A process for the oxidation of hydrogen sulfide to sulfur trioxide with subsequent sulfur trioxide removal comprises oxidizing hydrogen sulfide to sulfur trioxide in at least one catalyst-containing reactor and feeding the effluent from the last reactor to a candle filter unit for SO.sub.3 removal, where it is mixed with an injected alkaline sorbent slurry or powder to form an alkali sulfate and a hot clean gas. Preferably the oxidation is done in two reactors, the first oxidizing H.sub.2S to SO.sub.2 over a monolith type catalyst and the second oxidizing SO.sub.2 to SO.sub.3 over a VK type catalyst.

A method and apparatus for cleaning and recycling stack gas from coal-fired power plants, from natural or propane burning heating plants, or from cement kilns by using renewable catalysts of zeolite to separate pollutants into recyclable and reusable materials. The method reduces from the stack gas carbon monoxide (CO), carbon dioxide (CO.sub.2), nitrogen oxide (NOx), sulfur oxide (SOx) as well as halogens such as chloride and fluorides and trace metals particularly, mercury, lead, and zinc. The method and apparatus also result in production of fertilizer products by purging with gaseous or liquid nitrogen the zeolite beds through which the stack gas flows. The oxygen generated may be recycled to the burners in the plant.

An integrated device for removal of both liquid-containing droplets and pollutants from a gas stream includes a plurality of passageways and a plurality of exposed surface portions, different ones of the surface portions disposed along different ones of the plurality of passageways. The plurality of passageways include an inlet and an outlet for the flow of a gas stream therethrough, wherein each passageway includes at least one segment configured to perturb the flow of at least a portion of the gas stream between the inlet and the outlet. Such gas perturbation enhances gas stream contact with the exposed surfaces. Portions of the exposed surfaces comprise a sorbent-polymer-composite material adapted for contact conversion of sulfur oxides to sulfuric acid droplets. The exposed surfaces are disposed to enhance the removal of liquid-containing droplets and contact conversion of sulfur oxides to sulfuric acid droplets.

A red mud utilization method based on co-processing of industrial exhaust gas, sewage treatment and an environment-friendly and high-performance civil functional material, belongs to the technical field of environmental science and cementitious material preparation, and relates to a preparation process of a solid waste-based cementitious material, specifically including the steps: preparing an environment-friendly and high-performance red mud-based civil functional material by using slag obtained after sewage treatment with red mud and other solid wastes in physical and chemical activation and high-temperature calcination methods. The compressive strength of a solid waste-based cementitious material prepared by using the method can reach 29 MPa, the leaching quantity (lower than 3.0 ppm) of toxic elements such as heavy metals is far lower than the national standard requirement, and a solid waste-based cementitious material with great performance can be prepared.

A process for treating effluent streams in a renewable transportation fuel production process is described. One or more of the sour water stream and an acid gas stream are treated directly in thermal oxidation section. The process allows the elimination or size reduction of a sour water stripper unit, waste water treatment plant, and sulfur recovery unit.

The present invention describes the process of preparing ceramics for the absorption of ACIDIC gases, which worsen the greenhouse effect, that are released in combustion systems, or that are present in closed environments. In relation to carbon dioxide, principal target of the present invention, the process of absorption, transport, processing and transformation of the gas into other products is described. The process uses ceramic materials prepared through the solid mixture of one or more metallic oxides, with one or more binding agents and an expanding agent. The product generated can be processed and the absorbent system regenerated. The carbon dioxide obtained in the processing can be used as analytic or commercial carbonic gas, various carbamates and ammonium carbonate.

An apparatus for evaporating waste water and reducing flue gas acid gas emissions includes an evaporator device configured to receive a portion of flue gas emitted from a combustion unit and waste water for direct contact of the flue gas with the waste water to cool and humidify the flue gas, and to evaporate the waste water. An alkaline reagent as well as activated carbon may be mixed with the waste water prior to waste water contact with the flue gas. Solid particulates that are dried and entrained within the cooled and humidified flue gas can be separated from the flue gas via a particulate collector.

The invention concerns a method for treating a hydrocarbon feed gas stream containing at least CO.sub.2 and H.sub.2S to recover a high quality purified CO.sub.2 gas stream, comprising a. Separating said hydrocarbon feed gas stream into a sweetened hydrocarbon gas stream, and an acid gas stream; b. Introducing said gas stream into a Claus unit, c. Introducing the tail gas into a hydrogenation reactor and then into a quench contactor of the Tail Gas Treatment Unit (TGTU); d. Contacting said tail gas stream with a non-selective amine-based solvent into a non-selective acid gas absorption unit of the TGTU; e. Sending the off gas to an incinerator; f. Contacting said enriched gas stream (vii) with a selective H.sub.2S-absorption solvent into a selective H.sub.2S-absorption unit thereby recovering a highly purified CO.sub.2 gas stream and a H.sub.2S-enriched gas stream, as well as the device for carrying said method.

Disclosed is a method for producing a photocatalyst for air cleaning. The present production method comprises the steps of: preparing titanium dioxide (TiO.sub.2); attaching platinum to a surface of the titanium dioxide; and attaching fluoro to the platinum-attached surface of the titanium dioxide to obtain surface-modified titanium dioxide.

Structured adsorbent beds comprising a high cell density substrate, such as greater than about 1040 cpsi, and a coating comprising adsorbent particles, such as DDR and a binder, such as SiO.sub.2 are provided herein. Methods of preparing the structured adsorbent bed and gas separation processes using the structured adsorbent bed are also provided herein.