Brussels – The formation recently by the standards body ASTM International of a committee on recycled carbon black could prove to be a major step forward for those promoting pyrolysis as a tire recycling technology, an industry pundit said recently.
ASTM Committee D36, Recovered Carbon Black (rCB), had its first meeting March 23 in Brussels in conjunction with the annual meeting of the European Tyre Recycling Association, according to DK Enterprises Inc., a Sacramento, Calif.-based "sustainable solutions" enterprise.
There were 42 attendees at the meeting, including rCB producers, feedstock suppliers, lab technicians, testing facility representatives and other persons interested in pyrolysis, DK said.
"For the tire recycling industry to grow, there is a high priority to find and develop qualified customers and end-users; utilize best management practices; identify the economic value and sustainable benefits; and address the potential in new technologies," DK President Denise Kennedy said.
"The customers, end-users and manufacturers need to depend on consistent quality and quantity of feedstock material in order to move forward," she said.
There also were two subcommittee meetings of D36 in Brussels — one to evaluate current carbon black standards from ASTM Committee D24 and determine how much of that standard can be applied to rCB, and the other to discuss the development of standards for rCB.
Kennedy also serves as chair of D36.40, Subcommittee on Environmental Safety and Sustainability, and as sub task chair D11.20.01 (Recycled Rubber).
Pyrolysis is defined as the thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen.
More specifically for the rubber industry, pyrolysis is the technology of breaking down rubber into its component carbon black, oil and steel under high heat. It has been the subject of many attempts at commercialisation over the past several decades.
Among the attempts was in the early 1980s, when Goodyear built a pilot pyrolysis plant. The tire maker concluded that it would take more than nine years to regain the investment on a pyrolysis facility.
That judgment dogged future efforts to make pyrolysis a success, combined with complaints that the carbon black and oil produced by various pyrolysis technologies were of low quality.
However, this perception changed over time, to the point where prominent figures in the recycling industry were endorsing it.
"Today, the technologies have significantly improved, the manufacturing costs have been reduced and the market prices for carbon and oil have significantly increased," Richard Gust, president of national accounts for Liberty Tire Recycling L.L.C., said in a 2014 article on the future of tire recycling.
Also, Titan Tire Reclamation Corp. — a subsidiary of Titan International Inc. — has opened a site at Fort McMurray, Alberta, that uses thermal reactors to break down scrap mining tires into oil, steel and carbon black. The company has plans to open similar facilities in Australia and Chile.
Two other pyrolysis companies that have established places in the recycling industry are Pyrolyx U.S.A. (formerly Reklaim Corp.), which plans to build the largest rCB plant in the world, and Delta-Energy Group L.L.C., whose depolymerisation process produces two different rCB lines, Phoenix Black and Zephyr Black.
Steven J. Renegar, vice president of sales for Pyrolyx U.S.A., and Bill Cole, vice president of product management for Delta-Energy, are both involved in ASTM Committee D36.
"It was great," Renegar said of the first meeting in Brussels. Recycled carbon black is a unique material, he added, which necessitates separate standards from conventional carbon black.
"Pyrolysis is not new to the marketplace, but there were no real guidelines that customers or suppliers could use," Renegar said. "rCB is not the same as carbon black, and not all the tests for carbon black can be used for rCB."
Whereas traditional carbon black is 99.9% carbon, rCB ranges from 88-90% carbon, according to Renegar. The material's uses depend on application, acting as a supplemental material in some cases and as a replacement for conventional carbon black in others, he said.
The purpose of D36, according to Cole, is to bring together a group of people who want to clarify standards for rCB and develop their own testing for the material.
"It will be a lot like D24 — I think that's where we will end up," he said.
Both Cole and Renegar agreed that traditional carbon black manufacturers have no interest in developing standards for rCB.
The next meetings for D36 are scheduled for June 15 in Toronto; 6 Dec in New Orleans; 28 June, 2018, in San Diego; and 6 Dec, 2018, in Washington, DC.