A low emissions modular flare stack includes a plurality of flare stack burner modules, each including a main fuel source configured to selectively deliver a main fuel stream for dilution by a flow of combustion air, a main igniter configured to cause ignition of the main fuel stream emitted from the main fuel source, a distal flame holder configured to hold a combustion reaction supported by the main fuel stream when the distal flame holder is at or above a predetermined temperature, and a pre-heating apparatus configured to pre-heat the distal flame holder to the predetermined temperature. The low emissions modular flare stack includes a common combustion air source configured to provide combustion air to each of the plurality of flare stack burner modules, and a wall encircling all of the plurality of flare stack burner modules, the wall being configured to laterally contain combustion products corresponding to all of the plurality of flare stack burner modules.

Systems and methods for reducing NO.sub.x and CO emissions in a natural draft heater are disclosed. For example, the disclosure provides embodiments of systems and methods for controlling a draft value within a heater shell to deliver an amount of excess air to a burner to thereby maintain at least one of NO.sub.x emissions not exceeding 0.025 lb/MMBtu (HHV) and CO emissions not exceeding 0.01 lb/MMBtu (HHV) in a natural draft heater.

A gas burner for use in low-oxygen environments in which the oxygen concentration is insufficient to ensure complete combustion. The burner includes a central air supply that is annularly surrounded by a gas supply, thereby preventing the fuel from burning out with a delay in places where burn-out is detrimental to a system or plant.

The invention relates to a method for operating a fluidized bed boiler, comprising: a) setting the ratio of secondary oxygen containing gas to primary oxygen containing fluidizing gas to a value ranging from 0.0 to 0.8; b) carrying out the combustion of fuel with a fluidized bed comprising ilmenite particle; and to a fluidized bed boiler.

The invention relates to a method for operating a fluidized bed boiler, comprising: a) setting the ratio of secondary oxygen containing gas to primary oxygen containing fluidizing gas to a value ranging from 0.0 to 0.8; b) carrying out the combustion of fuel with a fluidized bed comprising ilmenite particle; and to a fluidized bed boiler.

Exemplary embodiments of a system and method for bimodal air control in a kettle-style grill are configured to be detachably mounted to the exterior of a kettle-styled grill such as, but not limited to, a Weber® charcoal grill. When mounted to the kettle-styled grill, a plenum-like component directs air flows to the interior of the grill's kettle via the kettle's lower body damper holes. A manually adjustable intake damper in the plenum component allows, restricts, or prevents a drawn ambient air flow into the plenum component. Separately, a forced air flow generated by a fan may also be provided into the plenum component. Adjustment of the intake damper may also adjust damper blades inside the grill's kettle. Ash that falls out of the kettle's damper holes falls through the plenum component and is captured in an ash receptacle that is removably mounted to the plenum component.

Techniques for controlling a solid fuel combustion appliance, e.g., a wood burning stove, are disclosed. A control system measures an exhaust gas temperature of airflow through an outlet of the solid fuel combustion appliance. The control system determines a derivative of the exhaust gas temperature with respect to time. The derivative of the exhaust gas temperature with respect to time is compared to a predetermined threshold. The control system modulates the inlet damper in response to determining that the derivative of the exhaust gas temperature with respect to time reaches the predetermined threshold.

A method to operate a fuel-operated vehicle heater comprising the lowering of a combustion air ratio λ between supplied combustion air and supplied fuel to a combustion chamber of the fuel-operated vehicle heater from a starting value λ.sub.start>1 to a range λ<λ.sub.start for a time period Δt.

The present disclosure is directed to systems and methods for low-CO.sub.2 emission combustion of liquid fuel with a gas-assisted liquid fuel oxygen reactor. The system comprises an atomizer that sprays fuel and CO.sub.2 into an evaporation zone, where the fuel and CO.sub.2 is heated into a vaporized form. The system comprises a reaction zone that receives the vaporized fuel and CO.sub.2. The system includes an air vessel having an air stream, and a heating vessel adjacent to the air vessel that transfers heat to the air vessel. The system comprises an ion transport membrane in flow communication with the air vessel and reaction zone. The ion transport membrane receives O.sub.2 permeating from the air stream and transfers the O.sub.2 into the reaction zone resulting in combustion of fuel. The combustion produces heat and creates CO.sub.2 exhaust gases that are recirculated in the system limiting emission of CO.sub.2.

The present disclosure is directed to systems and methods for low-CO.sub.2 emission combustion of liquid fuel with a gas-assisted liquid fuel oxygen reactor. The system comprises an atomizer that sprays fuel and CO.sub.2 into an evaporation zone, where the fuel and CO.sub.2 is heated into a vaporized form. The system comprises a reaction zone that receives the vaporized fuel and CO.sub.2. The system includes an air vessel having an air stream, and a heating vessel adjacent to the air vessel that transfers heat to the air vessel. The system comprises an ion transport membrane in flow communication with the air vessel and reaction zone. The ion transport membrane receives O.sub.2 permeating from the air stream and transfers the O.sub.2 into the reaction zone resulting in combustion of fuel. The combustion produces heat and creates CO.sub.2 exhaust gases that are recirculated in the system limiting emission of CO.sub.2.