A system for digesting biodigestible feed that preferably includes the steps of comminuting the feed, introducing feed, an oxygen-containing gas, an accelerant, and bacteria into a digestion zone, the bacteria being suitable for digesting the feed under aerobic, anaerobic, and anoxic conditions. The contents of the digestion zone can be changed from aerobic operation to either anoxic or anaerobic operation, or vice versa, without changing the bacteria in the digestion zone.

Various techniques are described for enhanced combustion of hot water extraction (HWE) derived liquor. For example, the HWE derived liquor can be pre-treated prior to introduction into a combustion chamber. The pre-treatment can include subjecting HWE derived liquor to filtration to remove suspended solids, evaporation to produce a first stage concentrated HWE liquor; additional concentration to produce a second stage concentrated HWE liquor; additional filtration to remove additional suspended solids; and pre-heating to produce a preheated HWE liquor. The preheated HWE liquor can be atomized and combined with pre-heated combustion air supplied into a combustion chamber to effect combustion of the HWE derived liquor.

Oxycombustion process wherein a combustor is fed with a fuel, a comburent and compounds under the form of coherent aggregates having Young modulus 10.sup.4 MPa, the combustor being isothermal and flameless.

Various techniques are described for enhanced combustion of hot water extraction (HWE) derived liquor. For example, the HWE derived liquor can be pre-treated prior to introduction into a combustion chamber. The pre-treatment can include subjecting HWE derived liquor to filtration to remove suspended solids, evaporation to produce a first stage concentrated HWE liquor; additional concentration to produce a second stage concentrated HWE liquor; additional filtration to remove additional suspended solids; and pre-heating to produce a preheated HWE liquor. The preheated HWE liquor can be atomized and combined with pre-heated combustion air supplied into a combustion chamber to effect combustion of the HWE derived liquor.

Problem to be Solved To provide a waste gasification melting apparatus which, even if a fuel gas is used as an alternative to a part of the coke, the temperature of the coke bed can be sufficiently raised, and a method using the same. Solution A waste gasification melting apparatus including an oxygen rich air supply apparatus 14 for blowing oxygen rich air into a tuyere 5, and a fuel gas supply apparatus 15 for supplying a fuel gas to the tuyere 5, and a controller 16 for controlling the oxygen rich air supply apparatus 14; the oxygen rich air supply apparatus 14 mixing air and oxygen to prepare oxygen rich air and supply the oxygen rich air to the tuyere 5; and the controller 16 controlling the amount of air to be mixed and the amount of oxygen to be mixed in the oxygen rich air supply apparatus 14 so as to give an oxygen concentration of the oxygen rich air in accordance with the amount of fuel gas supplied to the tuyere 5 from the fuel gas supply apparatus 15.

A method to thermally convert alternative fuels within a loop seal reactor by utilizing preheated/calcined cement meal as the heat source within which alternative fuels are immersed, subjected to drying, pyrolysis and subsequently charred, and an apparatus utilized to practice such method.

A waste-to-energy conversion apparatus comprising a primary combustion chamber capable of holding a load of waste, and the primary combustion chamber further comprises a heat source to heat the waste and generate a syn gas stream, grates, within the primary chamber, capable of supporting the load of waste during heating, a mixing chamber wherein the syn gas is mixed with additional combustion gas, a multi-chambered secondary combustion chamber for combusting the mixture of syn gas and additional combustion gas, and an energy extraction system for extracting the heat energy generated by the combustion of the mixture of syn gas and additional combustion gas.

A process for the remediation of contaminated particulate materials by the addition of an environmentally benign, carbonaceous fuel source in low concentration to enable or enhance smoldering combustion. The process may be applied to both in situ and ex situ treatments. In an ex situ smoldering process for the remediation of contaminated particulate materials in a continuous manner, contaminated feed is introduced near the top of a treatment unit and treated product emerges near the bottom. A smoldering front is maintained in the unit, fed by the fuel in the contaminated particulate material and a supply of combustion-supporting gas, such as air.

A method and system for cost effectively converting a feedstock using thermal plasma, or other styles of gassifiers, into a feedwater energy transfer system. The feedstock can be any organic material, or fossil fuel. The energy transferred in the feedwater is converted into steam which is then injected into the low turbine of a combined cycle power plant. Heat is extracted from gas product issued by a gassifier and delivered to a power plant via its feedwater system. The gassifier is a plasma gassifier and the gas product is syngas. In a further embodiment, prior to performing the step of extracting heat energy, there is provided the further step of combusting the syngas in an afterburner. An air flow, and/or EGR flow is provided to the afterburner at a rate that is varied in response to an operating characteristic of the afterburner. The air flow to the afterburner is heated.

A process for the remediation of contaminated particulate materials by the addition of an environmentally benign, carbonaceous fuel source in low concentration to enable or enhance smoldering combustion. The process may be applied to both in situ and ex situ treatments. In an ex situ smoldering process for the remediation of contaminated particulate materials in a continuous manner, contaminated feed is introduced near the top of a treatment unit and treated product emerges near the bottom. A smoldering front is maintained in the unit, fed by the fuel in the contaminated particulate material and a supply of combustion-supporting gas, such as air.