Process and apparatus is disclosed for providing a chemical reaction between calcium oxide containing grit particles to produce calcium hydroxide and heat, capturing the heat of hydration and using it to preheat water initially at ambient temperature, to rise to an elevated temperature to increase the amount of lime present in the water to a supersaturated lime suspension level, with the chemical reaction running to completion, followed by cooling. Heat from a water jacket may be used to raise the temperature in the lime slaker.

Process and apparatus is disclosed for providing a chemical reaction between calcium oxide containing grit particles to produce calcium hydroxide and heat, capturing the heat of hydration and using it to preheat water initially at ambient temperature, to rise to an elevated temperature to increase the amount of lime present in the water to a supersaturated lime suspension level, with the chemical reaction running to completion, followed by cooling. Heat from a water jacket may be used to raise the temperature in the lime slaker.

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.

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.

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.

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 chemical processing method includes decomposing a metal carbonate in a first tube by exposure to a first quantity of heat, producing a metal oxide and carbon dioxide; and hydrating the metal oxide in a second tube concentric with the first, by exposure to steam, producing a metal hydroxide and a second quantity of heat. The partial pressure of the steam and/or of the carbon dioxide is controlled so that the hydration reaction occurs at a second temperature above a first temperature at which the decomposition reaction occurs. The inner one of the concentric tubes has an inner tube wall. At least some of the second quantity of heat flows from the second tube through the inner tube wall to the first tube, providing at least a part of the first quantity of heat.

A chemical processing method includes decomposing a metal carbonate in a first tube by exposure to a first quantity of heat, producing a metal oxide and carbon dioxide; and hydrating the metal oxide in a second tube concentric with the first, by exposure to steam, producing a metal hydroxide and a second quantity of heat. The partial pressure of the steam and/or of the carbon dioxide is controlled so that the hydration reaction occurs at a second temperature above a first temperature at which the decomposition reaction occurs. The inner one of the concentric tubes has an inner tube wall. At least some of the second quantity of heat flows from the second tube through the inner tube wall to the first tube, providing at least a part of the first quantity of heat.