Transforming Scrap Tires into Amine-Functionalized Activated Carbon Adsorbents for Landfill Gas Upgrading (Student Poster #21)

Abstract Description: Scrap tire waste generation in the U.S. has increased by over 32% since 2013, while the reuse of tire-derived materials has decreased by more than 25%, resulting in a 123% rise in landfill disposal in the same period. These statistics underscore the need for new markets and innovative recycling solutions. This study explores the conversion of scrap tires into amine-functionalized activated carbon (aminocarbon) materials for landfill gas (LFG) purification. LFG, generated through the anaerobic decomposition of organic waste in landfills, is comprised of methane (CH4; 50-60 vol.%), carbon dioxide (CO2; 40-50 vol.%), and smaller amounts of hydrogen sulfide (H2S), water vapor, and siloxanes. Upgrading LFG into renewable natural gas (RNG) supports clean energy production while mitigating greenhouse gas and odor emissions.
To evaluate the feasibility of scrap tire-derived adsorbents for LFG treatment, tire waste was characterized to determine composition and pre-treatment needs. Carbonization was conducted using microwave heating and muffle furnace methods, followed by activation to produce porous activated carbon (AC). Select AC samples were modified with diethanolamine (DEA), tetraethylenepentamine (TEPA), and branched polyethylenimine (PEI) at loadings of 20, 30, and 40 wt.%. CO2 adsorption capacities were tested under dry conditions (30 vol.% CO2, balance N2), with the performant sample being further assessed under humid conditions. H2S adsorption performance was evaluated to determine the multifunctionality of the synthesized adsorbents. Preliminary results show that tire-derived aminocarbons exhibit significant potential for removing multiple LFG contaminants.

Acknowledgements:
This work was supported by funding from the Florida Hinkley Center for Solid and Hazardous Waste Management.

Keywords: Amine modification, Activated Carbon Adsorbents, Landfill Gas