Regenerator reflux water

A reclaimer first put on-line will have a vapor outlet temperature of about 270°F. When this temperature reaches 295°F, the reclaimer should be taken off-line and cleaned. You can delay removing the reclaimer from service by adding steam or water to the shell side. Regenerator reflux water is the usual source of water. 

The water dilutes the amine salts in the reclaimer, thereby reducing the boiling point. If regenerator reflux water has been used, the amine system water balance remains unchanged. Unfortunately, the pounds per hour of dilution water added must be subtracted from the reclaimer duty. When the reclaimer duty is 40-50% of its clean duty, it should be washed. The heavy ammonia odor emitted from the reclaimer as it is steamed and washed is normal. 

Foaming. Dirt reduces the surface tension of liquids. Particulates will cause amine to foam. Foaming in regenerators results in high amine concentrations in the regenerator reflux water. Foaming in the scrubbers causes amine to be carried overhead with the hydrocarbon being scrubbed. 

Regenerator Reflux Water Sti ping, Neumaier and Schillmoller (1955) outline anoth method for eliminating corrosion by ammonia and cyanide in the amine regenerator over-... 

Reflux water pH. To protect the regenerator condensers from the corrosive effects of low pH water, a small amount of amine entrainment is needed. The reflux water must have at least one-half wt% amine. To ensure this concentration, tie in a 1-in. iine from the lean amine pump to the inlet of the condenser. Incidentally, ammonia often accumuiates in the reflux water and can be accidentally titrated as amine by the lab. This will not hurt anything. 

If substantial reflux is provided, one can be sure that the amine is well stripped before it is drawn off the reboiler trapout tray. The regenerator reflux rale (Ib/hr water) should be 10%-30% of the reboiler steam rate. To double-check stripping efficiency, pull samples of lean amine and reboiler feed. Both should have the same H2S concentration. Remember, H2S must be stripped out of the regenerator trays, not in the regenerator reboiler. This is important enough to repeat Keep a decent reflux rate in the regenerator to prevent reboiler tube corrosion. 

Reducing the water vapor content of acid gas to a minimum also increased Claus capacity. During periods when one of the two sulfur trains was out of service, the amine regenerator reflux drum temperature was reduced from 135°F to 110 F. This was achieved by spraying treated water on the exterior of the amine regenerators overhead fin fan tube bundles. This reduced the water content of the acid gas from 10% to 5% and thus increased sulfur recovery capacity by 2%. 

Ihe simplest modification of the flow system in F ine 2-10 is the inclusion of a water wash at the top of the absorber to reduce losses of amine with the purified gas. If acid gas condensate from the regenerator reflux drum is used for this purpose, no draw-ofi tray is required because it is necessary to readmit this water to the system at some point. It should... 

In the regenerator overhead condenser, the gaseous ammonia and HCN are reabsorbed in the condensed reflux water. Ammonia dissolved in the reflux water provides the alkalinity to absorb and retain add gases, such as H2S, CO2, and HCN in solution. 

Without a reflux water purge, ammonia, H2S, CO2, and HCN are trapped in the amine regenerator overhead system. If both ammonia and HCN are present, the net effect is a substantial increase of the HCN, H2S, and CO2 concentrations in the amine regenoator ovo -bead system. 

A reflux water purge to reduce the concmtration of ammonium cyanide and bisulfide in the amine regenerator overhead. See Figure 3-1. 

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

In the presence of anhydrous hydrogen fluoride at 30°, cellulose is transformed into a polymeric product, called cellan.77 This substance is water-soluble, strongly dextrorotatory ([mineral acid, and only faintly reducing. Molecular-weight determinations (by cryoscopy) on cellan acetate ([a]n + 128°) and on the regenerated polymer indicated it to have a Pn of 14. 

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