2005 Fiscal Year Final Research Report Summary
Basic Sorption-Desorption Characteristics of NOx and SOx by Mixed Oxide Sorbents
| Project/Area Number |
16360402
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Catalyst/Resource chemical process
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| Research Institution | Kyoto University |
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Principal Investigator |
EGUCHI Koichi Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (00168775)
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| Co-Investigator(Kenkyū-buntansha) |
KIKUCHI Ryuji Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (40325486)
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| Project Period (FY) |
2004 – 2005
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| Keywords | NO_x sorption-desorption / SO_2 sorption-desorption / SO_2 poisoning / Base Oxide Additives / Pt-Li_2O / TiO_2 / FT-IR / Perfectly Mixed Flow Reactor Mode / Continuously Stirred Tank Reactors |
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| Research Abstract |
Sulfur-tolerant NO sorbents based on Pt/TiO_2 were developed by adding base oxide additives such as M_xO_y (M= Li, Na, K, Cs, Sr, Bo, La). The base oxide additives were effective in improving the NO sorption capacity of Pt/TiO_2 under both SO_2-free and SO_2-containing atmosphere. Under SO_2-containing atmosphere, the NO uptake during sorption reaction for 6 h was not affected over Pt-Li_2O/TiO_2, whereas it was significantly deteriorated over the other sorbents. TPD spectra of H_2S in H_2 after sorption reaction of 6h in SO_2-containing atmosphere showed SO_2 stored on Pt-Li_2O/TiO_2 was released at the lowest temperature. In addition to weak basicity of lithium compared to other additives, Li_2TiO_3 formed over Pt-Li_2O/TiO_2 could lead to instability of the sulfates on Pt-Li_2O/TiO_2, giving rise to desorption of sulfur-containing species at the lowest temperature. In situ FT-IR indicated formation of bulk-like sulfate that needs high temperature to decompose was slow over Pt-Li_2O/TiO_2, which also contributed to the excellent SO_2-tolerance of Pt-Li_2O/TiO_2.
NO and NO_2 sorption characteristics were simulated using continuously-stirred tank reactor model. Model parameters included in the model were determined by series of experiments. In these experiments, the following findings were obtained : 1) NO_x uptake was raised by increasing W/F (catalyst weight/gas flow rate) and the concentration of NO and NO_2, 2) NO_x uptake was increased upon feeding NO_2 due to limitation of oxidation of NO to NO_2, 3) NO_x uptake was proportional to W/F during NO_2 sorption reaction. NO and NO_2 sorption curves were successfully simulated by the model, and NO_x uptake was well predicted for various operating conditions. The NO_x concentration at position x in the axial distance in the reactor and operation time t, represented as V_x, t, was expressed as a function of NO_x inlet concentration V_<in> and surface coverage θ(t), V_<x, t>= exp(- 1.75θ)V_<in>(1-θ)-0.0242 exp(2.00θ)θ.
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[Book] 触媒活用大事典2004
Author(s)
江口浩一(「触媒活用大事典」編集委員会 編)
Total Pages
1134
Publisher
工業調査会
Description
「研究成果報告書概要(和文)」より
