"With the cellulosic ethanol process, you have leftover material that has lignin and some cellulose in it, but it's not really a feed material anymore," Riding said. "Your choices of how to use it are a lot lower. The most common choices would be to either burn it for electricity or dispose of the ash."
When the researchers added the high-lignin ash byproduct to cement, the ash reacted chemically with the cement to make it stronger. The researchers tested the finished concrete material and found that replacing 20 percent of the cement with cellulosic material after burning increased the strength of the concrete by 32 percent.
"We have been working on applying viable biofuel pretreatments to materials to see if we can improve the behavior and use of ash and concrete," Riding said. "This has the potential to make biofuel manufacture more cost effective by better using all of the resources that are being wasted and getting value from otherwise wasteful material and leftover materials. It has the potential to improve the strength and durability of concrete. It benefits both industries."
The research could greatly affect Kansas and other agricultural states that produce crops such as wheat and corn. After harvesting these crops, the leftover wheat straw and corn stover can be used for making cellulosic ethanol. Cellulosic ethanol byproducts then can be added to cement to strengthen concrete.
"The utilization of this byproduct is important in both concrete materials and biofuel production," Ataie said. "If you use this in concrete to increase strength and quality, then you add value to this byproduct rather than just landfilling it. If you add value to this byproduct, then it is a positive factor for the industry. It can help to reduce the cost of bioethanol production."
The researchers have
|Contact: Kyle Riding|
Kansas State University