Biofuel waste offers concrete gains for greener cement
Waste from biofuel could drive the production of more sustainable concrete through a pioneering closed loop process.
Researchers are experimenting with ways to produce cement that will absorb CO2 emitted from factory flues. According to a report from Climate News Network, the University of Kansas out in the US is leading the work, by substituting some of the cement in a concrete mix with the by-products of biofuel production.
The by-products being used are lignin residue, a woody substance produced from generating biofuel from cellulose waste such as wood chips and straw. This residue usually has to be burned or buried.
When the Kansas team added 20% lignin waste to their cement, the subsequent chemical reaction delivered a concrete considered 30% stronger than traditional types.
Civil engineer Feraidon Ataie, one of the lead researchers on the project, said the process not only delivers a more sustainable alternative, but has several other benefits.
"If you use this in concrete to increase strength and quality, then you add value to this by-product rather than just landfilling it," he said.
"If you add value to the by-product, then it is a positive factor for the industry. It can help reduce the cost of bioethanol production."