Reduction of Nitrogen Oxide Emissions for Lean Burn Engine Technology

Reduction of Nitrogen Oxide Emissions for Lean Burn Engine Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Lean-burn engines offer the potential for significant fuel economy improvements in cars and trucks, perhaps the next great breakthrough in automotive technology that will enable greater savings in imported petroleum. The development of lean-burn engines, however, has been an elusive goal among automakers because of the emissions challenges associated with lead-burn engine technology. Presently, cars operate with sophisticated emissions control systems that require the engine's air-fuel ratio to be carefully controlled around the stoichiometric point (chemically correct mixture). Catalysts in these systems are called "three-way" catalysts because they can reduce hydrocarbon, carbon monoxide, and nitrogen oxide emissions simultaneously, but only because of the tight control of the air-fuel ratio. The purpose of this cooperative effort is to develop advanced catalyst systems, materials, and necessary engine control algorithms for reducing NOX emissions in oxygen-rich automotive exhaust (as with lean-burn engine technology) to meet current and near-future mandated Clean Air Act standards. These developments will represent a breakthrough in both emission control technology and automobile efficiency. The total project is a joint effort among five national laboratories, together with US CAR. The role of Lockheed-Martin Energy Systems in the total project is two fold: characterization of catalyst performance through laboratory evaluations from bench-scale flow reactor tests to engine laboratory tests of full-scale prototype catalysts, and microstructural characterization of catalyst material before and after test stand and/or engine testing.

Reduction of Nitrogen Oxide Emissions for Lean Burn Engine Technology

Reduction of Nitrogen Oxide Emissions for Lean Burn Engine Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Lean-burn engines offer the potential for significant fuel economy improvements in cars and trucks, perhaps the next great breakthrough in automotive technology that will enable greater savings in imported petroleum. The development of lean-burn engines, however, has been an elusive goal among automakers because of the emissions challenges associated with lead-burn engine technology. Presently, cars operate with sophisticated emissions control systems that require the engine's air-fuel ratio to be carefully controlled around the stoichiometric point (chemically correct mixture). Catalysts in these systems are called "three-way" catalysts because they can reduce hydrocarbon, carbon monoxide, and nitrogen oxide emissions simultaneously, but only because of the tight control of the air-fuel ratio. The purpose of this cooperative effort is to develop advanced catalyst systems, materials, and necessary engine control algorithms for reducing NOX emissions in oxygen-rich automotive exhaust (as with lean-burn engine technology) to meet current and near-future mandated Clean Air Act standards. These developments will represent a breakthrough in both emission control technology and automobile efficiency. The total project is a joint effort among five national laboratories, together with US CAR. The role of Lockheed-Martin Energy Systems in the total project is two fold: characterization of catalyst performance through laboratory evaluations from bench-scale flow reactor tests to engine laboratory tests of full-scale prototype catalysts, and microstructural characterization of catalyst material before and after test stand and/or engine testing.

NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines

NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines PDF Author: B. Ashok
Publisher: Elsevier
ISBN: 0128242280
Category : Technology & Engineering
Languages : en
Pages : 488

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Book Description
NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines: Approaches Toward NOx Free Automobiles presents the fundamental theory of emission formation, particularly the oxides of nitrogen (NOx) and its chemical reactions and control techniques. The book provides a simplified framework for technical literature on NOx reduction strategies in IC engines, highlighting thermodynamics, combustion science, automotive emissions and environmental pollution control. Sections cover the toxicity and roots of emissions for both SI and CI engines and the formation of various emissions such as CO, SO2, HC, NOx, soot, and PM from internal combustion engines, along with various methods of NOx formation. Topics cover the combustion process, engine design parameters, and the application of exhaust gas recirculation for NOx reduction, making this book ideal for researchers and students in automotive, mechanical, mechatronics and chemical engineering students working in the field of emission control techniques. Covers advanced and recent technologies and emerging new trends in NOx reduction for emission control Highlights the effects of exhaust gas recirculation (EGR) on engine performance parameters Discusses emission norms such as EURO VI and Bharat stage VI in reducing global air pollution due to engine emissions

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.

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines PDF Author: Nigel N. Clark
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, a percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions, with added EGR to prevent preignition. It was observed that the relative air/fuel ratio, injected NO quantity, added EGR fraction, and engine operating points affected the NO decomposition rates. While operating under these modified conditions, the highest NO decomposition rate of 92% was observed. In-cylinder pressure data gathered during the experiments showed minimum deviation from peak pressure as a result of NO injections into the engine. A NOx adsorption system, from Sorbent Technologies, Inc., was integrated with the Cummins engine, comprised a NOx adsorbent chamber, heat exchanger, demister, and a hot air blower. Data were gathered to show the possibility of NOx adsorption from the engine exhaust, and desorption of NOx from the sorbent material. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a benchtop adsorption system was constructed. The temperature of this apparatus was controlled while data were gathered on the characteristics of the sorbent material for development of a system model. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passed over fresh sorbent material. A mass heat transfer analysis was conducted to analyze the possibility of using hot exhaust gas for the desorption process. It was found in the adsorption studies, and through literature review, that NO adsorption was poor when the carrier gas was nitrogen, but that NO in the presence of oxygen was adsorbed at levels exceeding 1% by mass of the sorbent. From the three experimental campaigns, chemical kinetic modeling analysis, and the scaled benchtop NOx adsorption system, an overall SNR system model was developed. An economic analysis was completed, and showed that the system was impractical in cost for small engines, but that economies of scale favored the technology.

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


Emissions Reduction

Emissions Reduction PDF Author: A. Tomita
Publisher: Elsevier
ISBN: 9780080440897
Category : Nature
Languages : en
Pages : 340

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Book Description
Over the past decade the topic of emissions reduction and control has remained an important area of research due to the enforcement of various Government policies in an attempt to minimize the impact on the environment. One area in which a great deal of research has been conducted to address this policy is NOx/SOx suppression. However, despite the progress that has been made over this time period, further research into the most effective method of reducing NOx/SOx emissions is still urgently required. In developed countries, a more stringent requirement in the level of emissions (such as is NOx/SOx component of less than 10ppm) will be enforced in the near future. Developing countries will also need a new technology that is effective and that is suited to each countries needs. Additional research and development efforts are thus necessary to meet such requirements. This compendium contains a collection of key papers themed around NOx/SOx emissions from combustion of hydrocarbon resources and the attempts to secure an efficient and effective method for reducing these emissions. These key papers are taken from the journals Fuel, Fuel Processing Technology and Progress in Energy and Combustion Science.

Controlling Nitrogen Oxides

Controlling Nitrogen Oxides PDF Author: Alice Hastings
Publisher:
ISBN:
Category : Combustion gases
Languages : en
Pages : 28

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Book Description


Catalytic Reduction of Nitrogen Oxide Emissions with Lower Hydrocarbons for Natural Gas-fired Lean-burn Engines

Catalytic Reduction of Nitrogen Oxide Emissions with Lower Hydrocarbons for Natural Gas-fired Lean-burn Engines PDF Author: Sreshtha Sinha Majumdar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A hydrothermally stable dual-catalyst aftertreatment system for emission control of nitrogen oxides (NOx) with lower hydrocarbons (CHx) has been developed for natural gas-fired stationary lean-burn engines. The dual-catalyst system consists of a physical mixture of a reduction catalyst, palladium supported on sulfated zirconia (Pd/SZ) and an oxidation catalyst, cobalt oxide supported on ceria, CoOx/CeO2. The multifunctional aftertreatment system oxidizes nitric oxide (NO) to nitrogen dioxide (NO2), reduces NO2 to nitrogen (N2), and oxidizes carbon monoxide (CO) and the unutilized hydrocarbons. For practical applications in environmental catalysis, the catalytically active powder catalyst needs to be wash-coated onto a monolith core. To prevent permanent loss of activity due to physical separation of the wash-coat from the walls of the monolith core, adhesivity enhancing materials (binders) are added to the wash-coat. A novel method of incorporating binder to the active catalyst in situ during sol-gel synthesis is presented in this work. Alumina binder incorporated into Pd/SZ in situ during sol-gel synthesis was chosen for further development of a catalytically active washcoat based on activity tests under simulated engine-exhaust conditions. The alumina binder-incorporated Pd/SZ catalyst slurry controlled at pH 1 and calcined at 700°C demonstrated the most promising NOx reduction and CH4 oxidation activity. Cyclic thermal shock tests demonstrated enhanced adhesive properties of the wash-coat to the walls of the cordierite monolith core. Thus, a catalytically active wash-coat with superior adhesive properties was developed for practical application in a real-world aftertreatment unit.

Control Techniques for Nitrogen Oxides Emissions from Stationary Sources

Control Techniques for Nitrogen Oxides Emissions from Stationary Sources PDF Author:
Publisher:
ISBN:
Category : Combustion gases
Languages : en
Pages : 396

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Control Technology for Nitrogen Oxide Emissions from Stationary Sources

Control Technology for Nitrogen Oxide Emissions from Stationary Sources PDF Author: Organisation for Economic Co-operation and Development
Publisher: Paris, France : Organisation for Economic Co-operation and Developpement [sic] ; [Washington, D.C. : Sold by OECD Publications and Information Center]
ISBN:
Category : Science
Languages : en
Pages : 172

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Book Description