Process for removing mercury from flue gases

Process for removing mercury from mercury-containing flue gases of a furnace within which a combustion or incineration is carried out, wherein

• bromine, a bromine compound, a mixture of bromine compounds or a mixture of bromine and a bromine compound or compounds, is fed to the furnace or to the flue gas of the furnace in a plant section downstream of the furnace, or to both the furnace and the flue gas, the temperature during the first contact of the bromine, said bromine compound, said mixture of bromine compounds or of said mixture of bromine and a bromine compound or compounds with the flue gas being at least 500° C.,
• the combusion or incineration is carried out in the presence of a sulphur compound, and then the flue gas is subjected to a cleanup for removing mercury from the flue gas,
• wherein the temperature during the contact of the bromine compound, said bromine compound, said mixture of bromine compounds or of said mixture of bromine and a bromine compound or compounds with mercury-containing flue gas is at least 800° C. and wherein the cleanup for removing mercury from the mercury-containing flue gas substantially removes mercury from the mercury-containing flue gas and includes atleast one of a wet scrubbing stage and a dry cleanup stage, the dry cleanup stage comprising at least one sorbent, and
• wherein sulphur, a sulphur compound or a mixture of sulphur compounds is added to said furnace based on measuring a measured mercury content of the mercury-containing flue gas.

A process for removing mercury from mercury-containing flue gases of a furnace, comprising:

• carrying out a combustion or incineration process, within the furnace, in the presence of a sulphur compound;
• feeding bromine, a bromine compound, a mixture of bromine compounds or a mixture of bromine and one or more bromine compounds to at least one of the furnace or a flue gas of the furnace in a plant section downstream from the furnace, a temperature at first contact of the bromine, bromine compound, mixture of bromine compounds, or mixture of bromine and one or more bromine compounds with the mercury-containing flue gas being at least 800° C.;
• and
• subjecting the mercury-containing flue gas to a cleanup for substantially removing mercury from the mercury-containing flue gas, wherein the cleanup for substantially removing mercury from the mercury-containing flue gas includes a dry cleanup stage comprising at least one sorbent;
• and
• the process further comprising adding sulphur, a sulphur compound or a mixture of sulphur compounds to said furnace based on a measured mercury content of the mercury-containing flue gas.

A process for removing mercury from mercury-containing flue gases of a furnace, comprising:

• carrying out a combustion or incineration process, within the furnace, in the presence of a sulphur compound;
• feeding bromine, a bromine compound, a mixture of bromine compounds or a mixture of bromine and one or more bromine compounds to at least one of the furnace or a flue gas of the furnace in a plant section downstream from the furnace, a temperature at first contact of the bromine, bromine compound, mixture of bromine compounds, or mixture of bromine and one or more bromine compounds with the mercury-containing flue gas being at least 800° C.;
• and
• subjecting the mercury-containing flue gas to a cleanup for substantially removing mercury from the mercury-containing flue gas, wherein the cleanup for substantially removing mercury from the mercury-containing flue gas includes a dry cleanup stage comprising at least one sorbent;
• and
• wherein feeding the bromine, bromine compound, mixture of bromine compounds or mixture of bromine and one or more bromine compounds to the furnace comprises:
• applying the bromine, bromine compound, mixture of bromine compounds or mixture of bromine and one or more bromine compounds in an aqueous solution of the bromine, bromine compound, mixture of bromine compounds or mixture of bromine and one or more bromine compounds to a waste feed for a waste incineration process;
• and
• feeding the waste feed to the furnace,
• the process further comprising adding sulphur, a sulphur compound or a mixture of sulphur compounds to said furnace based on measured mercury content of the mercury-containing flue gas.

Process for removing mercury from mercury-containing flue gas of a furnace within which a combustion or incineration of coal containing sulfur is carried out, comprising the steps of:

• feeding bromine to the mercury-containing flue gas, the temperature during the first contact of the bromine with the mercury-containing flue gas being at least 800° C., and the combustion or incineration being carried out in the presence of a sulphur compound such that a gas phase reaction takes place between the bromine and the mercury so as to produce a bromine-contacted mercury-containing flue gas wherein the mercury is essentially completely oxidized;
• wherein said bromine is selected from the group consisting of bromine, a bromine compound, a mixture of bromine compounds and a mixture of bromine and a bromine compound or compounds, and wherein the feeding step feeds bromine to the furnace or to the flue gas of the furnace in a plant section downstream of the furnace, or to both the furnace and the flue gas;
• and
• subjecting the bromine-contacted mercury-containing flue gas to a cleanup for removing oxidized mercury whereby mercury is substantially removed from the bromine-contacted mercury-containing flue gas, wherein the cleanup includes at least one of a wet scrubbing stage and a dry cleanup stage, the dry cleanup stage comprising at least one sorbent.

Process for removing mercury from mercury-containing flue gas of a furnace within which a combustion or incineration of coal containing sulfur is carried out, comprising the steps of:

• feeding bromine to the mercury-containing flue gas, the temperature during the first contact of the bromine with the mercury-containing flue gas being at least 800° C., and the combustion or incineration being carried out in the presence of a sulphur compound such that a gas phase reaction takes place between the bromine and the mercury so as to produce a bromine-contacted mercury-containing flue gas wherein the mercury is essentially completely oxidized;
• wherein said bromine is selected from the group consisting of bromine, a bromine compound, a mixture of bromine compounds and a mixture of bromine and a bromine compound or compounds, and wherein the feeding step feeds bromine to the furnace or to the flue gas of the furnace in a plant section downstream of the furnace, or to both the furnace and the flue gas;
• and
• subjecting the bromine-contacted mercury-containing flue gas to a cleanup for removing oxidized mercury whereby mercury is substantially removed from the bromine-contacted mercury-containing flue gas, wherein the cleanup includes at least one of a wet scrubbing stage and a dry cleanup stage, the dry cleanup stage comprising at least one sorbent, wherein the mass ratio of bromine to mercury in the flue gas is in the range from 102 to 104.

Process for removing mercury from mercury-containing flue gas of a furnace within which a combustion or incineration of coal containing sulfur is carried out, comprising the steps of:

• feeding bromine to the mercury-containing flue gas, the temperature during the first contact of the bromine with the mercury-containing flue gas being at least 800° C., and the combustion or incineration being carried out in the presence of a sulphur compound such that a gas phase reaction takes place between the bromine and the mercury so as to produce a bromine-contacted mercury-containing flue gas wherein the mercury is essentially completely oxidized;
• wherein said bromine is selected from the group consisting of bromine, a bromine compound, a mixture of bromine compounds and a mixture of bromine and a bromine compound or compounds, and wherein the feeding step feeds bromine to the furnace or to the flue gas of the furnace in a plant section downstream of the furnace, or to both the furnace and the flue gas;
• and
• subjecting the bromine-contacted mercury-containing flue gas to a cleanup for removing oxidized mercury whereby mercury is substantially removed from the bromine-contacted mercury-containing flue gas, wherein the cleanup includes at least one of a wet scrubbing stage and a dry cleanup stage, the dry cleanup stage comprising at least one sorbent, wherein the feeding step is carried out by adding bromine in an amount such that the gas phase reaction essentially completely oxidizes the mercury in the mercury-containing flue gas.