The Effect of H2 O on the Use of Ethanol as Reductant in the SCR System

The Effect of H2 O on the Use of Ethanol as Reductant in the SCR System

In this experimental study, effects of H2O on the use of ethanol as reducing agents were investigated on the AgPt-W-Ti/Cordierite catalyst. Ag-Pt-W-Ti/Cordierite catalyst was synthesized using the impregnation methodfor selective catalytic reduction (SCR) of NOx. To investigate the effects of H2O addition on the NOx conversionratios, tests were carried out at 200-270 ° C under 30000 h-1 GHSV using three different reductants (ethanol,5% H2O - 95% ethanol, 10% H2O - 90% ethanol). The catalytic activity of the catalyst increased with increase inexhaust gas temperature. The highest NOx conversion ratio was 89.9% at 270 oC with ethanol. The tests showedthat when the H2O content of the reductant increased from 5% to 10%, the NOx conversion ratios significantlydecreased at temperatures below 240 oC. NOx conversion ratios enhanced as engine load increased.

___

  • [1] Mousavi, S.M., Panahi, P.N. (2016). Modeling and optimization of NH3-SCR performance of MnOx/γ-alumina nanocatalysts by response surface methodology. Journal Taiwan Institute Chemical Engineers, 69: 68-77.
  • [2] Li, L., Li, P., Tan, W., Ma, K., Zou, W., Tang, C., Dong, L. (2020). Enhanced low-temperature NH3-SCR performance of CeTiOx Catalyst via surface Mo modification. Chinese Journal of Catalysis, 41: 364-373.
  • [3] Zhou, T., Yuan, Q., Pan, X., Bao, X. (2018). Growth of Cu/SSZ-13 on SiC for selective catalytic reduction of NO with NH3. Chinese Journal of Catalysis, 39: 71-78.
  • [4] More, P.M., Nguyen, D.L., Granger, P., Dujardin, C., Dongare, M.K., Umbarkar, S.B. (2015). Activation by pretreatment of Ag-Au/ Al2O3 bimetallic catalyst to improve low temperature HC-SCR of NOx for lean burn engine exhaust. Applied Catalysis B: Environmental, 174- 175: 145-156.
  • [5] Xu, L., Li, X-S., Crocker, M., Zhang, Z-S., Zhu, A-M. (2013). A study of the mechanism of low-temperature SCR of NO with NH3 on MnOx/CeO2. Journal of Molecular Catalysis A: Chemical, 378: 82- 90.
  • [6] Cha, W., Ehrman, S.H., Jurng, J. (2016). CeO2 added V2O5/TiO2 catalyst prepared by chemical vapor condensation (CVC) and impregnation method for enhanced NH3-SCR of NOx at low temperature. Journal Environmental Chemical Engineering, 4: 556-563.
  • [7] Wang, J., Peng, Z., Chen, Y., Bao, W., Chang, L., Feng, G. (2015). In-situ hydrothermal synthesis of Cu-SSZ-13/cordierite for the catalytic removal of NOx from diesel vehicles by NH3. Chemical Engineering Journal, 263: 9-19.
  • [8] Rasmussen, S.B., Abrams, B.L. (2017). Fundamental chemistry of V-SCR catalysts at elevated temperatures. Catalysis Today, 297: 60- 63.
  • [9] Fuji, M., Shiroki, Y., Menchavez, R.L., Takegami, H., Takahashi, M., Suzuki, H., Izuhara, S., Yokoyama, T. (2007). Fabrication of cordierite filter by in-situ solidification for high temperature dust collection. Powder Technology, 172: 57-62.
  • [10] Twigg, M.V. (2007). Progress and future challenges in controlling automotive exhaust gas emissions. Applied Catalysis B: Environmental, 70: 2-15.
  • [11] Li, F., Shen, B., Tian, L., Li, G., He, C. (2016). Enhancement of SCR activity and mechanical stability on cordierite supported V2O5-WO3/ TiO2 catalyst by substrate acid pretreatment and addition of silica. Powder Technology, 297: 384-391.
  • [12] Shigapov, A.N., Graham, G.W., McCabe, R.W., Peck, M.P., Plummer Jr H.K. (1999). The preparation of high-surface-area cordierite monolith by acid treatment. Applied Catalysis A.: General, 182: 137-146.
  • [13] Liu, Q.Y., Liu, Z.Y., Huang, Z.G., Xie, G.Y. (2004). A honeycomb catalyst for simultaneous NO and SO2 removal from flue gas: preparation and evaluation. Catalysis Today, 93-5: 833-837.
  • [14] Chen, C., Cao, Y., Liu, S., Chen, J., Jia, W. (2018) Review on the latest developments in modified vanadium-titanium-based SCR catalysts. Chinese Journal of Catalysis, 39: 1347-1365.
  • [15] Yang, C., Yang, J., Jiao, Q., Zhao, D., Zhang, Y., Liu, L., Hu, G., Li, J. (2020). Promotion effect and mechanism of MnOx doped CeO2 nano-catalyst for NH3-SCR. Ceramics International, 46: 4394-4401.
  • [16] Piumetti, M., Bensaid, S., Fino, D., Russo, N. (2015). Catalysis in diesel engine NOx aftertreatment: a review. Catalysis, Structure & Reactivity, 1: 155-173.
  • [17] Ström, L., Carlsson, P.A., Skoglundh, M., Härelind, H. (2016). Hydrogen-assisted SCR of NOx over alumina-supported silver and indium catalysts using C2-hydrocarbons and oxygenates. Applied Catalysis B: Environmental, 181: 403-412.
  • [18] Gunnarsson, F., Phil, J.A., Toops, T.J., Skoglundh, M., Harelind, H. (2017). Lean NOx reduction over Ag/alumina catalysts via ethanol-SCR using ethanol/gasoline blends. Applied Catalysis B: Environmental, 202: 42-50.
  • [19] Frobert, A., Raux, S., Rousseau, S., Blanchard, G. (2013). Analysis of the coupling of HC-SCR by ethanol and NH3-SCR on real engine emissions. Topics in Catalysis, 56: 125-129.
  • [20] Deng, H., Yu, Y., He, H. (2015). Discerning the role of Ag-O-Al entities on Ag/γ-Al2O3 surface in NOx selective reduction by ethanol. The Journal of Physical Chemistry C, 119: 3132-3142.
  • [21] Vliehikki, A., Petallidou, K.C., Kalamaras, C.M., Kolli, T., Huuhtanen, M., Maunula, T., Keiski, R.L., Efstathiou, A.M. (2014). Selective catalytic reduction of NOx by Hydrogen (H2-SCR) on WOx-promoted Ce2Zr1-ZO2 solids. Applied Catalysis B: Environmental, 156-157: 72-83.
  • [22] Dong, G-J., Zhao, Y., Zhang, Y-F. (2014). Preparation and performance of V-W/x(Mn-Ce-Ti)/y(Cu-Ce-Ti)/cordierite catalyst by impregnation method in sequence for SCR reaction with urea. Journal of Fuel Chemistry and Technology, 42: 1093-1101.
  • [23] Ma, S., Zhao, X., Li, Y., Zhang, T., Yuan, F., Niu, X., Zhu, Y. (2019). Effect of W on the acidity and redox performance of the Cu0.02Fe0.2WaTiOx (a=0.01, 0.02, 0.03) catalysts for NH3-SCR of NO. Applied Catalysis B: Environmental, 248: 226, 238.
  • [24] Ahmad, M.A.C.M., Keskin, A., Özarslan, H., Keskin, Z. (2020). Properties of ethyl alcohol-water mixtures as a reductant in a SCR system at low exhaust gas temperatures. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 1556-7230.
  • [25] Resitoglu, I.A., Altinisik K., Keskin A., Ocakoglu K. (2020). The effects of Fe2O3 based DOC and SCR catalyst on the exhaust emissions of diesel engines. Fuel, 262, 116501.
  • [26] Keskin A., Yaşar A., Candemir O.C., Özarslan H. (2020). Influence of transition metal based SCR catalyst on the NOx emissions of diesel engine at low exhaust gas temperatures. Fuel, 273, 117785.
  • [27] Zhao B., Ran R., Guo X., Cao L., Xu T., Chen Z., Wu X., Si Z., Weng D. (2017). Nb-modified Mn/Ce/Ti catalyst for the selective catalytic reduction of NO with NH3 at low temperature. Applied Catalysis A: General, 545, 64-71.
  • [28] Du X., Gao X., Fu Y., Gao F., Luo Z., Cen K. (2012). The co-effect of Sb and Nb on the SCR performance of the V2O5/TiO2 catalyst. Journal of Colloid and Interface Science, 368, 406-412.