Progress 06/01/10 to 01/31/11
Outputs
OUTPUTS: Task 1: Synthesis, characterization, and bench testing of catalysts for engine (diesel or gasoline) exhaust purification was performed. Catalysts were synthesized by coprecipitation. Surface areas and pore sizes were obtained for candidate materials. An existing reactor system was utilized enabled testing of a fixed bed of adsorbent contained in a quartz tube within a Pyrex sleeve that was capable of being filled with coolant. The temperature of the reactor could be controlled between ambient temperature and 600C. Feed gas flows were controlled via rotameters and gas feed (simulated exhaust) was humidified using a bubbler placed upstream of the reactor. Sample ports were placed both upstream and immediately downstream of the reactor. Screening of materials was performed using ethylene (1500 - 2500ppm) oxidation (in air) as the test reaction, since ethylene simulates the overall exhaust hydrocarbon compoisition. Experiments were performed under both dry and humidified ethylene/air streams containing between 2 and 20 pm ethylene. Task 2: Ceramic monoliths coated with preferred catalysts were prepared using slurry coating and impregnation methods. Cordierite or mullite monoliths were prepared with alumina sol coatings, followed by deposition of catalyst or catalyst precursor. Testing of small monolith samples was performed using both ethylene in air and a more complex mixture containing ethylene (2000ppm), CO (1000ppm), and NOx (400ppm), in addition to water and O2. Effectiveness of catalyst candidates in soot oxidation/combustion was tested by coating catalyzed monoliths with diesel soot, followed by oxidation in a simulated exhaust mixture containing NO, O2, and water. Task 3: Using the performance of preferred catalyst candidates determined during Phase I, a small prototype catalytic converter was designed. Design variables were identified and initial values for them were proposed. The reactor size required for the converter was estimated. Task 4: Structured catalysts developed in Tasks 1 - 3 were tested in diesel engine exhaust. Soot deposited and inlet and exit CO, CO2, NO, NO2, and C2H4 were monitored for both candidate catalyzed monoliths and a blank Al2O3/Cordierite) monolith. PARTICIPANTS: James H. White - Primary Investigator Dr. White's role in this program was as the primary investigator and as such he provided the research direction, performed the majority of the data evaluation, and wrote all reports. Nicholas R. Jentzsch - Research Engineer Mr. Jentzsch's role consisted of designing and fabricating experimental equipment and performing bench and engine testing of catalyst powders and monolith supported catalysts. Yen Touysinhthiphonexay - Research Associate Mr. Touysinhthiphonexay's role was in the synthesis of catalyst materials and coated monoliths. TARGET AUDIENCES: Companies and individuals within the engine emissions control and catalyst markets. PROJECT MODIFICATIONS: None.
Impacts
In order for a new emissions control system to be considered viable in the current marketplace it needs to meet certain technical as well as cost criteria. In regard to the former, it must be able to function in under variable, fuel lean, and humid. Any catalyst needs to exhibit high, steady, continuous activity over an extended period of time. During Phase I, Eltron developed a monolith supported catalyst which demonstrated activity for removal of CO, VOC, soot, and NOx under simulated exhaust conditions and, in a preliminary fashion, sized and identified design features of a prototype exhaust purification device. Data collected during the Phase I also showed that Eltron's best catalyst candidate was shown capable of removing a large fraction (up to 100%) of the NOx in real diesel exhaust. Financial assistance through the United States Department of Agriculture was crucial in the success of the Phase I. The assistance allowed us to purchase raw materials for test reactors and catalyst synthesis, fund a technician who could run the experiments and log data on the project, and fund a primary investigator to interpret the data, evaluate results, and make decisions moving forward.
Publications
- No publications reported this period
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