UNIVERSITY of Illinois professors of agricultural and biological engineering Yuanhui Zhang and Lance Schideman have combined research efforts to develop an innovative system that uses swine manure to produce biocrude oil, grow algal biomass, capture carbon, purify wastewater and recycle nutrients.
Zhang has spent more than a decade researching the conversion of swine manure and biomass into crude oil. Schideman has done significant research in the area of integrated algal systems for wastewater treatment and bioenergy production.
"We first convert swine manure into crude oil in a hydrothermal liquefaction reactor," Schideman said. "There is a very strong wastewater that comes off that process. It contains nutrients that can be used to grow algae that simultaneously clean the water. Lately, we've added low-cost, bioregenerable adsorbents into the system that allow us to grow additional bacterial biomass and further improve effluent water quality.
"Our recent research -- a combination of experimental work and some computer modeling -- has shown that we can reuse the nutrients multiple times and, thus, amplify biofuel production from waste feedstocks," he explained. "If we start with a particular waste stream that has one ton of volatile solids in it, we might be able to produce three, five or even 10 tons of algal and bacterial biomass. This new biomass is then recycled back into the biofuel production process. It can also clean the water with the goal of making it suitable for environmental discharge or reuse in some other application. So, we get more bioenergy and more clean water resources -- both good things in the long run."
Schideman said they are also focusing on developing markets for downstream products of the bio-crude oil.
"This crude oil is similar to, but not exactly like, petroleum. It generally has higher oxygen and higher nitrogen content than traditional petroleum but lower sulfur content. Some of those things are positive; some are negative, but regardless, they're different. We have to understand those differences in order to make the new materials compatible with existing infrastructure."
Schideman acknowledged that while they are making important advances in their research, there is also a need to expand collaborations and work with other researchers at the Illinois Sustainable Technology Center and the university's department of civil and environmental engineering.
"There is still significant work that needs to be done in order to better understand the bio-oil products and their potential use in different applications. We look forward to working with others to accelerate the development of bio-oil products that can provide sustainable alternatives to petroleum."