A Parametric Study of Diesel Oxidation Catalyst Performance on CO Reduction in Diesel Dual Fuel Engine Exhaust

2015 ◽  
Vol 656-657 ◽  
pp. 538-543 ◽  
Author(s):  
Sirichai Jirawongnuson ◽  
Worathep Wachirapan ◽  
Tul Suthiprasert ◽  
Ekathai Wirojsakunchai
Keyword(s):  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Engine Exhaust ◽  
Gas System ◽  
Diesel Oxidation ◽  
Co Reduction ◽  
Exhaust Gas Temperature

In this research study, a synthetic exhaust gas system is employed to simulate various exhaust conditions similar to those from conventional diesel and Dual Fuel-Premixed Charge Compression Ignition (DF-PCCI) combustion. OEM DOC is tested to compare the effectiveness of reducing CO from both exhaust characteristics. Variations of the temperature and the concentration of CO, THC, and O2 are done to investigate DOC performance on CO reductions according to Design of Experiment (DOE) concept. The results showed that in DF-PCCI exhaust conditions, DOC requires higher exhaust gas temperature as well as O2 concentration to reduce CO emissions.

A Physically-Based, Control-Oriented Diesel Oxidation Catalyst (DOC) Model for the Applications of NO/NO2 Ratio Estimation Using a NOx Sensor

2010 ◽  
Author(s):  
Ming-Feng Hsieh ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Ratio Estimation ◽  
Engine Exhaust ◽  
Diesel Oxidation ◽  
Physically Based ◽  
Aftertreatment Systems

NO and NO2 are generally considered together as NOx in engine emissions. Since NO2/NOx ratio is small in diesel engine exhaust gas, very often, existence of NO2 is ignored in studies/applications. However, current diesel aftertreatment systems generally include diesel oxidation catalysts (DOCs) at upstream of other catalysts such as diesel particulate filter (DPF) and selective catalytic reduction (SCR). DOC can significantly increase the NO2 fraction in the exhaust NOx. Because NO2 and NO have completely different reaction characters within catalysts, e.g. NO2 can assist DPF regeneration while NO cannot, and SCR De-NOx rate can be increased with higher NO2/NOx ratio (no more than 0.5), considerations of NO2 in aftertreatment systems are becoming necessary. Nevertheless, current onboard NOx sensors cannot differentiate NO and NO2 from NOx. This induces an interest in the method of estimating the concentrations of NO and NO2 in the exhaust gas by available measurements. In this paper, a physically-based, DOC control-oriented model which considers the NO and NO2 related dynamics and an engine exhaust NO/NO2 prediction method were proposed for the purposes of NO/NO2 ratio estimation in diesel engine aftertreatment systems, and the developed model was validated with experimental data.

scholarly journals Optimizing CO Reductions in a Diesel Oxidation Catalyst under Diesel Dual Fuel Exhaust Conditions

2017 ◽  
Vol 21 (5) ◽  
pp. 93-103 ◽  
Author(s):  
Tul Suthiprasert ◽  
Tanes Limpurimongkol ◽  
Sirichai Jirawongnuson ◽  
Tanet Aroonsrisopon ◽  
Ekathai Wirojsakunchai
Keyword(s):  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Dual Fuel ◽  
Diesel Oxidation

Assessment of a Syngas-Diesel Dual Fuelled Compression Ignition Engine

2010 ◽  
Author(s):  
Bibhuti B. Sahoo ◽  
Niranjan Sahoo ◽  
Ujjwal K. Saha
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Gas Flow ◽  
Direct Injection ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Gas Temperature ◽  
Compression Ignition Engine ◽  
Exhaust Gas Temperature

Synthesis gas (Syngas), a mixture of hydrogen and carbon monoxide, can be manufactured from natural gas, coal, petroleum, biomass, and even from organic wastes. It can substitute fossil diesel as an alternative gaseous fuel in compression ignition engines under dual fuel operation route. Experiments were conducted in a single cylinder, constant speed and direct injection diesel engine fuelled with syngas-diesel in dual fuel mode. The engine is designed to develop a power output of 5.2 kW at its rated speed of 1500 rpm under variable loads with inducted syngas fuel having H2 to CO ratio of 1:1 by volume. Diesel fuel as a pilot was injected into the engine in the conventional manner. The diesel engine was run at varying loads of 20, 40, 60, 80 and 100%. The performance of dual fuel engine is assessed by parameters such as thermal efficiency, exhaust gas temperature, diesel replacement rate, gas flow rate, peak cylinder pressure, exhaust O2 and emissions like NOx, CO and HC. Dual fuel operation showed a decrease in brake thermal efficiency from 16.1% to a maximum of 20.92% at 80% load. The maximum diesel substitution by syngas was found 58.77% at minimum exhaust O2 availability condition of 80% engine load. The NOx level was reduced from 144 ppm to 103 ppm for syngas-diesel mode at the best efficiency point. Due to poor combustion efficiency of dual fuel operation, there were increases in CO and HC emissions throughout the range of engine test loads. The decrease in peak pressure causes the exhaust gas temperature to rise at all loads of dual fuel operation. The present investigation provides some useful indications of using syngas fuel in a diesel engine under dual fuel operation.

Application of the Regularization Chaos Prediction Model in Aero-Engine Performance Parameters

2012 ◽  
Vol 424-425 ◽  
pp. 347-351 ◽  
Author(s):  
Yong Sheng Shi ◽  
Jun Jie Yue ◽  
Yun Xue Song
Keyword(s):  
Prediction Model ◽  
Simulation Analysis ◽  
Search Algorithm ◽  
Engine Performance ◽  
Forecasting Model ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Engine Exhaust ◽  
Aero Engine ◽  
Exhaust Gas Temperature

Based on the research of complexity and non-linearity of aero-engine exhaust gas temperature (EGT) system, a regularization chaotic prediction model was proposed to build short time forecasting model of EGT. In this paper, in order to gain the best parameter to improve the accuracy of the forecasting model, a simple search algorithm arithmetic was adopted. The simulation analysis shows that the proposed forecasting model obviously exceeded the traditional chaotic forecasting model on prediction accuracy. Therefore, this arithmetic is efficient and feasible for a short-term prediction of aero-engine exhaust gas temperature

Effect of Exhaust Back Pressure on Performance and Emission Characteristics of Diesel Engine Equipped with Diesel Oxidation Catalyst and Exhaust Gas Recirculation

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Sangamesh Bhure
Keyword(s):  
Fuel Consumption ◽  
Exhaust System ◽  
Diesel Oxidation Catalyst ◽  
Back Pressure ◽  
Oxidation Catalyst ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Diesel Oxidation ◽  
Gas Recirculation ◽  
Exhaust Valves

Currently the emission norms are becoming more stringent, continuous modifications are taking place in existing I.C engines as well as in after treatment devices (ATDs). Exhaust Gas Recirculation (EGR) and Diesel Oxidation Catalyst (DOC) are the mandatory ATDs controlled electronically to optimize engine brake power, fuel consumption and emissions. The conversion efficiency of ATDs mainly depends on exhaust pressure, temperature, flow rate and fluid characteristics of exhaust gas. However, the installation of ATDs increases the exhaust back pressure in the exhaust system. The back pressure of engine also depends on the parameters like engine operating conditions, design of exhaust valves, valve lift time, exhaust gas dynamics and exhaust manifold design etc. In this paper the attempt is made to study the effect of back pressure on performance and emission of diesel engines equipped with EGR and DOC. Here we have not modified the intake and exhaust valves instead, we varied the back pressure of exhaust system using back pressure control valve (BPCV). BPCV is operated manually at three positions, they are 100%, 87.5% and 75% BPCV lifts. The readings are taken in different combinations of BPCV lifts and brake torque at 20, 40, 60, and 80 N-m. The results obtained shows variation of BPCV lift and brake torque effected on performance of engine, DOC and EGR operations as well as fuel consumption. The NOx is reduced by 15%; HC and CO are reduced significantly. However, there is an increase in brake specific fuel consumption (BSFC) and exhaust smoke.

Evaluation of Effective Active Site on Pd Methane Oxidation Catalyst in Exhaust Gas of Lean Burn Gas Engine

2019 ◽  
Author(s):  
Yoshifuru Nitta ◽  
Yudai Yamasaki
Keyword(s):  
Active Sites ◽  
Oxidation Process ◽  
Estimation Method ◽  
Oxidation Catalyst ◽  
Pd Catalyst ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Ch4 Oxidation ◽  
Lean Burn ◽  
Exhaust Gas Temperature

Abstract Lean-burn gas engines have recently attracted attentions in the maritime industry, because they can reduce NOx, SOx and CO2 emissions. However, since methane (CH4) is the main component of natural gas, the slipped methane which is the unburned methane emitted from the lean-burn gas engines likely contributes to global warming. It is thus important to make progress on exhaust aftertreatment technologies for lean-burn gas engines. A Palladium (Pd) catalyst for CH4 oxidation is expected to provide a countermeasure for slipped methane, because it can activate at lower exhaust gas temperature. However, a deactivation in higher water (H2O) concentration should be overcome, because H2O inhibits CH4 oxidation. This study was performed investigates the effects of exhaust gas temperature or gas composition on active Pd catalyst sites to clarify CH4 oxidation performance in the exhaust gas of lean-burn gas engines. The authors developed the method of estimating effective active sites for the Pd catalyst at various exhaust gas temperature. The estimation method is based on the assumption that active sites used for CH4 oxidation process can be shared with the active sites used for Carbon mono-oxide (CO) oxidation. The molecular of chemisorbed CO on the active sites of the Pd catalyst can provide effective active sites for CH4 oxidation process. To clarify the effects of exhaust gas temperature and compositions on active Pd catalyst sites, the authors developed an experimental system for the new estimation method. This paper introduces experimental results and verifications of the new method, showing that chemisorbed CO volume on a Pd/Al2O3 catalyst is increased with increasing Pd loading in 250–450 °C, simulated as a typical exhaust gas temperature range of lean-burn gas engines. The results provide a part of the criteria for the application of Pd catalysts to the reduction of slipped methane in exhaust gas of lean-burn gas engines.

Evaluating the Influence of Biogas Flow Rate and Addition of Cerium Oxide Nanoparticles on the Performance of a Dual Fuel Engine Using Taguchi Method

2017 ◽  
Vol 17 ◽  
pp. 179-193
Author(s):  
M. Feroskhan ◽  
Ismail Saleel
Keyword(s):  
Cerium Oxide ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Equivalence Ratio ◽  
Volumetric Efficiency ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Brake Thermal Efficiency ◽  
Exhaust Gas Temperature

Biogas is a promising alternative fuel for compression ignition (CI) engines owing to its renewability and carbon neutrality. In this study, biogas was used along with diesel in a CI engine in dual fuel mode, i.e. biogas is inducted along with air and this mixture is ignited by the in-cylinder injection of diesel. The viability of using cerium oxide (CeO2) nanoparticles as an additive to diesel was also explored. The effects of three parameters, viz. biogas flow rate and concentration of CeO2 nanoparticles and applied load on engine performance were investigated under constant speed operation. These parameters were varied in the ranges of 0 - 12 litre/min, 0 - 35 mg/litre and 5 - 22 N.m respectively. The experimental test matrix was reduced to 16 trials using Taguchi’s approach. Performance was quantified in terms of brake thermal efficiency, volumetric efficiency, diesel consumption, exhaust gas temperature and overall equivalence ratio. The criteria for optimum performance were defined as maximum brake thermal and volumetric efficiencies and minimum diesel consumption, exhaust gas temperature and overall equivalence ratio. Optimum operating conditions were identified by evaluating the signal to noise ratio (SNR) for each performance parameter and using the higher-the-better (HTB) or lower-the-better (LTB) condition as applicable. Contributions of individual parameters towards the performance indices were found using ANOVA. Load was found to be the main contributing factor for brake thermal efficiency, exhaust gas temperature and overall equivalence ratio. Biogas flow rate showed significant contribution towards volumetric efficiency. Biogas flow rate and load had comparable influences on diesel consumption. Addition of nanoparticles showed minor contribution towards all the performance parameters.

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