Secondary air injection

About: Secondary air injection is a(n) research topic. Over the lifetime, 11452 publication(s) have been published within this topic receiving 112147 citation(s).

Process for the gasification of coal in situ

Abstract: Process for the gasification of coal in situ comprising driving shafts or tunnels into a coal seam, injecting air into the bore holes to ignite and burn the coal to raise its temperature ceasing the flow of air when the coal is hot enough to support the endothermic water gas reaction, and injecting steam into the hot coal formation, such steam preferably being preheated by the flue gases taken from the same end of the bore holes where the air was injected, and recovering product gases, including carbon monoxide and hydrogen, and also product oil, exiting the tunnel at the other end of the bore holes. When the temperature of the coal drops during injection of steam to a level which will just permit combustion, the steam flow is stopped, and the cycle is repeated by air injection and flue gas removal at the front end of the bore holes, and through the tunnel connected therewith. This cyclic process is repeated until the entire mass of coal within the area encompassed by the bore holes is exhausted.

Processes for secondarily recovering oil

Abstract: A secondary recovery process using injected air to pressurize the formation and maintain mobility of the reservoir oil by diluting the oil with carbon dioxide. Carbon dioxide is produced as a by-product of air injection, either by auto-oxidation of carbonaceous materials in the reservoir rock, or by ignition of oil in the reservoir. Efficiency of oxidation is observed by testing O 2 content of the effluent gas; it is desirable to hold the oxygen content in the effluent gas to less than 3% by volume in the effluent gas. When this content cannot be reached by auto-oxidation, it is necessary to ignite the oil.

Horizontal well gravity drainage combustion process for oil recovery

Abstract: An in-situ combustion method is provided for the recovery of viscous oil from an oil-bearing reservoir. A linear array of vertical air injection wells is drilled into the reservoir; the wells are completed in the upper portion of the reservoir. One or more gas production wells are provided, remote from the row of injection wells, said gas production wells also being completed in the upper portion of the reservoir. A horizontal oil production well is completed in the bottom portion of the reservoir, aligned with and positioned in spaced relation beneath the vertical injection wells. The reservoir is prepared for ignition and combustion is initiated at each of the injection wells. A hot fluid-transmissive chamber is formed around each of the injection wells as combustion proceeds. Combustion gas communication is established with the gas production wells. Heated oil and water, produced by the combustion front in each hot chamber, drains under the effect of gravity and is produced from the horizontal production well. The main features of the process are the implementation of gravity drainage to a basal horizontal well in a combustion process and the splitting of liquid and gas production.

Exhaust emission control system of internal combustion engine

Abstract: An exhaust emission control system of an internal combustion engine capable of post injection is disclosed which provides control such that the injection timing in sub injection is set to a point earlier than the target injection timing when the sub injection is started, and the injection timing in the sub injection is then delayed to the target injection timing. This realizes the post injection under the optimum conditions and enables an efficient rise in the exhaust temperature while inhibiting deterioration of the drivability due to a rapid change in torque.

Device for purifying exhaust gas of engine

Abstract: An engine has a plurality of the cylinders. The cylinders are divided into a first cylinder group and a second cylinder group, and each cylinder group is connected, via a corresponding branch exhaust passage, to a common interconnecting exhaust passage. In the interconnecting exhaust passage, an exhaust gas purifying catalyst is arranged. The air-fuel ratio of the exhaust gas of the first cylinder group is made lean to feed oxygen to the exhaust gas purifying catalyst, and the air-fuel ratio of the second cylinder group is made rich to feed fuel for heating to the exhaust gas purifying catalyst, so that the oxygen and the fuel for heating react with each other to heat the exhaust gas purifying catalyst to reactivate the exhaust gas purifying catalyst when the reactivation of the exhaust gas purifying catalyst is must be performed. In each branch exhaust passage, a start catalyst is arranged.