Dehydration by Adsorption.

Water vapor also can be removed from natural gas by use of a solid desiccant as an adsorption medium. The adsorption process is a very complex phenomenon involving transfer of the component adsorbed from the gas phase to contact with the solid. Technical Data used in the field explained in petroleum courses in Islamabad.

For this reason the most effective adsorbents have extremely large surface areas per unit of mass. This means that their surface is honeycombed with capillaries that serve to provide the necessary surface area. A flow sheet of a typical dry desiccant dehydration unit is shown in Fig. 14.22. There must be at least two desiccant beds for continuous operation because adsorption is a batch process. The main gas stream flows through an inlet separator where all free liquids are removed. Any liquids can be harmful to the dehydration process. Free water will reduce the capacity of the unit if not removed.

Hydrocarbons can poison the bed if not properly regenerated. The main gas stream then flows through a pressure-reducing valve that controls the flow of the regeneration gas by inducing a pressure drop in the main gas stream. The gas then flows through one of the two adsorption towers where it contacts the desiccant and the water vapors are removed. The main gas stream flows to the sales gas line through a gas-to-gas heat exchanger where heat is removed from the regeneration gas. Some more details of petroleum courses in Islamabad are as under.

The second adsorption tower is regenerated while the other tower adsorbs water vapor from the main gas stream. Regeneration gas (approximately 10 to 15% of the total gas flow) is taken from the main gas stream upstream of the pressure reducing valve and passed through a heater where the temperature is raised to approximately 450°F. The hot gas then passes through the desiccant bed.

The water adsorbed through the bed is vaporized and swept out of the bed by the regeneration gas. The hot, wet regeneration gas passes through the gas-to-gas exchanger where it is cooled by the main gas stream. The water condensed from the gas is separated in the regeneration gas scrubber. The regeneration gas flows into the main gas stream downstream of the pressure-reducing valve. Because of the regeneration gas flow, the pressure drop through a solid desiccant dehydration unit will be higher than for a TEG unit and will be approximately 25 psi for the system. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join petroleum courses in Rawalpindi.