Issue 64, 2016, Issue in Progress

Effect of HBr formation on mercury oxidation via CaBr2 addition to coal during combustion

Abstract

Adding CaBr2 to coal to enhance elemental mercury (Hg0) oxidation during combustion has been an effective mercury control technology, but the added CaBr2 may increase levels of noxious Br2 or HBr gases in flue gas. Temperature-programmed decomposition (TPD) experiments were conducted to verify the effect of CaBr2 addition on Hg0 oxidation. The results indicated that the amount of Hg0 released initially decreased with increasing amounts of CaBr2 additive and then held steady. The optimal amount of additive was 200 μg g−1. CaBr2 addition effectively oxidized Hg0 released at relatively low temperatures only. The generation of HBr was confirmed by mass spectrometry. The formation of HBr occurred over a temperature range of 250 °C to 400 °C, and the HBr concentration first increased and then remained stable as levels of CaBr2 additive were increased in coal. The maximum concentration of HBr was 18 ppm and corresponded to 200 μg g−1 CaBr2. Further analysis indicated a strong, negative linear correlation between the amount of Hg0 released and the HBr concentration in flue gas. Based on these findings and previous studies, the possible mechanism of oxidation of Hg0 by CaBr2 was analyzed.

Graphical abstract: Effect of HBr formation on mercury oxidation via CaBr2 addition to coal during combustion

Supplementary files

Article information

Article type
Paper
Submitted
03 May 2016
Accepted
10 Jun 2016
First published
15 Jun 2016

RSC Adv., 2016,6, 59009-59015

Effect of HBr formation on mercury oxidation via CaBr2 addition to coal during combustion

Y. Yang, W. Xu, Y. Wu, J. Xiong, T. Zhu, X. Zhou and L. Tong, RSC Adv., 2016, 6, 59009 DOI: 10.1039/C6RA11468G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements