Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Process and device for pneumatically conveying a powdery material comprising the steps of Pneumatically conveying a powdery material in a pneumatic conveying pipeline (first) and into said recipient by a flow generated by a blower, A powdery material dosing step, A fluctuation step of pressure drop in said pneumatic conveying pipeline or up to said recipient,
wherein a sonic device generates sonic waves inside said pneumatic conveying pipeline or up to said recipient and provides a counteraction on the fluctuation step of the pressure drop in said pneumatic conveying pipeline or up to said recipient.

Process and device for pneumatically conveying a powdery material comprising the steps of Pneumatically conveying a powdery material in a pneumatic conveying pipeline (first) and into said recipient by a flow generated by a blower, A powdery material dosing step, A fluctuation step of pressure drop in said pneumatic conveying pipeline or up to said recipient,
wherein a sonic device generates sonic waves inside said pneumatic conveying pipeline or up to said recipient and provides a counteraction on the fluctuation step of the pressure drop in said pneumatic conveying pipeline or up to said recipient.

Mineral additive blend compositions and a method for operating a furnace are provided in order to avoid combustion problems such as agglomeration, deposition, corrosion and reducing emissions. A method for operating a furnace, such as a fluidized-bed reactor, pulverized-fuel combustor, and grate combustor, includes introducing fuel and a mineral additive blend including a clay and a functional mineral into the furnace.

Mineral additive blend compositions and a method for operating a furnace are provided in order to avoid combustion problems such as agglomeration, deposition, corrosion and reducing emissions. A method for operating a furnace, such as a fluidized-bed reactor, pulverized-fuel combustor, and grate combustor, includes introducing fuel and a mineral additive blend including a clay and a functional mineral into the furnace.

Disclosed is a desulfurization system using a catalyst for desulfurization, including a coal feed unit for conveying a combustible substance, a spray unit for spraying a catalyst for desulfurization, a coal pulverization unit for pulverizing the combustible substance conveyed from the coal feed unit, and a combustion unit for combusting the pulverized combustible substance, wherein during transfer of the combustible substance from the coal feed unit to the coal pulverization unit, the catalyst for desulfurization is sprayed using the spray unit and is mixed with the combustible substance. The desulfurization system of the invention can be simply and easily applied to various combustion facilities because, during the transfer of the combustible substance from the coal feed unit to the coal pulverization unit, the catalyst for desulfurization is sprayed and is mixed with the combustible substance, thereby efficiently reducing sulfur oxide (SO.sub.x) emission due to combustion of fossil fuel.

Disclosed is a desulfurization system using a catalyst for desulfurization, including a coal feed unit for conveying a combustible substance, a spray unit for spraying a catalyst for desulfurization, a coal pulverization unit for pulverizing the combustible substance conveyed from the coal feed unit, and a combustion unit for combusting the pulverized combustible substance, wherein during transfer of the combustible substance from the coal feed unit to the coal pulverization unit, the catalyst for desulfurization is sprayed using the spray unit and is mixed with the combustible substance. The desulfurization system of the invention can be simply and easily applied to various combustion facilities because, during the transfer of the combustible substance from the coal feed unit to the coal pulverization unit, the catalyst for desulfurization is sprayed and is mixed with the combustible substance, thereby efficiently reducing sulfur oxide (SO.sub.x) emission due to combustion of fossil fuel.

A boiler performs mixed-fuel combustion of a sulfur-containing fuel and ammonia as a fuel, and includes a furnace having a plurality of wall parts, a burner installed on at least one of the wall parts of the furnace, and an ammonia injection port that is configured to cause the ammonia to be burned as the fuel to flow along an inner wall surface of the wall part where the burner is not installed.

A boiler performs mixed-fuel combustion of a sulfur-containing fuel and ammonia as a fuel, and includes a furnace having a plurality of wall parts, a burner installed on at least one of the wall parts of the furnace, and an ammonia injection port that is configured to cause the ammonia to be burned as the fuel to flow along an inner wall surface of the wall part where the burner is not installed.

A combustion device is installed in a furnace, is configured to inject and burn ammonia as a fuel, and includes an inner tube nozzle disposed in a center part of the combustion device when viewed in an injection direction of the fuel, and configured to inject the ammonia, and an outer tube nozzle disposed to surround the inner tube nozzle from outside in a radial direction when viewed in the injection direction of the fuel, and configured to inject the ammonia around the inner tube nozzle.