Cerium-ferrierite Catalyst Systems for Reduction of NOx in Lean Burn Engine Exhaust Gas PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Cerium-ferrierite Catalyst Systems for Reduction of NOx in Lean Burn Engine Exhaust Gas PDF full book. Access full book title Cerium-ferrierite Catalyst Systems for Reduction of NOx in Lean Burn Engine Exhaust Gas by Germaine Seijger. Download full books in PDF and EPUB format.
Author: Germaine Seijger
Publisher: IOS Press
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 248
Get Book Here
Book Description
Contents of this Doctoral Dissertation include: NOx emission reduction from lean burn engines, automotive exhaust gas emissions, Reactions of NOx in the atmosphere Engine market share and sales trends, Ferrierite characteristics, synthesis and application, Characteristics of the group of FER framework structures, Screening of silver and cerium exchanged zeolite catalysts for the lean burn reduction of NOx with propene, Hydrocarbon NOx reduction in lean burn exhaust gas over Ce-FER catalysts, Approach to the kinetics of NOx reduction with propene over Ce-H-Ferrierite, In SITU preparation of ferrierite coatings on cordierite honeycomb supports, Concluding remarks
Author: Germaine Seijger
Publisher: IOS Press
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 248
Get Book Here
Book Description
Contents of this Doctoral Dissertation include: NOx emission reduction from lean burn engines, automotive exhaust gas emissions, Reactions of NOx in the atmosphere Engine market share and sales trends, Ferrierite characteristics, synthesis and application, Characteristics of the group of FER framework structures, Screening of silver and cerium exchanged zeolite catalysts for the lean burn reduction of NOx with propene, Hydrocarbon NOx reduction in lean burn exhaust gas over Ce-FER catalysts, Approach to the kinetics of NOx reduction with propene over Ce-H-Ferrierite, In SITU preparation of ferrierite coatings on cordierite honeycomb supports, Concluding remarks
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having an SCR catalyst comprising silver tungstate on an alumina support. The emissions treatment system may be used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines. An emissions treatment system may further comprise an injection device operative to dispense a hydrocarbon reducing agent upstream of the catalyst.
Author: Saiful Bari
Publisher: BoD – Books on Demand
ISBN: 9535111205
Category : Technology & Engineering
Languages : en
Pages : 282
Get Book Here
Book Description
Diesel engines, also known as CI engines, possess a wide field of applications as energy converters because of their higher efficiency. However, diesel engines are a major source of NOX and particulate matter (PM) emissions. Because of its importance, five chapters in this book have been devoted to the formulation and control of these pollutants. The world is currently experiencing an oil crisis. Gaseous fuels like natural gas, pure hydrogen gas, biomass-based and coke-based syngas can be considered as alternative fuels for diesel engines. Their combustion and exhaust emissions characteristics are described in this book. Reliable early detection of malfunction and failure of any parts in diesel engines can save the engine from failing completely and save high repair cost. Tools are discussed in this book to detect common failure modes of diesel engine that can detect early signs of failure.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Get Book Here
Book Description
Lean burn gasoline and diesel engines provide improved fuel economy when compared to engines operating under stoichiometric fuel/air conditions. At the same time, lean burn and diesel engines present a problem for emission control. Because they operate under oxidizing conditions, the conventional three-way catalyst is not effective in NOx reduction [1,2]. In addition, the wide temperature range of automobile exhaust gases present a challenge for catalyst design. The temperature of exhaust gases from a light duty diesel engine can vary from 150 to 500 C, depending on the operating conditions. To date, a catalyst that operates with high NOx conversion efficiency over the entire operating range has not been found. Non-thermal plasma assisted catalysis has been shown to be a promising technology for NOx reduction in lean burn and diesel exhaust gases [3,4]. The approach exploited in this paper is to use a plasma in combination with several catalysts, each of which are active over unique temperature ranges. It was reported in the literature, that the one of the essential roles of plasma treatment is to oxidize NO to easier reducible NO2 [7]. In this contribution, the other important function of plasma treatment, namely partial oxidation of propylene, will be demonstrated.
Author: Bijesh Man Shakya
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Get Book Here
Book Description
The combination of NOx storage and reduction (NSR) and selective catalytic reduction (SCR) catalyst is a promising technology for the reduction of NOx emission from the exhaust of lean-burn or diesel engine vehicles. In the combined NSR/SCR system, NH3 generated in LNT during the rich phase is utilized in the SCR for additional NOx conversion. Therefore, the performance of the combined NSR/SCR depends strongly on the NH3 generating function of the NSR catalyst. Earlier studies show that lower Pt dispersion NSR catalysts give higher selectivity to NH3 making them ideal candidates for this particular application. In the first part of the work, we performed experiments on lower Pt dispersion catalysts to gain insights on the mechanistic effects of Pt dispersion on NOx conversion and selectivity. We also developed an improved crystallite-scale model of NSR that explicitly accounts for the crystallite scale gradients of the stored NOx. The calibrated model is able to capture the effects of Pt dispersion, rich phase duration and overall cycle time on cycle-averaged conversion and selectivity trends. In the second part, we carried out a simulation study of dual-layer NSR+SCR monolithic catalyst using (1+1)-D model of catalytic monolith with individually-calibrated global kinetic models. Simulations show that multiple combinations of catalyst loading can attain a given NOx conversion and N2 selectivity, and that there exists a loading of SCR washcoat for a given NSR catalyst for which the NOx conversion is maximum. Simulations of the dual-brick monolith are also performed to analyze the effects of catalyst architecture. Under identical conditions, the simulations show that dual-layer catalyst outperforms the dual-brick largely because of the better utilization of generated NH3. Finally, we performed an optimization study to identify optimal loading and configuration of combined Fe+Cu zeolite catalyst that gives overall high NOx removal efficiency over a broad range of temperature. Simulations suggest that the brick configuration in which Fe- brick is followed by Cu- catalyst is slightly better than dual-layer in which Fe- is coated on top of Cu- architecture. This is attributed to the diffusional limitations in the washcoat that is more pronounced in the dual-layer catalysts.
Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2626
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The purpose of this research is to demonstrate that the use of a reverse-flow oxidation catalyst reactor (RFOCR), both with and without supplemental fuel injection (SFI), will result in significant reductions of methane (CH4) in a simulated lean-burn natural gas exhaust mixture. Methane reduction is investigated as a function of the directional duration of the exhaust gases through the oxidation catalyst, gas hourly space velocity (GHSV), and exhaust gas temperature. The CH4 catalytic chemical reaction, at an elevated exhaust gas temperature, is an exothermic reaction and elevating the temperature across the catalyst reactor corresponds to an increase in CH4 conversion. Periodically reversing the inlet and outlet exhaust direction through the catalyst traps the heat released from the chemical reaction, raising the overall temperature of the exhaust gas through the RFOCR. This study demonstrates the ability of the RFOCR to trap heat, thereby increasing CH4 oxidation. This ability to trap heat provides a significant advantage over standard unidirectional flow catalytic converters. Additionally, to increase CH4 conversion at relatively low feed temperatures, the injection of a supplemental fuel mixture consisting of carbon monoxide (CO) and hydrogen (H2) was evaluated. The experimental results confirm that, when compared with unidirectional flow, periodically reversing the flow of exhaust mixture through a catalyst reactor can significantly improve CH4 conversion. Results also indicate that the effect of switching time (ST) on CH4 conversion vary significantly with gas hourly space velocity (GHSV) and temperature. Furthermore, results indicate that by introducing supplemental fuel into the feed mixture at low engine operating conditions CH4 conversion is notably improved by elevating the temperature across the catalyst reactor through the combustion of carbon monoxide and hydrogen. However, extended durations of increased CH4 conversion during reverse-flow operations is not possible after supplemental fuel injection is terminated.
Author: Marco Piacentini
Publisher:
ISBN:
Category :
Languages : en
Pages : 220
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Core samples cut from full size commercial Fe-and Cu-zeolite SCR catalysts were exposed to a slipstream of raw engine exhaust from a 1.9-liter 4-cylinder diesel engine operating in conventional and PCCI combustion modes. Subsequently, the NOx reduction performance of the exposed catalysts was evaluated on a laboratory bench- reactor fed with simulated exhaust. The Fe-zeolite NOx conversion efficiency was significantly degraded, especially at low temperatures (
