EP-4739946-A1 - IRON FUEL COMBUSTION ARRANGEMENT

EP4739946A1EP 4739946 A1EP4739946 A1EP 4739946A1EP-4739946-A1

Abstract

The present invention therefore relates to an iron fuel combustion arrangement comprising a combustion chamber for combusting a combustible medium comprising iron fuel to provide a combusted medium comprising iron oxide and a separation unit downstream of said combustion chamber for filtering iron oxide from said combusted medium. Said combustion chamber includes radiative and/or convective heat exchange. Said iron fuel combustion arrangement further comprises a cooling section located downstream of said combustion chamber and upstream of said separation unit. Said cooling section comprises first air inlet means providing air having a temperature below the temperature of said combusted medium comprising iron oxide for cooling said combusted medium comprising iron oxide. Said cooling section comprises a converging portion arranged to increase the speed of said combusted medium comprising iron oxide passing from said combustion chamber to said separation unit to increase homogeneity of said combusted medium comprising said air provided by said first air inlet means.

Inventors

SEIJGER, Vincent Jacobus Theodorus
VERHAGEN, Marcus Wilhelmus Petrus

Assignees

Renewable Iron Fuel Technology B.V.

Dates

Publication Date: 20260513
Application Date: 20240705

Claims (15)

1. Iron fuel combustion arrangement (100) comprising a combustion chamber (120) for combusting a combustible medium comprising iron fuel to provide a combusted medium comprising iron oxide and a separation unit (130) downstream of said combustion chamber for filtering iron oxide from said combusted medium, wherein said combustion chamber includes radiative and/or convective heat exchange wherein said iron fuel combustion arrangement further comprises a cooling section (140) located downstream of said combustion chamber and upstream of said separation unit, wherein said cooling section comprises first air inlet means (150) providing air having a temperature below the temperature of said combusted medium comprising iron oxide for cooling said combusted medium comprising iron oxide; wherein said cooling section comprises a converging portion (160) arranged to increase the speed of said combusted medium comprising iron oxide passing from said combustion chamber to said separation unit to increase homogeneity of said combusted medium comprising said air provided by said first air inlet means.
2. Iron fuel combustion arrangement according to claim 1 , wherein said air provided by said first air inlet means has a temperature below the sintering temperature of iron oxide particles.
3. Iron fuel combustion arrangement according to claim 1 or 2, wherein said air provided by said first air inlet means has a temperature below 800 °C, preferably below 500 °C, more preferably below 200 °C, even more preferably below 50°C, most preferably below 30°C.
4. Iron fuel combustion arrangement according to any of the preceding claims, wherein said converging portion forms an inclination angle a in respect of the longitudinal axis x of the iron fuel combustion arrangement, preferably wherein said inclination angle a is between 45 and 60 degrees.
5. Iron fuel combustion arrangement according to any of the preceding claims, wherein the smallest diameter of said cooling section is 25-99% of the largest diameter of said combustion chamber.
6. Iron fuel combustion arrangement according to any of the preceding claims, wherein said cooling section comprises a throat portion (165) positioned downstream of said converging portion.
7. Iron fuel combustion arrangement according to any of the preceding claims, wherein said cooling section further comprises second air inlet means (155) downstream of said first air inlet means, arranged to provide a boundary layer between said combusted medium comprising iron oxide and walls of said converging portion for preventing iron oxide deposition at said walls.
8. Iron fuel combustion arrangement according to claim 7, wherein said second air inlet means are further arranged for cooling said combusted medium.
9. Iron fuel combustion arrangement according to any of the preceding claims, wherein said first and/or said second air inlet means comprise at least two air inlets disposed tangentially or radially in the circumference wall of said cooling section.
10. Iron fuel combustion arrangement according to any of the preceding claims, wherein said first and/or said second air inlet means comprise at least two air inlets angled in a forward direction.
11. Iron fuel combustion arrangement according to any of the preceding claims, wherein said first and/or said second air inlet means are for providing environmental air.
12. Iron fuel combustion arrangement according to any of the preceding claims, wherein any one or more of said first and/or said second air inlet means are connected to an output (180) of said combustion arrangement for recirculation of flue gas into said cooling section.
13. Iron fuel combustion arrangement according to any of the preceding claims, wherein said first and/or said second air inlet means comprise one or more control valves for control of the supply of air of said respective inlet.
14. Iron fuel combustion arrangement according to any of the previous claims, wherein any one or more of said first and/or said second air inlet means is comprised in an airbox housing.
15. Iron fuel combustion arrangement according to any of the preceding claims, wherein said combustion chamber and/or said cooling section has a circular or polygon shaped cross-section, or a cross-section which consists of a transition from a circular to a polygon shaped or vice versa.

Description

TITLE Iron fuel combustion arrangement TECHNICAL FIELD The present invention relates to an iron fuel combustion arrangement. BACKGROUND Energy is indispensable. The amount of energy consumed worldwide has increased enormously over the last decades. Although the amount of energy originating from renewable energy sources such as wind and solar has increased over the last decades and especially over the last years, a large part of the energy still originates from fossil fuels. With the use of fossil fuels also comes the highly undesirable carbon dioxide, CO2, emission. And in order to achieve climate objectives, the total CO2 emission should be reduced significantly. To this end, carbon-neutral fuel, and even more carbon-free fuel, is a preferable source of energy and promising resource to fulfil worldwide energy requirements but still meet the climate objectives. Carbon- neutral fuel is considered fuel does not release more carbon into the atmosphere than it removes, whereas carbon-free fuel produces no net-greenhouse gas emissions or carbon footprint at all. Typically, with carbon-neutral fuel, CO2 or other greenhouse gasses are used as feedstock. Heat intensive industries are responsible for a large part of the total CC>2-emissions. But for many industries there are currently few or no fossil fuel alternatives available that on the one hand are scalable, and on the other hand able to provide sufficient energy with a high degree of certainty and consistency, yet are completely CC>2-emission-free. Solar energy and wind energy can partly meet this need. However, due to the fact that they are intermittent, they are often not, or insufficiently suitable to replace fossil fuels and to meet the demand for energy from these industries at all times. In recent years, a lot of research has therefore been carried out into a feasible alternative that is fully CC>2-emission-free. Iron fuel has the potential to meet that need and to become the candidate of choice. Iron fuel is a very promising fuel in which energy is stored in the iron powder when and where needed. In the right conditions, iron powder is flammable and has the property that when the iron powder is burned, a lot of energy is released in the form of heat. This heat can then be used to generate hot air, hot water, steam or electricity for use in any kind of application or industry. Another important property of iron powder is that only rust remains during combustion, while the amount of CO2 which is released during the combustion of the iron powder is significantly reduced. The rust, as a product, can be easily collected and converted back into the iron powder in a sustainable manner, which makes it a circular process. The fact that the iron fuel is circular and easy and safe to transport makes it an ideal clean and sustainable alternative for fossil fuels to meet the demand for energy in various industries but also in all kinds of other applications. Although the use of iron fuel may already be a proven clean and sustainable alternative to fossil fuels, there are also several challenges. One of the challenges lies in integrating an iron fuel combustion arrangement in existing buildings where the space for a combustion arrangement may be limited, or on location where the height of the total installation is limited for example due to local regulations. The known iron fuel combustion arrangements can be quite large due to the required length of the combustion chamber to maximize heat exchange. Therefore, there is a need for an iron fuel combustion arrangement that provides an improved balance between dimensions of the combustion arrangement and efficiency of the arrangement. SUMMARY It is an object of the present invention to provide an improved iron fuel combustion arrangement. It is a further object of the present invention to provide an iron fuel combustion arrangement with an improved balance between dimensions of the combustion arrangement and efficacy of the arrangement. The present invention therefore relates to an iron fuel combustion arrangement comprising a combustion chamber for combusting a combustible medium comprising iron fuel to provide a combusted medium comprising iron oxide and a separation unit downstream of said combustion chamber for filtering iron oxide from said combusted medium. Said combustion chamber includes radiative and/or convective heat exchange. Said iron fuel combustion arrangement further comprises a cooling section located downstream of said combustion chamber and upstream of said separation unit. Said cooling section comprises first air inlet means providing air having a temperature below the temperature of said combusted medium comprising iron oxide for cooling said combusted medium comprising iron oxide. Said cooling section comprises a converging portion arranged to increase the speed of said combusted medium comprising iron oxide passing from said combustion chamber to said separation unit to increase homogeneity of