Reducing molten salt’s corrosive effect

With purification, salt could store solar thermal energy

Oak Ridge National Laboratory scientists recently demonstrated a low-temperature, safe route to purifying molten chloride salts that minimizes their ability to corrode metals. This method could make the salts useful for storing energy generated from the sun’s heat.

The experiment, detailed in Frontiers of Chemical Engineering, involved using thionyl chloride to remove corrosion-causing impurities from the salts. Without this purification, the salts corrode pipes and storage tanks.

The team melted a commercial carnallite — an abundant mineral being considered for solar-thermal energy storage — and put it into contact with inert gas saturated with thionyl chloride to cause a reaction. The scientists monitored reaction conditions by measuring salt temperature and by analyzing the off-gas through infrared spectroscopy.

“Using high-temperature molten salts to store energy as heat could be key in making solar energy a consistent source of electricity, replacing fossil fuels,” said ORNL’s Joanna McFarlane, who led the team that performed the experiment.

Caption: This diagram demonstrates how a concentrating solar thermal plant could use molten salts to store solar energy that could later be used to generate electricity. Credit: Jaimee Janiga/ORNL, U.S. Dept. of Energy


VERIFI-ing and tracking carbon’s big footprint

Online tool monitors energy efficiency of industrial plants

Researchers at Oak Ridge National Laboratory have developed an online tool that offers industrial plants an easier way to track and download information about their energy footprint and carbon emissions.

Visualizing Energy Reporting Information and Financial Implications, or VERIFI, is a tool that uses an open-source framework with a utility dashboard. It allows energy coordinators and plant managers to monitor and improve their understanding of energy and water use patterns including the amount of carbon emitted from industrial processes. Users can generate automatic reports, too.

“Industries want to know how to conserve and improve efficiency while reducing costs but often don’t know how to begin or lack the time to track it,” ORNL’s Kristina Armstrong said. “VERIFI provides a user-friendly platform for monitoring energy efficiency benchmarks and baselines and allows for the visualization of energy and utility bills.”

ORNL is testing VERIFI for the Department of Energy’s Better Plants Program.

Caption: A new online tool called VERIFI, developed by ORNL researchers, provides an easy-to-use dashboard for plant managers to track emissions produced by industrial processes. Credit: ORNL, U.S. Dept. of Energy


Moss genome study identifies two new species

Sphagnum evolution could reveal carbon storage insights

A team from Oak Ridge National Laboratory, Duke University and other institutions studying Sphagnum moss have identified two new species in North America, and they are learning how evolution may affect the species’ role in carbon storage.

Researchers looking at moss samples from far-flung habitats used genome sequencing and advanced computation to identify differences within the Sphagnum magellanicum complex. So far, they discovered S. magni and S. diabolicum, which differ in geographic distribution and may have evolved in response to climate.  

“By understanding their evolution and genetic diversity, we can start to link some of the traits of these organisms to their impact on carbon cycling,” said ORNL’s Bryan Piatkowski. 

Sphagnum is the chief engineer of peatlands in the Northern Hemisphere, where one-third of terrestrial carbon is stored. The moss’s response to warmer temperatures can inform predictions about how much carbon will stay locked away in soils or be released to the atmosphere. — Stephanie Seay

Caption: Scientists used genome sequencing and computational biology to tease out the genetic profile of a new moss species, Sphagnum magni, typically found in the southeastern United States. Credit: Blanka Aguero, Duke University


Ultrasound for battery health

Approach drives car battery reuse, reduces pollution

Scientists at Oak Ridge National Laboratory are using ultrasounds — usually associated with medical imaging — to check the health of an operating battery. The technique uses sensors as small as a thumbnail, which could be attached to a lithium-ion battery inside a car.

Companies can use this technology to immediately learn which batteries are healthy enough to be resold. “We are combining expertise at ORNL’s Battery Manufacturing Facility with ultrasound measurement expertise to identify good batteries that can be reused, reducing waste,” said ORNL’s Hongbin Sun.

Ultrasound waves can continuously monitor battery material property and structural changes while the battery charges or discharges. Sun’s team, including BMF staff and experts in ORNL’s Nuclear Energy and Fuel Cycle Division, identified the best testing methods to correlate ultrasound results with a battery’s state of charge. “This is key to measuring battery life, performance and safety,” Sun said.

Caption: Researcher Sun Hongbin examines material changes to a battery made in the DOE’s Battery Manufacturing Facility using an ultrasound sensor. Credit: Carlos Jones/ORNL, U.S. Dept. of Energy

Journal Link: Frontiers of Chemical Engineering