Glycol dehydration process

Most glycol dehydration processes are continuous. That is, gas and glycol flow continuously through a vessel (the contactor" or absorber ) where they come in contact and the glycol absorbs the water. The glycol flows from the contactor to a reboiler (sometimes called "reconcentrator or regenerator where the water is removed or stripped from the glycol and is then pumped back to the contactor to complete the cycle. 

Figure 11-8. Flow diagram of typical glycol dehydration process. (Bentley, 1991)...

Fontenot, C. E., Perry, L. A., Smith, R. S., and Zabicik, D. J., 1986, Economic Comparison of Two Enhanced Glycol Dehydration Processes, Proc. Laurance Reid Gas Conditioning Conf, University of Oklahoma, Norman, OK, p. F-1. 

Figure 12-5. Comparative initiai equipment costs fortypicai dry-desiccant and glycol dehydration processes in high-pressure natural gas service.

Senatoroff has published a complete discussion of the principles and plant design details of the diethylene glycol dehydration process. 

At low vapor rates, valve trays will weep. Bubble cap trays cannot weep (unless they are damaged). For this reason, it is generally assumed that bubble cap trays have nearly an infinite turndown ratio. This is true in absorption processes (e.g., glycol dehydration), in which it is more important to contact the vapor with liquid than the liquid with vapor. However, this is not true of distillation processes (e.g., stabilization), in which it is more important to contact the liquid with the vapor. 

Contactor pressures have little effect on the glycol absorption process as k>ng as the pressures remain below. 3,000 psig. At a constant temperature liic water content of the inlet gas decreases with increasing pressure, thus less water must be removed if the gas is dehydrated at a higher pre.s-sure. In addition, a smaller contactor can be used at high pressure as the actual velocity of the gas is lower, which decreases the required diameicr of the contactor. 

Figure 1-4. Flow diagram of the Dehydrate process (1) absorption column, (2) glycol sill, (3) vacuum drum.

The glycols used in natural/synthetic gas dehydration processes. 

Theoretical analysis and motion simulation work has resulted 1n a basic understanding of fluid motion Inside process equipment. In turn, the specific affects In two and three phase separators, treaters, glycol dehydrators and other process equipment has been analyzed. This research has lead to the establishment of process equipment sizing criteria for all types of vessel motion transmitted from the marine vessel, also the designs of baffling and other Internals to dampen and control the fluid motion have been established together with the optimization of equipment layout on marine vessels. 

The dehydration process may also affect antigen preservation and various special dehydration procedures have claimed improved tissue antigenicity. Similarly, certain types of paraffin, celloidin, and polyethylene glycol have been shown to be useful for immunohistology (Larsson 1993). 

Uses Defoamer for industrial and food-processing systems (fermentation, brine systems, wine, yeast, etc.), chemical processing (adhesive mfg., water-based ink mfg., latex processing, soap mfg., starch processing. paint additive, alcohol fennentation), wastewater treatment, petrochemical (resin polymerization, glycol dehydrators, ethylene oxide prod., urea prod.)... 

Currently, PRISM membranes provide an attractive alternative to traditional glycol dehydration systems (Figure 14.8) based on simple process designs, lower costs, and the other benefits listed below. These benefits become even more pronounced as the industry produces natural gas from very remote locations [55]. An offshore membrane system for Shell Nigeria was designed to dry 600000NmVh of natural gas from an inlet dew-point of 41 °C to an outlet dew-point of 0°C at 38 bar. It was designed and built by Petreco, an Air Products PRISM Membranes licensed partner. Other plants were installed in Italy and Holland. 

Several temperatures were tried for the dehydration process In some experiments treatment with Cellosolve (2-ethoxyetha-ethylene glycol monoethyl ether) was performed prior to soaking in alcohol (99.5%). 

About 35 different variations of the in situ method was originally tried, with about the same number of chemicals. Of all the various chemicals tested as first soaking medium in the dehydration process, however, ethylene glycol was the only one that did not cause shrinkage of the gel slices. Ethylene glycol is a rather viscous medium and thus occasional stirring had to be done. 

Propylene glycol is a diol (propane-1, 2-diol). It is in use in cutaneous preparations, dissolved in the aqueous phase, as a humectant, to slow down a dehydration process. Other applications are the use as softening agent and as vehicle for ear drops intended for the external auditory meatus (see Sect. 9.5.3). 

Three process requirements must be met for gas to be dried in a standard glycol dehydration unit ... 

Although the selective oxidation reaction (8-1) is not reversible, the products of reaction 8-1 (S and H2O) can react by the reverse of reaction 8-3 to reduce overall sulfur recovery. Therefore, in the MODOP process, water is removed from the gas stream in the quench tower to improve the conversion of hydrogen sulfide to sulfur. Conversion can be further increased by removal of additional water in a glycol dehydration tower after the quenching... 

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