A portable or handhold air cleaning system, whose air flow pipeline made of highly reflective and low absorptive material for UVC or UVB light acts also as a UV light waveguide, is invented. The system features a TEC cooled LED light source; air flow warm up mechanism; and UV light absorption/air cleaning enhancement device. The system is useful for travellers and office workers during flu and hay-fever seasons.

A portable or handhold air purification system, whose air flow pipeline made of highly reflective and low absorptive material for UVC or UVB light acts also as a UV light waveguide, is invented. The system is based on the design concept of maximizing UV light exposure dosage to deactivate all the pollutants in the air flow going through to allow the system to use UVC and/or UVB LED. The system also has some features around the middle point of the air flow path to either further increase light exposure, or clean the air flow through the interaction between the specially designed nano particles and incoming UV light. Moreover, an ozone filter and an air heating devices, with energy either from the heat sink of LED's TEC or a device based on plasmonic resonance induced photothermal effects, are placed near the air outlet of the system for further enhancement. The system is very useful for travelers in the closed environment such as in a airplane, or on a train. It can also use in office during flu season as well as provide cleaned air supply to its users against the hay-fever.

Provided is catalyst material useful for the selective catalytic reduction of NOx in lean burn exhaust gas, wherein the catalyst material is a hydrothermally stable, low SAR aluminosilicate zeolite loaded with a synergistic combination of one or more transition metals, such as copper, and one or more alkali or alkaline earth metals, such as calcium or potassium.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

Catalyst compositions, articles, systems and methods related to a three-way-catalyst composition comprising alumina doped with a transition metal.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

The invention is a method and a sulfuric acid plant design for reduction of start-up SO.sub.2, SO.sub.3 and H.sub.2SO.sub.4 emissions in sulfuric acid production, in which SO2 is converted to SO.sub.3 in n successive catalyst beds, where n is an integer >1. The final catalytic beds are used as absorbents for SO.sub.2 to SO3 during the start-up procedure, and one or more of the m beds downstream the first bed are purged, either separately or simultaneously, with hot gas, where m is an integer >1 and m<n, during the previous shut-down. Also, one separate purge with hot gas is used on the final bed.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

An exhaust purification apparatus for an internal combustion engine is provided with an NO.sub.x storage and reduction type catalyst in an exhaust passage. The NO.sub.x storage and reduction type catalyst comprises a base member, an upstream side coat layer arranged on the base member, and a downstream side coat layer arranged at a downstream side in the direction of exhaust flow from the upstream side coat layer. The upstream side coat layer does not include a Ce-containing oxide but includes a precious metal catalyst. The downstream side coat layer contains a Ce-containing oxide and precious metal catalyst. A length of the upstream side coat layer is a length of 5 to 62.5% of the total length of the upstream side coat layer and the downstream side coat layer, while the remaining part of the coat layer aside from the upstream side coat layer is the downstream side coat layer.

The Invention relates to a nitrogen oxide storage catalyst composed of at least two catalytically-active washcoat layers on a support body, wherein a lower washcoat layer A comprises cerium oxide, an alkaline earth metal compound and/or an alkali compound, platinum and palladium, and manganese oxide, and an upper washcoat layer B disposed on the washcoat layer A comprises cerium oxide, platinum and palladium and does not contain any alkali and alkaline-earth compounds, and to a method for converting NO.sub.x in exhaust gases from motor vehicles which are operated with lean-burn engines.