The design of any of the distillation processes discussed requires choosing an operating pressure, bottoms temperature, reflux condenser temperature and number of trays. This is normally done using any one of several commercially available process simulation programs which can perform the iterative calculations. Some typical parameters for design are shown in Table 9-4. The actual …
Read More…Category: Gas Processing
Gas Processing – Fractionation
The bottoms liquid from any gas plant may be sold as a mixed product. This is common for small, isolated plants where there is insufficient local demand. The mixed product is transported by truck, rail, barge or pipeline to a central location for further processing. Often it is more economical to separate the liquid into …
Read More…Gas Processing – Cryogenic Plants
Figure 9-3 shows a typical cryogenic plant where the gas is cooled to -100°F to ~150°F by expansion through a turbine or Joule-Thompson (J-T) valve. In this example liquids are separated from the inlet gas at 100°F and 1,000 psig. It is then dehydrated to less than 1 ppm water vapor to assure that hydrates …
Read More…Gas Processing – Refrigeration
In a refrigeration plant the inlet gas is cooled to a low enough temperature to condense the desired fraction of LPG and NGL. Either freon or propane is used as the refrigerant. Figure 9-2 shows a typical refrigeration plant. The free water must be separated and the dew point of the gas lowered before cooling …
Read More…Absorption/Lean Oil
The oldest kind of gas plants are absorption/lean oil plants, where a kerosene type oil is circulated through the plant as shown in Figure 9-1. The “lean oil” is used to absorb light hydrocarbon components from the gas. The light components are separated from the rich oil and the lean oil is recycled. Typically the …
Read More…Gas Processing
The term “gas processing” is used to refer to the removing of ethane, propane, butane, and heavier components from a gas stream. They may be fractionated and sold as “pure” components, or they may be combined and sold as a natural gas liquids mix, or NGL. The first step in a gas processing plant is …
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