Abstract: In an exhaust gas purification system having an oxidation catalyst and an exhaust gas purifying unit formed so as to include a filter and a selective reduction-type NOx catalyst, at least one of supply of the fuel component and supply of ammonia or an ammonia precursor in an amount that is increased when a prescribed condition under which a part of a fuel component supplied to exhaust gas passes through to a downstream side of the oxidation catalyst is satisfied as compared to a non-passing time supply amount that is a supply amount of ammonia or the ammonia precursor to be supplied when the prescribed condition is not satisfied is controlled such that ammonia for NOx selective reduction by the increased ammonia or ammonia precursor reaches the exhaust gas purifying unit before the passed fuel component.

Abstract: An internal combustion engine, wherein a chemical thermal storage device is provided with a first heater including a first element generating heat when chemically adsorbing a reaction medium supplied from a storage part through a first connection pipe and desorbing the reaction medium if heated by the heat of exhaust in a state chemically adsorbing the reaction medium and a second heater including a second element generating heat when chemically adsorbing a reaction medium supplied from a storage part through a second connection pipe and desorbing the reaction medium if heated by the heat of exhaust in a state chemically adsorbing the reaction medium and wherein the control device controls the opening degrees of the first valve and the second valve so that the reaction medium supplied to the second heater is preferentially recovered at the storage part.