Lee TsungYu, Liou Sihyu, Bai Hsunling
a Institute of Environmental Engineering, National Chiao Tung University , Hsinchu , Taiwan , Republic of China.
J Air Waste Manag Assoc. 2017 Mar;67(3):292-305. doi: 10.1080/10962247.2016.1231144.
A series of iron-manganese oxide catalysts supported on TiO and titanium nanotubes (TNTs) were studied for low temperature selective catalytic reduction (SCR) of NO with NH in the presence of SO The results showed that the specific surface area and the amount of Brønsted acid sites were highly correlated. The results also demonstrated that higher Mn/Mn ratios and larger specific surface areas might be the main reasons for the excellent performance of MnFe-TNTs catalyst after SO poisoning. The SO poisoning effect could be minimized by reducing the GHSV, increasing the reaction temperature, or increasing the [NH]/[NO] molar ratio. The results also indicated that the formation of ammonium sulfate had a stronger effect on the NO conversion efficiency as compared to the formation of metal sulfate. Thus operating the low temperature SCR at above 230 C to avoid the formation of ammonium sulfate would be the priority choice when SO poisoning is a concerned issue. Implications: Low-temperature selective catalytic reduction (SCR) has attracted increasing attention due to that it can reduce the energy consumption for the SCR process employed in industries such as steel plants and glass manufacturing plants. However, it also suffers from the sulfur dioxide (SO) poisoning problem. This study investigates the possibility of using titania nanotubes (TNTs) as the support of Mn/Fe bimetal oxide catalysts for low-temperature SCR to reduce the SO poisoning. The results indicated that the MnFe-TNT catalyst can tolerate SO for a longer time as compared with the MnFe-TiO catalyst.
研究了一系列负载在TiO和钛纳米管（TNTs）上的铁锰氧化物催化剂，用于在SO存在下用NH对NO进行低温选择性催化还原（SCR）。结果表明，比表面积和布朗斯台德酸位数量高度相关。结果还表明，较高的Mn/Mn比和较大的比表面积可能是MnFe-TNTs催化剂在SO中毒后表现优异的主要原因。通过降低气体时空速、提高反应温度或提高[NH]/[NO]摩尔比，可以将SO中毒效应降至最低。结果还表明，与金属硫酸盐的形成相比，硫酸铵的形成对NO转化效率的影响更强。因此，当关注SO中毒问题时，在230℃以上运行低温SCR以避免硫酸铵的形成将是优先选择。 启示：低温选择性催化还原（SCR）由于可以降低钢铁厂和玻璃制造厂等行业中SCR工艺的能耗而受到越来越多的关注。然而，它也存在二氧化硫（SO）中毒问题。本研究探讨了使用二氧化钛纳米管（TNTs）作为Mn/Fe双金属氧化物催化剂的载体用于低温SCR以减少SO中毒的可能性。结果表明，与MnFe-TiO催化剂相比，MnFe-TNT催化剂能够更长时间地耐受SO。
