Page 51 - Plastics News September 2017

TECHNOLOGY

How two microbes joined forces Karnataka, U.S. researchers

to produce bio-diesel from develop cheaper plastics

carbon waste pplying high-end technologies of the laboratory to
Athe cruder machines used in industries, a team of
sing microbes growing researchers from the National Institute of Technology,
Uin two diverse climatic Karnataka, and the New York University, U.S., have
developed composite plastics that are up to 36%
conditions, Indian scientists
lighter than those being used. The team focussed on
have found a way to convert
incorporating hollow microspheres into high density
carbon-rich waste materials
polyethylene, the most commonly moulded plastic
into bio-fuel. A team of product. Through a trial and error method spanning
researchers from Delhi’s two years, researchers have managed to shed plastic
Jawaharlal Nehru University use by 20%. They have replaced it with fly ash
(JNU) not only discovered two cenospheres and glass microballoons.
distinctly different species “The problem with composite materials is that it
is done in controlled conditions in the laboratory
of bacteria from Aravalli marble mines near Alwar and
which cannot be replicated in the industry. But with
from the high-altitude Pangong Lake in Ladakh, but also
the technique we have developed, low-cost, light-
found that they can combine forces to produce bio-diesel
weight composites can be produced at any industry
from carbon-containing waste materials. The bacterium using the normal compression moulding machines,”
identifi ed and isolated from the marble rocks in Rajasthan,
calledSerratia sp. ISTD04, is capable of sequestering
atmospheric carbon dioxide into organic compounds such
as lipids. Meanwhile, lipase, which the team isolated
from cold-loving bacterium Pseudomonas sp. ISTPL3, can
convert these lipids into bio-diesel.
“This lipase is nothing but an enzyme that works as
a catalyst to produce bio-diesel,” said Indu Shekhar
Thakur, who led the research. “We hope this can be a
cost-effective way of converting a waste product to an said Mrityunjay Doddamani, lead researcher and an
assistant professor in the Mechanical Engineering
eco-friendly fuel,” he said, adding that the team had
already fi led for patents. The fi ndings recently appeared Department of the institute in Surathkal. The
researchdone along with M.L. Jayavardhan from
in two publications: Journal of Energy and Environmental
Sustainability and Bioresource Technology . According NITK; B.R. Bharath Kumar from the Jain College of
Engineering and Technology at Hubbali; and Ashish K.
to Thakur, the microbe isolated from the marble mines
not only sequesters carbon dioxide implicated in climate Singh, Steven E.
Zeltmann and Nikhil Gupta from NYU was published in
change, but also converts it into valuable organic
compounds. “What is signifi cant is that 60 per cent of its the journal, Composites Part B , recently. While hollow
microspheres and composites are lighter and cheaper,
body weight is nothing but lipids that can be converted
into bio-diesel through a catalytic process,” he said. This the challenge facing the team was to ensure the
microspheres remained intact despite the processes
catalytic processcalled transesterifi cation can be done
using either chemical catalysts or enzymes such as the of industrial moulding.
By successfully imbibing hollow spheres into otherwise
one the scientists isolated from the microbe found in the
brackish water of Pangong Lake, which is shared between solid plastic base, Prof. Doddamani said the density
of the material was brought down by nearly half. The
India and China.
The scientists said they were amazed to see the lipase end material was found to have a signifi cantly greater
ability to absorb energy. The researchers believe that
has very high conversion efficiency. They have also
demonstrated that the lipase could be recycled several this could see the production of more light-weight
material and the reduced use of plastics.
times.

51 September 2017 | Plastics News