Reformer Assisted Lean NO.sub.x Catalyst Aftertreatment System and Method

Reformer Assisted Lean NO.sub.x Catalyst Aftertreatment System and Method PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A method and apparatus for catalytically processing a gas stream passing therethrough to reduce the presence of NO.sub.x therein, wherein the apparatus includes a first catalyst composed of a silver-containing alumina that is adapted for catalytically processing the gas stream at a first temperature range, a second catalyst composed of a copper-containing zeolite located downstream from the first catalyst, wherein the second catalyst is adapted for catalytically processing the gas stream at a lower second temperature range relative to the first temperature range, a hydrocarbon compound for injection into the gas stream upstream of the first catalyst to provide a reductant, and a reformer for reforming a portion of the hydrocarbon compound into H.sub. 2 and/or oxygenated hydrocarbon for injection into the gas stream upstream of the first catalyst. The second catalyst is adapted to facilitate the reaction of reducing NOx into N.sub. 2, whereby the intermediates are produced via the first catalyst reacting with NOx and hydrocarbons.

Reformer Assisted Lean NO.sub.x Catalyst Aftertreatment System and Method

Reformer Assisted Lean NO.sub.x Catalyst Aftertreatment System and Method PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A method and apparatus for catalytically processing a gas stream passing therethrough to reduce the presence of NO.sub.x therein, wherein the apparatus includes a first catalyst composed of a silver-containing alumina that is adapted for catalytically processing the gas stream at a first temperature range, a second catalyst composed of a copper-containing zeolite located downstream from the first catalyst, wherein the second catalyst is adapted for catalytically processing the gas stream at a lower second temperature range relative to the first temperature range, a hydrocarbon compound for injection into the gas stream upstream of the first catalyst to provide a reductant, and a reformer for reforming a portion of the hydrocarbon compound into H.sub. 2 and/or oxygenated hydrocarbon for injection into the gas stream upstream of the first catalyst. The second catalyst is adapted to facilitate the reaction of reducing NOx into N.sub. 2, whereby the intermediates are produced via the first catalyst reacting with NOx and hydrocarbons.

Heavy-Duty Emissions Control

Heavy-Duty Emissions Control PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 2

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Book Description
Progress has been made in the control of combustion processes to limit the formation of environmentally harmful species, but lean burn vehicles, such as those powered by diesel engines used for the majority of commercial trucking and off-road applications, remain a major source of nitrogen oxides (NOx) and particulate matter (PM) emissions. Tighter control of the combustion process coupled with exhaust gas recirculation has brought emissions in line with 2004 targets worldwide. Additional modifications to the engine control system, somewhat limited NOx control, and PM filters will likely allow the 2007 limits to be met for the on-highway regulations for heavy-duty engines in the United States. Concern arises when the NOx emission limit of 0.2 g/bhphr set for the year 2010 is considered.

Plasma-Assisted Heterogeneous Catalysis for NOx Reduction in Lean-Burn Engine Exhaust

Plasma-Assisted Heterogeneous Catalysis for NOx Reduction in Lean-Burn Engine Exhaust PDF Author: B. Penetrante
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Book Description
Recent developments in catalytic control of NOx are revealing the significance of NO2 as an intermediary for achieving higher NOx removal efficiencies. This paper discusses the combination of the plasma with a catalyst to improve the selective reduction of NOx under lean-burn conditions. It is shown that the main effect of the plasma is to enhance the gas-phase oxidation of NO to NO2. The reduction of NOx to N2 is then accomplished by the heterogeneous reaction of NO2 with activated hydrocarbons on the catalyst surface. By using a plasma, one can take advantage of a new class of catalysts that are potentially more durable, more active, more selective and more sulfur-tolerant compared to conventional lean-NOx catalysts. The plasma-assisted catalytic reduction process can be implemented with any type of plasma reactor and does not require a specific type of electrical power supply. It can also easily accommodate any type of catalyst support structure.

Lean NOx Trap Catalysis for Lean Burn Natural Gas Engines

Lean NOx Trap Catalysis for Lean Burn Natural Gas Engines PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
As the nation's demand for energy grows along with concern for the environment, there is a pressing need for cleaner, more efficient forms of energy. The internal combustion engine is well established as one of the most reliable forms of power production. They are commercially available in power ranges from 0.5 kW to 6.5 MW, which make them suitable for a wide range of distributed power applications from small scale residential to large scale industrial. In addition, alternative fuels with domestic abundance, such as natural gas, can play a key role in weaning our nations dependence on foreign oil. Lean burn natural gas engines can achieve high efficiencies and can be conveniently placed anywhere natural gas supplies are available. However, the aftertreatment of Nox emissions presents a challenge in lean exhaust conditions. Unlike carbon monoxide and hydrocarbons, which can be catalytically reduced in lean exhaust, NOx emissions require a net reducing atmosphere for catalytic reduction. Unless this challenge of NOx reduction can be met, emissions regulations may restrict the implementation of highly efficient lean burn natural gas engines for stationary power applications. While the typical three-way catalyst is ineffective for NOx reduction under lean exhaust conditions, several emerging catalyst technologies have demonstrated potential. The three leading contenders for lean burn engine de-NOx are the Lean NOx Catalyst (LNC), Selective Catalytic Reduction (SCR) and the Lean Nox Trap (LNT). Similar to the principles of SCR, an LNT catalyst has the ability to store NOx under lean engine operation. Then, an intermittent rich condition is created causing the stored NOx to be released and subsequently reduced. However, unlike SCR, which uses urea injection to create the reducing atmosphere, the LNT can use the same fuel supplied to the engine as the reductant. LNT technology has demonstrated high reduction efficiencies in diesel applications where diesel fuel is the reducing agent. The premise of this research is to explore the application of Lean NOx Trap technology to a lean burn natural gas engine where natural gas is the reducing agent. Natural gas is primarily composed of methane, a highly stable hydrocarbon. The two primary challenges addressed by this research are the performance of the LNT in the temperature ranges experienced from lean natural gas combustion and the utilization of the highly stable methane as the reducing agent. The project used an 8.3 liter lean burn natural gas engine on a dynamometer to generate the lean exhaust conditions. The catalysts were packaged in a dual path aftertreatment system, and a set of valves were used to control the flow of exhaust to either leg during adsorption and regeneration.

Method to Monitor HC-SCR Catalyst NOx Reduction Performance for Lean Exhaust Applications

Method to Monitor HC-SCR Catalyst NOx Reduction Performance for Lean Exhaust Applications PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A method for initiating a regeneration mode in selective catalytic reduction device utilizing hydrocarbons as a reductant includes monitoring a temperature within the aftertreatment system, monitoring a fuel dosing rate to the selective catalytic reduction device, monitoring an initial conversion efficiency, selecting a determined equation to estimate changes in a conversion efficiency of the selective catalytic reduction device based upon the monitored temperature and the monitored fuel dosing rate, estimating changes in the conversion efficiency based upon the determined equation and the initial conversion efficiency, and initiating a regeneration mode for the selective catalytic reduction device based upon the estimated changes in conversion efficiency.

New Combustion Systems in SI & Diesel Engines, and Combustion & Emission Formation Processes in Diesel Engines

New Combustion Systems in SI & Diesel Engines, and Combustion & Emission Formation Processes in Diesel Engines PDF Author:
Publisher:
ISBN: 9780768014846
Category : Diesel motor
Languages : en
Pages : 210

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Book Description


Nitrogen oxides (NOx) why and how they are controlled

Nitrogen oxides (NOx) why and how they are controlled PDF Author:
Publisher: DIANE Publishing
ISBN: 1428902805
Category :
Languages : en
Pages : 57

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Book Description


Annual Index/abstracts of SAE Technical Papers

Annual Index/abstracts of SAE Technical Papers PDF Author:
Publisher:
ISBN:
Category : Automobiles
Languages : en
Pages : 1218

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Design and Development of Heavy Duty Diesel Engines

Design and Development of Heavy Duty Diesel Engines PDF Author: P. A. Lakshminarayanan
Publisher: Springer Nature
ISBN: 9811509700
Category : Technology & Engineering
Languages : en
Pages : 914

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Book Description
This book is intended to serve as a comprehensive reference on the design and development of diesel engines. It talks about combustion and gas exchange processes with important references to emissions and fuel consumption and descriptions of the design of various parts of an engine, its coolants and lubricants, and emission control and optimization techniques. Some of the topics covered are turbocharging and supercharging, noise and vibrational control, emission and combustion control, and the future of heavy duty diesel engines. This volume will be of interest to researchers and professionals working in this area.

Fuel Cells: Technologies for Fuel Processing

Fuel Cells: Technologies for Fuel Processing PDF Author: Dushyant Shekhawat
Publisher: Elsevier
ISBN: 0444535640
Category : Technology & Engineering
Languages : en
Pages : 569

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Book Description
Fuel Cells: Technologies for Fuel Processing provides an overview of the most important aspects of fuel reforming to the generally interested reader, researcher, technologist, teacher, student, or engineer. The topics covered include all aspects of fuel reforming: fundamental chemistry, different modes of reforming, catalysts, catalyst deactivation, fuel desulfurization, reaction engineering, novel reforming concepts, thermodynamics, heat and mass transfer issues, system design, and recent research and development. While no attempt is made to describe the fuel cell itself, there is sufficient description of the fuel cell to show how it affects the fuel reformer. By focusing on the fundamentals, this book aims to be a source of information now and in the future. By avoiding time-sensitive information/analysis (e.g., economics) it serves as a single source of information for scientists and engineers in fuel processing technology. The material is presented in such a way that this book will serve as a reference for graduate level courses, fuel cell developers, and fuel cell researchers. - Chapters written by experts in each area - Extensive bibliography supporting each chapter - Detailed index - Up-to-date diagrams and full colour illustrations