NMSU researchers strive to create transportation fuels from algae

NMSU researchers strive to create transportation fuels from algae
DATE: 07/30/2018
WRITER: Tiffany Acosta, 575-646-3929, tfrank@nmsu.edu
CONTACT: Catherine Brewer, 575-646-8637, cbrewer@nmsu.edu
Three years ago Catherine Brewer was asked to join a university collaboration on bioalgal energy. The assistant professor in the Department of Chemical and Materials Engineering at New Mexico State University, who specializes in biomass processing, accepted the new challenge.

Brewer and her research group replaced Shuguang Deng on NMSU’s team of the National Science Foundation New Mexico EPSCoR project, Energize New Mexico: Bioalgal Energy. The collaboration includes teams from the University of New Mexico and Eastern New Mexico University, as well as NMSU’s Departments of Civil Engineering, Plant and Environmental Sciences, Fishery and Wildlife Sciences and Biology.

“The biggest impact of this research is the ability to get energy out of wastewater treatment rather than only put energy in,” Brewer said.

One of the project goals is to create transportation fuels, ideally jet fuels, from materials such as algae. Brewer’s group is tasked with cooking algae via a process called hydrothermal liquefaction through a high-temperature and high-pressure reactor at conditions near the critical point of water: 290-350 degrees Celsius (550-660 degrees Fahrenheit) and 100-200 atmospheres of pressure.

“My group’s job has been to take different algae strains grown under slightly different conditions and see how much bio-crude oil we can get out of the biomass,” Brewer said. “We want to recover as much energy as we can. We could just burn plain algae: dry it up and burn it, but liquid fuels are a lot harder to do than solid fuels.

“The tightness of specifications around jet fuels has made it more difficult to get renewable fuels into that space,” she said. “It has to be just the right molecules with just the right properties.”

Since 2015, Brewer’s team has been working on different reactor configurations: 100 mL and 2L batch reactors, and the redesign of a pilot-scale continuous flow reactor. The continuous flow reactor was a goal of the EPSCoR project because it represents the next step of scaling up the process toward commercial applications.

Among the new features in the reactor redesign are special self-cleaning filters to remove solids while they are hot (and prevent heavy oils from condensing on the chars and clogging the reactor), and upgrades for system safety.

“Our reactors are pretty hardcore,” Brewer said. “The conditions are not easy, but that’s how we cook the algae.

“The reason these reactor designs take so long is you want to make sure you do it right so when there are failures, it’s a matter of cleaning and not a matter of injuries or permanent damage,” she added.

In addition to a multiple-university collaboration, the project is a multiple-department effort for NMSU.

Additional researchers on the project include Omar Holguin, Plant and Environmental Science associate professor and project lead at NMSU, Nirmala Khandan, Civil Engineering professor, Wiebke Boeing, Fishery and Wildlife Sciences professor, Wayne Van Voohries, Biology professor emeritus, and Umakanta Jena, Chemical and Materials assistant professor.

“With the combination of biologists, civil engineers, chemical engineers, chemists, we can cover the entire supply chain and make sure improving one area doesn’t hurt another area – that we improve the supply chain all the way around,” Brewer said.

“One of the reasons I love working on these research projects is that you have to work together. I don’t grow algae. I should never be depended on to keep anything alive. There’s a reason I cook dead plants, because they die on me, even cacti. I work with people who grow and study the algae,” she said.