System and process for oxy-fuel calcination of lime-bearing sludge

A calcination system for lime-bearing sludge, comprising:

• a calciner at least partially sealed from atmospheric air intrusion;
• a lime-bearing sludge supply coupled to the calciner;
• an oxygen supply having a percentage of oxygen greater than atmospheric air coupled to the calciner;
• a hydrocarbon fuel supply coupled to the calciner;
• a gas conditioning chamber sealed from air intrusion and arranged to receive calciner exhaust gas from the calciner and add heat to the calciner exhaust gas;
• an oxygen supply having a majority percentage of oxygen coupled to a burner of the gas conditioning chamber;
• a carbon dioxide supply having a majority percentage of carbon dioxide coupled to the burner of the gas conditioning chamber;
• and
• a hydrocarbon fuel supply coupled to the burner of the gas conditioning chamber;
• and
• at least one water spray to inject water into the gas conditioning chamber to cool the calciner exhaust gas via evaporation;
• wherein the calciner exhaust gas in the gas conditioning chamber is maintainable below a threshold temperature at which particles contained in the calciner exhaust gas experience fusion or sintering by adjusting a ratio of oxygen from the oxygen supply to carbon dioxide from the carbon dioxide supply.

A calcination system for lime-bearing sludge, comprising:

• an impact mill dryer arranged to receive the lime-bearing sludge and disperse the lime-bearing sludge into dried lime-bearing sludge solids for mixing with a transportation gas;
• a cyclone coupled to the mill to receive the dried lime-bearing sludge solids and the transportation gas to at least partially separate the dried lime-bearing sludge solids from the transportation gas and form a gas of primarily carbon dioxide as a product;
• a lime mud feeder coupled to the cyclone to receive the dried lime-bearing sludge solids from the cyclone;
• a calciner coupled to the lime mud feeder to receive the dried lime-bearing sludge solids from the lime mud feeder to calcinate in a chamber containing a percentage of oxygen greater than atmospheric air, the calciner being at least partially sealed from atmospheric air and having a hydrocarbon fuel supply coupled to the calciner;
• a gas conditioning chamber sealed from air intrusion and arranged to receive calciner exhaust gas from the calciner and add heat to the calciner exhaust gas;
• an oxygen supply having a majority percentage of oxygen coupled to a burner of the gas conditioning chamber;
• a carbon dioxide supply having a majority percentage of carbon dioxide coupled to the burner of the gas conditioning chamber;
• a hydrocarbon fuel supply coupled to the burner of the gas conditioning chamber;
• and
• at least one water spray to inject water into the gas conditioning chamber to cool the calciner exhaust gas via evaporation;
• wherein the calciner exhaust gas in the gas conditioning chamber is maintainable below a threshold temperature at which particles contained in the calciner exhaust gas experience fusion or sintering by adjusting a ratio of oxygen from the oxygen supply to carbon dioxide from the carbon dioxide supply.