Over time, Vartega plans to expand the recycled products that it offers. It is already working with partners to develop the technology to recover resins and sell them, and it may expand into thermoplastics recycling at some point as well.
Solving a Big Problem
One very large recycling challenge, and one that’s been garnering a lot of press attention recently, is end-of-life composite blades from wind turbines. Media outlets, including NPR, BBC and Bloomberg Green, have carried stories about the very limited options that currently exist for recycling these giant composite components. A Bloomberg article published online on March 9 notes that in the U.S. alone about 8,000 of these blades will be removed from service annually for the next four years, and almost all of them are destined for landfills.
Companies in the U.S. and Europe are trying out a variety of wind blade recycling solutions. According to an article in Energy News Network, Global Fiberglass Solutions is slicing them into pellets that can be used for flooring and other construction materials, while Bloomberg reports that the Danish company Miljorskam is grinding them up into highway noise barriers.
For more than two years, ACMA has been working with IACMI, CHZ Technologies, Continental Structural Plastics, A. Schulman and the University of Tennessee, Knoxville, to develop a technology that recycles wind blades and other thermoset composites. The goal is not only to reclaim the glass and carbon fibers, but also to recover the energy used in their production.
The team began with the testing of several different composites using CHZ’s Thermolyzer™ technology at an undisclosed location. The facility is designed to recycle a wide variety of materials, including composites, railroad ties, utility poles and plastics. It can handle between six to 10 tons of material a day.
The Thermolyzer uses continuous, oxygen-free, pyrolysis to break down the composite materials into glass fibers and/or carbon fibers, as well as a clean gas that can be used for powering the process. The equipment also converts any toxic materials in the composite into inert salts.
During the project’s first phase, the Thermolyzer processed composite materials from four different sources: a tractor panel that contained both glass and carbon fibers; a GFRP sheet molding compound (SMC) automotive panel; a wind turbine blade cap made with carbon fiber; and wind blades that contained glass fiber, balsa wood and other materials.
“Each of these materials had different resins and different fibers that had some unique characteristics. They had to be processed in a way that optimized the recovered fiber properties,” says Chuck Ludwig, managing director of CHZ Technologies. That required adjusting the temperatures and dwell times. For composites that contained glass fiber, the team also modified the process to reduce the strains and stresses on the glass fibers so that they would retain as much of their modulus and rigidity as possible.