[P003] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P02-293] Sustainable Synthesis of Carbamate-Based Ionic Liquids from CO₂ and Their Application in Microalgal lipid Extraction

○Liang-Chin Chen¹ (1. Yuan Ze University (Taiwan))

Keywords:

Carbon dioxide valorization,Carbamate-based ionic liquids,Dry ice,Chlorella biomass,Green extraction

[Objectives]
The sustainable utilization of carbon dioxide (CO₂) has emerged as a pivotal strategy for developing low-energy, recyclable, and environmentally benign chemical processes. This study aims to establish a facile and integrated platform that combines CO₂ valorization, ionic liquid synthesis, and microalgal biorefinery. Specifically, the research evaluates the use of dry ice as a solid, safe, and readily handled CO₂ source for synthesizing carbamate-based ionic liquids to be used as green extraction solvents.
[Considerations]
The study focused on the influence of amine molecular structures, such as chain length and functional groups, on CO₂ absorption efficiency. Additionally, the amine-to-CO₂ molar ratio was identified as a critical parameter to balance the stability of the resulting ionic liquids and the viscosity required for optimal extraction. The sublimation rate of dry ice was also carefully controlled to ensure maximum reaction conversion.
[Methods]
Sublimated CO₂ from dry ice was introduced into three selected secondary amines: diallylamine (DA), dibutylamine (DB), and dipropylamine (DP). The successful formation of the resulting carbamate-based ionic liquids was confirmed using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses. Subsequently, these ionic liquids were employed as green solvents to extract pigments from Chlorella biomass. The extraction performance and chemical profiles were characterized using gas chromatography-mass spectrometry (GC-MS).
[Results]
The results demonstrated that both the molecular structure of the amine and the amine-to-CO₂ molar ratio played critical roles in carbamate formation and overall extraction efficiency. The optimal conversion conditions were identified as: DA:CO₂ = 2:1, DB:CO₂ = 1.7:1, and DP:CO₂ = 2:1.
[Conclusions]
The research demonstrates that utilizing dry ice as a solid CO₂ source for ionic liquid synthesis is both a practical and safe approach. These carbamate-based ionic liquids exhibited superior performance in extracting pigments from Chlorella biomass, successfully integrating CO₂ capture with high-value biorefinery processes. Overall, this work provides a competitive and sustainable technological framework for green solvent development and circular economy applications.