Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• High cost of polymers for carbon capture membranes limits application.
• Cellulose acetate (CA) offers an inexpensive alternative for membrane fabrication.
• Need for enhanced membrane performance in CO2/CH4 separation.

Purpose of the Study:

• Fabricate pure and mixed matrix membranes (MMMs) for carbon capture from natural gas.
• Investigate the effect of polyethylene glycol (PEG) and multi-walled carbon nanotubes (MWCNTs) on membrane properties.
• Enhance CO2/CH4 selectivity and mechanical/thermal stability of CA-based membranes.

Main Methods:

• Solution casting technique used to prepare CA, CA/PEG, and CA/PEG/MWCNTs membranes.
• Membrane characterization via Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and tensile testing.
• Permeation studies conducted using single and mixed gas experiments to evaluate CO2/CH4 selectivity.

Main Results:

• CO2/CH4 selectivity increased 8-fold for pure membranes with 10% PEG and 14-fold for MMMs with 10% MWCNTs in single gas tests.
• Mixed gas experiments showed a 13-fold increase in selectivity for 10% PEG and an 18-fold increase for MMMs with 10% MWCNTs.
• Fabricated MMMs exhibited a tensile strength of 13 MPa and superior thermal stability compared to pure CA membranes.

Conclusions:

• Incorporation of PEG and MWCNTs significantly enhances CO2/CH4 selectivity in CA-based membranes.
• MMMs demonstrate potential for efficient and cost-effective carbon capture applications.
• The developed membranes offer improved mechanical and thermal properties suitable for industrial use.