Synergy between two natural gas sweetening processes

• A carbonate based natural gas sweetening process is simulated.
• Effects of addition of certain amounts of sodium hydroxide to the solution are investigated.
• The additive amount is adjusted to: 1-reach pipeline specs 2-complete removal of acid gases.
• The process is simulated in different sour gas flow rates.
• The needed solution flow rate and modified solution flow rate are evaluated and compared.

Merox process is a developed process for natural gas sweetening. However this process has one main disadvantage, which is the fact that carbon dioxide in the feed gas consumes the sorbent solution. High efficiency of carbonate based solutions for removal of bulk of CO2 from natural gas is a well-known fact. The alkalinity is important in removal of acid gases by potassium carbonate solution. The main idea behind this work was to investigate the possibility of inhibition of Merox solution consumption by a synergy between Merox and carbonate based sweetening processes. In this study, a carbonate based sweetening process is simulated using Aspen Plus simulator for sweetening the natural gas produced in one of gas fields located in Iran. The effects of addition of sodium hydroxide to the solution on the gas sweetening performance and efficiency are investigated. It is revealed that modifying the solution of this process using sodium hydroxide increases the capacity of the solution in removing acid gases.