The present disclosure relates to systems and methods for separation of sulfurous material(s) from a multi-component feed stream. The systems and methods can comprise contacting the multi-component feed stream with a solvent in a contacting column so that at least a portion of the sulfurous material(s) is transferred from the multi-component feed stream to the solvent. A stream of a substantially purified gas can thus be provided along with a liquid stream comprising at least a majority of the sulfurous material. In particular, the solvent can comprise liquid carbon dioxide, which can be particularly beneficial for removing sulfurous materials from multi-component feed streams.

A gas-solid separating method and a gas-solid separating system for simple substance sulphur in sulphur-containing exhaust are provided. The gas-solid separating method for simple substance sulphur in sulphur-containing exhaust comprises the following steps: first, cooling sulphur-containing exhaust at an extremely high speed; then, separating dust; finally, recycling a heavy liquid phase solvent and simple substance sulphur. The system comprises a quick cooling system, a low-temperature washing and purifying system, a light liquid phase and heavy liquid phase separating system, a washing liquid recycling system and a simple substance sulphur recycling system.

Device to dry a damp compressed gas, whereby the device (2) is provided with a dryer that is provided with a liquid desiccant and configured to bring compressed gas in contact with the aforementioned desiccant that is capable of absorbing moisture from the compressed gas, characterised in that the dryer is a membrane dryer (11); the device (2) to dry compressed gas contains a circuit (20) in which the aforementioned liquid desiccant is placed and means to allow the circulation of the desiccant in the circuit (20), consecutively through the membrane dryer (11) with a membrane (13) that forms a partition between the compressed, gas on one side and the liquid desiccant on the other side of the membrane (13), whereby the membrane (13) is impermeable or virtually impermeable to the gas in the compressed gas but selectively permeable to the moisture in the compressed gas; a heat exchanger (29} to heat up the liquid desiccant; a regenerator (22) used to remove at least partially the moisture absorbed in the liquid desiccant before this is returned through the membrane dryer (11) for a following cycle, whereby the regenerator (22) is formed by a housing (23) through which the liquid desiccant with the moisture absorbed therein is guided in moisture-transfer contact with a flushing agent that is simultaneously guided through the housing (23) and is capable of absorbing moisture from the liquid desiccant upon contact; and the circuit (20) is provided with a closable bypass (45) between a branching point in the circuit downstream from the regenerator (22) and upstream from the membrane dryer (11) and a confluence point in the circuit downstream from the membrane dryer (11) and upstream from the regenerator (22).

Methods and systems for producing aromatics and light olefins from a mixed plastics stream are described. The method may include feeding a plastic feedstock to a dechlorination operation to melt the plastic feedstock to release HCl and generate a liquid plastic stream; feeding the liquid plastic stream to a pyrolysis reactor, the pyrolysis reactor to generate hydrocarbon vapors; feeding the hydrocarbon vapors to an acid gas removal reactor with a solid inorganic alkali salt disposed within the reaction vessel to remove residual HCl and sulfur-containing compounds from the hydrocarbon vapors to generate a plastic derived oil; and feeding the plastic derived oil to a steam enhanced catalytic cracking reactor to generate a product stream comprising light olefins having a carbon number of C.sub.2-C.sub.4 and aromatics. The associated system for processing mixed plastics into aromatics and light olefins is also described.

Disclosed is a production device and production method of electronic grade hydrofluoric acid. The method includes vaporizing the raw material industrial anhydrous hydrogen fluoride by an evaporator, transporting the vaporized hydrogen fluoride to a purification tower, obtaining a high purity hydrogen fluoride gas through rectification, transporting the high purity hydrogen fluoride gas to an absorption tower for absorption by a certain concentration of hydrofluoric acid in the liquid phase, obtaining the crude electronic grade hydrofluoric acid, and obtaining the electronic grade hydrofluoric acid product through ultrapure filtration. The disclosure overcomes the technical problems of small yield and low purity of the prior art. The production process meets the requirements of environmental protection. The disclosure is suitable for industrialized large-scale production.

The invention pertains to methods of reducing dissolved elements such as arsenic, selenium and mercury in aqueous solutions using, for example, various barium compounds to partition said elements to a solid phase. Such methods are particularly useful for reducing such elements at various points in coal and oil-fired power plants prior to final waste water treatment.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

The removal of carbon dioxide using sequestration materials that include salts in molten form, and related systems and methods, are generally described.

A method for stripping CO.sub.2 from a biocatalyst-containing CO.sub.2-rich absorption solution to produce a biocatalyst-containing CO.sub.2-lean absorption solution and a CO.sub.2-rich gas is provided. The method includes generating a stripping gas from a portion of the biocatalyst-containing CO.sub.2-lean absorption solution in a stripping gas generation unit, and contacting the biocatalyst-containing CO.sub.2-rich absorption solution with the stripping gas in a gas-liquid contactor to produce the CO.sub.2-lean absorption solution and the CO.sub.2-rich gas.

This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.