Fabrication of multilayer cellulose filters isolated from natural biomass for highly efficient air filtration for replacement of synthetic HEPA filters

Abstract

Indoor air pollution can be extensively reduced by using a molecular air filtration system. However, widely utilized synthetic polymer-based filtration medium can lead to waste management difficulty after use. Consequently, this work aimed to synthesize highly efficient air nano-filters derived from renewable and biodegradable resources namely EFB and Pulp. The study successfully presented an air filter from 100 % natural cellulose using a facile physical multilayer filter fabrication method. A combination of chemical and mechanical treatment was applied to prepare nanocellulose. The chemical composition analysis showed that 66–67 % nanocellulose yield was efficiently isolated from both raw materials. The highest particle filtration efficiency (PFE) of 97.30 % (0.3 μm particle size) greater than that of commercial HEPA filters was achieved from multilayer acid-derived microfiber@mechanically treated nanofibers from EFB with low-pressure drop of 11.56 mm H2O. When %PFE and pressure drop were taken into consideration, all single-layer and multilayer-patterned fiber filters in this study provided high quality factor (QF) beyond 0.01 Pa−1 which is the target of the air filter. The findings revealed that the pattern-layer filters through TBA-induced freezing-drying technique could achieve the removal of microbial model and Particulate Matters (PM1.0) represented as 0.1 and 0.3 μm particles, at the very low-pressure drop. Therefore, this study not only enhances the value of natural lignocellulosic wastes but also presents inspiring concepts for creating biodegradable cellulose-based air filters that will pave the way to more eco-friendliness and sustainability for synthetic filter replacement.