Catalytic decomposition of PCDD/Fs on a V
catalyst: effect of NaCl
Received: 3 December 2017 /Accepted: 13 March 2018 /Published online: 22 March 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
The effect of NaCl addition on the properties, activity, and deactivation of a V
catalyst was investigated
during catalytic decomposition of gas-phase polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs).
The extent of deactivation relates directly to the NaCl loading of the catalyst. Poisoning by sodium neutralizes acid sites, interacts
strongly with active VO
species, and reduces the redox capacity of catalysts. In addition, NaCl is also a chlorine source and may
actually accelerate the synthesis of new PCDD/Fs. Washing a catalyst with dilute sulfuric acid largely restores catalytic activity,
breaking the interaction of Na
ions and dispersed vanadia and removing Na from the catalyst surface. Consequently, catalyst
acidity and redox capacity almost recover. Furthermore, sulfate residues react with surface adsorbed water to generate Brønsted
acid sites, ensuing a surge of strong acidity of the catalysts.
Municipal solid waste (MSW) incinerators inevitably release
PCDD/F (Olie et al. 1977). Due to their great toxicity, stringent
regulations have been implemented for controlling the emissions
of PCDD/F (Chang et al. 2002; Huang and Buekens 1995;
McKay 2002). Catalytic decomposition is a promising method
for eliminating PCDD/F from stationary sources (Bertinchamps
et al. 2006;Duetal.2018; Finocchio et al. 2006;Luetal.2014).
Vanadium-tungsten catalysts supported on titanium oxide
) carriers are basically applied not only in se-
lective catalytic reduction (SCR) of NO
, but also to decompose
PCDD/F in gaseous streams as well (Bertinchamps et al. 2005;
Goemans et al. 2003;Hungetal.2014).
Alkali oxides and salts, present in fly ash, however, can
intensely deactivate SCR catalysts. Municipal solid wastes
(MSW) contain much higher content of alkali chlorides than
most typical fossil fuels. During incineration, these chlorides
sublimate. When the temperature of flue gas again declines,
they condense onto the widely available particulate matter or,
in clean flue gas, form submicron aerosol particles. Such par-
ticles are largely composed of NaCl, KCl, and Na
(Christensen and Livbjerg 1996; Christensen et al. 1998;
Zheng et al. 2004).
Especially NaCl and KCl have been reported to deactivate
-based catalysts during the selective catalytic reduction
(Chen et al. 2011; Gao et al. 2014;Lietal.
2015a;Tangetal.2010). However, the effect of alkali ions
during the catalytic decomposition of chlorine-containing or-
ganic compounds, such as chlorinated benzenes or PCDD/F,
is still ill documented. Thus, it is important to determine
whether the catalyst is still able to decompose PCDD/F effi-
ciently in the presence of sodium salt deposits. In this study,
we chose NaCl as representative of sodium salts in flue gas.
The relationship between catalytic activity and the surface
properties of catalyst mixed with NaCl is discussed.
Moreover, different methods were comparatively tested to re-
generate the deactivated catalysts.
Responsible editor: Vítor Pais Vilar
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s11356-018-1740-9) contains supplementary
material, which is available to authorized users.
* Longjie Ji
* Shengyong Lu
State Key Laboratory of Clean Energy Utilization, Zhejiang
University, Hangzhou 310027, China
Beijing Construction Engineering Group Environmental
Remediation Co., Ltd., Beijing 100015, China
Environmental Science and Pollution Research (2018) 25:15474–15483