Life Support Researchers build biorefinery system to supply water and air on mars

By Charlie Bier for La Louisiane, The Magazine of the University of Louisiana at Lafayette

NASA intends to put scientists on Mars by 2030. The mission? To explore the viability of establishing human colonies there.

If the plan comes to fruition, scientists will be about 50 million miles away, living in space camps that regulate air pressure, oxygen levels, and temperature – conditions necessary for survival.

The temperature on Mars can dip as low as minus 225 degrees Fahrenheit. The planet’s atmosphere is toxic; 96 percent of it is carbon dioxide.

Still, the fourth planet from the sun holds the most promise for supporting human life. It gets enough sunlight to send temperatures as high as 70 degrees. The sunlight is sufficient to power solar panels that could produce energy. It has enough gravity to support human existence.

And, despite a longstanding belief that water exists only as ice or vapor due to cold temperatures and low pressure, scientists have discovered several slopes on Mars where briny water might flow when temperatures rise.

But residency on the Red Planet would require self-sufficiency, ways for inhabitants to convert carbon dioxide into oxygen, for example, or wastewater into drinkable water.

NASA and the Louisiana Board of Regents, through the LaSPACE program, awarded UL Lafayette’s Energy Institute of Louisiana and the University’s College of Engineering a three-year, $2.2 million grant last year to develop a biorefinery system. Such a system would create potable water, enable the conversion of carbon dioxide into oxygen, produce gases that could be used to generate electricity, and provide protein that could be used as food.

Dr. Mark Zappi, director of the Energy Institute and a professor of chemical engineering, is leading a team of faculty and student researchers who are developing a biorefinery system.

NASA selected UL Lafayette for the project, Zappi said, because University researchers have been studying processes for converting waste into byproducts and alternative energy for about two decades. So far, they have converted organic material such as alligator fat, rice hulls, algae and bagasse – remnants of stalks of sugar cane after its juice has been extracted – into biofuels and other “bio-based” products.

University researchers are aiming to carry that commitment to sustainable energy and chemicals into space.

“The really cool thing about the biorefinery system is that in addition to an almost complete recycle of life-support chemicals – water and oxygen – it will produce byproducts that would assist in sustaining life for long periods of time,” Zappi explained.

One key component of the project is examining the most efficient and effective ways to convert “black water” – human waste – and “gray water” – dirty dish and bath water – into drinking water or for reuse in kitchens.

The biorefinery system will include bioreactors that contain algae, microorganisms that convert carbon dioxide into oxygen.

“The algae inside the reactor is like any other plant. Carbon dioxide helps the algae grow, but oxygen is also released through photosynthesis. So the oxygen will be able to go back into space colony cabins,” Zappi explained.

Researchers are also devising methods for converting food waste into hydrogen and methane. The gases can generate power, and the organic acids from the digested food waste can be converted into lipids or proteins. Lipids – fats and oils – can be used to make lubricants for a variety of functions, including greasing machinery gears. Protein can be used to make edible “cakes.”

Treatment of human waste would provide fertilizer that could be used for cultivating crops. “So you would have not only all of the benefits associated with waste management, but also a means for providing food,” Zappi explained. Someday, this concept could be a model for cities on Earth, he added.

Bimi Shrestha, a doctoral student in chemical engineering, is a member of a team researching optimal ways to reduce organic pollutants and solids through anaerobic digestion, which also produces biogases such as methane. The process happens when organic material is broken down inside sealed bioreactors devoid of oxygen.

Shrestha and fellow researchers will conduct experiments with a bench-scale reactor they are building with materials such as plastic pipe, in addition to commercial bioreactors.

Chemical engineering doctoral student Bimi Shrestha studies ways to convert food waste and wastewater into hydrogen and methane. The gases could be used to generate power on Mars. (University of Louisiana at Lafayette/Doug Dugas)

The scientists are examining wastewater from Lafayette Consolidated Government treatment plants and food waste provided by the University’s Dining Services. They are evaluating factors such as the amount of gas produced and chemical composition under different conditions, including the amount of water, temperature and acidity or alkalinity of water-based substances.

“We’re analyzing how much solids have been digested, as well as the amount of biogas being produced, using data accrued over a period of time,” Shrestha said.

Over the course of the project, faculty and student researchers will build a pilot-scale biorefinery system as part of what’s shaping up to be a modern-day space race. Russia, Japan and the European Space Agency, which has 22 member countries, are working on similar systems.

Who makes it to Mars first will depend, in large part, on who develops the most efficient, economical system, Zappi said.

The strength of the UL Lafayette project is that “while others are developing systems with components such as waste stream management or water management, none is as comprehensive as ours,” he said.

Top photo: This NASA artist’s concept depicts astronauts and human habitats on Mars.

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