Abstract: The invention provides a N2O removal method for a waste gas which is capable of stably decomposing and removing N2O even if the steam concentration in the waste gas is fluctuated. N2O is reduced and removed by bringing the waste gas containing N2O into contact with a reducing agent in the presence of a N2O decomposition catalyst. The temperature of the waste gas to be brought into contact with the N2O decomposition catalyst or the addition amount of the reducing agent is controlled in accordance with the steam concentration in the waste gas in a prior stage of the N2O decomposition catalyst. Therefore, the N2O decomposition efficiency is prevented from being decreased. An iron-zeolite based catalyst may be used as the N2O decomposition catalyst and methane, propane, ammonia, etc. may be used as the reducing agent.

Abstract: The invention provides a N2O removal method for a waste gas which is capable of stably decomposing and removing N2O even if the steam concentration in the waste gas is fluctuated. N2O is reduced and removed by bringing the waste gas containing N2O into contact with a reducing agent in the presence of a N2O decomposition catalyst 9. The temperature of the waste gas to be brought into contact with the N2O decomposition catalyst 9 or the addition amount of the reducing agent is controlled in accordance with the steam concentration in the waste gas in a prior stage of the N2O decomposition catalyst 9. Therefore, the N2O decomposition efficiency is prevented from being decreased. An iron-zeolite based catalyst may be used as the N2O decomposition catalyst and methane, propane, ammonia, etc. may be used as the reducing agent.

Abstract: A liquid film is formed on the surface of a porous body provided with a hydrophobic layer and hydrophilic layer, by moving thereon an ionic liquid having a selective absorption capacity of specific gas, and the specific gas within the gas to be processed is absorbed into the liquid film by bringing pressurized gas to be processed into contact with the liquid film. The specific gas is, for example, a carbon dioxide gas and the ionic liquid is, for example, an imidazolium salt. The specific gas absorbed into the liquid film is passed through the porous body by the use of a difference in pressure, whereby it is collected on a low pressure side. The specific gas absorbed into this collected liquid is then separated into a gas and a liquid by a separator, and the specific gas is released and collected.

Abstract: Liquid film 7 is formed on the surface of a porous body 2 provided with a hydrophobic layer 6a and hydrophilic layer 6b, by moving thereon an ionic liquid having a selective absorption capacity of specific gas, and the specific gas within the gas to be processed is absorbed into the liquid film 7 by bringing pressurized gas to be processed into contact with the liquid film 7. The specific gas is, for example, a carbon dioxide gas and the ionic liquid is, for example, an imidazolium salt. The specific gas absorbed into the liquid film 7 is passed through the porous body 2 by use of a difference in pressure, and is collected on a low pressure side 11. The specific gas absorbed into this liquid that has been collected is separated into gas and liquid by a separator 8, and the specific gas is released and collected.