Papers by Keyword: Hot Gas Filtration

Abstract: Increasing air pollution caused mainly by exhaust emission has become a serious concern for public health. In order to efficiently control the exhaust emission from the origin, hot gas filtration is required in many industries, such as thermal power regeneration, metal refining/recycling, and biomass/coal gasification. This study aimed to develop a hybrid filter composed with ultrafine fibrous polyimide (PI) filtration layers and carbon woven fabric supporting layers for hot gas filtration. Uniform PI ultrafine fibers around 200 nm with small pores about 2.2 μm were electrospun on carbon fabrics supporting layers to serve as the filtration layer. During filtration test, NaCl aerosols (0.3 mm), which mimicked PM 2.5 particles were accumulated on the top of filtration layer and formed dust cake, but limited aerosols were observed on the carbon fabric supporting layers. It was proved that PI fiber mats played the key role in filtration. The filtration efficiency could be maintained above 95% after 9 min and reached 99.4 %. This research proved that the multi-scale polyimide/carbon fibers hybrid filters possessed the potential to serve as filtration media in bag filters for hot gas filtration.

Abstract: Electrospun membrane filters used to remove particles from hot gases were highly desired to meet the requirement of application in high temperature. Polyimide is a kind of high performance polymer, especially for excellent thermal stability and chemical resistance. In this paper, the polyimide precursor poly (amic acid) (PAA) was synthesized from 3,3’,4,4’-oxydiphthalic anhydride (ODPA) and 4,4’-methylenedianiline (MDA), the polyimide (PI) ultrathin fiber membrane was fabricated by electrospinning and followed by thermal imidization. Scanning electron microscope (SEM), infrared spectrometry (IR), and thermogravimetric analysis (TGA) were used for the characterizations of the polyimide ultrathin fiber Membrane, the tests show that the diameter of ultrathin fiber is uniform with an average size of around 400nm and the membrane is thermally stable at a high temperature of 500°C.