A method and system for removing at least dissolved hydrogen sulphide or another targeted constituent from a feedstock is provided wherein the targeted constituent has a gas: liquid equilibrium. In some embodiments, the method includes the steps of: contacting the feedstock in at least one stripping vessel with a stripping gas to produce a gas stream containing at least hydrogen sulphide gas; conveying the gas stream from the at least one stripping vessel to an oxidation reactor; contacting the gas stream with an oxidizing agent in the oxidation reactor so as to oxidize the at least hydrogen sulphide gas to produce sulphuric acid; and conveying the produced sulphuric acid from the oxidation reactor to the at least one stripping vessel so as to reduce a pH value of the feedstock within the stripping vessel.

A method and system for removing at least dissolved hydrogen sulphide or another targeted constituent from a feedstock is provided wherein the targeted constituent has a gas: liquid equilibrium. In some embodiments, the method includes the steps of: contacting the feedstock in at least one stripping vessel with a stripping gas to produce a gas stream containing at least hydrogen sulphide gas; conveying the gas stream from the at least one stripping vessel to an oxidation reactor; contacting the gas stream with an oxidizing agent in the oxidation reactor so as to oxidize the at least hydrogen sulphide gas to produce sulphuric acid; and conveying the produced sulphuric acid from the oxidation reactor to the at least one stripping vessel so as to reduce a pH value of the feedstock within the stripping vessel.

A method of generating hydrogen gas includes providing a colony of sulfur-reducing bacteria and a colony of sulfur-oxidizing bacteria. The colonies can be submerged in a body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid. The sulfuric acid can react with manganese to produce hydrogen gas and manganese sulfate.

A method of generating hydrogen gas includes providing a colony of sulfur-reducing bacteria and a colony of sulfur-oxidizing bacteria. The colonies can be submerged in a body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid. The sulfuric acid can react with manganese to produce hydrogen gas and manganese sulfate.

A method of separating oxygen from a body of water includes providing a colony of denitrifying bacteria submerged in the body of water. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides present in the body of water to nitrogen gas. The method can also include collecting the nitrogen gas and bubbling the nitrogen gas through a portion of water from the body of water to remove dissolved oxygen from the portion of water. This can form a mixture of the nitrogen gas and oxygen gas.

A reactor having a shell comprising one or more reactor tubes located within the shell, said reactor tube or tubes comprising a plurality of catalyst receptacles containing catalyst; means for providing a heat transfer fluid to the reactor shell such that the heat transfer fluid contacts the tube or tubes; an inlet for providing reactants to the reactor tubes; and an outlet for recovering products from the reactor tubes; wherein the plurality of catalyst receptacles containing catalyst within a tube comprises catalyst receptacles containing catalyst of at least two configurations.

A reactor having a shell comprising one or more reactor tubes located within the shell, said reactor tube or tubes comprising a plurality of catalyst receptacles containing catalyst; means for providing a heat transfer fluid to the reactor shell such that the heat transfer fluid contacts the tube or tubes; an inlet for providing reactants to the reactor tubes; and an outlet for recovering products from the reactor tubes; wherein the plurality of catalyst receptacles containing catalyst within a tube comprises catalyst receptacles containing catalyst of at least two configurations.

A process for producing sulfuric acid and cement clinker may use calcium sulfate that is formed as a solid by-product and separated off in phosphoric acid production in a reaction of raw phosphate with sulfuric acid to form phosphoric acid. The process comprises treating calcium sulfate separated from the phosphoric acid with an acid to obtain a suspension comprising purified calcium sulfate, separating the purified calcium sulfate in solid form from the liquid phase of the suspension, mixing the purified calcium sulfate with admixtures and reducing agents to obtain a raw meal mixture for cement clinker production, burning the raw meal mixture to obtain the cement clinker, with formation of sulfur dioxide as offgas, and subjecting the sulfur dioxide formed to offgas purification and feeding the sulfur dioxide as raw material to sulfuric acid production to produce the sulfuric acid. The sulfuric acid produced may be used as starting material in phosphoric acid production.

An improvement in a wet scrubbing process for treating gaseous industrial process streams which contain one or more of SO.sub.2, SO.sub.3, H.sub.2SO.sub.4 which comprises contacting the stream of gas with a countercurrent flow of liquid derived from a circulating liquid stream which includes (i) a purge stream configured to remove a portion of the circulating liquid having a concentration of H.sub.2SO.sub.4 from the process, and (ii) a liquid make-up stream configured to replace the portion of the circulating liquid that is removed from the circulating liquid stream, the improvement comprising controlling the flow of liquid make-up whereby the concentration of H.sub.2SO.sub.4 in the purge stream is increased to a useful value; and filtering the purge stream to remove unwanted contaminants to yield a clarified purge stream.

Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.