Industrial Combustion Processes | Industrial Furnaces

At CanmetENERGY, we strive to improve and develop innovative low-emissions processes. For new plants, improved processes can be used to make changes in the energy efficiency of a system. Sometimes these strategies can be adopted to retrofit existing plants. Examples of improved processes include:

• Direct reduced iron
• Iron ore pelletization
• Oxy-fired blast furnace to produce iron and capture carbon dioxide (CO₂)
• Industrial VOC-GHG (volatile organic compound-greenhouse gas) control using non-thermal plasma

Direct Reduced Iron
We have developed cold-loaded pelletization and associated processing flow sheets for the development of direct reduced iron (DRI) processes. The DRI process can be used to replace conventional coke oven and blast furnace technologies. DRI processes have been developed but are still in their infancy. Although these processes are recognized as having sizable efficiency benefits, industry is still using conventional steel-making processes that are recognized as inefficient and result in huge environmental emissions.
Iron Ore Pelletization
We have entered into a partnership with the Quebec Cartier Mining Company (QCM) for research and development, which is directed at reducing the energy and emissions associated with the production of iron ore pellets for use in the Canadian iron and steel industry. The research will be directed at the development of innovative energy-efficient technology for the pelletization of iron ore that takes place between the mining operation and the blast furnace operation. The production of iron and steel accounts for approximately 10% of Canada’s industrial energy consumption and a corresponding percentage of its industrial greenhouse gases (GHGs). Pelletization is responsible for approximately 15% of those totals. Through research, development and innovation, the partners are working to reduce the energy and emissions associated with pelletization by 30% or more.
Oxy-Fired Blast Furnace to Produce Iron and Capture CO₂
The amount of iron produced from ore to support steel production in Canada was about 9 Mt in 2006. This iron was almost completely produced by blast furnace technology. Due to the use of carbon monoxide (CO) as the reducing agent in the process, the GHG emissions associated with blast furnace iron-making operations are significant. It is estimated that the amount of CO₂ released by blast furnace operations in 2006 was over 10 Mt.
We conducted a technical and economic feasibility study of a novel process to produce iron and capture CO₂. The process uses oxygen instead of air in blast furnace iron-making process. This process was found to have many advantages:

• The use of a high oxygen content blast significantly intensifies the hot metal production process and results in an increase in productivity.  
• The oxygen blast operation can also be integrated with combined-cycle power generation. The nitrogen-free operation produces a clean furnace off-gas with high caloric value, which allows the off-gas to be used for gas turbine power generation. Additionally, the waste heat from the blast furnace can be used for steam turbine power generation.  
• The furnace off-gas may also be used to produce hydrogen gas, which is a valuable material. The CO concentration of the nitrogen free blast furnace off-gas is high. At sufficient concentrations and assisted by a catalyst, the CO can be reacted with steam to produce hydrogen and CO₂ by the water-shift reaction.

Industrial VOC-GHG Control Using Non-Thermal Plasma
Non-thermal plasma is a low energy discharge state of gaseous molecules. Its energy intensity is low so that the temperatures of the molecules and their excited species do not increase; however, the excited radicals and ions may undergo chemical reactions or decomposition. In industrial emission control applications, volatile organic carbons (VOCs) and other GHGs are either oxidized or decomposed by non-thermal plasma into harmless species.
We are developing dielectric barrier discharge plasma technology for mitigating industrial VOCs and GHGs (some VOCs are strong GHGs). One specific GHG of interest is sulphur hexa-fluoride (SF6). SF6 is among the worst GHGs and is widely used in the magnesium casting and smelting industry, semi-conductor manufacturing, and in electricity transmission switchgear boxes. SF6 has a global warming potential (GWP) of 23,900. In other words, the emission of one ton of SF6 is equivalent to emitting 23,900 tons of CO2. In Canada, the annual SF6 emission amount is 2.7 Mt. Currently, there is no method to recover or destroy the SF6 used in industrial processes.

In the work conducted with the dielectric barrier discharge plasma technology, a new star-shaped discharge element was designed and tested, giving a very strong and effective plasma discharge. Nearly 100% decomposition of SF6 has been achieved at a wide range of SF6 concentrations. The energy efficiency of the developed technology for this GHG abatement is about 766,684 kg CO2 eq/MWh, roughly two orders of magnitude higher than CO2 capture from power generation boilers by amine scrubbing.
Although CanmetENERGY’s current research is targeting SF6, the technology and the research facility can also be readily applied to other industrial VOCs and GHGs. We are currently seeking partners, collaborators, and users interested in the developed SF6 decomposition technology. For further information, please contact us.

Managed by CanmetENERGY at the Ottawa (Ontario) Research Centre.