Triethylene glycol dehydration with

Figure 20.8 shows a schematic flow diagram for a typical triethylene glycol dehydration system. The lean glycol is pumped to the top of an absorber column and flows downward in countercurrent contact with the water-wet gas entering the bottom of the... 

Acid-catalyzed dehydration of aldoses and ketoses yields furan derivatives in 40-80% 3ueld. Recently the reaction has been carried out in an organic solvent, e.g., dioxan or triethylene glycol, or with I2 in dimethylformamide at 100°. Often D-fructose is employed as starting material. This ketose gives glucose via an enediol, which 3uelds 5-hydroxymethylfurfural or its 0-acyl derivative by dehydration. 

A few other dehydration systems are also widely used which employ glycol injection and contact with the gas. Mono-, or di-, or triethylene glycol solution is used for this purpose. The principles are very similar to the methanol dehydration system. The disadvantages associated with the glycol methods are inadequate distribution in the gas-gas exchangers, difficulty to remove from the dehydrated gas, foaming, and mutual solubility between the hydrocarbon liquids and the glycol solution. 

In the process of extraction of heavy hydrocarbons, a Uquid saturated with heavy hydrocarbons can be taken as the absorbent, for example, petroleum, solar or transformer oil, weathered condensate etc. For the absorption dehydration of gas, glycols are used diethylene glycol (DEG) or triethylene glycol (TEG). 

Glycol dehydrators are used to scrub water from natural gas to meet pipeline specifications but also pose a potential hazard to membrane systems. An upset in dehydrator operations can flood manbrane modules with triethylene glycol (TEG), commonly employed as the working fluid. 

Note CO2 removal was followed by dehydration with triethylene glycoL ... 

For the case shown in Figure 11-32, it is assumed that a natural gas stream is saturated with water at SOO psia and 90°F and that it is desired to dehydrate this gas to a water content of 10 Ib/MMscf (dew point 28°F). With triethylene glycol a concentration of 98.5% can readily be attained with simple atmospheric pressure regeneration. The dew-point chart. Figure 11-15, shows an equilibrium dew point of about I5°F for this glycol concentration, equivalent to a 13°F approach at the top of the column. 

Charts for estimating the required internal diameter of natural gas dehydration columns using triethylene glycol and equipped with valve-type trays have been presented by Camer-inelli (1970). One of these charts, for the case of 24-in. tray spacing, is reproduced in Figure 11-33. The chart is based on a constant gas inlet temperature of I20°F however, for pressures up to the maximum shown, 1,200 psia, gas temperature was found to have very little effect. The column size obtained from the chart is based on a design gas capacity of about 70% of flooding. 

---