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.

A process for calcining a feed material can include passing a solid particulate material through a burner or adjacent a burner for being pass through a flame formed by the burner to facilitate calcination of the material. The material can be emitted from the flame of the burner within a calciner for passing through a body of the calciner to an outlet for further calcination of the material so the material has a pre-selected residence time as it is passed through the flame and calciner to an outlet. The residence time can be 20 seconds to 30 seconds, 1-3 minutes, less than 5 minutes in some embodiments. Some embodiments can facilitate calcination of a CaCO.sub.3 material so the calcined solid material output from a calciner is comprised of Ca(OH).sub.2 (e.g. is mostly Ca(OH).sub.2, is over 90 weight percent Ca(OH).sub.2, etc.).

A process for calcining a feed material can include passing a solid particulate material through a burner or adjacent a burner for being pass through a flame formed by the burner to facilitate calcination of the material. The material can be emitted from the flame of the burner within a calciner for passing through a body of the calciner to an outlet for further calcination of the material so the material has a pre-selected residence time as it is passed through the flame and calciner to an outlet. The residence time can be 20 seconds to 30 seconds, 1-3 minutes, less than 5 minutes in some embodiments. Some embodiments can facilitate calcination of a CaCO.sub.3 material so the calcined solid material output from a calciner is comprised of Ca(OH).sub.2 (e.g. is mostly Ca(OH).sub.2, is over 90 weight percent Ca(OH).sub.2, etc.).

An apparatus includes a fluidized bed vessel with inlet ports arranged to receive at least one feed stream comprising calcium oxide, calcium carbonate, water, and a fluidizing gas into a fluidized bed vessel. The calcium oxide contacts the water to initiate a hydrating reaction to produce calcium hydroxide and heat. The fluidized bed vessel is configured to operate with a fluidization velocity that fluidizes and separates at least a portion of the calcium carbonate and at least a portion of the calcium oxide into a first fluidization regime, and at least a portion of the calcium hydroxide and at least another portion of the calcium oxide into a second fluidization regime. The apparatus further includes a heat transfer assembly configured to transfer heat of the hydrating reaction to the calcium carbonate, and a cyclone configured to separate a portion of the fluidization gas from a portion of at least one of the calcium hydroxide, calcium carbonate or calcium oxide.

An apparatus includes a fluidized bed vessel with inlet ports arranged to receive at least one feed stream comprising calcium oxide, calcium carbonate, water, and a fluidizing gas into a fluidized bed vessel. The calcium oxide contacts the water to initiate a hydrating reaction to produce calcium hydroxide and heat. The fluidized bed vessel is configured to operate with a fluidization velocity that fluidizes and separates at least a portion of the calcium carbonate and at least a portion of the calcium oxide into a first fluidization regime, and at least a portion of the calcium hydroxide and at least another portion of the calcium oxide into a second fluidization regime. The apparatus further includes a heat transfer assembly configured to transfer heat of the hydrating reaction to the calcium carbonate, and a cyclone configured to separate a portion of the fluidization gas from a portion of at least one of the calcium hydroxide, calcium carbonate or calcium oxide.

Process for manufacturing a milk of lime of great fineness comprising at least the steps of providing one lime compound and forming said milk of lime with a process water and said lime compound.

Process for manufacturing a milk of lime of great fineness comprising at least the steps of providing one lime compound and forming said milk of lime with a process water and said lime compound.

A method includes transferring at least one feed stream including calcium oxide, calcium carbonate, water, and a fluidizing gas into a fluidized bed; contacting the calcium oxide with the water; based on contacting the calcium oxide with the water, initiating a hydrating reaction; producing, from the hydrating reaction, calcium hydroxide and heat; transferring a portion of the heat of the hydrating reaction to the calcium carbonate; and fluidizing the calcium oxide, calcium hydroxide, and the calcium carbonate into a first fluidization regime and a second fluidization regime. The first fluidization regime includes at least a portion of the calcium carbonate and at least a portion of the calcium oxide, and the second fluidization regime includes at least a portion of the calcium hydroxide and at least another portion of the calcium oxide. The first fluidization regime is different than the second fluidization regime.

A method includes transferring at least one feed stream including calcium oxide, calcium carbonate, water, and a fluidizing gas into a fluidized bed; contacting the calcium oxide with the water; based on contacting the calcium oxide with the water, initiating a hydrating reaction; producing, from the hydrating reaction, calcium hydroxide and heat; transferring a portion of the heat of the hydrating reaction to the calcium carbonate; and fluidizing the calcium oxide, calcium hydroxide, and the calcium carbonate into a first fluidization regime and a second fluidization regime. The first fluidization regime includes at least a portion of the calcium carbonate and at least a portion of the calcium oxide, and the second fluidization regime includes at least a portion of the calcium hydroxide and at least another portion of the calcium oxide. The first fluidization regime is different than the second fluidization regime.