To treat organic sludge while keeping facility costs, cement production efficiency, and a reduction in clinker production amount to a minimum. An organic sludge treatment device includes: a fractionation device 7 that fractionates a preheated raw material R2 from a preheater cyclone 4C excluding a bottommost cyclone of a cement burning device 1; a mixing device 8 that mixes an organic sludge S with the fractionated preheated raw material, and that dries the organic sludge using sensible heat of the preheated raw material; and a supply device (mixture chute 12, double-flap damper 13, shut damper 14) that supplies a mixture M from the mixing device to a calciner furnace 5 of the cement burning device or to a duct disposed between a kiln inlet portion of a cement kiln 2 and the calciner furnace. The treatment device may be provided with an introduction device for introducing an exhaust gas G2 including dust, odor and water vapor from the mixing device to a gas outlet of a bottommost cyclone 4A of the cement burning device.

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.

A rotary kiln includes a stationary fuel nozzle and a perforated flame holder positioned within an inclined rotating shell. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder to shift most heat transfer from the combustion reaction from radiation heat transfer to convective heat transfer.

A fuel made from co-products derived from a lignocellulosic biomass fermentation process is used to fuel a cement production process. Filter cake and syrup co-products are mixed and dried, then burned in a cement kiln to create the temperatures needed for cement production.

To treat organic sludge while keeping facility costs, cement production efficiency, and a reduction in clinker production amount to a minimum. An organic sludge treatment device includes: a fractionation device 7 that fractionates a preheated raw material R2 from a preheater cyclone 4C excluding a bottommost cyclone of a cement burning device 1; a mixing device 8 that mixes an organic sludge S with the fractionated preheated raw material, and that dries the organic sludge using sensible heat of the preheated raw material; and a supply device (mixture chute 12, double-flap damper 13, shut damper 14) that supplies a mixture M from the mixing device to a calciner furnace 5 of the cement burning device or to a duct disposed between a kiln inlet portion of a cement kiln 2 and the calciner furnace. The treatment device may be provided with an introduction device for introducing an exhaust gas G2 including dust, odor and water vapor from the mixing device to a gas outlet of a bottommost cyclone 4A of the cement burning device.

Method of operating a rotary furnace for the production of hydraulic binder so as to reduce ring formation therein, whereby the longitudinal temperature profile in the furnace is varied during furnace operation by injecting at least one fluid other than the main fuel(s), the primary oxidizer and hot air from the material cooler with at least one continuously or discontinuously varying injection parameter.

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 to 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 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.

The present invention relates to a process and apparatus for improving the combustion of a secondary fuel supplied in a first stream in a rotary kiln, wherein the rotary kiln has a burner assembly comprising a main burner and a plurality of feed channels for various media, of which one is designed for the supply of a secondary fuel, in particular in the form of particles or shreds in a stream of compressed air. According to the invention, a tubular oxygen lance for an oxygen-rich gas, in particular, technical grade gaseous oxygen, or an oxygen-rich liquid, in particular, technical grade liquid oxygen, with an angled nozzle at its end, is arranged in or on a feed channel of the burner assembly, whereby the oxygen lance is brought into such a position that the oxygen emerging from a nozzle forms a second stream that strikes a first stream of secondary fuel. The present invention may be considered for new constructions of burner assemblies for rotary kilns, but mainly serves for retrofitting existing burner assemblies in which mostly feed channels are available as required for inserting an oxygen lance in the present invention. Targeted delivery of gaseous or liquid oxygen, or oxygen-enriched gas or liquefied gas to a secondary fuel can significantly improve the combustion process and consequently significantly reduce exhaust emissions, in particular, the emission of carbon monoxide.

A Portland cement production (PCP) process is conjoined with a waste-to-energy (WTE) process using refuse-derived fuels (RDFs). Both processes operate simultaneously to reduce harmful compounds being discharged into the environment. The PCP and WTE processes are conjoined by borrowing a minor portion of pre-heated comminuted limestone from a PCP process feedstream and diverting it to the WTE process. Some of the pre-heated comminuted limestone is converted to CaO. The calcium compounds from the pre-heated comminuted limestone act as a fluxing agents and sorbents to bind with and remove undesired impurities, such as elemental particulate matter, excess CO.sub.2 and acid gasses associated with sulfur and chlorine that are released during the pyrolization of RDFs. The ash, char waste and reacted calcium compounds from the pyrolization process can be comingled and returned to the PCP process as a secondary cement meal feedstock.