Amine Cooler

The amine cooler is typically an air-cooled, fin-fan cooler, which low-er.s the lean amine temperature before it enters the absorber. The lean amine entering the absorber should be approximately 10°F warmer than the sour gas entering the absorber. Lower amine temperatures may cause the gas to cool in the absorber and thus condense hydrocarbon liquids. Higher temperatures would increase the amine vapor pressure and thus increase amine losses to the gas. The duty for the cooler can be calculated from the lean-amine flow rate, the lean-amine temperature leaving the rich/lean exchanger and the sour-gas inlet temperature. 

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Amine cooler leaking Reboiler or reclaimer leaking... 

If the feed gas is near its hydrocarbon dewpoint, hydrocarbon condensation inside the contactor and related foaming can be avoided by keeping the temperature of the lean amine solution about 10 to 1S°F above that of the gas in the amine contactor. This is usually accomplished by using a temperature difference controller to control a bypass around the lean amine cooler. 

In this example we selected a final outlet temperature of 100°F, This would be sufficiently low if the gas were only going to be compressed and dehydrated. For our case, we must also treat the gas for H2S and COt removal (Chapter 7). If we chose an amine unit, which we will in all likelihood, the heat of the reaction could heat the gas more than 10° to 20 T. making the next step, glycol dehydration, difficult (Chapter 8). In such a case, it may be better to cool the gas initially to a lower temperature so that it is still below 110°F at the glycol dehydrator. Often this is not possible, since cooling water is not available and ambient air conditions are in the 95°F to 1()0°F range. If this is so, it may be necessary to use an aerial cooler to cool the gas before treating, and another one to cool it before dehydration. 

The hot lean amine proceeds to the rich/lean amine exchanger and then to additional coolers to lower its temperature to no less than 10°F above the inlet gas temperature. This prevents hydrocarbons from con-... 

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. 

The functional groups that typically participate in this type of polymerization are carboxyl, amine, and alcohol groups. Examples of step growth polymers include polyesters and nylons, which are often spun into fibers used to manufacture carpeting and fabrics, and polycarbonates, which are converted into compact discs, jewel cases, and the large bottles used in water coolers. 

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. 

Oxidation Oxidation of the lubricant basestock leads to viscosity increase and consequent issues of pumpability, fuel economy and ultimately oil starvation. Oxidation products also include organic acids which can cause corrosion and deposits around the engine but particularly in the cooler parts of the engine, discussed previously in detail in Chapters 4 and 7. Dedicated antioxidants such as phenols and amines are used to control oil oxidation, and the antiwear agent ZDDP also acts as a powerful antioxidant. 

Condensers and coolers are used to bring the products down closer to normal temperatures, and the remaining excess hydrogen is removed in gas-liquid separators. The hydrogen can be recycled after compression in a recycle compressor. The amine is separated from the water in a liquid-liquid separator. If significant amounts of amine are present in the water phase, the latter may be subjected to extraction by fresh nitro compound before it is fed to the reduction tower. 

An abnormal temperature profile. For instance, in amine absorbers, foaming will cause the reaction to occur higher up in the column (22). The rich solution will become cooler, while the lean gas will become warmer. A significant decrease in the temperature difference between the inlet and outlet gas, accompanied by a drop in the temperature difference between the rich and lean solution, will suggest foaming. 

Fig. 2.13. Split flow amine sulfur ronoval process, (a) Absorber, (b) regenerator (c) lean/rich solution heat exchanger (d) cooler, (e) reboiler, (f) reclaimer, (g) condenser...

The gas leaving the hydrogenation reactor is first cooled in a waste heat boiler to about 170°C and then in a quench cooler to approximately 35°C. The quenching operation uses circulating water from which the heat is removed in a cooler. Unlike the Sulfreen process described above, this process produces condensate as the gas is cooled below the steam dew point this condensate has to be withdrawn from the water loop and fed to a stripper to remove H2S. A blower delivers the almost dry gas from the quench cooler to an absorber to eliminate the hydrogen sulfide by means of an amine wash liquor. 

Hydrocarbons condense in cold amine. The lean-amine temperature must be 10 F above the dew point of the sweet gas. Cooler amine will condense liquid hydrocarbons and initiate foaming. Cold amine (JCF) will in itself have a tendency to foam. 

Leaking amine water cooler, 103 Leaking drawoff trays, 23-25 welded trapout pans, 23-24 Leaking feed-effluent exchanger (glycol), 444-445... 

The cooler on the overhead system of the stripper tower controls the quantity of water and amine that is recovered from the overhead streams. This may be an air- or water-cooled exchanger or combination of these. These must effectively cool if excessive amine is not to be lost. These exchangers will also affect downstream corrosion, because the corrosivity of these acid gases is definitely increased by increasing temperature. 

A modification diat has been used successfiilly to increase the add gas loading of the ridi amine (and thereby decrease the required solution flow rate) is the installation of a side cooler (or int cooler) to reduce the tNtqtetatnre inside the absorber. The concept has proved particularly usefiil for DGA plants operating in Saudi Arabia where air cooling is used (Huval and van de Veime, 1981). The optimum location for a side cooler is rqmrted to be the point where half the absorptim occurs above and half below the cooler, wbidi results in a location near the bottom of the column (Thompson and King, 1987). 

The plant equipment is basically simple, only an absorber (usually 20 plates), a rectifier or regenerator (also 20 plates), exchangers, a cooler for the amine solution, and a reboiler at the base of the rectifier for supplying heat to the process. Thus, this is an opportunity to introduce the details that are necessary in actual plant operations (Fig. 20-18), by showing a more complete type of flow diagram. 

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