3D Porous Nanocellulose Based Filter from Palm Bunch Using Tert-Butyl Alcohol-Assisted Pore Inducive Technique for Airborne Particulate Matter Retention

Environmental hazards, especially particulates, and microbiological pollutants, have resulted in significant negative impacts on human health. In this study, 3D biodegradable cellulose filters were made from nanocellulose and tested for the removal efficiency of airborne particulates. Cellulose was first extracted from palm empty fruit bunches (EFBs) using green Deep Eutectic Solvents (DESs) under moderate temperature and then homogenized at high pressure to produce cellulose at the nanoscale size. Three types of renewable choline chloride (ChCl)-based DESs were used: lactic acid, 1,3-butanediol, and oxalic acid. The maximum cellulose yield from DES pretreatment was 38.78 % based on raw EFB (100 % cellulose yield based on cellulose in EFB) with ChBu60 C and the maximum nanocellulose yield was 68.49 % based on cellulose in EFB with ChLa80 C after 12-pass high pressure homogenization. The cellulose air filter was fabricated using tert-butyl alcohol (tBuOH) solvent exchanged under freeze-drying conditions and characterized by different state-of-the-art techniques. It was shown that the ChBu80 C filter had the lowest pressure drop (10.16 mmH₂O or 2.07 mmH₂O cm⁻²) and the maximum particle filtration efficiency (32.51 % for 0.1 μm and 93.63 % for 1.0 μm particles). The process simulation and techno-economic analysis were performed for nanocellulose production and air filter fabrication to select the most feasible technology.