Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

A device for producing granules that include ammonium sulfate may include a mixing device, an atomizing device and a fluidized bed. The mixing device may be utilized to produce a composition comprising ammonium sulfate and aluminum sulfate. The atomizing device may be disposed downstream of the mixing device and may be utilized to atomize the composition produced in the mixing device. The fluidized bed may also be disposed downstream of the mixing device. The fluidized bed may be utilized for producing the granules. Further, with respect to a process for producing granules comprising ammonium sulfate, a step of granulating a composition comprising ammonium sulfate and aluminum sulfate may involve providing ammonium sulfate-containing nuclei, fluidizing the ammonium sulfate-containing nuclei, and atomizing the composition onto the nuclei.

A device for producing granules that include ammonium sulfate may include a mixing device, an atomizing device and a fluidized bed. The mixing device may be utilized to produce a composition comprising ammonium sulfate and aluminum sulfate. The atomizing device may be disposed downstream of the mixing device and may be utilized to atomize the composition produced in the mixing device. The fluidized bed may also be disposed downstream of the mixing device. The fluidized bed may be utilized for producing the granules. Further, with respect to a process for producing granules comprising ammonium sulfate, a step of granulating a composition comprising ammonium sulfate and aluminum sulfate may involve providing ammonium sulfate-containing nuclei, fluidizing the ammonium sulfate-containing nuclei, and atomizing the composition onto the nuclei.

Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates. The processes may be controlled by use of one or more processors.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

A method of producing ammonium persulfate by electrolyzing ammonium sulfate is characterized in that an ammonium sulfate aqueous solution is supplied as an anode-side feedstock, a solution containing less than 1.0 mol of acid-derived acid dissociable hydrogen ions per 1.0 mol of amount of charge transfer is supplied as a cathode-side feedstock, and electrolysis is performed to produce ammonium persulfate on the anode side and at least ammonia on the cathode side. Since ammonium sulfate not dependent upon the ammonium sulfate produced within the system can be used as a main feedstock, the method is industrially advantageous and, further, because of an electrolytic method, the method enables the coproduction not only of ammonium persulfate but also of valuable materials such as ammonia and hydrogen and, furthermore, enables the production of ammonium persulfate at a high current efficiency.