USC’s efforts to become more sustainable have reached almost every corner of the university park and health sciences campus — including the chemistry labs.
At USC Dornsife College of Letters, Arts and Sciences, chemistry professors Jessica Parr and Travis Williams recently implemented techniques to make their respective research labs more environmentally friendly and advance both university priorities and their discipline’s best practices.
In 1998, the American Chemical Society developed 12 Principles of Green Chemistry, which include actions such as developing safer chemicals, energy efficiency, and pollution prevention.
The chemical world has also emphasized the proper disposal of waste, Parr said. At USC, this includes practices as simple as properly labeling waste for USC Environmental Health and Safety to ensure proper disposal.
“I think the whole community sees this as our responsibility to figure out how to fix things and turn things around and show that we care about the environment overall,” Parr said.
For example, Parr’s freshman labs have all but eliminated the use of mercury in experiments, including replacing old mercury thermometers. Likewise, in experiments that produce water or salt that can be poured down the drain, students are instructed to use a waste container for the product.
“Hopefully, if we introduce students to these practices early on as they progress to other lab experiences, they will retain some of these ideas and sustainable processes,” she said.
Replacement of devices for more energy efficiency
Efforts such as switching from Bunsen burners or other open flames to electric hot plates have become common in chemistry over the past 50 years as the field has attempted to move away from the use of fossil fuels, primarily for safety reasons. The next challenge is how labs can reduce energy use in general, Williams said. Hotplates may not make the list of the biggest energy consumers in a lab, but X-ray machines are definite competitors.
When it comes to sustainability, generating X-rays for things like diffraction and tomography is a hugely energy-intensive activity. And when machines use so much energy, coolers need to be running to keep them from overheating and using even more energy.
That’s why Williams’ lab—with help from the Anton Burg Foundation and the National Science Foundation—introduced a new machine for the chemistry department’s X-ray lab that significantly reduced energy consumption.
“We’ve upgraded to a new microfocus diffractometer that’s not only a much better scientific tool, but it also uses a fraction of the electricity,” Williams said. “Then we put blinds on the windows to keep the sun’s heat out, and now we’ve almost halved our electricity use.”
The method is known as X-ray crystallography, which is used to obtain a three-dimensional molecular structure from a crystal. This technology allows the positions of atoms in each crystal to be accurately mapped by viewing the crystal’s diffraction pattern from an X-ray beam.
The chemistry core laboratory has three x-ray machines of different sizes. The largest machine, which Williams dubbed the “beast,” was replaced in November with a newer model that uses a fraction of the energy. The old machine required a maximum of about 16 kilowatts (kW) of power to operate, compared to the new machine, which only consumed a maximum of about 7 kW. Running the new machine continuously for an hour is a maximum of 7 kilowatt hours (kWh), with Williams typically measuring around 5 or 6 kWh.
In terms of heat generated, the old machine was producing around 24,000 British Thermal Units (Btus) per hour; The new machine only produces 8,500 Btus per hour. To put that in perspective, an air conditioner needed to cool 24,000 Btus is the same unit needed to cool a four bedroom apartment.
“It’s not like a stir plate where you save a few amps,” Williams said. “We could retire two air conditioners because we use a lot less electricity and produce less heat.”
Green chemistry, sustainability and the future
Earlier this year, around 3 p.m. on a sunny Sunday in May, California ran on 100% renewable energy for the first time. Though it was relatively brief, Williams said the moment was remarkable and a step in the right direction.
“Having kissed the intersection of California’s green power exports has me rethinking my research directions toward our new life in a post-scarcity electricity market,” Williams said. “Shall we desalt? How do we produce? How do we fuel planes, trains and cars in this new world?”
Parr knows there is no one-size-fits-all technology that will solve the big problems we face, but she said it’s the small changes made by people in all areas that will have the biggest impact.
“Similar to climate change, I’m not sure we have that silver bullet yet,” she said. “But I think everyone can always do a little bit better than what they’re doing now.”
More stories about: Chemistry, faculty, sustainability