Natural gas flow has a valuable pressure exergy which is currently destroyed in throttling valves at exit of the gas fields. In the current study, this pressure exergy has been calculated for an actual case. Exergy analysis was based on actual condition of the Shanol gas field, which is situated in Iran, in the summer. It is assumed to be a good representative of Iran’s whole gas fields. Exergy has been calculated for a constant enthalpy process (throttling process) and isentropic process for real gas and ideal gas. Based on the Iran natural gas daily production rate, the results indicate that the maximum obtainable energy is about 5600 MW. By considering converting efficiency of 75%, one can extract 4200 MW electrical power. The computations for a constant enthalpy process show very good agreement with actual data.

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