A process for simultaneous removal of hydrogen sulfide (H.sub.2S ) and heavy metals from mixture includes charging a contaminated aqueous composition containing heavy metal ions to a reactor. The process also includes passing a H.sub.2S -containing gas composition via a plurality of gas spargers through the contaminated aqueous composition present in the reactor to form a H.sub.2S-containing contaminated aqueous composition and a purified gas composition. The process further includes reacting the H.sub.2S from the H.sub.2S -containing contaminated aqueous composition with the heavy metal ions in the H.sub.2S -containing contaminated aqueous composition to form a metal sulfide precipitate in a metal-sulfide-containing contaminated aqueous composition. In addition, the process includes at least partially introducing the metal-sulfide-containing contaminated aqueous composition to a solid-liquid separator and removing the metal sulfide precipitate from the metal-sulfide-containing contaminated aqueous composition to form a purified aqueous composition.

A process for preparing sulfuric acid may involve melting elemental sulfur in a melting stage to give molten sulfur. Sulfuric acid is subsequently produced from the molten sulfur. Further, sulfur-containing offgases formed in the melting stage may be subjected to oxidation in a supplementary oxidation stage in which sulfur-containing components of the offgases are oxidized to sulfur dioxide. The process may further involve processing the sulfur dioxide to give at least one reaction product. The melting stage may be operated without emissions by processing all of the offgases from the melting stage. An apparatus may be employed for carrying out such a process.

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

A media design for modular use in an air cleaning or HVAC systems to removes gas phase contaminants. The design allows for a control of gas contaminant removal using variable media length, path length, and contact time to ensure a contained MTZ length and low pressure drop. In one embodiment, the design includes a filter module at an angle to an airflow and an air filter mounted within the filter frame. The filter module may include channels therethrough that are oriented at the optimum angle in relation to the airflow to provide the required dwell time and pressure drop for a given application.

A method for recovering sulfur from an acid gas feed is provided. The method comprising the steps of mixing the acid gas feed and an absorption process outlet stream to form a combined Claus feed, introducing the combined Claus feed and a sulfur dioxide enriched air feed to a Claus process to produce a Claus outlet gas stream, introducing the Claus outlet gas stream to a thermal oxidizer, treating the thermal oxidizer outlet stream in a gas treatment unit to produce a dehydrated stream, introducing the dehydrated stream to a membrane sweeping unit to produce a sweep membrane residue stream and a sulfur dioxide enriched air feed, introducing a sweep air stream to a permeate side of the membrane sweeping unit, and introducing the sweep membrane residue stream to a sulfur dioxide absorption process to produce the absorption process outlet stream and a stack feed.

The present invention describes methods for absorbing a targeted chemical compound from a gas stream into a scrubbing solution for various uses and with various benefits. Methods are described to produce a gas stream that can be further processed with operational benefits, such as through condensing and wastewater treatment with a lower load on the wastewater treatment system. Methods are described for adsorbing the targeted compound with reduced condensation of water from the gas stream. Methods are described for producing a liquid stream comprising an absorbed form of the targeted compound for use as a saleable product, such as adsorbing ammonia for the production of a fertilizer, wherein the concentration of the absorbed form may be increased through reduced condensation from the gas stream. Methods are described for producing a lower volume liquid waste stream from the absorption process through the use of reduced condensation of the gas stream.

A method for recovering sulfur from an acid gas feed is provided. The method comprising the steps of mixing the acid gas feed and an absorption process outlet stream to form a combined Claus feed, introducing the combined Claus feed and a sulfur dioxide enriched air feed to a Claus process to produce a Claus outlet gas stream, introducing the Claus outlet gas stream to a thermal oxidizer, treating the thermal oxidizer outlet stream in a gas treatment unit to produce a dehydrated stream, introducing the dehydrated stream to a membrane sweeping unit to produce a sweep membrane residue stream and a sulfur dioxide enriched air feed, introducing a sweep air stream to a permeate side of the membrane sweeping unit, and introducing the sweep membrane residue stream to a sulfur dioxide absorption process to produce the absorption process outlet stream and a stack feed.

A method for recovering sulfur from an acid gas feed is provided. The method comprising the steps of mixing the acid gas feed and an absorption process outlet stream to form a combined Claus feed, introducing the combined Claus feed and a sulfur dioxide enriched air feed to a Claus process to produce a Claus outlet gas stream, introducing the Claus outlet gas stream to a thermal oxidizer, treating the thermal oxidizer outlet stream in a gas treatment unit to produce a dehydrated stream, introducing the dehydrated stream to a membrane sweeping unit to produce a sweep membrane residue stream and a sulfur dioxide enriched air feed, introducing a sweep air stream to a permeate side of the membrane sweeping unit, and introducing the sweep membrane residue stream to a sulfur dioxide absorption process to produce the absorption process outlet stream and a stack feed.

A process for preparing sulfuric acid may involve melting elemental sulfur in a melting stage to give molten sulfur. Sulfuric acid is subsequently produced from the molten sulfur. Further, sulfur-containing offgases formed in the melting stage may be subjected to oxidation in a supplementary oxidation stage in which sulfur-containing components of the offgases are oxidized to sulfur dioxide. The process may further involve processing the sulfur dioxide to give at least one reaction product. The melting stage may be operated without emissions by processing all of the offgases from the melting stage. An apparatus may be employed for carrying out such a process.