The National Magnetic Resonance Facility at Madison (NMRFAM) housed in the UW–Madison Department of Biochemistry is home to state-of-the-art technology for biomolecular nuclear magnetic resonance (NMR) spectroscopy and related techniques. The facility’s equipment requires helium, and with worldwide supplies dwindling, has recently installed a helium recovery system to increase sustainability and cut costs.
NMR enables researchers to probe the structures and dynamics of biological macromolecules and to identify structure-function relationships. The facility offers instrumentation, software, and expertise. NMR excels at uncovering molecular interactions, for example, between drugs and drug targets or between macromolecules themselves. NMR can also be used to probe the composition of small molecules in biological fluids, such as plasma, cerebral spinal fluid, urine, and cell/organ extracts. This type of structural work is important in many areas of research, such as the search for new antibiotics.
All nine of the NMR magnets at NMRFAM are “superconducting.” As long as they remain cooled at liquid helium temperature (4º Kelvin or about ‒450º Fahrenheit), they behave like permanent magnets. The liquid helium used to cool each system boils off slowly and has to be replenished. The problem is that helium is a scarce nonrenewable resource extracted from the ground, which escapes from the Earth’s atmosphere when released.
“It’s rare to find new sources for helium, and the sites where it has been found are all running dry, so helium is getting more and more expensive to buy, and there are a lot of geopolitics involved,” says Paulo Falco Cobra, an NMRFAM instrumentation specialist. “When our helium costs reached $100,000 per year, we decided to invest in a way to efficiently recycle the helium on site and become more sustainable.”
NMRFAM applied for a supplement to the National Institutes of Health grant that supports the facility, and was successful in obtaining funds to purchase a helium recovery system.
The system was delivered and installation was completed by Falco Cobra and NMRFAM’s now-retired Mark Anderson. The system recovers helium lost while filling the spectrometers and also can recover the daily boil off from each magnet. It collects the helium in large bags as a gas and then compresses the gas, runs it through a purifier to remove contaminating gasses, and liquefies the helium to be put back into the spectrometers.
Once fully functional, the system will recover and recycle 80% of the helium used at NMRFAM, cutting costs down to just $20,000 per year and serving as a hedge against anticipated future price increases.
“Helium is a noble gas so is very stable and won’t degrade,” Falco Cobra adds. “It’s very exciting to be able to save money and help the environment by being more sustainable.”