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.

A process for treating effluent streams in a renewable transportation fuel production process is described. One or more of the sour water stream and an acid gas stream are treated directly in thermal oxidation section. The process allows the elimination or size reduction of a sour water stripper unit, waste water treatment plant, and sulfur recovery unit.

Methods of sequestering CO.sub.2 from a gaseous source of CO.sub.2 are provided. Aspects of the methods include employing an alkali enrichment protocol, such as a membrane mediated alkali enrichment protocol, in a CO.sub.2 sequestration protocol. Also provided are systems for practicing the methods.

The use of a composition including at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, the acido-basic neutralising agent having at least 2 pKa's and being characterised by: pKa 1≤pKa 2, pKa 1>2, pKa 2<12, 4<½ (pKa 1+pKa 2)<10 pKa 1, representing the smallest of the basic pKa's and pKa 2 representing the largest of the acidic pKa's. Also, a method for decontaminating an atmosphere contaminated by a corrosive gas comprising the spraying of the neutralising agent, and to a decontamination device.

The invention is directed to a continuous process to treat a hydrogen sulphide comprising gas comprising the following steps: (a) contacting the hydrogen sulphide comprising gas with an aqueous alkaline solution further comprising sulphide oxidising bacteria thereby obtaining a loaded aqueous solution comprising sulphide compounds and sulphide oxidising bacteria. (b) contacting the loaded aqueous solution with an oxygen comprising gas to regenerate the sulphide oxidising bacteria to obtain a liquid effluent comprising regenerated sulphide oxidising bacteria which is partly used as the aqueous alkaline solution in step (a). (c) separating elemental sulphur as prepared by the sulphide oxidising bacteria in steps (a) and (b) from the loaded aqueous solution of step (a) and/or from the liquid effluent of step (b) and wherein the consumption of oxygen in step (b) is measured and wherein the supply of oxygen in step (b) is controlled by the measured consumption of oxygen.

A solvent and method for removing carbon dioxide from a gaseous mixture flow with high carbon dioxide partial pressures are disclosed. The solvent includes a secondary or tertiary amine, an amine activator, a physical solvent (e.g., thioalkanol), and a carbonate buffer. The solvent contains less than about 60% by weight of water and is in a single liquid phase.

A process for treating a sulfurous fluid to form gypsum and magnesium carbonate, whereby the sulfurous fluid is scrubbed with a sequestrating agent to yield a scrubbed fluid, gypsum and magnesium sulfate. The flue gas desulfurized gypsum is isolated from the magnesium sulfate solution by filtration or centrifugation. The magnesium sulfate is reacted with a carbonate salt to produce a magnesium carbonate whereby the reaction conditions are controlled to control the properties of the magnesium carbonate produced.

A system for sulphur removal from a flue gas. The system includes an absorber, a reaction tank and a buffer tank. The buffer tank is connected to the reaction tank by a communicating vessel passage.

A method and a plant for capturing CO2 from an incoming flue gas. The flue gas can be exhaust gas from coal and gas fired power plants, cement factories or refineries. The incoming exhaust gas is cooled, mixed with air and compressed, and thereafter introduced into a combustion chamber together with gas and/or liquid fuel. Part of the combustion is achieved by separate burners with cooling/combustion air feed with a volume equal to the volume of CO2 captured. Said burners will elevate the temperature in the combustion chamber allowing combustion of exhaust gas with low oxygen content. CO2 is captured at high partial pressure before expansion by the gas turbine to produce power and generate steam in the heat recovery unit. The gas turbine will operate with high efficiency close to design parameters with respect to inlet temperature, pressure and flow.

A carbon processing system comprises an air mover and a multi-stage reactor. The multi-stage reactor processes ambient air and generates carbon dioxide and generates exhausted gas released to ambient air. In operation, air contacts the base solution via the air mover. The air reacts with the base solution thereby generating a base solution having carbon dioxide and generating exhaust (absorption reaction). Next, the exhaust is released from the reactor. Next, heat is applied to the base solution having carbon dioxide thereby generating carbon dioxide and generating a base solution without carbon dioxide (desorption reaction). The base solution without carbon dioxide generated after applying heat is reusable in processing new air. The absorption reaction and desorption reaction are reversible reactions resulting in regeneration of the base solution into its form prior to contact with the air yielding high scalability and less processing volume as required by many conventional carbon processing techniques.