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Pig manure will be used to produce asphalt
Last reviewed: 02.07.2025
A team of researchers from North Carolina has developed a unique way to make asphalt road surfaces. The experts have proposed replacing expensive oil with a cheaper and more accessible option – pig manure.
The search for a cheap biological alternative to oil has been going on for quite a long time, and during the research it was found that manure contains the same oils as oil, only of lower quality. Research has shown that manure is not suitable for producing gasoline, but is quite suitable for making asphalt pavement.
The scientists were supported by the Science Foundation, which allocated funds for research work, and they were able to develop a technology that turns pig waste into black bitumen - a binder used in the production of asphalt. It is worth noting that oil-based binders are quite expensive, while the cost of bitumen from manure will be slightly more than 0.50 cents per 4.5 liters, in addition, the new material is more environmentally friendly.
The process of producing manure bitumen differs from the standard method used in oil refineries - today, oil is processed mainly to produce fuel, and the remainder is sent to make asphalt pavement.
According to one of the researchers who developed the bio-road surface, Ellie Finney, the process of producing manure bitumen involves breaking down the molecular structure of manure and re-synthesizing the adhesive structure on a bio-base. The resulting viscous material is cheaper, does not require high temperatures for mixing and compaction, and will last much longer than traditional asphalt.
Scientists also noted that asphalt from manure will not have a characteristic smell, since volatile fatty acids, which give a pungent unpleasant smell to animal waste, evaporate during the processing. In addition, dry substances remaining in the process of bio-asphalt production can be used as fertilizer.
The experts tested the new bio-asphalt and the road surface showed good results (including 20 thousand cycles of simulating the mileage of trucks). According to the scientists, the test results meet the requirements of the Department of Transport, as a result of which a special company was created to conduct larger-scale research.
According to Ellie Finney, the commercial side of the issue has its economic benefits, primarily in terms of helping farms and the construction industry.
Asphalt made from pig waste could help solve one of the problems of farms – wastewater, especially those located in large states. Every year, about 20 billion liters of pig manure are produced in the world, the cost of one and a half kilometers of road from two lanes using traditional petroleum-based asphalt is more than $ 800. Researchers noted that in the United States alone there are about 4 million kilometers of asphalt pavement, the cost of laying and repairing which can be significantly reduced by using biomaterial and without causing significant harm to the environment.