Investigation on the PCDD/Fs distribution of quenched off-gas from electric arc furnace. (June 2021)

• Record Type: Journal Article
• Authors: Dong, Maolin
• Is Part Of: Chemosphere. Volume 272(2021)
• Publication Date: 2021-06
• Subjects: Electric arc furnace PCDD/Fs quenching congener distribution; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.129932
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The method of quenching was adopted to reduce the emission of PCDD/Fs from a pilot scrap preheated EAF. Because quenching can effectively inhibit the de novo synthesis of dioxins. Meanwhile the temperatures at the inlet and outlet of the quenching part of EAF off-gas were measured to investigate the quenching effect. The results show that the temperatures of the off-gas are quenched from about 1300 °C to about 250 °C in the whole tap-to-tap cycle of EAF, which attains the expected cooling effect. The dioxin Toxic Equivalent Quantity (TEQ) concentrations and congener distributions of off-gas and three kinds of sampling ash were analyzed. The results indicate that the TEQ concentration of PCDD/Fs is 0.13 ng-I-TEQ/Nm 3 at the outlet of the chimney A (D4), which is far below the dioxin emission limit for EAFs (0.5 ng-I-TEQ/Nm 3 ) in China. At the same time the fingerprint suggests that the quenching effectively restrains the de novo synthesis, and dioxins de novo synthesize in the following flue and bag filter to some extent. Highlights: The method of quenching was adopted to reduce the emission of PCDD/Fs from a pilot scrap preheated electric arc furnace. The dioxin TEQ concentrations and congener distributions of off-gas and sampling ash for the EAF were analyzed. The fingerprint suggests that the quenching effectively restrains the PCDD/F de novo synthesis.