mCDR 2023: Coupling Desalination with Novel mCDR Membranes
Abstract
Large-scale Marine Carbon Dioxide Removal (mCDR) is necessary to simultaneously mitigate global temperature rise and lower ocean acidification. Although a few electrochemical mCDR approaches have previously been proposed, alternate pathways that require less electricity and energy should be explored to lower costs. One approach to lower the cost of mCDR is to use a passive membrane contactor coated in materials that can locally lower the pH so that less electricity is needed split CO2 gas out of water. Another pathway to lower mCDR costs is to integrate the process into desalination infrastructure, which has many synergies with mCDR. This proposal investigates novel coated membranes that can be used downstream from desalination membranes to simultaneously remove CO2 and other ionsfrom brine. The main objective of this project is to demonstrate the feasibility of using coated nanofiltration membranes to remove CO2 from seawater in a desalination. More specifically, the team is proposing to demonstrate at the lab-scale that CO2 gas can be removed from a synthetic reverse osmosis (RO) retentate stream using a specialized membrane coated with chemical groups that locallylower the seawater pH to release more CO2 gas. The team is investigating two chemical groups as membrane coatings: carbonic anhydrase and guanidine-functionalized aromatics. Both of these groups should locally lower the seawater pH, causing gaseous CO2 to be released from the seawater. These two surface coatings will be polymerized onto a few different nanofiltration membranes and experimentswill be performed to quantify their ability to remove gaseous CO2 from synthetic seawater. Experimental work will be complemented by multiphysics modeling and system-level technoeconomic assessment to determine the optimal membrane and system designs and costs. This project will lay the foundation for a novel approach to coupling passive mCDR with desalination for large-scale, cost-effective CO2 removal from seawater.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 24, 2024
- Source ID
- N000142412002
Entities
People
- Katherine Hornbostel
Organizations
- Office of Naval Research
- United States Navy
- University of Pittsburgh