(430c) CO2 Capturing Technology through Lignin-Based Polymers

Climate change, driven by excessive CO2 emissions, poses a pressing threat to global ecosystems and human well-being. CO2 capture technology has emerged as a promising approach to mitigate this challenge, enabling the capturing of CO2 from ambient air for storage and conversion into valuable products. In this presentation, we report an innovative and cost-effective polymer for CO2 capture and utilization for the first time, using abundant and non-food-based biomass lignin. The modified ionic polymer synthesized through the reaction of ion containing reagent with lignin under alkaline conditions. Subsequently, the modified lignin-based polymer is employed for CO2 capture from both direct air and concentrated CO2 sources at room temperature and atmospheric pressure. Structural characterization of the polymers is accomplished through 1H, 13C, and 2D-HSQC NMR, and FT-IR spectroscopy. The CO2 capture process is established through the formation of specific functional ions alongside the presence of CO2. The captured CO2 is precisely quantified by using inverse-gated proton decoupled 13C NMR with an internal standard. Remarkably, the amount of captured-CO2 of the ionic lignin polymer per one gram are 1.06 mmol (47 mg) from concentrated CO2 source and 0.60 mmol (26 mg) of CO2 from ambient air exposure. Significantly, the captured CO2 in the new polymer is utilized to synthesize cyclic carbonate as an example. The cyclization reaction in a unique reaction setup, where the CO2-captured lignin-based polymer as an active CO2 source. The reaction was successfully conducted by supplied CO2 from the new lignin-based polymer. Moreover, the fully controlled recycling of ionic lignin polymer achieved via repeated CO2 release ↔ CO2 capture. Hence, this novel methodology offers a promising pathway towards sustainable, recyclable CO2 capture and utilization and represents a significant step forward in the quest for effective carbon capture technologies.