In a method for supplying oxygen-enriched gas to an oxygen consuming process, in which the oxygen-enriched gas with a low nitrogen content is generated by supplying an anode-side feed gas comprising CO.sub.2 to the anode side of a solid oxide electrolysis cell, oxygen is generated on the anode side of the solid oxide electrolysis cell. This way, an anode-side product gas is formed, in which the oxygen-enriched gas comprises at least a part. The oxygen-enriched gas has a low nitrogen content, and the temperature of the oxygen-enriched gas exiting the solid oxide electrolysis cell is between 600 and 1000° C. The method has multiple advantages, first of all as regards energy saving.

Provided herein are compositions, methods, and systems related to cement blend composition comprising reactive vaterite cement and supplementary cementitious material (SCM) comprising aluminosilicate material.

Provided herein are compositions, methods, and systems related to cement blend composition comprising reactive vaterite cement and supplementary cementitious material (SCM) comprising aluminosilicate material.

A method for reducing combustion temperature and/or thermal radiation within a lime kiln of a pulp production plant, which kiln is a rotary kiln having a kiln tube (1) internally covered with refractory tiles (13) and having a burner (2) supplied by fuel for heating of the rotary kiln by a flame (3). The effects are achieved by supplying calcium carbonate containing particles to the flame (3) and/or to surrounding area around the flame (3). The particles are supplied into the rotary kiln by at least one lance (9) to the upper part of the flame (3). Calcium oxide containing particles may be supplied to the rotary kiln to areas surrounding the flame (3) for reducing the thermal radiation to an area over the flame (3) and/or to the area at the side of the flame (3), where the refractory tiles (13) of the kiln are rotating downwards.

A method for reducing combustion temperature and/or thermal radiation within a lime kiln of a pulp production plant, which kiln is a rotary kiln having a kiln tube (1) internally covered with refractory tiles (13) and having a burner (2) supplied by fuel for heating of the rotary kiln by a flame (3). The effects are achieved by supplying calcium carbonate containing particles to the flame (3) and/or to surrounding area around the flame (3). The particles are supplied into the rotary kiln by at least one lance (9) to the upper part of the flame (3). Calcium oxide containing particles may be supplied to the rotary kiln to areas surrounding the flame (3) for reducing the thermal radiation to an area over the flame (3) and/or to the area at the side of the flame (3), where the refractory tiles (13) of the kiln are rotating downwards.

Method of operating a long direct-fired inclined counterflow rotary kiln for the thermal treatment of material and counterflow rotary kiln adapted for same, whereby material to be treated is introduced into the kiln at the inlet end and treated material is evacuated from the kiln at the outlet end, whereby a main combustion zone extends inside the kiln over a distance of ¼ to ⅓ of the internal length L.sub.int of the kiln, whereby a supplementary combustion zone in which supplementary combustion takes place with an oxygen-rich oxidant extends inside the kiln over a distance from the inlet end of at most ¼ of the internal length L.sub.int, and whereby no combustion takes place in a heat exchange zone located between the main combustion zone and the supplementary combustion zone.

Embodiments described herein relate to capturing and sequestering CO.sub.2 emissions from the cement production process with the potential to produce carbon-negative cement. Methods described herein can include contacting calcium oxide (CaO) with ambient air at a carbonation station to form a first stream of calcium carbonate, combining the first stream of calcium carbonate with a second stream of calcium carbonate in a calciner to form a combined stream of calcium carbonate, and applying heat to the calciner to decompose the combined stream of calcium carbonate into a stream of calcium oxide and a CO.sub.2 stream. The method further includes sequestering the CO.sub.2 stream, dividing the stream of calcium oxide into a first calcium oxide stream and a second calcium oxide stream, feeding the first stream of calcium oxide to the carbonation station, and feeding the second stream of calcium oxide to a kiln to produce a clinker.

Systems and methods for impurity removal to limestone using modifications to the typical calcination process of turning calcium carbonate into calcium oxide. Specifically, substantially increasing the temperature to 1100° C. or higher and increasing soak time can result in reductions in certain undesirable impurities, particularly with regards to lead and lead compounds.

Systems and methods for impurity removal to limestone using modifications to the typical calcination process of turning calcium carbonate into calcium oxide. Specifically, substantially increasing the temperature to 1100° C. or higher and increasing soak time can result in reductions in certain undesirable impurities, particularly with regards to lead and lead compounds.

This invention relates to manufacturing briquettes, pellets and shapes from recycled asphaltic limestone powder derived from waste residential roofing products. Briquettes and pellets are manufactured through a densification process at varying temperatures, creating recycled asphalt pellets, asphalt limestone pellets and bio mass and coal fines briquettes. Various shapes, including curbs and posts, are manufactured through heat and pressure in molds. Seawalls, walkways and wall panels are manufactured by blending asphaltic limestone powders with polymer resins and extruded or pultruded into shapes.