SBIR Phase I: CAS: A light-based, energy-generating, carbon removal process

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase I project includes reducing the amount of greenhouse gases in the atmosphere and sequestering them permanently or reusing them to make sustainable chemicals. The Intergovernmental Panel on Climate Change (IPCC), the world’s most authoritative body of climate scientists and policymakers, has declared that billions of tons of carbon dioxide must be removed from the atmosphere annually by 2050 to prevent global temperatures from exceeding 1.5°C above pre-industrial levels, avoiding the worst impacts of climate change.

If successful, this research would provide a path to gigaton-scale carbon removal. The low energy requirements of the process could allow for deployment in locations distant from large energy infrastructure to bring the benefits and jobs of a new carbon removal industry to communities most affected by weather related events.

This project will commercialize a fundamentally new approach to carbon removal. The vast amount of carbon dioxide locked in seawater remains dissolved if it stays near neutral pH, but outgases spontaneously when acidified. This process uses a light-triggered reversible photoacid as a low-energy means to temporarily acidify seawater and drive out carbon dioxide, which can then be stored or used in industry.

The proprietary photoacid at the heart of the process changes its structural conformation when exposed to visible light and releases a proton. The resulting increase in acidity upon illumination provides the proton driving force for carbon capture. Sunlight not absorbed by the photoacid can be used to generate electricity with embedded polysilicon solar cells.

Two aspects of the system need to be improved for the process to be deployed at scale. The photoacid’s resistance to degradation needs to be increased or a simple and scalable process to recover the degraded photoacid needs to be demonstrated. In addition, the ion exchange membranes used in the initial lab prototype are expensive and need to be replaced with cheaper and higher flux membranes. If successful, these developments would lead to a scalable and affordable carbon removal process.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.