A desulfurization gas process includes water vapor, CO.sub.2 and SO.sub.x (x=2 and/or 3). In a treatment unit, the gas contacts a cooled alkaline aqueous solution having a temperature lower than an initial gas temperature, water and a carbonate of an alkali metal, to cool the gas, condense some water vapor and absorb SO.sub.x in the carbonate-containing solution, produce an SO.sub.x-depleted gas and an acidic aqueous solution including sulfate and/or sulfite ions. The SO.sub.x-depleted gas and a portion of the acidic aqueous solution can then be withdrawn from the treatment unit. Carbonate of the alkali metal can be added to remaining acidic aqueous solution to obtain a made-up alkaline aqueous solution. This solution can be cooled and reused as the cooled alkaline aqueous solution. An SO.sub.x absorbent solution includes a bleed stream from a CO.sub.2-capture process, sodium or potassium carbonate, and an acidic aqueous solution obtained from desulfurization.

According to an embodiment of the invention, a process for substantially completely removing sulfur dioxide and ammonia from a gas stream is disclosed. The process involves lowering the vapor pressure in a scrubber by contacting the gas stream with one or more streams of re-circulating chilled media. The process further involves adjusting the pH of the process solution in the scrubber to within a predetermined range. The lowering of the vapor pressure and pH adjustment results in an increase in the solubility of sulfur dioxide and ammonia in the process solution thereby facilitating a substantially complete removal of sulfur dioxide and ammonia from the gas stream.

Provided is a method for treating an oil gas, which can realize high-efficiency separation for and recovery of gasoline components, C.sub.2, C.sub.3, and C.sub.4 components. The method first conducts separation of light hydrocarbon components from gasoline components, and then performs subsequent treatment on a stream rich in the light hydrocarbon components, during which it is no longer necessary to use gasoline to circularly absorb liquefied gas components, which significantly reduces the amount of gasoline to be circulated and reduces energy consumption throughout the separation process. Besides, in this method, impurities, such as H.sub.2S and mercaptans, in the stream rich in the light hydrocarbon components are removed first before the separation for the components. This ensures that impurities will not be carried to a downstream light hydrocarbon recovery section, thus avoiding corrosion issues caused by hydrogen sulfide in the light hydrocarbon recovery section.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NO.sub.x, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

Methods and systems for treating an olefin-containing stream are disclosed. The disclosed methods and systems are particularly suitable for treating an off-gas stream in a refining or petrochemical process, such as from a fluid catalytic cracker (FCC), coker, steam cracker, and the like. The stream is treated in an absorber column to reject lighter stream components and to absorb ethylene and/or propylene into a solvent. The solvent is typically isobutane. The enriched solvent stream from the absorber column is fed to an alkylation reactor, which reacts the dissolved olefin with the isobutane solvent to produce an alkylate product.

The invention relates to a method for operating a production plant for producing a chemical product (1) by reacting a H-functional reactant (2) with phosgene (3) during an interruption in production when taking at least one plant part of the production plant out of operation, wherein low-oxygen and oxygen-rich phosgene-containing exhaust gas flows are directed separately from one another in different phosgene decomposition directions and separately from one another—at spatially different points—into a combustion device, wherein plant parts that have not been taken out of operation are operated in a closed-circuit operating mode. The invention also relates to a production plant for producing a chemical product by reacting H-functional reactants with phosgene, which is suitable for being operated with the method according to the invention.

The invention relates to a process and a plant for removing thiols from synthesis gas. Thiols and optionally thiophene and carbon disulfide are absorbed in a dedicated absorption stage with methanol as physical absorption medium. Methanol laden with at least thiols is freed of thiols in a stripping stage with methanol vapours as stripping gas and the methanol vapours-containing thiols are freed of methanol in a scrubbing stage. The process according to the invention minimizes methanol losses and the amounts of coolant required for the process.

The present invention relates to a method for upgrading biogas generated by a biological process wherein at least carbon dioxide is removed from the bio-gas. More specifically the present invention relates to method for upgrading a biogas comprising a first absorption step wherein the liquid effluent is subjected to a second absorption step and a flash step and the gas streams resulting therefrom are recycled. The present invention also relates a biogas upgrading plant.

A gas treatment system includes a first scrubber, a regenerative catalytic oxidizer (RCO) that treats gas that passes through the first scrubber, a second scrubber that treats the gas that passed through the regenerative catalytic oxidizer, and a dielectric barrier discharge (DBD) plasma reactor that treats the gas that passed through the second scrubber. The regenerative catalytic oxidizer includes a two-bed regenerative catalytic reactor.

A method for generating Renewable Natural Gas (RNG) from raw biogas is disclosed, in which carbon dioxide is removed from biogas to generate pipeline specification RNG by a combination of absorption and membrane processes. The absorption process provides for the initial bulk carbon dioxide removal. The membrane process provides for the simultaneous removal of carbon dioxide and water vapors to pipeline specification. The method is characterized by a reduced separation energy consumption as compared to stand-alone membrane and absorption unit separations for biogas upgrading.