Small-scale, modular power systems offer distinct advantages amid a changing energy landscape. Among other benefits, they expedite technology development, cut investment and operating costs, improve availability, reduce environmental impacts and offer flexibility in meeting location-specific needs.

As NETL strives to develop technological solutions to the nation’s energy challenges, the Lab is investigating ways to improve modular systems that convert coal to energy and other useful products through gasification. The combustion-free gasification process relies on chemical reactions to convert coal into clean power, chemicals, hydrogen and transportation fuels within an enclosed space. Gasification also captures carbon for storage or enhanced oil recovery.

The addition of pure oxygen enhances gasification systems; however, producing pure oxygen from ambient air within a modular system is a challenge. That’s why scientists at NETL are exploring the use of metal oxides, known as oxygen carriers, which absorb oxygen from the air and release it as a pure oxygen stream.

Complex metal oxides allow researchers to adjust the properties of the material to minimize shortcomings and optimize key factors, such as the amount of oxygen delivered, reactivity and kinetics of the carrier. Two families of complex metal oxides – perovskites and ferrites – are of particular interest to NETL because of their versatile potential within energy technologies. For instance, perovskites offer useful properties for chemical looping combustion, pollution remediation, syngas production, high-temperature gas sensors, solid oxide fuel cells, photovoltaics and other energy applications.

NETL researchers are working to understand how atomic-level changes affect process performance and economics for perovskites, which are used to generate gas-phase oxygen that can be blown into a gasifier or into a post-gasification process that uses syngas for chemical production. Researchers synthesized and characterized 40 unique perovskite compounds, demonstrating a link between composition, structure and oxygen release.

Computational tools and numerical methods were used to create a preliminary model for material design. Scientists are now studying thermodynamic data to develop process models that help them assess perovskite performance at a larger scale.
“Ultimately, identifying the fundamental workings of oxygen carrier materials will allow researchers to design and customize compositions not just for energy technologies, but also for a variety of applications that will benefit the public,” said Jonathan Lekse, Ph.D., NETL research scientist and acting technical portfolio lead for Advanced Reaction Systems. “To date, we have successfully designed, synthesized and modeled numerous oxygen carrier materials and found interesting links between composition and physical properties. The insight from these investigations will be used to identify the best materials for scale-up testing and ultimately real-world implementation.”

Identifying effective complex metal oxides will boost the efficiency of modular gasification systems by improving oxidation reactions, which in turn cuts costs and reduces the environmental impact of power production. NETL is exercising its world-class expertise in energy science to conduct innovative research that ultimately stimulates a growing economy and improves the health, safety, and security of all Americans.