Abstract: An exhaust gas purification system which, in a wider temperature range, can reduce and remove nitrogen oxides in an exhaust gas by a reduction catalyst with the use of hydrogen as a reducing agent is provided. The exhaust gas purification system has an electronic control device (41) which controls an EGR valve (4) and an EGR pipe (5) so that the concentration of oxygen in the exhaust gas obtained from a data map based on the state of an engine (10) becomes less than a predetermined value, and which controls a microreactor (19) so that hydrogen is added to the exhaust gas when the concentration of oxygen in the exhaust gas is less than the predetermined value.

Abstract: An exhaust gas purification system, which upgrades exhaust gas purification while curtailing an increase in an operating cost, is disclosed. The exhaust gas purification system comprises an SCR catalyst for reducing and removing nitrogen oxides in an exhaust gas from an engine (10) by bringing the nitrogen oxides into contact with a reducing agent, oxidation catalysts (11, 17) for oxidizing gas components in the exhaust gas, a water electrolysis device (24) for producing oxygen by electrolyzing water, and an oxygen supply pipe (29) for supplying the oxygen produced by the water electrolysis device (24) to the exhaust gas.

Abstract: An exhaust gas purification system which, in a wider temperature range, can reduce and remove nitrogen oxides in an exhaust gas by a reduction catalyst with the use of hydrogen as a reducing agent is provided. The exhaust gas purification system has an electronic control device (41) which controls an EGR valve (4) and an EGR pipe (5) so that the concentration of oxygen in the exhaust gas obtained from a data map based on the state of an engine (10) becomes less than a predetermined value, and which controls a microreactor (19) so that hydrogen is added to the exhaust gas when the concentration of oxygen in the exhaust gas is less than the predetermined value.

Abstract: An exhaust gas purification system, which upgrades exhaust gas purification while curtailing an increase in an operating cost, is disclosed. The exhaust gas purification system comprises an SCR catalyst for reducing and removing nitrogen oxides in an exhaust gas from an engine (10) by bringing the nitrogen oxides into contact with a reducing agent, oxidation catalysts (11, 17) for oxidizing gas components in the exhaust gas, a water electrolysis device (24) for producing oxygen by electrolyzing water, and an oxygen supply pipe (29) for supplying the oxygen produced by the water electrolysis device (24) to the exhaust gas.