Amine regeneration

Rich amine from the bottom of the HjS contactor goes to a flash separator to remove dissolved hydrocarbons from the amine solution. The rich amine is pumped from the separator to the amine regenerator,... 

In the amine regenerator, the rich amine solution is heated to reverse the acid-base reaction that takes place in the contactor. The heat is supplied by a steam reboiler. The hot, lean amine is pumped from the bottom of the regenerator and exchanges heat with the rich amine in the lean-rich exchanger and a cooler before returning to the contactor. 

First stage suction piping and vessels can be constructed from carbon steel since it is the same design pressure and conditions as amine regeneration reflux vessel. All other downstream piping, vessels, coolers, and equipment should be constructed from stainless steel. 

Reactions of Aminyl Radicals and Mechanisms of Amine Regeneration as Inhibitors of Oxidation... 

Denisov Aminyl Radical Reactions and Amine Regeneration... 

It was suggested that part of the aminyls of the DPA series participates in an amine regeneration via reactivity with ROO ... 

The sweetened gas goes overhead and is sent to the fuel gas system. The rich amine exits the bottom of the scrubber and is heated in the lean—rich exchanger. It then enters the amine regenerator, where a steam reboiler is used to heat the amine to 225—250 °F. At these temperatures, the salts are thermally dissodated to regenerate the amine. The add gas, composed primarily of H2S, is sent to a sulfur recovery unit that generates elemental sulfur. 

Arylamines from triazenes. Arylamines can be protected as triazenes (formation by reaction of the diazonium salts with a secondary amine). Regeneration of ArNH2 is accomplished by reductive cleavage using Al-Ni alloy in a basic solution. 

The stoichiometric coefficient f- 2(1 + kln/k lnn) and naturally depends on the kind of radical with which In- reacts. As found in experiments on the oxidation of cyclohexanol with a-naphthylamine (120° C, Wi = 1.86 X 1CT6 mole l-1 s-1), f increases with oxygen pressure from 16.6 (Pq2 = 0) to 48 (Pq2 = 760 torr). It follows that the degree of amine regeneration by reaction with hydroxyperoxy radicals is higher than that for hydroxyalkyl... 

Calcium chloride (fused) CaCl acid 0.14 (0.10-0.20) ojKiw) ( 2w) 291 hydratation Low cost and compatible with numerous gases but poor capacity and it must be cooled down to 0°C to reduce water vapor pressure. Not suitable for alcohols, phenols and amines. Regeneration difficult at 250 C. Can contain CaO that must be converted into CaCO, prior to drying CO,. 

In the real world, there is only one reliable way to prevent such situations. Liquid hydrocarbons must be separated from the rich amine upstream of the amine regenerator (see Chapter 4). 

The 4-psi increase in the reaction furnace pressure increased the acid gas pressure by an equivalent amount. This pressure rise backed up through the amine regenerator and raised the amine reboiler temperature by 6 F. Because the reboiler tube metallurgy was carbon steel, this increased temperature was of concern in regard to decreased reboiler tube life. To avoid accelerated corrosion, a corrosion inhibitor was injected into the reboiler... 

The HjS is then stripped in an ordinary amine regenerator and recycled back to the front-end of the sulfur plant. 

In the case of the amine regenerator, no explanation could be found for the fouling distribution. The solids (consisting mostly of iron and sulfur) were soluble in hydrochloric acid. The trays were hydraulically cleaned. 

Alonizing (refinery metallurgy), 427 Ambient heat loss, 30 Amine regenerator reflux drum, 119 Amine regenerator (tray fouling), 392-393... 

Brown amine (amine regeneration and scrubbing), 108 Bubble effect (superheated reactor vapor), 186... 

A blue tinge in the lean amine indicates the presence of cyanides. The cyanides are coming from the FCCU wet gas. They should have been scrubbed out of the wet gas with an aqueous-phase polysulfide wash. These cyanides will promote corrosive failures in amine regenerator overhead system and hydrogen blistering or cracking in piping and vessels that contact the lean amine. 

Condenser fouling. Rich amine regenerator feed splashes overhead. Particulates accumulate in the regenerator condensers, heat transfer is impaired to a certain extent, and the reflux temperature rises. 

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