Author: Xiaoyan She
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
Selective Catalytic Reduction of NOx with Methane Over Ag-alumina Catalysts in High-content SO2 Gas Streams
Author: Xiaoyan She
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
Selective Catalytic Reduction of NOx
Author: Oliver Kröcher
Publisher: MDPI
ISBN: 3038973645
Category : Science
Languages : en
Pages : 281
Book Description
This book is a printed edition of the Special Issue "Selective Catalytic Reduction of NOx" that was published in Catalysts
Publisher: MDPI
ISBN: 3038973645
Category : Science
Languages : en
Pages : 281
Book Description
This book is a printed edition of the Special Issue "Selective Catalytic Reduction of NOx" that was published in Catalysts
Selective Catalytic Reduction of NO with Methane Or Ethanol Over Silver-alumina Catalysts in the Presence of High Concentrations of SO2 and H2O
Author: Xiaoyan She
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
NO, SO2 and H2O Adsorption on Highly Dispersed Ag-alumina Catalyst for the Selective Reduction of NOx by Hydrocarbons
Author: Lu Zeng
Publisher:
ISBN:
Category : Aluminum oxide
Languages : en
Pages : 160
Book Description
Publisher:
ISBN:
Category : Aluminum oxide
Languages : en
Pages : 160
Book Description
NOx Reduction with Hydrocarbons Under Oxidizing Conditions Over Alumina Supported Metal Catalysts
Author: Erol Seker
Publisher:
ISBN:
Category :
Languages : en
Pages : 338
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 338
Book Description
Two-stage Catalytic Reduction of NOx with Hydrocarbons
Author: Umit S. Ozkan
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A two-stage system for the catalytic reduction of NO from lean-burn natural gas reciprocating engine exhaust is investigated. Each of the two stages uses a distinct catalyst. The first stage is oxidation of NO to NO{sub 2} and the second stage is reduction of NO{sub 2} to N{sub 2} with a hydrocarbon. The central idea is that since NO{sub 2} is a more easily reduced species than NO, it should be better able to compete with oxygen for the combustion reaction of hydrocarbon, which is a challenge in lean conditions. Early work focused on demonstrating that the N{sub 2} yield obtained when NO{sub 2} was reduced was greater than when NO was reduced. NO{sub 2} reduction catalysts were designed and silver supported on alumina (Ag/Al{sub 2}O{sub 3}) was found to be quite active, able to achieve 95% N{sub 2} yield in 10% O{sub 2} using propane as the reducing agent. The design of a catalyst for NO oxidation was also investigated, and a Co/TiO{sub 2} catalyst prepared by sol-gel was shown to have high activity for the reaction, able to reach equilibrium conversion of 80% at 300 C at GHSV of 50,000h{sup -1}. After it was shown that NO{sub 2} could be more easily reduced to N{sub 2} than NO, the focus shifted on developing a catalyst that could use methane as the reducing agent. The Ag/Al{sub 2}O{sub 3} catalyst was tested and found to be inactive for NOx reduction with methane. Through iterative catalyst design, a palladium-based catalyst on a sulfated-zirconia support (Pd/SZ) was synthesized and shown to be able to selectively reduce NO{sub 2} in lean conditions using methane. Development of catalysts for the oxidation reaction also continued and higher activity, as well as stability in 10% water, was observed on a Co/ZrO{sub 2} catalyst, which reached equilibrium conversion of 94% at 250 C at the same GHSV. The Co/ZrO{sub 2} catalyst was also found to be extremely active for oxidation of CO, ethane, and propane, which could potential eliminate the need for any separate oxidation catalyst. At every stage, catalyst synthesis was guided by the insights gained through detailed characterization of the catalysts using many surface and bulk analysis techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, Temperature-programmed Reduction, Temperature programmed Desorption, and Diffuse Reflectance InfraRed Fourier Transform Spectroscopy as well as steady state reaction experiments. Once active catalysts for each stage had been developed, a physical mixture of the two catalysts was tested for the reduction of NO with methane in lean conditions. These experiments using a mixture of the catalysts produced N2 yields as high as 90%. In the presence of 10% water, the catalyst mixture produced 75% N{sub 2} yield, without any optimization. The dual catalyst system developed has the potential to be implemented in lean-burn natural gas engines for reducing NOx in lean exhaust as well as eliminating CO and unburned hydrocarbons without any fuel penalty or any system modifications. If funding continues, future work will focus on improving the hydrothermal stability of the system to bring the technology closer to application.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A two-stage system for the catalytic reduction of NO from lean-burn natural gas reciprocating engine exhaust is investigated. Each of the two stages uses a distinct catalyst. The first stage is oxidation of NO to NO{sub 2} and the second stage is reduction of NO{sub 2} to N{sub 2} with a hydrocarbon. The central idea is that since NO{sub 2} is a more easily reduced species than NO, it should be better able to compete with oxygen for the combustion reaction of hydrocarbon, which is a challenge in lean conditions. Early work focused on demonstrating that the N{sub 2} yield obtained when NO{sub 2} was reduced was greater than when NO was reduced. NO{sub 2} reduction catalysts were designed and silver supported on alumina (Ag/Al{sub 2}O{sub 3}) was found to be quite active, able to achieve 95% N{sub 2} yield in 10% O{sub 2} using propane as the reducing agent. The design of a catalyst for NO oxidation was also investigated, and a Co/TiO{sub 2} catalyst prepared by sol-gel was shown to have high activity for the reaction, able to reach equilibrium conversion of 80% at 300 C at GHSV of 50,000h{sup -1}. After it was shown that NO{sub 2} could be more easily reduced to N{sub 2} than NO, the focus shifted on developing a catalyst that could use methane as the reducing agent. The Ag/Al{sub 2}O{sub 3} catalyst was tested and found to be inactive for NOx reduction with methane. Through iterative catalyst design, a palladium-based catalyst on a sulfated-zirconia support (Pd/SZ) was synthesized and shown to be able to selectively reduce NO{sub 2} in lean conditions using methane. Development of catalysts for the oxidation reaction also continued and higher activity, as well as stability in 10% water, was observed on a Co/ZrO{sub 2} catalyst, which reached equilibrium conversion of 94% at 250 C at the same GHSV. The Co/ZrO{sub 2} catalyst was also found to be extremely active for oxidation of CO, ethane, and propane, which could potential eliminate the need for any separate oxidation catalyst. At every stage, catalyst synthesis was guided by the insights gained through detailed characterization of the catalysts using many surface and bulk analysis techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, Temperature-programmed Reduction, Temperature programmed Desorption, and Diffuse Reflectance InfraRed Fourier Transform Spectroscopy as well as steady state reaction experiments. Once active catalysts for each stage had been developed, a physical mixture of the two catalysts was tested for the reduction of NO with methane in lean conditions. These experiments using a mixture of the catalysts produced N2 yields as high as 90%. In the presence of 10% water, the catalyst mixture produced 75% N{sub 2} yield, without any optimization. The dual catalyst system developed has the potential to be implemented in lean-burn natural gas engines for reducing NOx in lean exhaust as well as eliminating CO and unburned hydrocarbons without any fuel penalty or any system modifications. If funding continues, future work will focus on improving the hydrothermal stability of the system to bring the technology closer to application.
NOx Reduction in Rich Catalytic Quick Lean Combustion of Synthesis Gas and in Ethanol Selective Catalytic Reduction
Author: Yuk Fai Tham
Publisher:
ISBN:
Category :
Languages : en
Pages : 322
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 322
Book Description
Activity Patterns in the Catalytic Reduction of SO2 on Some Transition Elements in Alumina
Author: Larry A. Haas
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 24
Book Description
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 24
Book Description
Reformate Assisted Hydrocarbon Selective Catalytic NOx Reduction Over Silver Supported on Alumina Catalysts
Author: William L. Johnson
Publisher:
ISBN:
Category :
Languages : en
Pages : 290
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 290
Book Description
NOx Trap Catalysts and Technologies
Author: Luca Lietti
Publisher: Royal Society of Chemistry
ISBN: 1788014758
Category : Science
Languages : en
Pages : 434
Book Description
Vehicle exhaust emissions, particularly from diesel cars, are considered to be a significant problem for the environment and human health. Lean NOx Trap (LNT) or NOx Storage/Reduction (NSR) technology is one of the current techniques used in the abatement of NOx from lean exhausts. Researchers are constantly searching for new inexpensive catalysts with high efficiency at low temperatures and negligible fuel penalties, to meet the challenges of this field. This book will be the first to comprehensively present the current research on this important area. Covering the technology used, from its development in the early 1990s up to the current state-of-the-art technologies and new legislation. Beginning with the fundamental aspects of the process, the discussion will cover the real application standard through to the detailed modelling of full scale catalysts. Scientists, academic and industrial researchers, engineers working in the automotive sector and technicians working on emission control will find this book an invaluable resource.
Publisher: Royal Society of Chemistry
ISBN: 1788014758
Category : Science
Languages : en
Pages : 434
Book Description
Vehicle exhaust emissions, particularly from diesel cars, are considered to be a significant problem for the environment and human health. Lean NOx Trap (LNT) or NOx Storage/Reduction (NSR) technology is one of the current techniques used in the abatement of NOx from lean exhausts. Researchers are constantly searching for new inexpensive catalysts with high efficiency at low temperatures and negligible fuel penalties, to meet the challenges of this field. This book will be the first to comprehensively present the current research on this important area. Covering the technology used, from its development in the early 1990s up to the current state-of-the-art technologies and new legislation. Beginning with the fundamental aspects of the process, the discussion will cover the real application standard through to the detailed modelling of full scale catalysts. Scientists, academic and industrial researchers, engineers working in the automotive sector and technicians working on emission control will find this book an invaluable resource.