Mechanical engineering professor Lulin Jiang, Ph.D., and her research team at Baylor University have developed a cutting-edge method for the clean, efficient combustion of biofuels using the novel Swirl Burst injector, setting a new standard for ultra-clean burning of challenging fuels.
In Fuel, researchers at Baylor University’s Cornerstone Atomization and Combustion Lab (CAC) published a breakthrough study on their Swirl Burst (SB) injector—a revolutionary technology capable of efficiently burning glycerol/methanol blends. This combination was once difficult to combust. This technology addresses the challenge of burning viscous biofuels like glycerol, enabling near-zero emissions and offering a cleaner, more sustainable solution for fuels that traditionally pose combustion difficulties.
Dr. Lulin Jiang, assistant professor of mechanical engineering and lead investigator at CAC, highlighted the broader implications of this work: “Our research demonstrates how viscous bio-waste can be transformed into clean energy, showcasing the potential of the Baylor combustion technology.”
One of the biofuel industry's biggest challenges has been glycerol, a byproduct of biodiesel production. While abundant, glycerol’s high viscosity has made it difficult to burn efficiently, and conventional injectors often require costly pre-treatment like fuel preheating. The SB injector, however, eliminates this need. The SB injector enables a cleaner combustion process with dramatically reduced emissions by atomizing the fuel into fine droplets that burn entirely.
The results are profound: the SB injector can significantly cut emissions of harmful pollutants like carbon monoxide (CO) and nitrogen oxides (NOx), often associated with conventional combustion systems. Dr. Jiang notes that the implications for the biodiesel industry are game-changing: “This technology allows biodiesel producers to convert glycerol waste into a viable fuel source, reducing costs and promoting a circular economy.”
The SB injector could drastically change the economics of biofuel production by allowing biodiesel plants to turn waste into energy without expensive fuel processing. This would provide a pathway to cleaner, more affordable fuel alternatives.
Beyond its technical capabilities, the SB injector represents a major leap forward in energy resilience and sustainability. Its flexibility enables the combustion of various glycerol/methanol ratios without the need for hardware modifications, making it an ideal solution for power plants looking to meet strict emissions regulations without overhauling their existing systems.
This innovation supports the move toward a circular economy by offering an effective way to combust waste glycerol. More importantly, it promotes energy equity by turning what was once considered bio-waste into a renewable energy source that can provide cost-effective power to economically disadvantaged regions.
“Being able to transform waste glycerol into renewable energy not only addresses environmental concerns but also promotes energy resilience and equity,” says Dr. Jiang. “This technology empowers economically disadvantaged groups by providing access to cleaner energy solutions in the face of a changing climate.”
Dr. Jiang’s team meticulously tested three different glycerol/methanol fuel blends—50/50, 60/40, and 70/30—at various atomizing air-to-liquid mass ratios (ALR). All fuel blends demonstrated combustion efficiencies exceeding 90%, with near-zero emissions of CO and NOx, even when the fuel was not preheated or insulated. This is a dramatic improvement over traditional injectors like air-blast or pressure-swirl systems, which often struggle to handle high-viscosity fuels and generate higher emissions.
“The high viscosity tolerance and fuel flexibility of the SB injector is groundbreaking,” Dr. Jiang explains. “Not only can it handle waste glycerol, but it also shows potential for other waste-based bio-oils, making biofuels far more cost-effective. This could open the door to broader applications of biofuels for energy generation.”
The SB injector sets a new standard for combustion technology, proving that waste glycerol and other biofuels can be burned efficiently without expensive treatment or high emissions. This breakthrough can potentially reduce the environmental footprint of biodiesel production while making biofuel more economically viable.
The research isn’t confined to academic journals. Dr. Jiang and her team are actively involved in the National Science Foundation’s (NSF) prestigious National Innovation Corps (I-Corps™) program, which helps researchers commercialize their technologies. The SB injector’s potential to revolutionize fuel-flexible combustion aligns perfectly with the program’s goal of bringing economically and societally impactful innovations to market.
Additionally, Baylor University and the City of Waco have partnered on the NSF Civic Innovation Challenge project, which aims to reduce methane emissions and other air pollutants by transforming landfill waste into clean energy. Baylor’s research team earned a $1 million pilot project grant, and they hope to further advance this important work as one of 19 teams that reached the next stage of the NSF Challenge.