Researchers at the University of Louisville’s (UofL) Conn Center for Renewable Energy Research have embarked upon a pilot project to develop a process that transforms soy hulls left over from soybean processing into 3D printable materials.
UofL has been awarded $350,000 from the United Soybean Board (USB) to develop the processes, which also produce a secondary value-added product, xylose, a natural, diabetic-friendly sugar.
“Agriculture and agricultural processing are keys to economic development and employment in the US,” said Mahendra Sunkara, director of the UofL Conn Center. “Xylose separation and use of soy hull fibers for natural fiber composites are potent opportunities for addressing worldwide farming economics, nutrition issues, and material needs from a renewable source.
“In conjunction with BioProducts LLC, the Conn Center expects the development of a pilot-scale operation in the next two years.”
Transforming soybeans into 3D printing feedstock
The US generates eight million tons of soy hulls from soybean processing each year, and the UofL will look to utilize these hulls within their pilot project. The research team is led by Jagannadh Satyavolu, theme leader for Biofuels and Biomass Conversion at the Conn Center, and Kunal Kate, a mechanical engineering professor at UofL’s JB Speed School of Engineering.
First, the researchers will deploy a patented process developed by UofL and licensed by BioProducts to produce xylose from the soy hulls. The remaining residual fiber, which is about 80 percent of the starting biomass, has a modified fiber structure post xylose extraction which can be used as a natural fiber in composites for various 3D printing applications.
In particular, these natural fiber composites have potential uses within industries that currently rely on petroleum-based fiberglass and carbon fiber composites to reduce weight and maintain strength, such as the automotive, civil engineering, military, and aerospace sectors. Presently, the overriding challenge of utilizing soy hulls to produce these fibers lies in creating efficient, economical, and achievable technology on a commercial scale.
Utilizing the USB funding
With its new funding, the Conn Center project will aim to develop a stable and efficient method of processing the soybean biomass into lightweight natural fiber composites that have the potential to meet the demands of these industries.
The USB grant will fund pilot phase development of the outcomes of previous UofL research, including 3D printing using soy hull-polymer composite filaments, xylose separation, and a patent application for polymer composite feedstock production.
During the pilot phase, the research team will attempt to optimize the process so that it can become commercially viable. This will involve achieving large volume production of xylose and composite filament samples for evaluation by commercial partners in the food and 3D printing industries.
Repurposing waste for 3D printing
Repurposing waste for additive manufacturing processes and applications, particularly from food and other biomatter, is an area that is being increasingly tapped into by those in the 3D printing sector. In fact, an Imagine 2050 report by Veolia suggests that the food and beverage, manufacturing, and chemical industries, in particular, have enormous potential to reduce their waste and generate new revenue streams.
Project BARBARA, a European Union-funded initiative, recently concluded four years of research into converting food waste into 3D printable materials suitable for prototypes within the automotive and construction sectors. Eight new bio-based materials were developed, derived from waste corn, pomegranate, lemon pigment, and almond shell. The next stage of the project will seek to scale up this work to eventually secure industrial investment.
Elsewhere, food waste has been repurposed for additive manufacturing processes including replacing petroleum-based PET with bioplastics derived from coffee powder and orange peel, and converting food waste into biodegradable PHAs.
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Featured image shows soy hulls are a by-product of soybean production. Image by Daina Krumins.