A chemical process captures and convert hydrogen sulfide (H.sub.2S) gas into elemental sulfur, polysulfide, sulfur dioxide and/or sulfuric acid while regenerating sodium hydroxide capture agent for further use in an initial H.sub.2S capture step. Processing may include initial sodium hydroxide scrubbing of gas streams containing H.sub.2S, electrochemical regeneration of the sodium hydroxide from sodium hydrosulfide or sodium sulfide, recovery of sulfur and/or sulfur dioxide from the electrochemical processing, and production of sulfuric acid from such sulfur and/or sulfur dioxide.

The present invention relates to an air purifier (1) comprising a body (2) having an inlet opening (I) through which the air in the environment is sucked and an outlet opening (O) through which the cleaned air is released, and a CO.sub.2 adsorption unit (3) which is provided on the body (2), which chemically adsorbs the carbon dioxide in the air taken into the body (2) by being supplied with air together with a basic solution and which has an inlet tube (5).

The invention describes a process for producing sulfuric acid by catalytic oxidation of SO.sub.2 to SO.sub.3 and subsequent absorption of the SO.sub.3 in sulfuric acid, wherein the SO.sub.3 is introduced into a first absorption stage (primary absorber) and at least partly absorbed there in concentrated sulfuric acid, wherein the SO.sub.3 not absorbed in the first absorption stage is supplied to a second absorption stage (secondary absorber) for the further absorption in concentrated sulfuric acid, and wherein the sulfuric acid is cooled after passing through the two absorption stages. The cooling of the sulfuric acid is effected in at least two heat exchangers connected in parallel, wherein one of the at least two heat exchangers is operated as partial evaporator and is cooled with boiler feed water/steam and the other one is cooled with cooling water and operated as pure acid cooler.

A method includes transferring at least one feed stream including calcium oxide calcium carbonate, water, and a fluidizing gas into a fluidized bed; contacting the calcium oxide with the water; based on contacting the calcium oxide with the water, initiating a hydrating reaction; producing, from the hydrating reaction, calcium hydroxide and heat; transferring a portion of the heat of the hydrating reaction to the calcium carbonate; and fluidizing the calcium oxide, calcium hydroxide, and the calcium carbonate into a first fluidization regime and a second fluidization regime. The first fluidization regime includes at least a portion of the calcium carbonate and at least a portion of the calcium oxide, and the second fluidization regime includes at least a portion of the calcium hydroxide and at least another portion of the calcium oxide. The first fluidization regime being different than the second fluidization regime.

A process for treating a petroleum fraction and for efficiently absorbing an organic halogen compound from a fluid mixture of the organic halogen compound and an inorganic halogen compound derived from crude oil. Also disclosed is an improvement in absorption performance of a halogen-compound-absorbing material, thereby reducing the frequency with which the absorbing material is exchanged. The absorbing agent includes attapulgite (palygorskite) having high absorption performance with respect to organic halogen compounds. Also disclosed is an absorption column in which the aforementioned absorbing agent and a halogen-compound-absorbing agent, that includes zinc oxide, are disposed in series, thereby making it possible to raise the treatment performance with respect to a fluid that contains, in high concentrations, the organic halogen compound in addition to the inorganic halogen compound.

A method for removing a halogen fluoride in a mixed gas by reacting the mixed gas containing a halogen fluoride including bromine or iodine with a removing agent, wherein the removing agent is a chloride, bromide or iodide of potassium, sodium, magnesium, calcium and barium. Also disclosed is a quantitative analysis method as well as a quantitative analyzer for a gas component contained in a hydrogen fluoride mixed gas, the method characterized by reacting a mixed gas containing a halogen fluoride and another gas component with a removing agent, thereby removing the halogen fluoride in the mixed gas, further removing produced by-products, and quantitatively analyzing a residual gas by a gas chromatograph.

The present disclosure is directed to methods for treating an organic material, including the steps of transporting the organic material into a first vessel; heating the organic material in the first vessel and applying a negative pressure to the organic material in the first vessel to a boiling point of the organic material, wherein the heat and negative pressure separates a portion of an ammonia from the organic material; removing the portion of the ammonia from the first vessel; transporting the removed portion of the ammonia from the first vessel to an acid solution in a second vessel; and separating a portion of the ammonia from the acid solution.

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.

The present invention discloses a method for removing carbon dioxide from a reaction gas. The present invention fully utilizes the available heat in each part of the carbon dioxide removal system to reduce external heat exchange, and thereby significantly reduces the carbon dioxide content in the gas returned to the reactor, and also greatly reduces the steam consumption during the regeneration of the rich decarburizing solution. The present invention also discloses a system for removing carbon dioxide from the reaction gas and use thereof.

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.