The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

Oxycombustion process wherein low ranking, gaseous, liquid, solid, optionally solid melting hydrocarbon fractions are used as fuels, having a vanadium content in an amount by weight from 50 to 5,000 ppm or higher, for producing energy, wherein magnesium is added as oxide, or as a water-soluble salt, the combustor being refractored and isotherm or quasi isotherm, flameless, working at temperatures comprised between 1,250 C. and 1,450 C. and under pressurized conditions, wherein the oxidant is oxygen, the oxidant being used in admixture with water or steam such that the ratio by moles oxidant:(water-steam) is comprised between about 1:0.4 and about 1:3 or the oxidant is used in admixture with flue gases recycled from the flue gases outletting the energy recovery equipments, wherein the water amount is higher than 30% by volume, optionally by adding water, the molar ratio oxidant:(water/steam) in flue gases being comprised from about 1:0.4 to about 1:3; the low ranking hydrocarbon fraction containing vanadium is fed in admixture with water or steam, such that the amount of water/steam in the mixture is at least 30% by weight with respect to the hydrocarbon fraction.

Oxycombustion process for producing energy wherein low ranking gaseous, liquid, solid, optionally solid melting hydrocarbon fractions are used as fuels, having a vanadium content in amounts by weight from 50 to 5,000 ppm or higher, and alkaline metals Ma in amounts from 20 to 10,000 ppm, wherein magnesium is added as oxide, or as a magnesium compound forming MgO in the combustion process, or mixtures thereof and a silico-aluminate wherein the molar ratio SiO.sub.2:Al.sub.2O.sub.3 ranges from 2:1 to 6:1; the combustor being refractored, isotherm or quasi-isotherm, flameless, working at temperatures in the range 1,250-1,450 C. and under pressurized conditions, wherein the oxidant being used in admixture with water or steam, the ratio by moles oxidant:(water/steam) being comprised between about 1:0.4 and about 1:3, or the oxidant is used in admixture with flue gases recycled from the flue gases outletting the energy recovery equipments, wherein the water/steam amount is higher than 30% by volume, optionally by adding water to the recycled flue gases, the molar ratio oxidant:(water/steam) in flue gases being comprised from about 1:0.4 to about 1:3; the hydrocarbon fraction being fed in admixture with water or steam, the amount of water/steam being at least 30% by weight with respect to the hydrocarbon fraction.

The invention relates to particular burners, and e.g. to a burner comprising a central main fuel lance, a pilot fuel conduit, a main oxidant conduit, an auxiliary oxidant conduit, and optionally a secondary fuel conduit, which are arranged in a particular and advantageous way to surround each other at least in their downstream sections. The invention further relates to furnaces including the burners and methods of operating the burners. Among others, the burners of the present invention allow a particularly advantageous way of including a pilot burner as an integral part of the main burner to ignite liquid fuel flame in a cold furnace. If required, the pilot flame can assist in extending the flammability limit or operating range of the liquid fuel burner.

A combustion system for operational connection to an energy conversion system and a method of providing thermal energy to the energy conversion system. The system comprises a combustor to be oxy-fired at above atmospheric pressure, using solid, liquid or gaseous fuels, with a supply of oxygen and supercritical carbon dioxide. The combustion gases from the combustor are delivered to a heat exchanger which interfaces with the energy conversion system. Temperatures in the combustor, and the delivery temperature to the heat exchanger, are controlled by selective recirculation of at least part of the combustion gases to the combustor, and by modulating the supply of oxygen and fuel to the combustor. Any combustion gases which are not recirculated are processed to separate carbon dioxide for use or sequestration. The system and method substantially eliminate emissions of carbon dioxide, while providing a highly efficient supply of thermal energy to the energy conversion system.

The present disclosure relates to systems and methods that are useful for controlling one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants and methods of carrying out a power production method utilizing different fuel chemistries. Combustion of the different fuel mixtures can be controlled so that a defined set of combustion characteristics remains substantially constant across a range of different fuel chemistries.

The present disclosure relates to systems and methods that are useful for controlling one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants and methods of carrying out a power production method utilizing different fuel chemistries. Combustion of the different fuel mixtures can be controlled so that a defined set of combustion characteristics remains substantially constant across a range of different fuel chemistries.

Systems and methods for operating a heating device are disclosed. An oxygen containing stream is first processed to produce an oxygen stream that comprises more than 25 vol. % oxygen. The oxygen stream is then mixed with an air stream to produce a combustion gas stream comprising 21.5 to 27 vol. % oxygen. A fuel is combusted in the combustion gas stream to provide heat for a heating device.