EXHAUST EMISSION CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine capable of easily and quickly estimating a sulfur concentration of fuel. SOLUTION: The exhaust emission control device of the internal combustion engine comprises an exhaust emission control catalyst 11 provided in an exhaust passage 5 of the internal combustion engine 1, and a pH sensor 25 for detecting pH of condensed water generated from exhaust gas passed through the exhaust emission control catalyst 11, wherein an ECU 40 assumes that the sulfur concentration of the fuel is within a predetermined range and estimates pH of the condensed water generated from the exhaust gas passed through the exhaust emission control catalyst 11 based on an operation state of the internal combustion engine 1 and estimates the sulfur concentration of the fuel supplied to the internal combustion engine 1 based on a difference between pH detected by the pH sensor 25 in the estimation of pH and the estimated pH. COPYRIGHT: (C)2008,JPO&INPIT