Adaptative burner for use of low CALorific gaseous products of industrial processes by coupling Oxycombustion and Heat RecoverY – CALOHRY
Combustion with preheated oxygen: a solution to value the industrial combustible effluents
Role of oxygen and combustible effluents temperatures on the behaviour of the flame and its efficiency.<br />Modelling of its impact on an industrial process<br />
Design of a burner prototype for optimized combustion of effluents
The gaseous effluents also called low valuable gases, produced by various industrial processes, appear as potential fuels for the industry today. They results from the fermentation of vegetable biomass, of the gasification of coal, fumes of coke oven gases or blast furnaces, gaseous residues of refinery; their calorific value allows to envisage their valuation for the power production in particular. <br />On the steelmaking sites, these gases which consist of CO, H2, CH4, CO2, N2 is burned with the air and mostly with the «rich« said gas (methane, propane) in gas turbines, steam turbines, heat engines to get back the energy or in flares for environmental reasons today; The rejections in the atmosphere of these poison gases being strictly regulated by rates of rejections. The combustion with air has the obvious advantage to use a widely available oxidizer, the air, but presents classic difficulties: limited efficiency, emissions of sometimes important NOx, low flexibility as soon as the process deviates from the point of nominal functioning. The substitution of air by oxygen allows raising all these technical issues.<br />The objective of the project is to develop a technology of oxy-combustion based on preheated oxygen in order to allow burning efficiently any composition of gaseous effluents. Indeed the pure oxygen and the preheating allow together to improve the stability of flames independently of the composition of the combustible gas.
At first, a test bench will be mounted in order to study these flames in laboratory. This bench will be equipped with diagnostics tools for:
• • The measure of the temperature,
• • the quantitative evaluation of the flows in the flame,
• • the recording of the shape and the colors of flames, necessary information to understand(include) the chemistry.
A sensitivity analysis on the temperature of the oxygen, on the type of gaseous effluent, on the energy of the flame will be performed to establish a complete panorama of all the industrial situations which could be met.
This data set obtained in the laboratory on these small scales flames (5 in 10 cms in height) will allow to develop a burner 10 times more powerful (length of flames from 1 to 2 meters).
Based on academic works, the project will go to the realization of a burner prototype tested in a furnace at 1000°C, installed on the platform of the research center of Air Liquide.
The works on this technology sending a rather wide range of compositions, the door is open for its application to any industry using gaseous effluents such as biogas or products of refinery.
The application of these gases is limited because of technical problems (adiabatic flame temperature too low) today but would be very possible with the solution developed by the project.
Results will be published in specialized press and may also be internally diffused in Air Liquide, CORIA and CMI Greenline.
Low quality gases, also called Low NCV gases, generated by industrial processes or waste recovering are today widely seen as a source of energy. Typical examples gases are biogas produced by vegetables waste fermentation, synthetic gases generated by biomass gasification (at ambient pressure or in pressurized conditions), Coke Oven Gases (COG) and Blast Furnace Gases (BFG) resulting from steelmaking operations and all sources of CO/CO2/CH4 mixtures emitted by various chemical industries (i.e. oil refinery).
In steelmaking plant, low NCV fuels that consist in CO/H2/CH4/CO2/N2 mixtures are burnt with air and additional gas (methane, propane,…) in steam turbines for getting heat, gas turbines for making power, motors for providing mechanical energy or simply in flares at elevated height for avoiding poisoning the urban atmosphere. Limited efficiency, NOx emissions, incompatibility to CCS solution (nitrogen in air), low flexibility equipment are some drawbacks of air combustion that can be improved by substitution with pure O2 combustion.
The objective of the project is to develop an oxy-burner that can work with any composition of low NCV fuel without additional methane (as existing today) and especially for specific workshops of steelmaking industry that wants to burn mixture of blast furnace gases that have variable composition. To avoid this extra fuel and to enhance combustion efficiencies, the innovation consists in preheating the oxygen and low NCV fuel that is known to ensure a better self-ignition and thus stabilized flame.
Phenomenological study, development of an industrial scale the technology and application at an industrial scale are the main tasks of the project. This innovative technology valuable for steelmaking industry will be opened to any process using low NCV gases as an alternative to meet sustainable growth targets.
Project coordination
Nniomar MARCANO (AIR LIQUIDE CTRE RECH C. DELORME)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partner
CMI CMI Greenline Europe
CORIA - CNRS DR NORMANDIE Complexe de recherche interprofessionnel en Aérothermochimie
AL CRCD AIR LIQUIDE CTRE RECH C. DELORME
Help of the ANR 381,900 euros
Beginning and duration of the scientific project:
December 2012
- 48 Months
