Abstract: The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

Abstract: The invention provides an environmentally friendly industrial process for treating sulfur-containing waste, resulting in recovered pure sulfur and a sulfur-free ash for landfilling.

Abstract: A system may include a sulfur recovery unit. The sulfur recovery unit may include an acid gas supply, which may supply acid gas, an oxygen supply, which may supply oxygen, a fuel supply, which may supply fuel. The fuel may have a higher heating value than the acid gas. Also, the sulfur recovery unit may include a thermal reaction zone, which may thermally recover sulfur from the acid gas by combustion of the fuel and the acid gas with the oxygen and through reaction of the acid gas with combustion products arising from the combustion.

Abstract: Methods for regenerating amorphous iron oxide hydroxide after being used as desulfurizer by (1) grinding a waste mixture into waste powder, wherein the waste mixture results from use of the composition comprising amorphous iron oxide hydroxide as desulfurizer; (2) preparing the waste powder into a suspension and charging the suspension with a gas containing oxygen to obtain a slurry comprising amorphous iron oxide hydroxide and elemental sulfur; and (3) placing the slurry or a solid resulting from filtering the slurry into a container and charging the slurry or the solid with air so that the elemental sulfur floats and the amorphous iron oxide hydroxide precipitates.

Abstract: A system and method for removing contaminant from sulfur (or sulphur) to a level that allows re-processed sulfur to reenter a supply chain. The system and method melt contaminated sulfur, filters the molten sulfur, and then dispenses the less contaminated sulfur after filtering it. More specifically, solid contaminated sulfur enters a settling tank, while heated molten sulfur circulates through the system and the settling tank. The circulation of the molten sulfur assists in the melting process of the solid sulfur, allowing the solid sulfur to melt efficiently. In preferred embodiments of the system, the system uses steam jacked sulfur lines and steam tracing to maintain temperatures for melting the solid sulfur and maintaining the molten state of the sulfur circulating through the system. Furthermore, the system comprises a programmable logic controller, which controls motors, pumps, valves, and environment monitoring instruments.

Abstract: This invention relates to a method and apparatus for gasifying or liquifying coal. In particular, the method comprises reacting a coal with a molten aluminum or aluminum alloy bath. The apparatus includes a reaction vessel for carrying out the reaction, as well as other equipment necessary for capturing and removing the reaction products. Further, the process can be used to cogenerate electricity using the excess heat generated by the process.

Abstract: Methods and systems for generating sulfuric acid are disclosed. In some embodiments, the method includes combusting a sulfur-containing material with a gas including oxygen to produce a first stream of sulfur dioxide, mixing water with the first stream of sulfur dioxide to produce a mixed stream, using an energy, electrolytically converting the mixed stream of sulfur dioxide and water into sulfuric acid and hydrogen, generating a source of energy from the hydrogen, and providing the source of energy as at least a portion of the energy for electrolytically converting the first stream of sulfur dioxide and water into sulfuric acid and hydrogen. In some embodiments, the system includes a first chamber for combusting a sulfur-containing material to produce a first stream of sulfur dioxide, an electrolytic cell for converting the first stream into sulfuric acid and hydrogen, and a fuel cell for generating an energy source from the hydrogen.

Abstract: A liquid separator system having a gas phase zone, an aqueous phase zone and a denser liquid zone is used to separate mixtures of fluids. The separator can be used for separating molten sulfur from liquid redox solution or reslurry water. The system includes a vessel with a top part and a bottom part. The vessel has a larger diameter at the top part than at the bottom part. The system also includes an inlet for introducing a redox solution or reslurry water and molten sulfur, which is denser than redox solution or reslurry water, into the vessel. An outlet near the bottom part of the vessel allows a flow of the molten sulfur from the vessel. An interface control structure senses an interface level between the redox solution or reslurry water and the molten sulfur, and the interface control structure controls the flow of molten sulfur from the outlet.

Abstract: Systems and methods for the collection of liquid sulfur with integrated degassing are described, wherein the system and methods include the use of one or more liquid jet pumps or eductors employing a pumped liquid sulfur recycle stream as motive fluid to boost sulfur rundown pressure. The new invention eliminates piping constraints inherent with conventional gravity flow, thus permitting location of the sulfur collection vessel above ground and remote from the sulfur recovery unit. In addition, the described methods provide entrainment and enough agitation in the liquid sulfur such that simultaneously degassing occurs within the sulfur collection piping and associated systems described herein. The instant systems and methods are integrated with the degassing system, meaning that the sulfur will be initially degassed during the collection process, and then further degassing occurs by the methods described herein.

Abstract: A process for removing H2S from a gaseous stream, wherein the gaseous stream is flowed through an absorber vessel where the stream is contacted with a sorbing liquor comprising a nonaqueous solvent containing dissolved sulfur, a tertiary amine base having sufficient strength and concentration to drive the reaction between H2S sorbed by the liquor and the dissolved sulfur to form a nonvolatile polysulfide which is soluble in the sorbing liquor, and a solubilizing agent for maintaining the solubility of polysulfide intermediates which may otherwise separate. The dissolved nonvolatile polysulfide in the sorbing liquor is converted to sulfur which remains dissolved in the liquor by contacting the liquor with oxidizing sulfur dioxide. The sorbing liquor following the oxidation of the polysulfide is cooled to a temperature at which the liquor is at or above saturation with respect to the dissolved sulfur.

Abstract: A sulfurous compound such as a sulfur-rich “float” (concentrate) obtained by flotation of the residue from the leaching of a zinc concentrate is heated at a temperature not lower than the melting point of sulfur but below its boiling point, preferably not higher than 200° C., more preferably not higher than 140° C., and the evolving gas containing sulfur vapor is cooled at a temperature less than the melting point of sulfur, preferably at ordinary temperature, to condense sulfur.