Mercury removal system, gasification system, gasification combined power generation system and mercury removal method

A mercury removal system provided in a powder supply system including a pulverizing machine that pulverizes a hydrocarbon raw material along with a dry gas supplied from the outside so as to become a powder raw material, the mercury removal system comprising:

• a removal agent supply device which supplies a mercury removal agent for removing mercury contained in a dry flue gas discharged from the pulverizing machine;
• and
• a mercury removal agent dust collector which collects the dust of the mercury removal agent so as to be separated into the mercury removal agent and a pure gas,
• wherein a gas discharge line to which the dry flue gas is supplied is connected to the mercury removal agent dust collector,
• wherein the removal agent supply device includes a mercury removal agent supply line which supplies the mercury removal agent, and
• wherein the mercury removal agent supply line is connected to the upstream side of the mercury removal agent dust collector in the circulation direction of the dry flue gas.