A method in which a parent hydrocarbon-rich material is processed so as to produce both a carbon-rich solid material that has a higher carbon to hydrogen ratio than that of the parent material and a carbon-deficient combustible gas that has a lower carbon to hydrogen ratio than the parent material. In the process, the material is activated by exposing it to a hot gas stream having elevated levels of one or both of carbon dioxide and water vapor. The combustible gas is combusted to produce heat. At least about 80% of the heat is used in one ore more endothermic steps that include drying coal or biomass.

A method in which a parent hydrocarbon-rich material is processed so as to produce both a carbon-rich solid material that has a higher carbon to hydrogen ratio than that of the parent material and a carbon-deficient combustible gas that has a lower carbon to hydrogen ratio than the parent material. In the process, the material is activated by exposing it to a hot gas stream having elevated levels of one or both of carbon dioxide and water vapor. The combustible gas is combusted to produce heat. At least about 80% of the heat is used in one ore more endothermic steps that include drying coal or biomass.

A method in which a parent hydrocarbon-rich material is processed so as to produce both a carbon-rich solid material that has a higher carbon to hydrogen ratio than that of the parent material and a carbon-deficient combustible gas that has a lower carbon to hydrogen ratio than the parent material. In the process, the material is activated by exposing it to a hot gas stream having elevated levels of one or both of carbon dioxide and water vapor. The combustible gas is combusted to produce heat. At least about 80% of the heat is used in one ore more endothermic steps that include drying coal or biomass.

Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.

Provided is a method for controlling a free lime content of a clinker by regulating the free lime content. Here the amount of sulfur trioxide resulting from fuel and the used amount of a fluorine-based mineralizer are regulated using the following Formulas (1) to (3), thereby controlling the free lime content (f.CaO) of the clinker.
f.CaO=0.29e.sup.(0.65A)(A=aSO.sub.3+b)(1)
a=0.0001F+9.2t0.18HM9.2(2)
b=0.0005F32.8t2.9HM+28.4(3) SO.sub.3 is an amount of sulfur trioxide in the clinker; a is a coefficient satisfying Formula (2); b is a coefficient satisfying Formula (3); F is an amount of fluorine in the clinker; when a burning temperature is X C., t=X/1450; and HM is a hydraulic modulus.

A method for reducing pollution in a cement kiln environment and a system for treating cement kiln exhaust gas are provided. The method includes the steps of: treating a cement kiln exhaust gas stream with a treating fluid, such as a water soluble alkaline-earth metal sulfide. In one application, the treating fluid is injected by spraying droplets into the cement kiln exhaust gas stream. A system for treating cement kiln exhaust gas includes a reagent containing a water soluble alkaline-earth metal sulfide in water, and a nozzle to spray the reagent into the cement kiln exhaust gas stream.

A combustion gas bleeding probe includes a gas pipe for bleeding a part of a combustion gas from a kiln, and a plurality of discharge ports each of which is provided penetrating through the gas pipe and each of which discharges a low-temperature gas in a direction that is perpendicular to a direction of flow of a bleed gas bled by the gas pipe and that is directed toward a center of the flow of the bleed gas. The discharge ports discharge the low-temperature gas such that a ratio of a momentum of the low-temperature gas per discharge port to a momentum of the bleed gas satisfies 1.2 to 4.0, and a value (m1) obtained by dividing a ratio of a wind speed of the low-temperature gas to a wind speed of the bleed gas by an inner diameter of the gas pipe satisfies 1.5 to 3.5.

The invention relates to a method and a system for obtaining a recyclable product from waste minerals by heating the mineral waste in a combustor by combusting waste fuel in a closed loop combustion process and treating the mineral waste with high levels of oxygen and/or carbon dioxide. A mixture of waste minerals for recycling and waste fuel for combustion is supplied to a combustor, also concentrated oxygen and recycled flue gas comprising carbon dioxide is supplied to the combustor for heating the mineral waste in an atmosphere of increased oxygen and carbon dioxide level to obtain a recyclable product from the waste minerals.

A method for denitrification of flue gases and a system, wherein flue gases generated in a rotary kiln are conveyed to a calcining zone for the deacidification of raw cement meal. Aqueous ammonia solution, ammonia, or ammonia-releasing substances for denitrifying the flue gases injected into the calcining zone according to the method of selective non-catalytic reduction (SNCR), and the flue gas stream, together with an ammonia slip generated during the denitrification, is passed through a heat exchanger and through at least one dedusting device. The flue gas is guided through a exhaust gas line via a catalyst for the decomposition of excess ammonia with residues of nitrogen oxide in accordance with a method of selective catalytic reduction (SCR), wherein the catalyst is arranged in a reactor provided in the exhaust line, and is no larger than is required for a sufficient decomposition of the ammonia.

Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.