Waste Turned Into Fatty Acids; Study Reveals New Process That Produces Energy-Rich Molecules to Make Fuels, Other Essential Chemicals

Researchers at the University of Wisconsin - Madison have recently demonstrated a new process that will turn waste into fatty acid, and eventually become useful, instead of useless.

A Wisconsin Energy Institute report specified that this new process of turning a plentiful Wisconsin waste into fatty acids, energy-filled molecules that can be employed to produce fuels and a great range of essential chemicals.

Someone who lives in Dairy City, a place where cheese and milk production is typical, it will not be surprising that Wisconsin becomes home to a lot of cows, nearly 3.5 million.

More so, those cows are producing a lot of manure. While it's chock full of minerals that can contribute to fertilizing crops, manure helps with greenhouse gas emissions, as well, and can result in contamination of waterways from runoff.

Transformed Into Multipurpose Chemicals

Essentially, researchers at UW-Madison's Wisconsin Energy Institute have published new research on how to turn the solid leftovers of cow manure into multipurpose chemicals known as medium-chain fatty acids.

Such fatty acids are valued as they can be employed to make biodiesel to power a vehicle, or into green jet fuels. The chemical's building block can be converted into things such as dyes, as well as herbicides, and even medicines.

According to Abel Ingle, a civil and environmental engineering graduate, with other scientists, has unveiled a method that's untangling the multifaceted mass of leftover cow manure solids into a sweet mixture that happens to be tasty to a specific set of microorganisms.

In turn, such bacteria are using their own metabolism to turn the sugars into medium-chain fatty acids. First, Ingle, together with the team needed to search for a way to break down such lumpy solids, and it turns out, there is a prototype for that.

'Cellulose and Hemicellulose'

Commenting on this recent finding published in Frontiers in Bioengineering and Biotechnology, Ingle said, the organic components of manure appear more like "plant matter." He added they are quite difficult to deconstruct, and thus there is a need to be clever about how the carbohydrates are broken down within that biomass into sugars that are easily fermented.

The UW-Madison-based Green Lakes Bioenergy Research Center bioenergy researchers have sought ways to do only that.

While the beginning material is different, there is a scientific pattern for transforming tough-t-breakdown organic material into something valuable.

According to UW-Madison's distinguished civil and environmental engineering professor Daniel Noguera, who also led the research, the plants' walls contain huge amounts of carbohydrates stored in polymers, which include "cellulose and hemicellulose," detailed in Scientific Reports.

Chemical and Biological Processes Used

Noguera also said they use chemical and biological processes to treat the said polymers in bioenergy crops like sorghum and switchgrass to convert them into easily fermented sugars. He added, they can do the same to break down the same carbohydrates ending up in manure.

While such pretreatments have evolved in the last 10 years, there are still lots of things to learn about doing so for "bovine waste."

To come up with a result, Ingle and the team trialed a few approaches to determine which one produces the largest quantity of palatable sugars. The team arrived at a result in which they douse the solids in acid, then fire up the mixture just a little over 100 degrees Celsius.

Ingle explained, the approach known as decrystallization dilutes acid pretreatment, while unconventional has been tried on manure in previous research, so the researchers knew there was a higher chance for it to succeed. He said the novelty "was feeding it to microorganisms."

Spitting Out 'Precious' Fatty Acids

There was a need for Ingle to find a community of bacteria that could last in a world of pretreated manure as these precious fatty acids, described in general in a ScienceDirect report, are being spat out.

It turns out, the Nine Springs Wastewater Treatment Plant of Madison Metropolitan Sewerage District was just the site to discover an inoculum that consists of a microbial community that was up for the task of fermenting complex mixtures of organic matter.

Based on their study, explained Ingle, they expected this community to generate medium-chain fatty acids in a certain capacity. He added it was just a matter of providing them with the right sugar to consume.

Related information about converting bovine waste into renewable energy is shown on KCET's YouTube video below:

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