Long-Range Marine Transport Carbon Capture with Seawater Sequestration

Long-range marine transportation contributes to approximately 2% of global CO2 emissions. Unlike land-based transportation, which can use battery electric or hydrogen fuel cell drivetrains, marine transport remains challenging to decarbonize. Because of this, post-combustion carbon capture from fossil-fueled ships is an attractive option for the near-term decarbonization of marine transportation. However, capturing CO2 from marine sources presents unique technical hurdles, including space and weight limitations, onboard CO2 compression and storage, excess power consumption, and variable exhaust conditions and operating profiles. Advanced Cooling Technologies, Inc. (ACT) and Jeevan Technology, Inc. (Jeevan) propose a novel carbon capture technology for long-range marine transportation based on a recently developed hybrid ion exchange sorbent (known as DeCarbonHIX) that offers high CO2 capture capacity and is amenable to regeneration with seawater causing no adverse environmental impact. A key advantage of the proposed CO2 capture technology is its ability to store captured CO2 in seawater as chemically stable alkalinity or sodium bicarbonate (same as baking soda). By storing captured CO2 in seawater, the need for onboard CO2 storage is eliminated, reducing the overall footprint of the shipboard capture system. The DeCarbonHIX CO2-selective sorbent is the only CO2 capture sorbent that can be directly regenerated by raw seawater. Another benefit of seawater carbon storage as bicarbonate is due to the slightly basic pH of the discharged bicarbonate. As bicarbonate is discharged from the vessel, a gentle increase in ocean pH is introduced, helping to reverse CO2-induced ocean acidification. The project team has demonstrated the CO2 capture and seawater storage potential of the DeCarbonHIX sorbent at the bench scale, showing that the sorbent adsorbs CO2 at a capacity several times that of existing sorbents and that the bicarbonate is stable in seawater. During Phase I, the team will further develop the technology by the following steps: 1) A conceptual design and feasibility study of a full-scale ship-based capture system. 2) Lab-scale testing of the capture process using simulated flue gas and regeneration by seawater and reset using a weak base solution. 3) Complete a physical design of a full-scale, long-range marine capture process with all major components defined and scaled. 4) Demonstrate the economic competitiveness of the proposed capture process through a preliminary life cycle and techno-economic analysis with comparisons against competing state-of-the-art technologies. The proposed technology represents a step change in how marine transport carbon capture is approached. It promises to deliver an overall capture process with reduced size, weight, and power compared to existing technologies and to help offset CO2-driven ocean acidification by discharging sodium bicarbonate. This technology is one piece of the puzzle to reversing climate change and could play a significant role if deployed in mass over the coming decades.