Process Simulation to Design Dehydration Systems with Separators and Inline Glycol Injection Segment

Abstract

Abstract Raw natural gas contains methane, ethane, propane, some amounts of heavier hydrocarbons and impurities like water vapour, sulphur compounds, carbon dioxide, nitrogen etc. Presence of these components along with methane reduces the calorific value of the natural gas. Also, high percentage of impurities in natural gas can block pipelines due to hydrate formation during transportation. Therefore, to meet the pipeline specifications, natural gas dehydration plants are used to lower the percentage of water in it. Dehydration of natural gas can be carried out with the help of the adsorbents as well as absorbents. Choosing a dehydrating agent and designing of dehydration plant depends on a number of factors. Gas flow rate, percentage of initial and final water composition, dew point depression attained, and cost are some of the important factors to be considered during designing of dehydration plant. In this paper, we highlight the simulation of a natural gas dehydration process which has an inline glycol injection system and then compare its efficiency with the conventional dehydration system. The cost of setting these two units is also compared. The simulation study shows that the glycol injection system significantly reduces the mole fraction of water in the natural gas.