Solving the world’s plastic problem
Alumna invents continuous,
zero-toxic-emission system that converts non recycled plastics into crude oil.
Deepak Kumar, MIT News Office
June 20, 2014
June 20, 2014
Plastic is becoming a major problem
worldwide: In 2012, the United States alone produced roughly 32 million tons of
plastic waste, while only recycling about 9 percent of its plastic, according
to the Environmental Protection Agency.
This is because of the growing use of
“nonrecycled” plastics, primarily made of polystyrene and polypropylene.
Seeing little return value, recyclers toss these plastics into landfills, where
they pile up and never decompose. As a result, landfill space is becoming a
concern.
But now MIT spinout PK Clean, founded by
Priyanka Bakaya MBA ’11, aims to end the landfilling of plastic with a
cost-effective system that breaks down nonrecycled plastics into oil, while
reusing some of the gas it produces to operate.
“Plastic comes from oil to begin with, so
it makes sense, instead of landfilling plastic, to convert it back to usable
fuel,” Bakaya says. “The goal is to end landfilled plastic waste forever — not
just domestically, but also globally.”
PK Clean’s so-called “continuous” system —
the first of its kind in the United States, according to Bakaya — runs on a
process called catalytic depolymerization, where heat and a catalyst break down
plastics into crude oil to sell to refineries.
About 70 to 80 percent of the product comes
out as oil. Roughly 10 to 20 percent becomes hydrocarbon gas that heats the
system, while the remainder is char residue.
Following a trial in Pune, India, PK Clean
last year built and installed its first full-scale commercial plant in Salt
Lake City, partnering with Rocky Mountain Recycling, Utah’s largest recycler.
Operating continuously, the plant can
convert up to 10 tons of plastic per day into 60 barrels of oil, with zero
toxic emissions. Produced at around $35 per barrel, the oil is sold to a nearby
refinery for around $100 per barrel.
After nearly a year of operations in Utah,
PK Clean plans to partner with other recyclers across the nation. Eventually,
Bakaya says the plan is to move to developing countries, “where plastic waste
is even more of an issue.”
Pushing the envelope in
design
Plastics come in seven categories: Type 1
(such as water bottles and soda bottles) and type 2 (foggy plastics, such as
milk cartons) are easily recycled. But types 3 through 7 — including plastic
foam, disposable utensils, plastic pipes, food-storage containers, and shampoo
bottles — are either not easily recycled or unrecyclable.
To convert these plastics into oil, PK
Clean first shreds them. The shreds are then entered into a reactor — which
runs at about 400 degrees Celsius — where a catalyst helps degrade the
plastics’ long carbon chains. This produces a vapor that runs through a
condenser, where it’s made into oil.
Systems using similar processes have been
around for years. But these have been too energy-inefficient and costly for
recyclers to adopt. On the other hand, PK Clean’s system, Bakaya says, costs a
quarter the price of other systems to run, while producing greater yields.
“We had to push the envelope with the
design and operating costs to make something that can be adopted and easily
used,” Bakaya says.
Much of the system’s innovation is in its
continuous operation. Other systems operate through “batch processing,” where
reactors heat up and then cool down again before the next batch is ready —
wasting significant energy and money. But the hydrocarbon gas produced by PK Clean’s
system maintains the reactor’s heat, avoiding constant rebooting and energy
loss.
Additionally, PK Clean adds a catalyst that
helps produce greater yields in the conversion process. Automated controls also
make the system much easier to use.
Within two years, Bakaya says, PK Clean
aims to produce more refined fuel that recyclers can immediately pump back into
their recycling trucks, without the need for oil refineries.
“The system is pretty close, but we have to
be on the exact specs, so we’d rather let a refinery handle that now,” Bakaya
says.
Throughout 2011, PK Clean won awards and
funding from tech entrepreneurship competitions, including the MIT Clean Energy
Prize (track winner), the MassChallenge (winner), the Rice Business Plan
Competition (best energy business plan), and the Cleantech Open (runner-up for
the national grand prize, and track winner).
Since then, Fortune, Forbes, Inc.,
and other publications have praised the company for its innovation, and lauded
Bakaya as a top entrepreneur in clean energy.
A clean-tech journey
Growing up in Australia, Bakaya was
introduced to clean technologies through a close family friend, inventor Percy
Kean — the creator of PK Clean’s catalytic depolymerization technology,
and the “PK” in the company’s name.
Kean had spent decades researching and
inventing clean technologies in his home, even turning his kitchen into a lab.
Bakaya and her family would visit him often. “He’d show me oil samples, light
it with a match, and say it came from waste. That sparked my imagination,” she
says.
Those fond memories lingered during
Bakaya’s undergraduate years at Stanford University, and during her career
forecasting oil prices on Wall Street in the mid-2000s. Oil had then crept up
to about $140 per barrel, ushering in a new demand for clean energy. So when
Kean died in 2007, Bakaya set out to commercialize his work.
Visiting a friend who was studying chemical
engineering at MIT, Bakaya sat in on an MIT Sloan School of Management class,
15.366 (Energy Ventures) — taught by Bill Aulet, managing director of the
Martin Trust Center for MIT Entrepreneurship — where she saw a path
forward.
“I thought, ‘Wow, this is exactly what I
need to get started on setting up this company,’” she says.
Enrolling in MIT Sloan, she spent two years
building her company. Classes such as 15.366, where students incrementally
design business plans, “really push you to think about all aspects of the
business,” Bakaya says.
Through that class, she also met graduate
student Arjun Gupta SM ’11, who helped with early designs of the system.
Outside the classroom, she frequented MIT’s
Entrepreneurship Club and Energy Club, where she found support among dozens of
other hopeful entrepreneurs. “Having other people going through the same thing
is something I wouldn’t have had if I hadn’t gone to MIT,” Bakaya says. Today,
this close group of 30 to 40 budding entrepreneurs still help one another
promote their businesses via social media.
After graduation, she says, PK Clean
benefitted — and continues to benefit — from the “MIT brand name.” Apart from
lending credibility to the technology, Bakaya believes coming from MIT helped
the company find early investors, and get chosen for a Bay Area incubator.
“Looking back, those three things at MIT
— the classes, the network, and the brand name — have been an
enormous help in launching the company and getting started,” Bakaya says. “PK
Clean wouldn’t be possible without MIT.”