3 September 2008

A New Bioplastic, Made by Bacteria

Microorganisms to recycle old plastic bottles and containers

The employee of the decade in green tech is scum.
University College Dublin (UCD) has come up with a way to recycle old plastic bottles and containers with microorganisms. The end result – the thing that comes out of the bacteria’s digestive system – is a new piece of plastic.

The difference, however, is that the plastic that comes out of the process is biodegradable. It can go safely into a landfill and will disappear over time, said Kevin O’Connor, the lead researcher on the project during a presentation at Copenmind, a university tech transfer conference taking place this week.

If the process can be brought up to an industrial level, it could help the world get rid of the nation-sized mass of plastic that humanity has generated. Right now, there are two general ways of dealing with old plastic.

Some countries, like England and Ireland, ship it to other countries after doing the green thing and recycling. Plastic bottles have a low recycling value; hence, a lot of the plastic ends up in landfills forever. (But the Irish are big into recycling – a 15 cent tax on plastic bags dropped their use by over 99 percent, O’Connor said.)

The other method to “recycle” plastic is to burn it. Sweden, Switzerland, Germany and other countries practice it. It yields useable energy, but it’s not the cleanest practice in the world either.

UCD’s process works like this. Polypropylene (plastic) is cooked until it turns into a styrene oil. The oil is then fed to microorganisms, which metabolically turn it into globules of fatty acids.

When 60 percent of the bacteria consists of those fatty acids, the microorganism is split open and the harvested fatty acids are converted to a biodegradable plastic. See why bacteria make such good workers? Try to do that to your new hire from Cal State Fullerton and the first thing he’ll do is file a worker’s compensation claim.

It’s good plastic too. The glass transition temperature – the temperature that makes it brittle – is a low minus 43.3 degrees Celsius, so it’s freezer safe. You can heat it to 278 Celsius.

“But it will degrade in a compost heat at 32 degrees because the microorganisms (in the landfill) release enzymes,” he said.

Industrial microbiology is the basis of a number of other start-ups, including Cambrios (microbes making industrial chemicals) and AgraQuest (biopesticides).

Melting the plastic into an oil requires energy. The overall balance, however, is better than if you made a second, separate bottle, O’Connor asserted. A kilogram of plastic yields 350 grams of new plastic. The missing oil goes to the microorganism: they feed off the oil to grow.

The group has filed for a few patents. Next year, it wants to move out of the lab and do a multi-kilogram recycling center with a large waste company.

Keep your eye on Ireland in cleantech and advance science, by the way. For years, the Irish tech industry primarily concentrated on serving as an outsourcing destination for multinationals. But in about 2000, the government – realizing that Ireland was no longer a low-cost center – began to invest in technology transfer center and incubators.

The pitch made to scientists is straightforward. Unless researchers can’t come up with interesting commercial applications, funding may get cut during austerity times, Pat Frain, who runs NovaUCD (the school’s incubator) told me earlier this year. Plus, you might become incredibly wealthy. Other incubation centers in Ireland are working on ocean power, semiconductors and material science. (See this masterpiece of cinema for more.) Another interesting project at UCD: BiancaMed, which has a wireless device that can tell you what happens to your body while you sleep.

Whether or not the incubator program ends up creating successful start-ups, however, won’t like be known for another five years.

Source: greenlight.greentechmedia.com, 2008-09-02.


Share on Twitter+1Share on FacebookShare on XingShare on LinkedInShare via email