Reducing mercury emissions from the burning of coal

A process for burning coal to reduce the amount of mercury released into the atmosphere comprising

• applying a liquid sorbent composition comprising a bromine compound onto the coal;
• delivering the coal containing the sorbent into a coal burning furnace;
• injecting a powder composition into the furnace during combustion, the powder composition comprising sources of calcium, silica, and alumina;
• combusting the coal together with the liquid sorbent and powder composition in the coal burning furnace to produce ash and combustion gases.

A method for burning mercury-containing coal in a combustion system comprising a furnace and convective pathway for flue gases downstream of the furnace, the method comprising:

• adding a liquid composition into the system;
• adding a powder composition comprising calcium, silica, and alumina into the system during combustion;
• and
• combusting coal to produce flue gases and fly ash;
• wherein the liquid composition comprises a bromine compound and the powder composition comprises at least 2% by weight silica and at least 2% by weight alumina.

A method for reducing mercury in the flue gases resulting from combustion of coal in the furnace of a coal burning system, comprising

• applying sorbent components comprising a halogen, calcium, silica, and alumina into the coal burning system;
• combusting the coal to produce ash and combustion gases;
• measuring a mercury level in the combustion gases;
• and
• adjusting the amount of halogen applied into the system based on the value of the mercury level.

A process comprising

• burning coal in the presence of 1-10% by weight of an added sorbent, the sorbent comprising about 30-75% by weight CaO, about 2-15% by alumina, about 5-20% by weight silica, about 1-10% by weight Fe2O3, and 0.1-5% by weight of alkali selected from Na2O and K2O;
• producing an ash by burning the coal;
• recovering the ash;
• and
• formulating a cementitious mixture comprising the ash.