Ammonia Formation over Pd/Rh Three-Way Catalysts during Lean-to-Rich Fluctuations: The Effect of the Catalyst Aging, Exhaust Temperature, Lambda, and Duration in Rich Conditions

2019 ◽  
Vol 53 (21) ◽  
pp. 12621-12628 ◽  
Author(s):  
Chengxiong Wang ◽  
Jianwei Tan ◽  
Gavin Harle ◽  
Huiming Gong ◽  
Wenzheng Xia ◽  
...  
Keyword(s):  
Exhaust Temperature ◽  
Catalyst Aging ◽  
Ammonia Formation

scholarly journals Kinetic and deuterium isotope analyses of ammonia electrochemical synthesis

RSC Advances ◽  
2021 ◽  
Vol 11 (29) ◽  
pp. 17891-17900
Author(s):  
Chien-I. Li ◽  
Hiroki Matsuo ◽  
Junichiro Otomo
Keyword(s):  
Electrochemical Synthesis ◽  
Surface Reaction ◽  
Electrochemical Promotion ◽  
Isotope Analyses ◽  
Ammonia Formation

Electrochemical promotion of ammonia formation is mainly governed by surface reaction with N2 and H2 in the cathode.

Fuel economy, NOx emissions and lean NOx trap efficiency: Lessons from current driving cycles

2021 ◽  
pp. 146808742110050
Author(s):  
José Rodríguez-Fernández ◽  
Juan José Hernández ◽  
Ángel Ramos ◽  
Alejandro Calle-Asensio
Keyword(s):  
Fuel Economy ◽  
Thermal Efficiency ◽  
Transport Sector ◽  
Lean Nox Trap ◽  
Ambient Temperatures ◽  
Exhaust Temperature ◽  
Driving Cycles ◽  
Vehicle Velocity ◽  
Two Factors ◽  
Lean Nox

Transport sector is within a profound changing period, but diesel engines are still called to play a significant role in future supported on their solid share in many regions and superior thermal efficiency compared to spark-ignited engines. This work identifies the parameters that most affect fuel consumption and NOx emissions on a diesel passenger car equipped with a lean NOx trap under different driving cycles and ambient temperatures. High average vehicle velocity was beneficial to reduce the fuel consumed per kilometer. The driving dynamics was of little importance, easily counteracted by a higher thermal efficiency, higher engine temperature (because of a longer trip) or/and an efficient gear shifting strategy. Moreover, at low ambient temperature the latter two factors doubled their weight on fuel economy. Regarding tailpipe NOx, keeping high aftertreatment performance was crucial. For this, low engine-out NOx emissions were four times more important than exhaust temperature or flow rate.

scholarly journals Performance and Regeneration of Methane Oxidation Catalyst for LNG Ships

2021 ◽  
Vol 9 (2) ◽  
pp. 111
Author(s):  
Kati Lehtoranta ◽  
Päivi Koponen ◽  
Hannu Vesala ◽  
Kauko Kallinen ◽  
Teuvo Maunula
Keyword(s):  
Methane Oxidation ◽  
Sulfur Poisoning ◽  
Oxidation Catalyst ◽  
Lean Burn ◽  
Marine Fuel ◽  
Efficient Catalyst ◽  
Worst Case ◽  
Exhaust Temperature ◽  
Unintended Effect ◽  
Methane Slip

Liquefied natural gas (LNG) use as marine fuel is increasing. Switching diesel to LNG in ships significantly reduces air pollutants but the methane slip from gas engines can in the worst case outweigh the CO2 decrease with an unintended effect on climate. In this study, a methane oxidation catalyst (MOC) is investigated with engine experiments in lean-burn conditions. Since the highly efficient catalyst needed to oxidize methane is very sensitive to sulfur poisoning a regeneration using stoichiometric conditions was studied to reactivate the catalyst. In addition, the effect of a special sulfur trap to protect the MOC and ensure long-term performance for methane oxidation was studied. MOC was found to decrease the methane emission up to 70–80% at the exhaust temperature of 550 degrees. This efficiency decreased within time, but the regeneration done once a day was found to recover the efficiency. Moreover, the sulfur trap studied with MOC was shown to protect the MOC against sulfur poisoning to some extent. These results give indication of the possible use of MOC in LNG ships to control methane slip emissions.

The Design of Exhaust Gas Cooler for Diesel Particulate Bag Filter

2015 ◽  
Vol 737 ◽  
pp. 608-611
Author(s):  
Xiu Ye Wang ◽  
Guo Bin Li ◽  
Nan Xu
Keyword(s):  
Diesel Exhaust ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Bag Filter ◽  
Engine Exhaust ◽  
Particulate Emission ◽  
Filter System ◽  
Exhaust Temperature ◽  
Diesel Exhaust Particulate ◽  
Exhaust Particulate

Currently, the application of bag-filter technology in controlling diesel exhaust particulate emissions has been close to practical stage. As one of the key links in bag-filter technology, engine exhaust cooling can directly influence working safety of the entire exhaust particulate filter system. Thermodynamic calculations and experimental research of water-cooled chiller has provided a feasible basis for water cooler to be used in actual diesel exhaust particulate emission control system. The cooler can make engine exhaust temperature drop from 400 to 180 . Even when engine works in high-speed and high-load condition, inlet exhaust temperature of cooler can descend from 500 to 190 or so after cooling, which can still meet bag-filter system requirement of below 200 .

Ruminal ammonia formation in relation to the protein requirement of sheep: III. Ruminal ammonia formation with various diets

1954 ◽  
Vol 44 (3) ◽  
pp. 270-273 ◽  
Author(s):  
E. F. Annison ◽  
Margaret I. Chalmers ◽  
S. B. M. Marshall ◽  
R. L. M. Synge
Keyword(s):  
Ammonia Production ◽  
Protein Requirement ◽  
Groundnut Meal ◽  
Rich Material ◽  
Protein Rich ◽  
Ammonia Formation

1. Ruminal ammonia concentrations were measured in sheep receiving basal diets of hay and meals with various supplementary sources of protein. Ammonia production from groundnut meal was great and from maize products slight. Herring meal behaved in an intermediate way.2. The extent of ammonia production from a given amount of protein-rich material was decreased when the amount of starch or cereal meal fed at the same time was increased.

Investigation of the Combustion Performance in a Three-Nozzle RQL Combustor

2016 ◽  
Author(s):  
Bing Ge ◽  
Yongbin Ji ◽  
Shusheng Zang ◽  
Yongwen Yuan ◽  
Jianhua Xin
Keyword(s):  
Air Flow ◽  
Lean Burn ◽  
Uniformity Coefficient ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Sector Model ◽  
Exhaust Temperature ◽  
Whole Process ◽  
Axial Temperature ◽  
Two Peaks

RQL (Rich-burn/Quick-quench/Lean-burn) is a candidate to support fuel flexible stationary power generation. The equivalence ratio of rich-burn zone (Φr) and the quench air flow are paramount for implantation of the whole process. In this paper, an experimental test stand with multi-sector model combustor was established. Rich premixed combustion were used in rich zone. The experiments which pay attention to the impacts of Φr and quench air flow on the combustion performance and emission are conducted. The results show that the flame in RQL combustor is segmented when Φr >1.4, presenting flameless combustion in rich zone and a pale blue flame in lean zone. Axial temperature distribution is M-type. Two peaks appear at the head and tail of the combustion chamber, and the valley is located in the quench zone. The concentration of CO decreases rapidly in quench zone because of the injection of quench air. However, the concentration of NOx increases quickly at the same time. The outlet emissions of CO and NOx in RQL combustor are maintained at low level (<20ppm@15%O2). With a decrease of Φr from 1.4 to 1.2, the emission of NOx increases, and the emission of CO decreases. With jet-to-mainstream mass-flow ratio increases from 1.28 to 2.22., the concentration of NOx in outlet declines gently, but the CO emission increase. The average exhaust temperature depresses gradually, and the uniformity coefficient of exhaust temperature increases.

scholarly journals Experiment Study on Performance of Air Source Heat Pump

2013 ◽  
Vol 805-806 ◽  
pp. 645-648
Author(s):  
Wei Xiu Shi ◽  
Li Sheng Pan
Keyword(s):  
Heat Pump ◽  
Temperature Difference ◽  
Heat Pumps ◽  
Outlet Temperature ◽  
Exhaust Temperature ◽  
Air Source Heat Pump ◽  
And Performance ◽  
Save Energy ◽  
C 30 ◽  
Set Up

Under the situation of energy crisis, air source heat pumps are paid more attention recently. In order to save energy, the feasibility and performance of air source heat pump are studied by experiment, and variation laws of exhaust temperature, evaporator outlet temperature and outlet presser of compressor were analyzed in this paper. Air source heat pump apparatus were set up and the experiment was during 10°C, 20°C, 30°C and 40°C. The results were as follows: exhaust temperature of compressor increases gradually with the increase of tank temperature, but the temperature difference between exhaust temperature of compressor and tank temperature becomes little; temperature difference in evaporator decreases; Compressor outlet pressure increases obviously.

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