This invention relates to processes for selective removal of contaminants from effluent gases. A sulfur dioxide absorption/desorption process for selective removal and recovery of sulfur dioxide from effluent gases utilizes a buffered aqueous absorption solution comprising weak inorganic or organic acids or salts thereof, to selectively absorb sulfur dioxide from the effluent gas. Absorbed sulfur dioxide is subsequently stripped to regenerate the absorption solution and produce a sulfur dioxide-enriched gas. A process for simultaneous removal of sulfur dioxide and nitrogen oxides (NO.sub.x) from effluent gases and recovery of sulfur dioxide utilizes a buffered aqueous absorption solution including a metal chelate to absorb sulfur dioxide and NO.sub.x from the gas and subsequently reducing absorbed NO.sub.x to form nitrogen. A process to control sulfate salt contaminant concentration in the absorption solution involves partial crystallization and removal of sulfate salt crystals.

A waste water processing system includes an upflow contacting column having a flue gas input for receiving flue gas having a temperature of at least 500 degrees F., a waste water input, and a flue gas output. The waste water input is coupled to a fluid injector, e.g., atomizing nozzles, positioned in the throat of a Venturi portion of the upflow contacting column or in a sidewall of the throat of the Venturi portion of the upflow contacting column. The flue gas in the upflow contacting column has a high velocity, e.g., a gas velocity exceeding 65 fps in the throat of the Venturi portion of the upflow contacting column at a position where the fluid injector is located. Drying additives such as recycled ash, lime, and/or cement may be, and sometimes are, input into the upflow contacting column downstream of the waste water input.

A multi-stage process for reducing the Environmental Contaminants in a Feedstock Heavy Marine Fuel Oil that is compliant with ISO 8217: 2017 Table 2 as a residual marine fuel except for the concentration of Environmental Contaminants, the process involving a core hydrotreating process and either a pre-treating step or post-treating step to the core process that is selected from a) a sulfur absorption process unit; b) an oxidative desulfurizing process unit; and c) a microwave treatment process unit. The Product Heavy Marine Fuel Oil is compliant with ISO 8217 Table 2 as residual marine fuel and preferably has a sulfur level has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 0.5% wt. A commercial scale process plant for conducting the process is disclosed.

A method of wet-scrubbing a waste gas containing sulfur dioxide (SO.sub.2) to produce potassium thiosulfate. The wet-scrubbing facility includes multiple horizontally disposed stages where a preceding stage passes partially-scrubbed waste gas to a succeeding stage. Each stage has a scrubber mechanism to scrub waste gas with circulating fluid that progressively reduces SO.sub.2 in the waste gas before atmospheric discharge. The scrubber mechanism may optionally include a packing material to facilitate absorption of SO.sub.2 by the fluid, a sump disposed at the output of the stage to receive fluid as it drains from the packing, and a circulation pump to circulate fluid from the sump to its packing and to cascade at least a portion of the fluid back to a preceding stage. A portion of the fluid is extracted and reacted in a reaction vessel with a cation to produce potassium thiosulfate.

A scrubber for cleaning exhaust fumes generated by internal combustion engines, in particular for reducing the concentration of the sulfur oxides SO.sub.x in exhaust fumes generated by the combustion of high sulfur content fuels, said scrubber comprising a main hollow tubular body, an inlet and an outlet for introducing and discharging said fumes into and from said main hollow tubular body, respectively, and inlet means for introducing at least partially atomized pressurized water into said main hollow body, wherein said inlet means comprise a plurality of nozzles arranged in said main hollow body and each adapted to dispense said at least partially atomized pressurized water.

This invention relates to a system and method for improving sulfur recovery from a Claus unit. More specifically, this invention provides a sorption based SO.sub.2 selective crosslinked polyionic liquid system and method for treating acid gas streams and minimizing sulfur dioxide emissions therefrom.

Proposed is a system for capturing carbon dioxide and sulfur oxide for ships that can capture carbon dioxide in flue gas using a basic alkaline mixture and use the captured carbon dioxide to capture sulfur oxides in the flue gas. The carbon dioxide and sulfur oxide capture system for ships uses sodium carbonate or sodium hydrogen carbonate prepared from the captured carbon dioxide as a desulfurization agent to capture sulfur oxides in the flue gas discharged from ships, thereby simultaneously producing carbon dioxide and sulfur oxides in one system.

A waste water processing system includes an upflow contacting column having a flue gas input for receiving flue gas having a temperature of at least 500 degrees F., a waste water input, and a flue gas output. The waste water input is coupled to a fluid injector, e.g., atomizing nozzles, positioned in the throat of a Venturi portion of the upflow contacting column or in a sidewall of the throat of the Venturi portion of the upflow contacting column. The flue gas in the upflow contacting column has a high velocity, e.g., a gas velocity exceeding 65 fps in the throat of the Venturi portion of the upflow contacting column at a position where the fluid injector is located. Drying additives such as recycled ash, lime, and/or cement may be, and sometimes are, input into the upflow contacting column downstream of the waste water input.

The plant according to the invention includes a reactor including a combustion chamber in which a fuel is fired with an oxidant to form a carbon dioxide-containing flue gas stream. The plant also includes a waste heat recovery unit in fluid connection with the combustion chamber, configured to capture heat from the flue gas stream. The plant also includes a flue gas compression unit in fluid connection with the waste heat recovery unit, configured to increase the pressure of the flue gas stream. The plant also includes a scrubber in fluid connection with the flue gas compression unit, configured to remove sulphur oxides and/or nitrogen oxides from the flue gas stream and to cool flue gas stream by means of the scrubbing medium. The plant also includes an absorption unit in fluid connection with the scrubber, configured to absorb carbon dioxide from the flue gas stream.

A system comprising a collocated thermal plant, water source, CO.sub.2 source and biomass growth module is disclosed. A method of improving the environment by utilizing the system is disclosed.