초록 ▼

A safe, reliable SCR system for reducing NOx emissions from an internal combustion engine hydrolyzes urea or like reagent under sufficient pressure to assure generation of ammonia, without production of solids that could foul injectors or catalysts. The heat for hydrolysis can be provided by the exh

A safe, reliable SCR system for reducing NOx emissions from an internal combustion engine hydrolyzes urea or like reagent under sufficient pressure to assure generation of ammonia, without production of solids that could foul injectors or catalysts. The heat for hydrolysis can be provided by the exhaust or an auxiliary means.

대표청구항 ▼

1. A method for reducing the emissions of NOx from a lean-burn engine having associated therewith an exhaust system having an exhaust passage leading to an SCR reactor effective for selective catalytic NOx reduction, comprising:supplying an aqueous urea solution at a preset pressure of at least abou

1. A method for reducing the emissions of NOx from a lean-burn engine having associated therewith an exhaust system having an exhaust passage leading to an SCR reactor effective for selective catalytic NOx reduction, comprising:supplying an aqueous urea solution at a preset pressure of at least about 50 psi into a vessel having an inlet and an outlet; heating the urea solution in the vessel at a temperature above the hydrolysis temperature for the urea solution to produce an ammonia-containing gas; responsive to control signals related to engine load and temperature measured within the exhaust gas passage, introducing the ammonia-containing gas from said vessel into the exhaust passage wherein exhaust from said engine is measured to have an exhaust gas temperature effective for selective catalytic reduction; and passing the exhaust gas containing ammonia through an SCR reactor.