Impact of Sodium on the Formation Mechanism and Physicochemical Properties of Coal-Derived Soot

Abstract

Ion-exchanged Na (INa) and adsorbed Na (ANa) concentrations have significant impact on the physicochemical properties of coal-derived aerosol, and product yields of soot and tar. INa effectively reduced tar release during primary pyrolysis, thus reducing soot yield. ANa had no clear effect on primary pyrolysis, but was easier to gasify. During the secondary pyrolysis, lowconcentrated gasified Na promoted aggregation of aromatics to form soot disordered core and increased soot yield. However, at sufficiently high concentration, Na mainly catalyzed tar cracking. Gasified Na can change size distribution of soot aggregates and promote the conversion of SO 2 to SO 4 2− . These two effects of Na were affected by Cl in pyrolysis gas. Na in soot can change the arrangement of graphite-like layers and increase sp 3 hybridized carbon bonding. INa can couple to carboxylate (COO − ) and promote formation of ether C−O structures in soot or tar.

Laser-induced fluorescence for studying the influence of potassium and sodium salts on PAH formation in sooting premixed flames

“…The enhanced PAH formation is suggested to be due to the partial oxidation of soot in the secondary flame zone. Furthermore, another recent study on coal-derived soot showed that Na in pyrolysis gas promoted the aggregation of aromatic compounds, potentially through Na + -π interactions to increase the soot yield [15]. In yet another study, it was shown that at low temperatures Na + promoted the aggregation of small PAH molecules, while inhibited the same at higher temperatures (> 1373 K) due to the dominance of catalytic effects [17].…”

“…There have been several studies on the influence of potassium and sodium on soot formation in applied systems, such as biomass and coal combustion systems [7,[10][11][12][13][14][15][16][17][18]. For example, addition of potassium has been found to reduce soot concentration [7], diminish particulate matter emissions [10] and improve catalytic activity in soot oxidation process [10][11][12][13].…”

“…For example, addition of potassium has been found to reduce soot concentration [7], diminish particulate matter emissions [10] and improve catalytic activity in soot oxidation process [10][11][12][13]. Likewise, sodium addition also showed catalytic activity for soot oxidation [14,15], and an increase in soot yield [15]. However, the effects of addition of potassium or sodium are found to vary across systems.…”

Fuzzy Multicriteria Decision-Making Analysis of Agricultural Product Logistics in Agricultural Economic Management

“…It is found that green manufacturing practice and green logistics practice are the crucial performance of green supply chain management and operation and can improve the economic and environmental performance of enterprises at the same time; research on the implementation of green supply chain management in the mining industry focuses on reducing the impact of the whole supply chain rather than the whole organization on the environment. Most Indian mining industries have insufficient understanding of the influencing factors of green supply chain management; Dong et al (2020) [7] pointed out that, in order to make the economy gradually dynamic and improve efficiency, it is essential to use the capabilities, methods, and qualifications of supply chain management to establish an appropriate corporate structure and management mechanism for coordination efforts. Over time, the gradual development of supply chain capability will lead to "snowball effect," and enhancing supply chain capability will have a synergistic effect on enterprises; in the past decades, with the improvement of environmental awareness, consumers and companies have faced greater pressure to reduce the emission of harmful chemicals and implement green practices in the whole process supply chain.…”

Roles of Ion-Exchangeable Sodium in the Conversion Process of Tar to Soot during Rapid Pyrolysis of Two Brown Coals in a Drop-Tube Reactor

“…We previously studied the effects of different forms of Na (ion-exchangeable state and physical adsorption state) on the formation characteristics of soot during the pyrolysis of Yimin brown coal at 1250 °C, and found that the inhibition of ion-exchangeable Na on soot formation was much stronger than that of physically adsorbed Na . Ion-exchangeable Na could also be released with volatiles in the form of organic bonding, and these organic-bound Na could promote the combination of surrounding carbon atoms with oxygen-containing substances .…”