SUMMARY
The use of biogas derived from palm oil mill effluent is important to combat climate change as it helps us to reduce the emission of greenhouse gases especially methane. Sime Darby built the first biogas plant at West Oil Mill, Carey Island in 2009 to initiate their move to reduce the total operational emissions by 40% by 2020. Biogas can be upgraded into Bio Natural Gas (BioNG) with higher calorific value and price by removing CO2. Biogas gas contains about 60% of biomethane and 40% of CO2. In this work, CO2 selective ionic liquid ((1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; [EMIM][TFSI]) was used to improve and functionalize polysulfone membrane incorporated with SAPO-34 zeolite after phase inversion. The effects of IL concentration on the membrane morphology and separation performance in CO2 capture were studied. Fourier transform infrared spectra confirmed that the asymmetric membranes were successfully impregnated with [EMIM][TFSI]. The interfacial defects in polysulfone/SAPO-34 membranes were reduced as shown in scanning electron microscopy images. Polysulfone/SAPO-34 membrane modified using 0.2 M of [EMIM][TFSI] for 2 hr achieve the highest CO2/CH4 selectivity of 35.08 and CO2 permeance of 24.89 GPU. The interfacial sealing using IL caused great improvement of CO2/CH4 selectivity of IL-modified polysulfone/SAPO-34 membranes, more than 600% improvement in comparison to the unmodified membrane. Generating engineering knowledge and findings on CO2 capture using ionic liquid and membrane is not only important in the purification of green energy, but it is also crucial to promote carbon capture and storage in the near future. This work is part of a research project sponsored by Institute of Climate Change-Sime Darby Foundation.