Novel Process Uses Animal Manure as a Source of Chemical Feedstock

Animal dung, often regarded as mere agricultural waste, contains a wealth of organic compounds that can be processed to extract valuable industrial chemicals such as methane, ammonia, and phosphates. Through various biochemical and thermal treatments—like anaerobic digestion and pyrolysis—these waste materials can be transformed into biofuels, fertilizers, and basic chemical feedstocks for industrial manufacturing. This not only removes the issue for farmers of what to do with the tons of waste their livestock produces but also offers a sustainable source of raw materials for chemical companies and helps place the chemical industry inside the circular economy.

However, despite its environmental promise, the extraction of industrial chemicals from faeces, such as pig or cow manure, is not currently economically viable on a large scale. This is because the processes involved are energy-intensive, slow, and yield relatively low quantities of usable compounds compared to traditional raw material sources. Furthermore, the costs of collection, processing, and waste management often outweigh the profits from the chemicals produced. To make this approach practical and scalable, a more efficient method of extraction is essential—one that minimizes energy input while maximizing output and remains cost-effective for widespread industrial adoption.

This has now been achieved thanks to a team of chemical engineers and animal biologists from the University of Illinois Urbana-Champaign that have created a scalable, low-energy process to extract valuable industrial chemicals from animal faeces. This discovery represents a significant step towards chemical industry sustainability and circularity.

“It’s incredible that we’re able to obtain industrial chemicals like VFAs [volatile fatty acids] from something like manure,” says Prof. Xiao Su, the study’s corresponding author. “Through our work, we believe that we are closer to circularity, where the waste is reprocessed into valuable resources, making chemical production more efficient and sustainable as a whole.”

According to a report in the journal Innovations the breakthrough is based on, “… the incorporation of selective ion-exchange membranes into an electrochemical separation system, the system is 80% more energy efficient than previous standard electrochemical processes.”

VFAs, which include acetate, butyrate, and propionate, are chemical building blocks that are utilised in a variety of goods, such as plastics, food additives, cosmetics, and medications. Microbial anaerobic digestion, in which microorganisms break down biowaste, has lately emerged as a more energy-efficient alternative to the carbon-intensive processing of petrochemical feedstocks that is commonly required for their manufacturing. However, their widespread use has been limited as currently there is no effective technique for removing VFAs from the resulting chemically complicated broths.

The study has now been published in the journal Advanced Functional Materials, which describes how the new approach in detail as follows, “… bicontinuous polyelectrolyte complex (PEC)-layered nanofiltration membranes are designed for the selective recovery of VFAs using redox-mediated electrodialysis.” Specifically noting the value gained from the novel process, stating that, “Treatment of synthetic and cow manure fermentation effluents showcases 2 to 4-fold enrichment of VFAs and simultaneous removal of co-existing organic acids, with an energy consumption as low as 1.5 kWh kg−1.”

In plain language, the team fermented a cattle dung broth and then separated the lower-weight VFAs from the longer-chain VFAs and other substances in the mixture before using a novel redox-mediated electrodialysis nanofiltration technology to separate the desired chemicals from the rest.

“This is an innovative approach to utilizing waste material from concentrated animal production facilities, which contribute to environmental pollution, and converting it into valuable industrial chemicals,” said Prof. Roderick Ian Mackie who collaborated on the study.

“Electrodialysis is a very common separation technique used mostly in water desalination,” explains Su who has extensively investigated the electrochemical separation technique with hopes to apply it to industrial chemistry. “The problem is that ion-exchange membranes normally used in electrodialysis are not designed to distinguish between valuable VFAs used in chemical production. Through our work, we have designed new membranes with specific properties that can identify and discriminate between particular chemical species such as VFAs of different sizes.”

Compared to traditional separation methods, this innovative approach is far more efficient and produces a lot less chemical waste because it separates molecules using electrical means rather than chemical ones. Furthermore, Su believes that the technology can easily be adapted to an industrial scale.

“The next phase of this work,” says Su, “is figuring out how to implement our technology in a full process.”

This breakthrough marks a promising turning point in how agricultural waste is viewed and utilised. By converting animal dung into high-value industrial chemicals through an energy-efficient, scalable process, the researchers have not only solved a long-standing problem for livestock farmers but also opened new doors for sustainable chemical manufacturing.

As this technology moves closer to commercial application, it may well redefine waste management practices and help shift the chemical industry toward a truly circular economy. A place where sustainable innovation can make even the most unlikely materials—like manure—become vital ingredients for the chemical industry’s greener future.

Photo credit: Wikimedia, Sebastian Marx on Unsplash, Fulvio Ciccolo, & Chelaxy designs