Filling abandoned oil and gas wells with bio-oil made from plant-based leftovers like corn stalks and forest debris could help remove carbon dioxide from the atmosphere, returning carbon underground in deep shafts once used to extract it.
The emerging practice, the focus of a recent study by an Iowa State University research team led by mechanical engineering professor Mark Mba-Wright, has a two-birds-one-stone appeal. Unwanted organic matter collected from forests and fields helps sequester carbon in long-term storage while also reducing the emissions and safety risks posed by the hundreds of thousands of orphaned U.S. oil wells.
“On the one hand, you have these underutilized waste products. On the other hand, you have abandoned oil wells that need to be plugged. It’s an abundant resource meeting an urgent demand,” Mba-Wright said.
Based on research by Mba-Wright’s team, a network of 200 mobile bio-oil production facilities could be an economically and technically feasible expansion of the technology, which is already in limited commercial use. The study, recently published in Energy Conversion and Management, estimated that the proposed system could sequester carbon dioxide for about $152 per ton, making it competitive with other methods of carbon dioxide removal but with far less upfront investment.