Mercury removal method and system

A mercury removal method for the removal of mercury components present in a gas during wet gas purification, said method comprising:

• a water washing step bringing the gas containing mercury components and not less than 10 ppm of hydrogen sulfide into contact with an absorbing fluid under pressurized conditions so as to cause mercury components to pass from the gas into the absorbing fluid;
• a flashing step subsequent to the water washing step spraying the discharged absorbing fluid under a lower pressure to separate it into gaseous components and waste water;
• and
• an adsorption removal step passing the gaseous components through a mercury remover provided with an adsorbent to remove mercury components therefrom by adsorption.

A mercury removal system for the removal of mercury present in a gas during wet gas purification, said system comprising:

• a water washing tower in which the gas containing both mercury components and hydrogen sulfide is introduced and an absorbing fluid is circulated through the tower under pressurized conditions so as to cause mercury components to pass into the absorbing fluid;
• a flash drum in which the absorbing fluid discharged from the water washing tower is sprayed under a lower pressure to separate it into gaseous components and waste water;
• and
• a mercury remover provided with an adsorbent in which the mercury components present in the gaseous components are removed by adsorption.