Abstract: Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving lime in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

Abstract: A system to calcine crushed carbonate, discharge alkaline oxide, and deliver an enhancing fluid having CO2, comprising: a pressurized insulated calciner having descendingly, a crushed alkaline carbonate feeder, a calciner fluid outlet manifold, a heated sideflow calciner fluid intake manifold, a preheated sideflow calciner fluid outtake manifold, a fluid inlet manifold to recirculate calciner fluid from the outlet manifold, and an alkaline oxide discharger; a pressurizer to repressurize sideflow calciner fluid, connected to intake and outtake manifolds; pressurizers to recirculate calciner outlet fluid to the inlet manifold, pressurize the calciner and deliver enhancing fluid comprising CO2; delivery and combustion systems to form a combustion fluid; a recuperating or regenerating refractory heat exchanger to heat sideflow calciner fluid with combustion fluid connected to the sideflow pressurizer, and fluid outtake and intake manifolds; and a controller operable to control combustion, heat exchange, calciner

Abstract: Applying an acid treatment to eggshells provides a sorbent with unexpectedly high CO2 capture capacity and ability to regenerate.

Abstract: An extremely compact, energy efficient air purifier for incinerating volatile organic chemical contaminants, and airborne organic particulates comprises a cylindrical ceramic heat transfer/storage element having many substantially identical axially parallel flow passages with very large surface area per mass, and a rotating guide for guiding the inlet air flow to a preset radial segment of the ceramic element. The air flow exiting from the preset radial segment is directed to the remaining segment in the opposite direction. The air flow exiting from the remaining segment is exhausted from the air purifier. Included is a pre-heater for heating the ceramic element at start up, and maintaining the air flow at a stable incineration temperature.

Abstract: A method for treating produced gypsum and, in particular, a method for treating flue-gas desulfurization gypsum forms highly active, modifiable gypsum binders of high strength with simultaneously drying, deagglomerating and dehydrating. Pursuant to the invention, produced gypsum (flue-gas desulfurization gypsum), with a particle size ranging up to 200 .mu.m, to which 10% by weight of milled natural gypsum is optionally added, is dehydrated at a material temperature of 335.degree. to 363.degree. K. and at a pressure ranging from 2.5 to 8 kpa, the dehydration being concluded when anhydrite III constitutes 50% to 100% by weight.

Abstract: A furnace for producing a melt for mineral wool production includes a shaft for preheating and melting of the raw material. A water-cooled grate is disposed in the bottom portion of the shaft, which supports a bed of ceramic filling bodies as well as the raw material. A combustion chamber is disposed underneath the shaft, which has a bottom portion for collecting the melt dripping from the shaft and an outlet for melt tapping. At least one main burner is disposed in the combustion chamber. Auxiliary burners are disposed above the grate. The bottom surface of the combustion chamber is larger, preferably 20 to 400% larger, than the transverse cross-sectional area of the shaft.

Abstract: Energy conserving limestone calcining system, including a process and apparatus in which in a first step or kiln zone limestone is heated, e.g., at 1700.degree.-2100.degree. F., sufficiently to achieve more than only about 50 or 60%, e.g.