a system for treating waste gases

Patent metadata

Field	Value
Publication number	US-2016153123-A1
Application number	US-201514944723-A
Country	US
Kind code	A1
Filing date	Nov 18, 2015
Priority date	Nov 19, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

The present patent of invention describes a recycling process to recover fibrous reinforcing material of composite materials, particularly carbon fiber, primary reactor compound ( 101 ), for the controlled pyrolysis and oxidation of the composite material matrix (resin) at low temperature (400° C. to 500° C.) and a system for treating waste gases produced by thermal decomposition of composite material matrixes which employs a secondary reactor ( 201 ), containing within the same a thermal plasma arc ( 211 ). The main characteristic of the process, within the scope of the carbon fiber recycling, is the possibility of maintaining the fabric web, obtaining fabrics made of pure carbon fiber, without a significant amount of residues and preserving their structural characteristics. The thermal plasma allows managing high temperatures (2,000° C. to 15,000° C.) in a controlled atmosphere, which allows the dissociation of long chains of molecules into ions that are recombined to produce combustible gases and other acid or alkaline gases that are easily neutralized and retained in gas cleaning systems.

First claim

1 . A process for recycling composite materials, wherein it comprises the following steps:
(i) preparing composite materials and placing them into a primary reactor ( 101 ); (ii) pyrolysis of the composite material in the primary reactor obtaining fibers with soot residues; and (iii) oxidation of the fibers with soot residues obtaining recovered fibers.

2 . The process, according to claim 1 , wherein in the pyrolysis step, the composite material is confined in the primary reactor at a controlled atmosphere, and heated at temperatures ranging between 400° C. and 600° C. for a period varying between 30 and 40 minutes.

3 . The process, according to claim 2 , wherein the pyrolysis step is followed by a gasification of the components of a polymeric matrix of the composite material.

4 . The process, according to claim 3 , wherein the pyrolysis is followed by a washing step of the fibers with soot residues in deionized water.

5 . The process, according to claim 4 , wherein during washing of the fibers with soot residues the deionized water is adsorbed by the fibers.

6 . The process, according to claim 5 , wherein, after washing, the fibers with soot residues return to the primary reactor for the oxidation step of the fibers with soot residues.

7 . The process, according to claim 6 , wherein the oxidation step takes place at a temperature ranging between 350° C. and 450° C.

8 . The process, according to claim 1 , wherein during pyrolysis in the primary reactor waste gases (W) are expelled.

9 . A system for treating waste gases produced by thermal decomposition of composite material matrixes wherein it comprises:
a secondary reactor which receives waste gases and reagent gases, performs a ionization of the waste gases and a subsequent recombination of ions with each other and with the reagent gases, producing combustible gases and neutralizable gases; a combustion chamber which receives and burns combustible gases produced by the secondary reactor; a gas washer which receives and washes the neutralizable gases; and an exhaust set consisting of an exhauster associate with a flue, which expels neutralized gases into the atmosphere.

10 . The system, according to claim 9 , wherein the secondary reactor comprises a plasma arc for the ionization of the waste gases.

11 . The system, according to claim 10 , wherein the temperature in the secondary reactor varies between 2,000° C. and 15,000° C.

Assignees

• Embraer Sa

Inventors

• Da Cruz Antônio Carlos
• Da Silva Fábio Santos
• Garcia Rafael Razuk

Classifications

• C08G85/008 Primary

  Cleaning reaction vessels using chemicals (mechanical methods B08B9/08) · CPC title

• B01D53/78

  with gas-liquid contact · CPC title

• B01D53/32

  by electrical effects other than those provided for in group B01D61/00 · CPC title

• D01F9/12 Primary

  Carbon filaments; Apparatus specially adapted for the manufacture thereof · CPC title

• B01D2259/818

  Employing electrical discharges or the generation of a plasma · CPC title