A process comprising the following steps: a) calcination of a metal carbonate by combustion of a fuel in the presence of a mixture of oxygen, water vapour and carbon dioxide, to generate a metal oxide, water vapour, carbon dioxide and heat; b) using the heat generated to drive an oxygen generation reaction; and c) use of the oxygen generated in step b) in calcination step a). The use of the process on carbon dioxide sequestration and/or in oxygen generation.

In various aspects, systems and methods are provided for integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process. The molten carbonate fuel cells can be integrated with a Fischer-Tropsch synthesis process in various manners, including providing synthesis gas for use in producing hydrocarbonaceous carbons. Additionally, integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process can facilitate further processing of vent streams or secondary product streams generated during the synthesis process.

In various aspects, systems and methods are provided for integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process. The molten carbonate fuel cells can be integrated with a Fischer-Tropsch synthesis process in various manners, including providing synthesis gas for use in producing hydrocarbonaceous carbons. Additionally, integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process can facilitate further processing of vent streams or secondary product streams generated during the synthesis process.

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.

Reaction schemes involving acids and bases; reactors comprising spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and associated systems and methods, are generally described.

Reaction schemes involving acids and bases; reactors comprising spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and associated systems and methods, are generally described. For example, methods comprising producing an acid and a base via electrolysis; dissolving a material comprising calcium using the acid to produce ions comprising calcium in a region of a reactor with a pH of 6 or less; precipitating solid calcium hydroxide from the ions comprising calcium using the base in a region of a reactor with a pH of 10 or higher; and utilizing the calcium hydroxide in a downstream process to form a cement are described.

A method and device for the combined manufacturing of cement clinker and calcined clay, in a cement manufacturing line by the steps: providing, preheating and precalcining a cement raw meal in a preheater and calciner section, sintering the precalcined cement raw meal in a rotary kiln and cooling the resulting cement clinker with a counter current air stream in a clinker cooler, and in a clay manufacturing line by the steps: providing and preheating a clay raw material in a heat exchange section, and calcining the preheated clay raw material suspended in gas in a flash calciner. Hot air from the cooler is divided into a first combustion air stream for sintering the cement raw meal and a second combustion air stream for calcining the clay raw material. Exhaust gas from calcining clay raw material is fed into the calcination of the preheated cement raw meal.

Systems and methods are provided for capturing CO.sub.2 from a combustion source using molten carbonate fuel cells (MCFCs). At least a portion of the anode exhaust can be recycled for use as part of anode input stream. This can allow for a reduction in the amount of fuel cell area required for separating CO.sub.2 from the combustion source exhaust and/or modifications in how the fuel cells can be operated.

A cement clinker manufacturing method implemented in a continuous production facility having at least one fuel combustion area for firing an inorganic raw material into hot clinker, then the hot clinker is cooled in: a first cooling step in a first cooler; and a second consecutive cooling step in a second cooler. The first cooling step is continually carried out by blowing an oxygen gas on the hot clinker to obtain partially cooled clinker, and all the heated oxygen gas, created by the first cooler, is sent to the combustion area for use as combustion gas by adjusting the amount of oxygen gas, blown in the first cooler, such as to cover the combustion gas needs of the facility without any excess; and the partially cooled clinker is stored in a storage chamber, and the second cooling step is intermittently carried out on the partially cooled clinker.

Reaction schemes involving acids and bases; reactors comprising spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and associated systems and methods, are generally described. For example, methods comprising producing an acid; dissolving a material comprising calcium in the acid to produce calcium ions; treating the calcium ions to produce solid calcium hydroxide and/or calcium oxide; and utilizing the solid calcium hydroxide and/or calcium oxide in a downstream process to produce a cement, wherein the downstream process comprises heating the solid calcium hydroxide and/or calcium oxide in a kiln are described.