EXHAUST EMISSION CONTROL DEVICE AND METHOD FOR NATURAL GAS ENGINE

摘要

PROBLEM TO BE SOLVED: To purify exhaust gas in all temperature areas at low cost without requiring a complicated structure in a natural gas engine. SOLUTION: Fuel gas is purified in advance by arranging adsorbent 7 between a fuel tank 4 and a fuel supply port 5 in an air intake passage 2 and making the adsorbent 7 adsorb NMOG in fuel gas supplied to the fuel tank 4. When the temperature of a catalyst 11 arranged in an exhaust passage 3 reaches an activation temperature, the adsorbent 7 is heated to a desorption temperature by a heater 9, NMOG is desorbed from the adsorbent 7 and the NMOG is purified by the catalyst 11.