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October 2007

Tire de-vulcanization is goal of Green Rubber Global
by Irwin Rapoport Write the Author

Charles Goodyear accidentally discovered the vulcanization process in 1839 when he found that adding sulphur strengthened the bonds between the chains of carbon, thereby making rubber products resistant to temperature changes, which gives rubber its durability, elasticity and strength.

A major attempt to find the formula for the successful and economical de-vulcanization of rubber is being undertaken in Gallup, New Mexico by Green Rubber Global (GRG), a subsidiary of the Malaysian-based Petra Group and backed by investors including actor Mel Gibson.An artists rendering of a Green Rubber  Global factory.

The multi-million dollar prototype plant, expected to open in 2008/2009, is being built with partial funding from the town, McKinley County ($1 million), and the state government ($3 million). The plant will be leased to GRG for 10 years.

Ten years ago an unsuccessful attempt was made to de-vulcanize rubber based on a chemical process developed by the late Dr. B. C. Sekhar, the father of Vinod Sekhar, the founder and president of the Petra Group.

Sekhar says that the amount of annually discarded tires in the United States translates into 1.5 billion gallons of lost fossil fuel. The tires will be de-vulcanized via DeLink, a patented chemical process.

“This reverses the vulcanization process and creates a de-vulcanized rubber compound that can be used to make a variety of rubber products,” says GRG president Rick Homans, who stresses that current tire recycling is limited to shredding and converting tires into crumb rubber.

The mechano-chemical process, says Homans, which can utilize standard rubber processing machines, results in zero-emissions and by-products. The current formula shows results in 100 parts of crumb rubber and two parts of the De-Link compound.

“Nothing is left on the table,” says Homans. “It’s all absorbed into the de-vulcanized rubber compound. DeLink separates the sulphur bonds and material reverts to its original state.”

Homans says the rubber can be used in the manufacturing of mats, hoses, fenders and tires.

Responding to critics who question the de-vulcanization research and cite the attempt undertaken 10 years ago by the Petra Group, Homan’s responds, “I don’t think there were too many questions about the science; there were questions about the economics. Then, the technology required 10 to 14 parts of DeLink per 100 parts of rubber.

The discovery of successful de-vulcanization has an extremely technical aspect that requires extensive studies.

“The price of rubber and oil were a lot lower then and there was not nearly the concern about the environment that there is today,” he adds. “We understand there is a lot of skepticism because this has been a process that been sought after for many years and there have been many claims that have proven less than credible.

“Our approach is going to have a lot of transparency, testing and letting the performance speak for itself with each customer,” he adds. “The test results from independent testing organizations like TARRC in the U.K. confirm the viability of this process. It seems to be a simple and effective process, one with the potential to transform the rubber industry in a positive way.”

The Washington, D.C.-based Rubber Manufacturers Association (RMA) has been one of those skeptical voices.

“It is in the best interests of RMA and other rubber manufacturers to encourage innovation in the industry and scientists and entrepreneurs like GRG through our partnership with the rubber industry to find solutions to the vexing problem of waste rubber,” says Homans, “which provides a limiting factor on the growth of the rubber industry. Right now to the credit of the RMA and the tire industries, they have worked out a solution that looks to be better – using waste tires as fuel for cement kilns.

“The position has been that there was a huge political, health and environmental problem – a visible one – with waste tires going into landfills,” he adds. “The industry has moved the waste, for the most part, from the landfills to smokestacks. This is where 45 percent of the waste tires in this country end up. There is no question that the rubber and cement industries are doing everything possible to limit the emissions, but it is not the best solution. The best solution according the United States EPA and all kinds of other industry groups is to find a way to re-use the rubber.”

Michael Blumenthal, the RMA’s senior technical advisor, defends his group’s skepticism. “As with all new technologies, the question at hand is whether this company can achieve the results they claim are possible,” he says.

“This is both expensive and time- consuming, and is a process which does not guarantee success,” he adds. “We would also like to point out that this is basically the same technology that failed to achieve any market share when it was first introduced into the United States marketplace, some 10 years ago.

“We have taken a wait and see attitude towards this venture,” he added. “They have made a lot of public statements. I believe that the challenge of reversing the vulcanization process will continue to attract the interest of scientists.”

Commenting on the use of tires as a fuel, Blumenthal says “it has (for energy recovery) been proven to be an env- ironmentally sound use.

Recently the EPA published a policy paper in support of tire derived fuel (TDF).” Moreover, he stresses that the RMA would endorse the use of de-vulcanized rubber.

“If a de-vulcanized rubber material can provide an engineering benefit and a cost advantage,” he says, “then it could be considered for use in the rubber industry.”

According to the RMA, approximately 13 percent of the scrap tires generated in the United States go into landfills, while some 55 percent go to the TDF market.

“It would seem that there might be more tires going to the pulp and paper industry today then into cement kilns,” says Blumenthal.

Should the process prove itself, GRG plans to open plants in major metropolitan areas in North America, Europe and Asia.

“The most important feature of locating a plant is access to waste tires and government and industry partners that want to dispose of these tires in an effective ‘green’ way,” says Homans. “We view the New Mexico plant as a pilot plant and we can base our research and development because of the continuous improvement of the manufacturing process and technology will be absolutely vital to our success in future years.”

Currently, says Homans, the tire recycling industry has been able to shred discarded tires, remove the steel and fiber, then mash it and pulverize it down to different sized crumb that can be used to make mats and other surfacing materials. Crumb rubber is also being used to manufacture rubber sidewalks and playground equipment, products that are now on the market and found in many cities and soon to be used to manufacture rubber rail ties.

“There has never been a way to reverse the vulcanization process,” says Homans. “The recycling industry has been very inventive and creative in the way that they use crumb rubber.”

He stresses that with global demand for rubber growing, the worldwide demand for rubber is expected to exceed supply in 2017.

“That is going to have a serious impact on the price of rubber and it is imperative that the industry find a way to expand the supply and recycling rubber into a rubber compound is best way to expand the supply,” says Homans. “One of the most effective uses of DeLink will be in factories that are making rubber products and they generate anywhere from 5 to 10 percent waste.

“Today that waste is considered a cost of doing business,” he adds. “What we can do for these companies are scoop up the waste and convert into a rubber compound that that can go back into the production process. We can eliminate the cost of waste and supply a new stream of compound at a lower cost.”