(144g) Multicomponent VOC Adsorption Behaviour on Functionalized Adsorbents

Separation techniques for volatile organic compounds (VOCs) are being exploited for various applications such as exhaled breath analysis. To identify and quantify VOCs in a feed stream via adsorption, selective sorbent materials are of major importance. Sorbents with the desired selectivity of target VOCs could lead to the development of inexpensive, energy efficient and rapid breath tests using adsorption and desorption mechanisms to detect and quantify these VOCs. In this work, several adsorbent materials, including activated carbon, zeolites, and functionalized metal organic frameworks (MOFs), have been tested for their VOC selectivity from simulated breath to acquire an in-depth understanding of VOC adsorption mechanisms on these materials in the presence of CO₂ and water. Adsorption loadings in functionalized adsorbents were lower than unfunctionalized adsorbents. Moreover, functionalized MIL-101 exhibited slower adsorption dynamics than the unfunctionalized MOF. CO₂ and water vapor breakthrough adsorption experiments were also carried out on the functionalized and unfunctionalized materials. Results showed both UiO-66-NH₂ and ML-101-NH₂ exhibit reduction in CO₂ breakthrough times at 50% relative humidity. However, water breaks through MIL-101-NH₂ faster than UiO-66-NH₂, but UiO-66-NH₂ reaches saturation faster. This implies that at high relative humidity, VOC selectively will be greatly reduced.