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 cement production system includes a wellbore extending from a surface into an underground magma reservoir. The wellbore is configured to heat a heat transfer fluid via heat transfer with the underground magma reservoir. Processes for cement production are driven at least in part by energy obtained from the underground magma reservoir.

A method for controlling an NOx concentration in an exhaust gas in a combustion facility by: measuring a reaction velocity k.sub.i of each of a plurality of chars, each corresponding to a plurality of types of pulverized coals; determining a relationship between the NOx concentration in the exhaust gas and the reaction velocity k.sub.i for each of the chars; (iii) blending the plurality of the types of the pulverized coal, wherein a blending ratio of the plurality of the types of the pulverized coal is determined by using, as an index, a reaction velocity k.sub.blend of the char of the blended pulverized coal, which corresponds to a target NOx concentration or below, on the basis of the relationship; and supplying the blended pulverized coal to the combustion facility as the fuel of the combustion facility.

A method for controlling an NOx concentration in an exhaust gas in a combustion facility by: measuring a reaction velocity k.sub.i of each of a plurality of chars, each corresponding to a plurality of types of pulverized coals; determining a relationship between the NOx concentration in the exhaust gas and the reaction velocity k.sub.i for each of the chars; (iii) blending the plurality of the types of the pulverized coal, wherein a blending ratio of the plurality of the types of the pulverized coal is determined by using, as an index, a reaction velocity k.sub.blend of the char of the blended pulverized coal, which corresponds to a target NOx concentration or below, on the basis of the relationship; and supplying the blended pulverized coal to the combustion facility as the fuel of the combustion facility.

High temperature furnaces, calcining, pyrolysis and other high temperature manufacturing processes, composition rearrangements, and equipment. Systems, equipment and processes using oxyfuel combustion using gaseous fuels for cement manufacture. Reactor furnaces using oxyfuel containing natural gas and gravity feed to process pellets forming a pellet bed into cement.

It is a production method of cement clinker comprising a calcination step of calcinating cement clinker powder raw material injected in a calcination kiln, with a kiln burner using a thermal energy source comprising gas fuel, wherein the used amount of gas fuel in the thermal energy source to be used in the kiln burner is adjusted so that the temperature of the kiln burner is lower that its heat resistant temperature.

Numerous examples of a vertical kiln for manufacturing cement are disclosed. In one example, a vertical kiln comprises a housing comprising a top opening to receive unprocessed material and a bottom opening to output processed material; a combustion system to heat the unprocessed material within the housing to generate the processed material; a thermocouple located within the housing to measure temperature; and a control system to control the combustion system in response to temperature data from the thermocouple.

The present invention concerns an apparatus and a method for manufacturing a product from a raw material. The apparatus comprises a rotary kiln having a first rotary kiln end and a second rotary kiln end, and a cooling unit which is connected to the second rotary kiln end, wherein a process direction is provided leading through the rotary kiln from the first rotary kiln end to the second rotary kiln end and further through the cooling unit, wherein the cooling unit is configured to transport the product in the process direction through the cooling unit for cooling the product, the rotary kiln comprising a burning unit at the second rotary kiln end, the burning unit being configured to receive a flammable material and an ignition gas to create heat inside the rotary kiln and to produce a combustion gas containing carbon dioxide, the rotary kiln being configured to transport raw material received at the first rotary kiln end in the process direction towards the second rotary kiln end, and, by using the heat, to transform the raw material into the product and into a resigning gas comprising carbon dioxide, characterized in that the apparatus comprises a gas outlet configured to remove an exhaust gas comprising the resigning gas and the combustion gas from the rotary kiln, and that the cooling unit is configured to transport a cooling gas in the process direction over the product.

A calcination and cement production apparatus comprising a calciner configured to be heated by combustion of a carbon based fuel and a hydrogen peroxide oxidant composition is disclosed.

Providing an implementable renewable fuel gas plant processes with management of greenhouse gases with minimal changes to existing plant set ups is a technical challenge to be addressed. Embodiments herein provide a system for renewable fuel gas generation and utilization in industrial plants with carbon dioxide as heat carrier. The system design integrates renewable fuel gas (H.sub.2) which is generated within the system and utilized to meet the thermal energy requirements of the production process. CO.sub.2 produced as byproduct of calcination in a process equipment, such as during calcination in cement plant is used as a heat-transferring medium to heat the H.sub.2. Further, the system provides recycling of the generated byproducts by separating the exhaust gases, comprised of CO.sub.2 and H.sub.2O. The H.sub.2O is recycled to generate H.sub.2 via electrolysis. The separated CO.sub.2 again serves as a heat-transferring medium, while the excess CO.sub.2 is sequestrated.