Capturing carbon dioxide (CO₂) from air and industrial emissions is vital for mitigating climate change. Existing methods like solvent adsorption/absorption, solid particle sorbents, and membrane separation often face challenges, such as high energy requirements, slow kinetics, limited sorption capacity, and complex regeneration processes. Similarly, removing heavy metals from aqueous environments is critical for environmental protection and public health. However, current techniques can be inefficient, generate secondary waste, and involve cumbersome handling and regenerations. These limitations highlight the need for advanced, energy-efficient, and easily deployable technologies that offer high capacity, rapid kinetics, minimal waste, and simplified operational processes for effective contaminant removal.

This invention introduces an innovative FAM technology for efficient removal of CO₂ from gases and heavy metals from fluids by creating a functionalized flat sheet sorbent through a one-step thermal treatment process involving coating layers of a polyamines-crosslinker- mixture onto a glass microfiber mat. Unlike existing approaches that utilize particle sorbents or methods like solvent extraction and membrane separation, this flat sheet format simplifies preparation, reduces waste, enhances handling with no moving parts, and performs effectively in convective flow applications with shorter contact times. The technology’s versatility and improved efficiency represent a significant advancement over traditional contaminant removal methods.

Under simulated post-combustion and direct air capture (DAC) conditions, the flat sheet sorbent displays 20% greater CO₂ adsorption capacity than an identically functionalized silica particle sorbent. Like its particle sorbent counterpart, it maintains its adsorption capacity following multiple rounds of sorption/desorption under standard conditions. As NETL’s polyamine particle sorbents are known to be regenerable at reduced temperatures (65-85°C) using a microwave-assisted method, the sheet sorbent can also be rapidly regenerated using microwaves, at an even lower temperature (40°C).

In wastewater treatment, the sheet sorbent is capable of selectively removing >95% of heavy metals and rare earth elements (REEs). For the uptake of heavy metals, such as lead, it exhibits faster kinetics than the particle sorbent.