Baylor engineers introduce ultra-clean biofuel combustion technology

"The current research demonstrates how viscous bio-waste can be transformed to clean energy by the Baylor combustion technology," stated lead author Lulin Jiang, Ph.D., the principal investigator of the CAC Lab and assistant professor of mechanical engineering at Baylor's School of Engineering and Computer Science.

Implications for biofuel use and emissions reduction
Traditional injectors struggle with burning glycerol - a common biodiesel byproduct - because of its high viscosity. The SB injector, however, can combust glycerol without needing expensive fuel processing or preheating. By generating fine fuel droplets, it achieves a complete and clean burn, significantly lowering harmful emissions like carbon monoxide (CO) and nitrogen oxides (NOx).

According to Jiang, this technology allows biodiesel producers to transform glycerol waste into a usable energy source, supporting a circular economy and reducing the environmental impact of power generation. The SB injector's capability to burn various glycerol/methanol ratios without changing the hardware makes it ideal for facilities needing to comply with strict emissions regulations.

"Being able to transform waste, such as waste glycerol, into cost-effective renewable energy promotes energy resilience and energy equity for economically disadvantaged groups in a changing climate," Jiang added.

Fuel blend testing
The team examined three glycerol-to-methanol blends - 50/50, 60/40, and 70/30 - based on theoretical heat release rates, with various air-to-liquid mass ratios (ALR) during atomization. All mixtures reached over 90% combustion efficiency, including complete combustion by the 50/50 blend, even without preheating or insulation, with near-zero CO and NOx emissions. This is a considerable improvement compared to conventional injectors that struggle with high-viscosity fuels.

Jiang noted, "The demonstrated high viscosity tolerance and fuel flexibility of the technology signifies that not only waste glycerol, but also the viscous source oils of biodiesel, and other waste-based bio-oils can be directly utilized for energy generation without further processing, significantly reducing biofuel cost and thus potentially stimulating its broad application."

This breakthrough could enhance the biodiesel industry's sustainability and reduce operational costs.

NSF National I-Corps and Civic Innovation Challenge
The research team is part of the National Science Foundation's National Innovation Corps (I-Corps) program, highlighting the transformative potential of their fuel-flexible combustion technology. The I-Corps initiative aims to accelerate the commercialization of research projects ready for market adoption.

In a related effort, Baylor is collaborating with the City of Waco on the NSF Civic Innovation Challenge Project to implement climate-smart waste energy solutions at the Waco Landfill. The project aims to cut methane emissions and other pollutants while converting waste into clean energy. Baylor and Waco are among 19 teams awarded a $1 million pilot project grant, advancing to the competition's next phase.

Funding sources
This research is supported by Baylor University's Startup fund, NSF CIVIC award No. 2228311 from the U.S. National Science Foundation, and NSF CIVIC award No. 2322319, co-funded by the National Science Foundation and the Department of Energy.

Research Report:Clean co-combustion of glycerol and methanol blends using a novel fuel-flexible injector