20 May 2013 23:03 [Source: ICIS news]
By Jeremy Pafford
SAO PAULO (ICIS)--One man’s love of cows may someday help mankind get rid of its plastic bag waste problem.
The end result of that bovine devotion is a breakthrough – the creation of compostable polyethylene (PE), said Narinder Bharj, a director at London-based polymer technology company Advanced Enzyme Science (AES). He made his comments on the sidelines of the 2013 Feiplastic convention.
The unnamed researcher who came up with compostable PE was attempting to solve a problem near to his heart – he was tired of seeing cows in India die from ingesting plastic bags or suffocating accidentally from them, Bharj said.
“So he thought: 'Well, we [people] did this. We must fix this.'” Bharj said.
It took eight years of research in which the Indian researcher processed about 80 tonnes of PE on his own, trying to find the right combination of enzymes that would breakdown PE in a short frame of time, said Bharj and Wayne Dobson, another director with AES.
Making compostable bags out of faux-plastic has been done before, but they did not have the strength and capabilities of PE, Bharj said. Also, the notion of using enzymes to break down the plastic is not a new one, but with thousands upon thousands of possible enzyme combinations, finding the right mix was always elusive, he said.
So it was with the Indian researcher – at least for eight years.
“This man must have had the patience of God himself,” Bharj said.
The patience paid off, the AES directors said, and the researcher found the right blend of enzymes to meld into the PE production process to make a version of the plastic that acts the same as a regular PE bag until it reacts with microbes in soil.
The microbes activate the enzymes in melded into the PE and start to break it down by inserting oxygen into the carbon chain – basically turning the substance into a carbohydrate, Bharj said. Because it is a carbohydrate, it could accidentally be ingested by an animal and processed like a food substance, thereby solving the problem the Indian researcher had, he said.
The entire breakdown of compostable PE takes three years at the most, and many times occurs within six months of it being composted, Bharj said. It all depends on the heat from the soil or compost pile, the number of microbes available and other factors.
AES was sold on the researcher’s technology, and the company has him on board with its launch through the Enzymoplast name. AES is marketing the sale and production process of the key enzymes to PE producers globally.
Interest in Enzymoplast has been brisk, Bharj and Dobson said, with major plastics players starting to pay attention. A few smaller businesses, such as KFC restaurants in southern India, are using the technologies for their PE bags, Bharj said.
The key is convincing businesses that make PE plastics to make the change, the directors said, as many producers do not deal their product post-production.
“I just wish more of the industry took the time to understand what it is that’s going on,” Bharj said. “They talk a good story, but that’s about it.”
As if the environmental benefits were not enough, Bharj said that it was discovered later in testing that, besides carbon dioxide, decomposing compostable PE emits ethanol and methanol – two fuel chemicals that, if gathered, could make the composted PE into an energy maker, Dobson said.
Also, tests have shown compostable PE to be 2-3% stronger than normal PE, which could allow producers to use less PE to in production and possibly make the implementation of the enzymes almost cost neutral, Bharj said.
Trials are underway to use compostable PE in the creation of polyethylene terephalthlic acid (PET) for use in making compostable drink bottles, he said. That could lead to the solving another long-term plastics waste problem – similar to the problem the Indian researcher was trying to solve.
“It goes back to day one. The man did it, and it wasn’t for commercial reasons. He had a thought,” Bharj said. “I think that gives us a good base as a company.”
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