Catalyctic reduction of nitric oxide by copper catalyzed granular activated carbon in the presence of oxygen
Date of Award
Master of Science in Applied Chemistry - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
James M. Grow
The catalytic reduction of nitric oxides by solid carbonaceous material consisting primarily of granular activated carbon or (GAC) was studied in a fix bed catalytic reactor in order to develop the technology for removing NO and soot simultaneously from diesel engine exhaust. The catalytic activity and conversion of NO as a function of reaction temperature was evaluated as a function of space velocity. The results show that at lean condition and high gaseous hourly space velocity, vis., 50,000 ~ 80,000, Cu-ZSM-5 does not perform as well with CO and GAC as it does with gaseous hydrocarbons(HC). Plain GAC has low activity for NO reduction at high temperature above 550°C under lean condition. However, copper-impregnated GAC has good activity for both NO reduction and carbon oxidation under lean conditions. Actually in presence of 1 to 10% oxygen, the activity and conversion of NO to N2 due to reaction with carbon is enhanced at a lower light off temperature of 350°C. Over 60% conversion was obtained at gaseous hourly space velocity of 50,000 ~ 80,000. Almost 100% conversion was obtained when GHSV was lowered to 20,000. In order to get insight on the mechanism of this reaction, the reduction of NO with CO was studied over various catalysts at the same condition. It was determined that the results are consistent with CO being an intermediate for the reduction of NO with carbon. We also investigated the deactivation of these catalysts. The results show that the presence of SO2 and water poison copper catalysts. For this reason, it is necessary to develop other catalysts for controlling both NOx and soot. This research is part of a NSF project for developing a novel technique to remove NOx soot simultaneously from diesel engines.
Xiao, Shan, "Catalyctic reduction of nitric oxide by copper catalyzed granular activated carbon in the presence of oxygen" (1999). Theses. 887.