Study on the formation of ultrafine particulate matter (PM) during char combustion in a wet oxy-combustion atmosphere. (March 2022)

• Record Type: Journal Article
• Authors: Lei, Yu; Niu, Yanqing; Ma, Wen'an; Wang, Guangyao; Wen, Liping; Huang, Haiyu; Hui, Shi'en
• Is Part Of: International journal of greenhouse gas control. Volume 115(2021)
• Publication Date: 2022-03
• Subjects: Char -- Oxy-combustion -- Ultrafine particulate matter -- H2O; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2022.103617
• Languages: English
• ISSNs: 1750-5836

Abstract

Highlights: Low H2 O(g) content inhibited ultrafine PMs formation, while higher H2 O(g) promoted it. Ultrafine PM was more sensitive to H2 O in oxy-fuel atmosphere with low O2 content. Competition between combustion temp and reduction atm affected ultrafine PM yield. H2 O(g) improved the growth of ultrafine particle in comparison with dry atmosphere. H2 O promoted the enrichment of AAEM and Fe, but had the opposite effect on si and al. Abstract: In this study, the effect of H2 O on the formation of ultrafine particulate matter (PM) in an oxy-combustion atmosphere with various O2 contents of 21%, 27%, and 33% was investigated in a high-temperature drop tube furnace at 1800 K. The combustion-generated ultrafine PM was collected by a 14-stage electrical low-pressure impactor for analyzing the mass- and number-based particle size distribution (PSD). The element composition of ultrafine PM was identified using inductively coupled plasma mass spectrometry. The results indicated that all the primary peaks of the mass- and number-based PSD of ultrafine PM were located nearby 0.2 μm under various O2 /CO2 /H2 O atmospheres. As H2 O content increased, both the mass and the number yield of ultrafine PM decreased initially and then increased, with an inflection point at 5% H2 O content. The inhibitory effects of 5% H2 O content on the formation of ultrafine PM at 21%, 27% and 33% O2 contents were −12.3%, −28.5%, and −33.5%, respectively, while the promoting effects of 30% H2 O content were 105.4%, 54.0%, and 7.0%, respectively. Thus, the yield of ultrafine PM in the oxy-combustion atmosphere with low O2 content fluctuates more with the increase of H2 O, and was more sensitive to H2 O. Moreover, with the increase of H2 O and O2 content, the average mass of ultrafine PM exhibited an enlarged tendency. And high H2 O content (30%) evidently favored the enrichment of alkali and alkaline earth metals (e.g. Na, K, Ca and Mg), as well as Fe in PM0.1, whereas the volatilization of Si and Al was suppressed.