Poor cows. They get smeared with blame for causing an unseemly amount of climate-warming methane emissions. The waste they create is a growing pollution problem too. Farms produce more manure than they can use as fertilizer, and the biological matter often ends up contaminating groundwater.
Researchers have now come up with a technique to turn cow manure into industrial-grade cellulose fibers, which are woven today to produce paper, textiles, and food packaging. Cellulose, a natural polymer found in plant cell walls, is one of the world’s most widely used materials.
The work, published in the Journal of Cleaner Production, presents a cheaper, more sustainable way to produce cellulose than some current manufacturing methods. And it does this while addressing a growing waste problem. Researchers estimate that the world will produce at least 5 billion metric tons of animal waste by 2030.
Present in cow dung are tiny fragments of cellulose fibers left over from the ruminants’ digestion of plants that they eat. Engineers at the University College London and Teesside University in the UK decided to see if they could extract the fragments and use them to make high-grade cellulose fibers.
The team collected cow manure from a local dairy farm. Using mild chemical reactions, they were able to relatively easily separate the tiny cellulose fragments in a liquid solution. “But when we tried to turn the fragments into fibers using pressurized spinning technology, it didn’t work,” said UCL mechanical engineering professor Mohan Edirisinghe.
Pressurized spinning is a manufacturing technique that Edirisinghe and his team invented in 2013. The process uses the forces of pressure and rotation together to spin fibers, ribbons, meshes and films from a jet of liquid or soft matter.
The process typically involves shooting the liquid jet vertically into a vessel. But for the dung-derived cellulose solution, the researchers realized after trial and error that turning the nozzles on their side and having them inject the jet horizontally into a containing still or flowing water led to cellulose fibers forming in the water.
Besides using natural waste as a raw material , the researchers write that “the entire processing procedure avoided the use/production of chemicals or waste that pose significant environmental hazards and was simple, efficient, and low-cost, in line with the requirements of a circular economy.”
Source: Yanqi Dai et al. Harnessing cow manure waste for nanocellulose extraction and sustainable small-structure manufacturing. Journal of Cleaner Production, 2025.
Image: ©Anthropocene Magazine (AI-generated)
