Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering


Zheng, Ming


After-treatment, Alternative Fuel, Butanol, Diesel, LNT, NOx




As regulations for nitrogen oxide (NOx) emissions continue to be tightened, the need for both alternative fuels and intensive exhaust after-treatment will increase. n-Butanol as an alternative fuel has demonstrated the potential to reduce both NOx and particulate matter (PM) emissions, simultaneously. The use of n-butanol in a compression ignition (CI) engine was studied on an engine test bench, at low and medium load. Engine-out NOx emissions were reduced with the application of exhaust gas recirculation (EGR), although, they were not low enough to meet emission regulations, indicating that further NOx reduction in the exhaust would be required. Lean NOx trap (LNT) experiments were conducted on an after-treatment flow bench using simulated exhaust conditions. n-Butanol proved to be a more effective reductant than diesel for regeneration at 3% exhaust oxygen concentration, due to a higher hydrogen production, although at 0% exhaust oxygen concentration, diesel was slightly more effective than n-butanol. The long breathing n-butanol LNT strategy of this work proved to be capable of reducing the fuel penalty associated with an LNT by nearly 90% compared to the conventional LNT operating schemes, while simultaneously achieving ultra-low NOx emissions.