Aqualung, a Norwegian start-up that wants to capture carbon with membranes, has signed Denbury, the US pipeline and enhanced-oil recovery firm, as a strategic investor.
Aqualung is commercializing a carbon dioxide–capture membrane based on research from the Norwegian University of Science and Technology. It uses immobilized amines and water vapor to selectively push CO2 to the inside of hollow polymer fibers, a configuration that the company says eliminates the need to regenerate a CO2 sorbent. Most commercial-scale carbon-capture operations are based on an aqueous amine sorbent that must be regenerated in an energy-intensive process.
Aqualung is targeting all heavy transport and industry, CEO Andrew Robbins says, but he expects the first adopters to be in cement, pulp and paper, and natural gas processing.
The firm is already testing its system at a Standard Lithium gas processing plant in Arkansas and is adding carbon capture to a cement kiln owned by the Nordic building material maker SigmaRoc. In the new deal, Denbury will invest an undisclosed amount in Aqualung and begin integrating the firm’s system in equipment for customers looking to pump emissions into Denbury’s CO2 pipeline network.
Mukunda Kaushik, a CO2 analyst at the consulting firm Lux Research, says membranes have a long history in natural gas processing. “But membranes haven’t been the best fit for postcombustion carbon capture historically,” he says, because they need high pressures and high CO2 concentrations to work well. Aqualung’s novelty comes from the patented amine layer that’s selective to CO2, he adds.
The approach is promising because it is simpler and requires less downtime than more established technology, Kaushik says, but it hasn’t been proved at scale.
Aqualung isn’t alone in bringing membrane carbon capture to market. Evonik Industries is adapting its gas separation membranes to the task, and the petrochemical maker Braskem recently agreed to pilot test a carbon-capture system from Compact Membrane Systems on flue gas at one of its polyolefin plants.