Biomass slurry fracture injection as a potential low-cost negative emissions technology

Negative emissions technologies (NETs) are systems which remove carbon dioxide directly from the atmosphere and sequester it in permanent storage and they are required to meet the goals of the Paris Agreement. However, all NETs are limited by biological, physical and economic factors. Here, we model the life cycle emissions, geospatial potential, technoeconomic feasibility of a new NET based on slurry fracture injection, a technique which has been used for decades in the oil and gas industry to dispose of wastes. In the proposed system, called biomass slurry fracture injection (BSFI), biogeneic wastes are injected into fractures created in permeable saline formations. We calculate that the costs of BSFI are generally lower than $95 tonne −1 of CO 2 removed, even at biomass prices above $75 dry tonne −1 . We conduct a geospatial feasibility analysis of the continental U.S. and conclude that adequate biomass, geological storage and wastewater is available to sequester 80 Mt CO 2 e yr −1 . We use global estimates of potential biomass availability to conclude that a mature industry might sequester on the order of 5 Gt CO 2 e yr −1 , over 10% of contemporary CO 2 emissions.