Abstract: Raw diesel fuel is reformed to produce partially oxygenated hydrocarbons in the liquid fuel by use of a nonthermal plasma reactor. The reformed diesel fuel is formed by passing a stream of air plasma bubbles through a liquid volume of diesel fuel to strip low molecular weight hydrocarbons from the fuel, while partially oxygenating an abundance of them as a reformate for addition to the exhaust. This reformed diesel fuel is introduced as a sidestream into the exhaust of a diesel engine or other lean-burn power plants as reactants for selective catalytic reduction of nitrogen oxides in the exhaust. Fresh fuel is added to the liquid volume as diesel reformate is stripped from it, and a portion of the stripped fuel is withdrawn from the liquid volume.