Abstract: An exhaust gas purification system includes a previous-stage oxidation catalyst device, an ammonia-based solution feeder, a Diesel Particulate Filter (DPF) device, a turbine of a turbocharger, and a NOx selective reduction catalyst device in the exhaust system of an internal combustion engine in this order from an exhaust port side. The NH3 production rate is improved, thereby improving the NOx removal rate; the temperature of the DPF device is kept high to increase the time and frequency of continuous regeneration, thus decreasing the frequency of forced regeneration of the DPF device and the amount of discharge of CO2 produced during the forced regeneration; and also corrosion of the turbine of the turbocharger by SOx is suppressed.

Abstract: A previous-stage oxidation catalyst device, a Diesel Particulate Filter (DPF) device, a turbine of a turbocharger, a previous-stage NOx selective reduction catalyst device, and a subsequent-stage NOx selective reduction catalyst device in an exhaust system of an internal combustion engine in this order from an exhaust port side. An ammonia-based solution feeder is on an inlet side or outlet side of the DPF device. The previous-stage NOx selective reduction catalyst device is a rare earth composite oxide catalyst, and the subsequent-stage NOx selective reduction catalyst device is a zeolite catalyst. The NOx removal rate is improved in wide ranges from low to high temperatures and to high flow rates, and the temperature of the DPF device is kept high to increase the time and frequency of continuous regeneration, thereby reducing the frequency of forced regeneration and an amount of discharge of CO2 during the forced regeneration.

Abstract: A previous-stage oxidation catalyst device, a Diesel Particulate Filter (DPF) device, a turbine of a turbocharger, a previous-stage NOx selective reduction catalyst device, and a subsequent-stage NOx selective reduction catalyst device in an exhaust system of an internal combustion engine in this order from an exhaust port side. An ammonia-based solution feeder is on an inlet side or outlet side of the DPF device. The previous-stage NOx selective reduction catalyst device is a rare earth composite oxide catalyst, and the subsequent-stage NOx selective reduction catalyst device is a zeolite catalyst. The NOx removal rate is improved in wide ranges from low to high temperatures and to high flow rates, and the temperature of the DPF device is kept high to increase the time and frequency of continuous regeneration, thereby reducing the frequency of forced regeneration and an amount of discharge of CO2 during the forced regeneration.

Abstract: An exhaust gas purification system includes a previous-stage oxidation catalyst device, an ammonia-based solution feeder, a Diesel Particulate Filter (DPF) device, a turbine of a turbocharger, and a NOx selective reduction catalyst device in the exhaust system of an internal combustion engine in this order from an exhaust port side. The NH3 production rate is improved, thereby improving the NOx removal rate; the temperature of the DPF device is kept high to increase the time and frequency of continuous regeneration, thus decreasing the frequency of forced regeneration of the DPF device and the amount of discharge of CO2 produced during the forced regeneration; and also corrosion of the turbine of the turbocharger by SOx is suppressed.

Abstract: An exhaust gas purification device to elevate the exhaust gas temperature on an inlet side of a diesel particulate filter. An oxidation catalyst and the diesel particulate filter are arranged in an exhaust path between exhaust ports of an engine and a turbocharger. The device also includes a urea spraying nozzle on an upstream side of the diesel particulate filter, and a selective catalytic reduction unit in an exhaust pipe on a downstream side of the turbocharger.

Abstract: An exhaust purification device and an exhaust purification method that utilizes this exhaust purification device enable effective utilization of exhaust gas heat and allow reduction in the size of the device. The exhaust purification device has an oxidation catalyst that is disposed in an exhaust passage of a diesel engine and purifies CO and HC in exhaust gas; a urea injection nozzle that is disposed downstream of the oxidation catalyst and generates ammonia through atomization of urea water into the exhaust gas; a turbine of a turbocharger, this turbine being disposed downstream of the urea injection nozzle and accelerating decomposition of urea through agitation of the atomized urea water; a DPF that is disposed downstream of the turbine and traps PM in the exhaust gas; and a selective reduction catalyst that is disposed downstream of the DPF and detoxifies NOx in the exhaust gas through a reduction reaction with ammonia.

Abstract: Provided are an exhaust purification device for a diesel engine and an exhaust purification method that utilizes the exhaust purification device enabling effective utilization of exhaust gas heat and allowing reduction in the size of the device, by virtue of the design of the layout of each post-processing units.

Abstract: Provided are an exhaust purification device for a diesel engine, and an exhaust purification method that utilizes this exhaust purification device enabling effective utilization of exhaust gas heat and allowing reduction in the size of the device, by virtue of the design of the layout of each post-processing units.

Abstract: An exhaust-gas after-treatment device having an oxygen storage capacitor substance which releases oxygen when the exhaust-gas is rich in air-fuel ratio and stores oxygen and heats up by itself when the exhaust-gas is lean in air-fuel ratio. The air-fuel ratio for the exhaust-gas flowing into the device is regulated so as to alternately come into the rich condition and the lean condition when the temperature of the exhaust-gas is not higher than a given temperature and when the device is not in a regeneration condition. Thus, when the device having a deNOx catalyst and a diesel particulate filter is not in a regeneration condition, the temperature of the device is raised by utilizing the self-heating function of the oxygen storage capacitor substance during oxygen absorption. As a result, the purification rate for NOx and particulate matter at the time when the temperature of the exhaust-gas is low is improved.

Abstract: In an exhaust-gas after-treatment device (10,10A) having an oxygen storage capacitor substance which releases oxygen when the exhaust-gas is rich in air-fuel ratio and storages oxygen and heats up by itself when the exhaust-gas is lean in air-fuel ratio, the air-fuel ratio for the exhaust-gas flowing into the exhaust-gas after-treatment device (10,10A) is regulated so as to alternately come into a rich condition (R) and a lean condition (L) when the temperature (Tg) of the exhaust-gas is not higher than a given temperature (Tc) and when the exhaust-gas after-treatment device (10,10A) is not in the condition of being regenerated. Thus, when an exhaust-gas after-treatment device (10,10A) having a deNOx catalyst and a DPF is not in the condition of the regeneration of deNOx catalyst, DPF regeneration, or the like, the temperature of the exhaust-gas after-treatment device (10,10A) is raised by utilizing the self-heating function of the oxygen storage capacitor substance during oxygen absorption.