Gas sweetening

Gas solubility Gas sweetening Gas-treating Gastric acid Gastric prokinetics Gastrin... 

With amines such as those used ia gas sweetening, it reacts forming mainly ureas ... 

Numerous processes have been developed for gas sweetening based on a variety of chemical and physical principles. These processes can be categorized by the principles used in the process to separate the acid gas and the natural gases as follows ... 

Figure 7-5 shows a typical hot carbonate system for gas sweetening. The sour gas enters the bottom of the absorber and flows counter-current to the potassium carbonate. The sweet gas then exits the top of the absorber. The absorber is typically operated at 230°F therefore, a sour/ sweet gas exchanger may be included to recover sensible heat and decrease the system heat requirements. 

LOCAT units can be used for tail-gas clean-up from chemical or physical solvent processes. They can also be used directly as a gas sweetening unit by separating the absorber/oxidizer into two vessels. The regenerated solution is pumped to a high-pres.sure absorber to contact the gas. A light slurry of rich solution comes off the bottom of the absorber and flows to an atmospheric oxidizer tank where it is regenerated. A dense slurry is pumped off the base of the oxidizer to the melter and sulfur separator. 

Sour gas sweetening may also be carried out continuously in the flowline by continuous injection of H2S scavengers, such as amine-aldehyde condensates. Contact time between the scavenger and the sour gas is the most critical factor in the design of the scavenger treatment process. Contact times shorter than 30 sec can be accommodated with faster reacting and higher volatility formulations. The amine-aldehyde conden-... 

The R D activities of GRI led to a group of two patents, for gas sweetening (and also useful for flue gas treatment), based on biocatalytic processes for the selective removal of sulfur compounds in the presence of other reactive gases. 

Industrial gases Hz, N2, O2, Ar, He, CO2, natural gas Sweetening and CO2 removal from natural gas, removal of hydrocarbons from air, preparation of protective gases Aromatic compounds... 

Alkanolamines. Gas sweetening, ie, removal of hydrogen sulfide and carbon dioxide, using alkanolamines was patented in 1930. Several amine solvents are available as of the mid-1990s. The most widely used are monoethanolamine [141-43-5], diethanolamine [111-42-2], diglycolamine [929-06-6], and methyldiethanolamine [105-59-9]. Amine processes are generally applicable when hydrogen sulfide concentration in the feed gas is relatively low (eg,... 

The chemical processing techniques considered for synfuels flowsheet for the removal and recovery of sulfur are similar to those employed in other industries - notably natural gas sweetening, petroleum hydrodesulfurization, and coke oven gas treatment -but with certain significant differences attributable to the operating conditions encountered in synfuels processing. 

Because of the presence of hydrogen sulfide in Jay field crude oil, complex facilities, including oil stabilization, gas sweetening, and sulfur-recovery units, were required to produce salable oil and gas. To initiate field production and to provide extended well tests, a small 2.000-B/D facility was installed initially. As development drilling proceeded, 6.S00- and 12,000-B/D modules were built when and where needed. By using the modular-facility design concept, the field producing capacity was more than 00,000 B/D within 2V4 years of discovery. 

Since HtS dissolved in water is very corrosive to carbon 4 steel, a comprehensive corrosion-control program is being conducted. In the field, each well is treated once per month by displacing inhibitor down to the perfora-. tions with stock tank oil. Corrosion coupons in the flow-lines are inspected every 6 months Little corrosion has been detected in the field. In the plants, corrosion in-hibitor is added daily to the gas-sweetening solvent, the salt water system, and the stabilizer overhead. Inhibitor is -Jj also added to bulk chemicals as received. Numerous corrosion coupons and probes are installed in each facility and are pulled for inspection every 1 to 3 months Corrosion rates have been low (less than I mil/year) asY result of the inhibitor injection program. 

Acid gases CO2/CH4 H2S/CH4 co2/n2 Enhanced oil recovery recover CO2 for reinjection Natural gas and landfill gas sweetening Sour gas sweetening Digester gas treatment Successful Successful Feasible, but no known installation Successful Must remove condensable hydrocarbons More robust and higher selectivity membranes are needed... 

Slurrisweet A process for removing sulfur dioxide from gas streams by absorption in an aqueous suspension of iron oxide particles. Developed by Gas Sweetener Associates from the 1980s but later abandoned. 

SulfaTreat A process for removing hydrogen sulfide and mercaptans from natural gas or carbon dioxide streams, using a proprietary solid absorbent, which is subsequently dumped. First developed by Gas Sweetener Associates, now licensed by Sulfa Treat, a business unit of MI-SWACO, MO. More than 1,000 plants were operating in 2000. 

Figure 1.2 shows the basic block diagram for the acid-gas injection process, including a block for the natural gas sweetening unit. For CCS, the sweetening block is replaced by a carbon capture block, but the rest of the process is unchanged. The four main components of the injection scheme are 1. compression, 2. pipeline, 3. injection well, and 4. reservoir. Each of these will be discussed in some detail in this book. 

X 30 mesh 38 28.5 and liquid hydrocarbon and natural gas sweetening (H2S and mercaptan removal). 

Separation of CO2 from gas streams is required in four areas (1) purification of natural gas (gas sweetening), (2) separation of CO2 from enhanced oil recovery (FOR) gas streams, (3) removal of CO2 from flue gas, and (4) removal of CO2 from biogas. A fifth area vital for the space age should be mentioned removal of CO2 from life support systems onboard space ships, and also in submarines. All these applications have different specifications for the purified gas or for the recovered CO2, and future membrane applications will most likely be based on tailor-made materials. 

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