One person’s trash is another’s treasure
For ExxonMobil, harnessing trash provides an unorthodox way to help power an energy-efficient manufacturing facility.
They say beauty is in the eye of the beholder, but you would be hard-pressed to find people who find trash attractive. Yet it turns out garbage looks pretty good to people interested in a novel source of energy. When trash in a landfill decomposes, it releases a combination of carbon dioxide and methane. Methane released into the atmosphere is actually a potent greenhouse gas, but if it is captured it can become a reliable and clean energy source.
In Louisiana, ExxonMobil’s Baton Rouge polyolefins plant is not too far from the East Baton Rouge Parish landfill. Normally a location near a municipal dump isn’t much of a selling point, but for the company it meant an opportunity to create a win-win situation by piping the naturally occurring landfill gas to the polyolefins plant.
“We found a solution for something that was considered waste, and turned it into something valuable while helping the environment,” says George Jones, an environmental coordinator for the company. “And it improved an already strong relationship with the parish.”
ExxonMobil’s polyolefins facility in Baton Rouge makes a variety of plastic products that are used in everything from automobiles to food containers. The manufacturing process relies on steam generated by three large, natural gas-fired boilers. The company saw that retrofitting the boilers to be able to run on landfill gas would not only reduce the plant’s gas bill, but also allow it to keep garbage-produced methane out of the atmosphere.
The plant’s staff tackled the challenge of converting the natural gas-powered boilers with enthusiasm. “I like trying out new technologies,” says James Michiels, an engineer who helped integrate methane-burning technology into the plant’s boilers. “For me it was an exciting opportunity because I got to try different things to make sure the transition to methane worked.”
Ultimately everything went according to plan, and now the polyolefins plant is the main consumer of methane generated by the Baton Rouge landfill. While the boilers still use natural gas to supplement the methane, the costs associated with keeping the boilers running dropped when methane was introduced as an energy source.
“We basically use everything they send us,” continues Michiels, “and as the landfill matures, they’ll be able to send even more.” According to the State of Louisiana, using this landfill’s gas to run the boilers is equivalent to removing 59,000 cars from the road. The impressive results have helped the project garner several accolades, including an Energy Efficiency Award from the American Chemical Council and an Environmental Leadership Award from the Louisiana Department of Environmental Quality.
Perhaps the greatest triumph, though, is transforming waste into a useful commodity. Instead of simply a place where trash goes, the landfill has become a source of energy that helps drive the local economy. “If you can turn waste into something positive,” says Jones, “then maybe you can change people’s perceptions of it.”