Incineration is still widely used to dispose of discarded tires. A green materials company is providing an alternative that monetizes waste rubber, saving significant energy and lowering the cost of making new tires - and even some plastics.
Lehigh Technologies takes industrial rubber and processes it into micronized rubber powders (MRP) that can be blended in with virgin rubbers and plastics. Over 140 million tires have mixed in MRP to date, and the company received a US$16 million investment last month to scale up its capacity and locations.
The powers are produced by flash freezing small chunks of industrial waste rubber with liquid nitrogen, and then grinding it through machinery that resembles a jet engine with teeth. The end product has many practical uses and saves resources.
Manufacturers that use MRP in their products save 30-40 percent over the cost of virgin materials and reduce oil consumption by 0.8 gallons for every pound of MPR that's used, said CEO Alan Barton. Georgia Tech's sustainability institute independently validated the energy savings, he noted.
New tires may contain a blend of up to 7 percent MRP, depending on their size (truck tires would contain more). Other rubber products such as the jigsaw floor tiles that are found at gymnasiums and convention centers could contain up to 40 percent MPR, Barton said.
The potential applications go well beyond rubber; adding a sprinkling of MRP can enhance unrelated products. It is also used to make plastic storage containers, makes asphalt roads more resistant to the extreme temperatures, and can improve the effectiveness of an automobile's foam insulation, Barton said.
Lehigh Technologies says that MRP offers nearly the same energy savings for plastics as it does with tires, but that claim has not yet been independently verified.
This waste rubber could otherwise have been burnt at a cogeneration plant or used to make concrete. Approximately 50% of industrial rubber is disposed of this way, Barton said. Engineering modern tires required many years of chemical research, but "the best we can do with all of that novel chemistry is to burn it? That's pretty bad," he added.
The company is not yet profitable, but getting into the black is the purpose of its latest round. Lehigh's process requires relatively low capital, and it has received no subsidies.
This is a good example of how scarcity and the rising cost of energy can compel innovation where it was overlooked in times of plenty.