New mild combustion experience in oxy-combustion The possibility to perform a Combustion Process without a flame front (Mild Combustion) have been largely investigated in a high diluted oxidant condition as focal conditioning parameter. Further investigations also carried out at CCA (Combustion research Combustion Centre) have demonstrated that it is obtainable in pressurized oxy combustion with low FGR to control the combustion temperature. Then, the main conditioning parameter to obtain mild combustion is more precisely defined by the temperature homogeneity and, consequently, by heat transfer control. As already presented at HiTACG in ESSEN >>>>

« Volume combustion » HiTACG, MILD,flameless, FLOX®, diluted … or « volume » Combustion Traditional combustion Che cosa c’enra Flame front: very high temperature Uniform high temperature Low temperature zones

Smooth gradients And “volume combustion” Focusing on…. Smooth gradients And “volume combustion” Non linear systems, “with more then three Catastrophic parameters are, by definition, Chaotic, i.e. they can be described statistically only” Flames are, by definition, chaotic system The lowering of gradients, by order of magnitudes, of catastrophic parameters moderates the system chaotic nature Comburent-fuel dilution with fumes by a flue gas recycling (lowering reactans concentration gradient) is an important feature for combustion reaction moderation (chemical uniformity) Preheating of reactans (by a heat recycling) is an important feature for temperature gradient moderation Volume combustion is the targeted solution

ISOTHERM 5MW pilot at CCA ISOTHERM® POWER Approach: High temperature OXY-Combustion Chamber; Under pressure Combustion run; Large heat capacity of the system and fast feed back control; Heat recovery by steam generation; Only simplified final flue gas treatment.

ISOTHERM® Demonstration Unit aerial view Oxygen Tank T-quench Blower Flue-gas Post treatment Reactor Boiler

New perspective in Gas Turbine Application New environmental issue will drive to very important challenge: To reduce pollutant emission in terms of: NOx; CO but also VOC; Sub micron particle; heavy metals; etc.. To be able to perform higher efficiency To be able of a wide range of fuels use To be CCS ready

Trends in power plants Thermodynamics Power Plant Concept General Trends in the Development of Power Plant Technologies Processes and technologies like CO2-free Power Plants, FuelCells and Combination-Cycle-Processes efficiency Further development of Steam-and-Gas-Combination-Processes and the Coal-Power Generation e.g. IGCC, STIG, HAT Ultra-supercritical Steam-Cycle-Processes Rerum Cognitio WDK-Process Rerum Cognitio WDK-Process Courtesy of WDK-process

How Gas turbine can answer this challenge Mild Combustion can be obtained considering the integration of actual already developed features as: ceramic bricks lined combustion chamber that reduce cold exposed surfaces; Steam injection in combustion (STIG Cycle) that introduce opacity in IR radiation transfer helping uniformity in temperature Higher temperature in turbine inlet also using steam cooling

Benefits of the “Mild Combustion” in Gas Turbine Application Easy treatment of very variable products composition as Low calorific Gasses or Hydrogen Strongly reduced pollutant impact: (NOx<3ppm; VOC and organic sub - micron particles strongly reduced) High temperature uniformity at Turbine inlet

Steam in Combustion As we know in STIG cycle steam help to increase efficiency but also to get mild combustion It is a low cost pressurized fluid if the latent heat can be recovered What happen if in a TG the air compressor is replaced by a boiler and the oxidant will be injected in double stream with the fuel ???

Thermodynamic efficiency improvements e.g. assume a standard cycle plus a topping one consisting in an internal heating of the fluid

Ambitious challenge expect the future of combustion in power generation High efficiency Free choice of low quality fuels; Zero emission; CO2 caption; The “Mild Combustion” can represent a very important solution for the future.