Mines Selected for $1.5 million DOE Grant To Convert Seaweed to Low-Carbon, High Energy Density Biocrude

December 19, 2024
Mines Selected for $1.5 million DOE Grant To Convert Seaweed to Low-Carbon, High Energy Density Biocrude
Schematic of the proposed technology approach to obtain oil biocrude from sugar kelp using catalytic hydrothermal liquefaction (CHTL).

South Dakota Mines was recently awarded a $1.5 million Department of Energy grant as part of a $20.2 million initiative funding 10 university and industry projects to advance mixed algae development for low-carbon biofuels and bioproducts.

Spread across seven states, the selected projects will focus on high-impact research and development to transform algae, including seaweed and other wet waste materials, into low-carbon fuels, chemicals, and agricultural products aimed at reducing emissions in domestic transportation and industry.

Rajesh Shende, Ph.D., interim department head and professor in the Karen M. Swindler Department of Chemical and Biological Engineering is leading the Mines research team. “This award is particularly interesting because South Dakota is landlocked and seaweed is a new feedstock for our campus for bioprocessing," he said.

Seaweed is an emerging resource crucial for biofuels and bioproducts but remains underutilized and challenging to convert due to its variability, unique chemistry and storage instability.

According to the DOE, the Mines project and others like it will help overcome the feedstock conversion challenges, support building biomass supply chains, and eventually improve carbon dioxide conversion to algae and enable greater volumes of sustainable aviation fuel (SAF).

Offshore seaweed farming requires minimal input, grows faster than terrestrial energy crops and doesn't compete with land-based agriculture, according to the DOE. Seaweed's low cellulose and lignin content, along with its unique polysaccharides and high moisture, salt, and mineral levels, present challenges and opportunities for various conversion technologies. Seaweed composition is species-dependent and can vary substantially with growth phase, season and geography for the same species.One of the partners in the South Dakota Mines $1.5 million DOE grant is Cold Current Kelp, a Maine kelp farm.

Shende, along with CO-PIs Drs. Anuradha Shende and Fan Zheng from Mines, are working with partners Idaho National Laboratory, Cold Current Kelp, GE Vernova and Rutgers University on bench-scale research and development to hydrothermally convert sugar kelp into low-carbon, stable and high-energy density biocrude that can be a precursor for SAF.

“The project will address knowledge gaps in optimal storage and preprocessing conditions to preserve hydrocarbons in the sugar kelp and reduce its salt and ash content,” Rajesh Shende said. “GE Vernova will develop a special alloy coating for the hydrothermal liquefaction reactor to endure corrosive reaction conditions.”

Another objective is to develop a new catalyst to maximize conversion of sugar kelp to energy-dense biocrude, he said.

The DOE grant will also offer educational opportunities for Mines students and future careers in fuel and other products from sugar kelp using hydrothermal liquefaction.

This is Rajesh Shende’s second award from the DOE’s Office of Energy Efficiency and Renewable Energy (EERE). He and his team are currently wrapping up a 2017 project where university researchers demonstrated the cost-effective production of biocarbon, carbon nanofibers, polylactic acid and phenol from biochemical waste streams, boosting revenue for Integrated Biorefinery Optimizations (IBR) and reducing fuel cost.