Researchers at Iowa State University are trying to determine whether crop residue could pay off in three ways simultaneously: as a source of biofuel, as a soil enhancer, and as a long-term sink for carbon dioxide.
At the heart of their investigation is a heating process known as pyrolysis that turns plant matter into biochar, a charcoal-like substance that seems to tie up carbon dioxide for hundreds of years.
“The concept of biochar was not invented here,” said Robert Brown, Iowa State’s Anson Marston Distinguished Professor in Engineering and director of its Bioeconomy Institute. “What we’ve done is to take it to an industrial scale. We were among the first to say, ‘Let’s look at our ability to translate this to a system where you get an energy benefit and a net greenhouse-gas reduction.’”