Disclosed is an improved process for regenerating solvent used to remove contaminants from a fluid stream. Said process comprises a solvent regeneration system (10) comprising a rich/lean solvent stripper column (29), reboiler (50), condenser (36), and reflux receiver (38) wherein the improvement is the location 46 of the condensed stripper gas return from the reflux receiver.

The present invention relates to an aqueous alkanolamine solution for the removal of hydrogen sulfide from gaseous mixtures containing hydrogen sulfide. The aqueous alkanolamine solution comprises (i) an amino compound with the formula:
R.sup.1R.sup.2NCH.sub.2CH(OH)CH.sub.2OH
wherein R.sup.1 and R.sup.2 independently represent lower alkyl groups of 1 to 3 carbon atoms, (ii) piperazine, and (iii) optionally a physical solvent, wherein said solution does not contain a strong acid. Further, the present invention relates to a process for removing hydrogen sulfide from a gaseous mixture containing hydrogen sulfide, and additionally other acid gases, if present, for example carbon dioxide, comprising the step of contacting the gaseous mixture contain hydrogen sulfide with the aqueous alkanolamine solution, preferably wherein the temperature of the aqueous alkanolamine solution is equal to or greater than 140 F. Examples of the gaseous mixtures include natural gas, synthesis gas, tail gas, and refinery gas.

A desulfurization and denitration agent which is a mixture of polyalcohol and/or polyglycol substances, polycarboxylic acid substances and alkaline substances heated to above 90 C. and yielding, after condensation and/or polymerization, macromolecular or high-polymer ethers and/or esters for use in removing sulfur dioxides and/or nitrogen oxides from gases.

Methods of reducing the water content of a wet gas are presented. In one case, the method includes exposing the gas to an amine-terminated branched polymer solvent to remove a substantial portion of the water from the wet gas, exposing the diluted solvent to carbon dioxide to phase separate the solvent from the water, and regenerating the solvent for reuse by desorbing the carbon dioxide by the application of heat. In another case, the method includes exposing the gas to a cloud-point glycol solvent to remove a substantial portion of the water from the wet gas, heating the diluted solvent to above a cloud point temperature for the solvent so as to create a phase separation of the solvent from the water so as to regenerate the solvent for reuse, and directing the regenerated solvent to a new supply of wet gas for water reduction.

A system and method for generating power from waste heat, the system including (1) a forward osmosis module having an FO membrane a water inlet, a water outlet, a draw solution solute inlet and a diluted draw solution outlet; (2) a hydro-turbine using the diluted draw solution for generating power; (3) a CO.sub.2 absorption reactor to permit the introduction of compressed CO.sub.2 into the diluted draw solution to cause substantial separation of draw solution solute from the water, which water can be processed for subsequent recycling to the FO module, the CO.sub.2 absorption reactor configured to discharge a mixture of separate draw solution solute and absorbed CO.sub.2; and (4) a heat exchanger for transferring waste heat from an incoming heated fluid to the mixture of draw solution solute and CO.sub.2.

A system for processing a gas stream can include a physical solvent unit, an acid gas removal unit upstream or downstream of the physical solvent unit, and an LNG liquefaction unit downstream of the acid gas removal unit. The physical solvent unit is configured to receive a feed gas, remove at least a portion of any C.sub.5+ hydrocarbons in the feed gas stream using a physical solvent, and produce a cleaned gas stream comprising the feed gas stream with the portion of the C.sub.5+ hydrocarbons removed. The acid gas removal unit is configured to receive the cleaned gas stream, remove at least a portion of any acid gases present in the cleaned gas stream, and produce a treated gas stream. The LNG liquefaction unit is configured to receive the treated gas stream and liquefy at least a portion of the hydrocarbons in the treated gas stream.

A gas conditioning system removes contaminants including carbon dioxide from flue gas, such as flue gas of a marine vessel, and includes a rotating backed bed assembly. The rotating packed bed assembly fluidly connects to an exhaust port of an engine, and receive a flue gas from the exhaust port. The rotating packed bed assembly includes a first rotating packed bed having an absorption agent to absorb a portion of the carbon dioxide from the flue gas, and a second rotating packed bed to receive the absorption agent from the first rotating packed bed and desorb at least some of the portion of the carbon dioxide from the absorption agent.

A gas conditioning system removes contaminants including nitrogen oxides and sulfur oxides from flue gas of a marine vessel, and includes an oxidizer unit and a direct contact cooler. The oxidizer unit receives an exhaust flue gas from a marine engine through a fluid inlet at a temperature between 150 degrees Celsius and 550 degrees Celsius, and converts at least a portion of the nitrogen oxides in the flue gas into nitrogen gas, nitrogen dioxide, or both. The direct contact cooler is fluidly connected to the oxidizer unit, and includes a housing defining a cooling chamber. The direct contact cooler directs the flue gas into contact with seawater residing in the cooling chamber and cools the flue gas to a temperature less than or equal to 60 degrees Celsius. The seawater removes some or all nitrogen dioxide and sulfur dioxide from the flue gas in the cooling chamber.

A gas conditioning system removes contaminants including nitrogen oxides and sulfur oxides from flue gas of a marine vessel, and includes an oxidizer unit and a direct contact cooler. The oxidizer unit receives an exhaust flue gas from a marine engine through a fluid inlet, such as at a temperature between 150 degrees Celsius and 550 degrees Celsius, and converts at least a portion of the nitrogen oxides in the flue gas into nitrogen gas, nitrogen dioxide, or both. The direct contact cooler is fluidly connected to the oxidizer unit, and includes a housing defining a cooling chamber. The direct contact cooler directs the flue gas into contact with seawater residing in the cooling chamber and cools the flue gas to a temperature less than or equal to 60 degrees Celsius. The seawater removes some or all nitrogen dioxide and sulfur dioxide from the flue gas in the cooling chamber.

Processes and facilities for recovering and purifying a pyrolysis gas formed by pyrolyzing waste plastic are provided. The purification process may comprise one or more treatment processes, including a caustic scrubber process, which may be included in a cracker facility or separate from the cracker facility. The resulting gas effluent stream from the caustic scrubber is particularly useful for recovering recycled chemical products and co-products from a downstream cryogenic separation process.