A composition is provided that has heat resistance sufficient for use as a hydrocarbon adsorbent and desorbs hydrocarbons slowly with respect to an increase in temperature. The composition includes an alkali metal and a zeolite having a YFI structure. A content of the alkali metal is 1 to 40 mass% based on a total mass of the composition, and a content of the zeolite having a YFI structure is 99 to 60 mass% based on the total mass of the composition.

Proposed is a pretreatment desulfurization method for marine fuel oil. The method includes a step of preparing a pretreatment desulfurization agent including (a) at least one oxide selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3, (b) at least one metal selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb, and (c) at least one liquid composition selected from the group consisting of sodium tetraborate (Na2B4O7.10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3). and hydrogen peroxide (H2O2). The method also includes a step of feeding the pretreatment desulfurization agent to a fuel supply line through which marine fuel oil is supplied to a marine engine at a certain ratio so that a fluid mixture containing the marine fuel oil and the pretreatment desulfurization agent is supplied to the marine engine, thereby adsorbing and removing sulfur oxides during combustion of the fluid mixture.

In view of above problems, an object of the invention is to provide a primary containment vessel venting system having a structure capable of continuously discharging vapor in a primary containment vessel out of the system and continuously reducing pressure of the primary containment vessel without discharging radioactive noble gases to the outside of the containment vessel and without using an enclosing vessel or a power source. In order to achieve the above object, an nuclear power plant of the invention includes a primary containment vessel which includes a reactor pressure vessel, a radioactive substance separation apparatus which is disposed inside the primary containment vessel and through which the radioactive noble gases do not permeate but vapor permeates, a vent pipe which is connected to the radioactive substance separation apparatus, and an exhaust tower which is connected to the vent pipe and discharges a gas, from which a radioactive substance is removed, to the outside.

A system for capturing and sequestering carbon dioxide includes nanoparticles formed from alkali or alkali metal oxides or hydroxides, such as lithium oxide. Carbon-dioxide containing effluent gasses are exposed to the nanoparticles in fixed beds or fluidized beds, or in a co-flow configuration. The nanoparticle metal oxides are converted to metal carbonates. The nanoparticles can be recovered and the carbon dioxide release by exposing the nanoparticles to an oxygen containing atmosphere at high temperatures.

A hydrocarbon adsorbent having a high hydrocarbon desorption start temperature and a method for adsorbing hydrocarbons that uses the hydrocarbon adsorbent are provided. The hydrocarbon adsorbent includes an alkali metal and a zeolite having a ring structure that includes at least 10 members is used. In the hydrocarbon adsorbent, a content of the alkali metal is 1 to 40 mass % based on a total mass of the hydrocarbon adsorbent, a content of the zeolite having a ring structure that includes at least 10 members is 99 to 60 mass % based on the total mass of the hydrocarbon adsorbent, and at least a portion of the alkali metal is in a state of being ion-exchangeable.

To provide a hydrocarbon reforming/trapping material which is capable of adsorbing and reforming a hydrocarbon. A hydrocarbon reforming/trapping material of the present invention has an SiO.sub.2/Al2O.sub.3 ratio of from 7 to 12, and contains an Fe(II)-substituted beta zeolite which is ion-exchanged by Fe(II) ions. The amount of supported Fe(II) is preferably 0.001-0.5 mmol/g with respect to the Fe(II)-substituted beta zeolite. This Fe(II)-substituted beta zeolite is suitably produced by dispersing and mixing a beta zeolite having an SiO.sub.2/Al.sub.2O.sub.3 ratio of from 7 to 12 in an aqueous solution of a water-soluble compound of divalent iron, and mixing and stirring the solution, so that Fe(II) ions are supported on the beta zeolite.

A vehicle air supply system, in particular in automotive vehicles. The essence of the air supply system according to the vehicle air supply system is that inside the system there is a photocatalyst between at least one air intake (1,2) and at least one supply port (5). The photocatalyst may be deposited on inner surfaces of at least one element selected from the group including vehicle's ventilation/air conditioning system (3), inlet ducts (4), supply ports (5), dampers (7) and filters (9). Preferably, the photocatalyst is given in the form of a bypass (6) or an insert (10) or an adapter (8).

A gas adsorbing material particle includes an additive material particle having a moisture adsorption property; and a layer of a gas adsorbing metal disposed on a surface of the additive material particle, wherein the gas adsorbing metal is inactivated by moisture and adsorbs a target gas, wherein an average thickness of the layer of the metal is less than or equal to about 37 micrometers.

An object of the present disclosure is to provide an exhaust gas purification catalyst demonstrating superior storage of NOx contained in exhaust gas.

The exhaust gas purification catalyst of the present disclosure has a substrate, a first catalyst layer containing a catalytic metal for NOx reduction and a NOx storage material and formed on the substrate, and a second catalyst layer containing a catalytic metal for NOx oxidation and formed on the first catalyst layer. In the exhaust gas purification catalyst of the present disclosure, the value obtained by dividing the volume of all large pores having a pore volume of 1000 μm.sup.3 or more by the total volume of all medium pores of having a pore volume of 10 μm.sup.3 to 1000 μm.sup.3 in the second catalyst layer is 2.44 or less.

Provided is an exhaust gas purification catalyst having high catalytic activity enabling combustion of PM (particulate matter) at low temperatures and excellent thermal resistance, an exhaust gas purification device and filter having high combustion efficiency of PM and excellent durability, and a method for producing the catalyst. The exhaust gas purification catalyst of the present invention is composite oxide particles containing at least one alkali metal, Si, and Zr.