A Study on <scp>CO₂</scp> Sorption Coefficient and Compatibility of Blend Cellulose Acetate Butyrate Membrane

ABSTRACT The emission of greenhouse gases, such as carbon dioxide (CO 2 ), is a major contributor to global warming and climate change. Meanwhile, the blend membrane plays a critical role in the membrane‐based separation technology. Up until now, the compatibility and sorption studies of the blend cellulose acetate butyrate (CAB) polymers at different molecular weights (Mns) of 12,000 and 65,000 dissolved in chloroform have not been fully examined for nonpolar CO 2 /Nitrogen (N 2 ) separation. In this work, CAB with Mn of 65,000 demonstrated stronger compatibility with chloroform. The sorption study also explored the impact of casting thickness and solvent evaporation time for efficient CO 2 /N 2 separation. The optimized membrane, M2 of casting thickness (250 μm), and solvent evaporation time (5 min), with permeance of 106.87 ± 1.03 GPU, displayed the best sorption results with a CO 2 solubility coefficient of 5.49 × 10 12 cm 3 (STP)/cm 4 cmHg, and CO 2 diffusivity coefficient of 2.80 × 10 12 cm 2 /s. This innovative membrane can reduce carbon emissions in the industrial sectors, thus representing a significant advancement in the global sustainable development goals.