For years, farming facilities across the country have utilized anaerobic digesters to convert cow manure into renewable energy. However, these digesters have been limited to a modest 30–40% efficiency. Now, groundbreaking research led by a team of BYU professors is revolutionizing the process, making it faster and more efficient than ever before by pretreating the waste with a special bacteria.
BYU professors created waste pretreatment to enhance chemical extraction that usually escapes anaerobic digesters. Their innovative design converts waste into a sludgy soup of small, chained molecules, which is then pumped into existing digesters to produce usable natural gas. The process significantly boosts methane gas capture efficiency to 80–85%, accomplishing the transformation in less than half the time. Instead of the conventional 30–45 days, the pretreated waste, including challenging plant waste, requires only one to two days of pretreatment and five to seven days in a regular digester for complete breakdown.
“We have been able to make a substantial improvement to an existing technology that I think is going to bless the world,” said BYU chemistry and biochemistry professor Jaron Hansen, a co-author of the study. “We were motivated because we have to be good stewards of the Earth.”
The pretreatment secret ingredient? A combination of bacteria and archaea that thrive in the most extreme environments on Earth. Hyperthermophiles survive best in temperatures ranging from 170–230 degrees Fahrenheit. With temperatures that high, one of the hyperthermophiles that initiates waste pretreatment can be found only in Russian hot springs. These microorganisms have existed for thousands of years, but they are newly recognized as waste treatment agents.
Implementing this waste pretreatment technology isn’t as simple as it sounds. “It’s not as easy as just mixing some bacteria and throwing it in a big tank,” said BYU plant and wildlife sciences professor Zach Aanderud, who co-authored the paper. “We use a lot of chemistry, genetics and sequencing. It’s really about understanding how the small things we can’t see generate a huge impact on our life and the environment.”
Waste products naturally generate methane when they are kept in holding ponds or dumped in landfills, eventually contributing to greenhouse gas emissions. By capturing this methane waste and using it to power homes, this technology reuses methane that is already being released into the environment. It’s a perfect way to remove waste — and the smell that accompanies it — resourcefully.
“Moving forward, I see this as a huge benefit,” said Aanderud. “We are reducing the amount of waste that the ever-growing population is creating, and we are generating energy in a renewable fashion that we can directly use.”
Aanderud said renewable energy can help the world rely less on fossil fuels and fracking, other sources of greenhouse gas emissions. Cleaning up waste will also prevent water contamination from toxic spills.
BYU’s patented waste pretreatment process is already showing promising results in real-world applications. Dairy farms in Indiana and Wisconsin have already implemented pretreatment in their everyday operations, each producing enough energy to power a small city. Top engineering companies like Jacobs and Aqua Engineering are using the patented design to convert municipal waste into natural gas, further contributing to sustainable energy production.
As an additional benefit, the new pre-digestion technology doesn’t require any new or costly infrastructure. Scientists can use existing tanks to capture the methane, funneling it directly into pipes that transport natural gas into homes.
BYU professors Hansen and Aanderud have been working on this project for over seven years with the help of more than 30 undergraduate and three graduate students. Their findings were published in 2021 and featured on the cover of the prestigious Biofuel Research Journal. Since then, the group has been working to improve their design.
“Science takes a long time,” said Aanderud. “The ah-ha moments are when my individual students realize what they are doing may have a huge impact in the world.”