Mechanical Engineering Magazine

TECH BUZZ ||ENERGY BY MICHAEL E. WEBBER MECHANICAL ENGINEERING | NOVEMBER 2014 | P.16

WE’RE BURYING MONEY IN THE GROUND. IT'S TIME WE REALIZED IT.

The world of waste is innovative in ways most Americans would never imagine. Advanced recycling centers in the United States, for instance, use multi-million dollar machines with high-tech conveyor systems to automatically sort different materials using lasers, optical scanners, blowers, magnets, rakes, crushers, vacuums, and other devices. Unsorted trash enters the system, and neatly separated bales of like materials exit.

As David Scott, the executive director of economic and energy affairs for the United Arab Emirates, once said, “Waste is what you have when you run out of imagination.” We can use our imagination to rethink our relationship with waste.

In spite of generating more than 20 percent of the world’s trash, Americans are pretty unsophisticated in the way we deal with it. Less than half of the 250 million tons of municipal solid waste produced annually is recycled, composted, or incinerated for energy. Most is buried in landfills.

Europeans, conversely, produce less trash per person and send very little of what they do make to landfills. Why? To begin with, they do not have much space for landfills. Europeans also have a different cultural approach to resource

WASTING AN
OPPORTUNITY
Americans generate a lot of trash and stick
most of it in landfills. We need to recover
more value from what we throw out.
make each ounce of material go further.
Americans often associate consumption
with power and conservation with weak-
ness; in Europe it’s the other way around.

Importantly, the European Union has strict regulations about the end-of-life for different consumer goods, including electronics and automobiles. These regulations mostly prohibit landfills as an option for a majority of the materials and puts a responsibility on manufacturers to create designs that can be disassembled and separated after the product life into useful materials. The result? Many of those expensive, high-value systems that automate the recycling process are imported from Europe.

Compared to Europeans, who build high-tech machinery to recover valuable materials, Americans seem backwards. We’re essentially burying money in the ground. It's time we realized it.

For example, baby diapers and some other plastics are hard to recycle and decompose slowly in landfills, but they have energy density the same as coal’s or better. These plastics can be converted into fuel pellets and used at boilers and cement plants to displace fossil fuels. Many plastics also can be liquefied into fuels that displace petroleum products. Fibers can be used as fuels or as input for building materials. Metals can be melted down and used again.

Cities still pay recyclers millions of dol-
lars to take away trash. But those costs are
dropping as the separation and recycling
technologies improve and the value of the
harvested materials increases.

Changing the way we look at trash will
require changes at every level of govern-
ment. At the state and local levels, decision
makers must recognize the value in trash;
we could be charging companies for the
right to “mine” our waste streams instead of
paying them to haul it away. Federal R&D can
bring down the costs of sorting and recycling
our trash and help improve scrubbers for
trash incinerators. Federal policymakers can
also implement strict, European-
style end-of-life requirements for
durable goods.

The U.S. military is already
operating in the new waste para-
digm. For the Department of De-
fense, waste is a strategic liability:
In some forward operating bases,
every pound of waste needs to be trucked
off site. And those trucks are soft targets
that put human lives at risk, so that reducing
trash isn’t just good for the environment—it
provides operational security.

Stateside, Fort Bliss and Fort Carson are both pursuing zero-waste initiatives. Doing so reduces the footprint of those bases and helps the military develop the expertise it needs in theater.

If reducing our waste and managing it better is good enough for our soldiers in harm’s way, it’s good enough for civilians here at home, too. We can push to turn our trash into treasure, and mechanical engineers should lead the way. ME

MICHAEL E. WEBBER is the Josey Centennial Fellow in Energy Resources and associate professor of mechanical engineering at the University of Texas at Austin.