The global effort to reduce carbon emissions has led to significant changes in various industries, including the iron and steel sector. In this blog, we will explore different strategies to decarbonize the combustion process, with a particular focus on steam methane reformers (SMRs) used in the production of direct reduced iron (DRI). Decarbonizing the iron and steel industry is crucial to addressing climate change and reducing greenhouse gas emissions.
Global Trends and the Need for Decarbonization
Governments and corporations worldwide are implementing policies to reduce carbon emissions and combat climate change. The steel industry, a significant contributor to carbon dioxide (CO2) emissions, is under scrutiny for its environmental impact. According to the World Economic Forum, the iron and steel sector accounts for approximately 19% of industrial CO2 emissions. Beyond this statistic, the International Energy Agency states that the iron and steel subsector is “not on track” to align with the net-zero scenario for 2050, emphasizing the urgent need to decarbonize the industry. Studies have shown that DRI and electric furnace technologies offer viable paths to decarbonization, with DRI reducing up to 33% of CO2 emissions compared to traditional blast furnace methods.
Understanding Direct Reduced Iron
Direct reduced iron is a high-quality iron product used as a feedstock in electric arc furnaces, blast furnaces, and other iron and steel making applications. It is available in different forms, including lumps, pellets, and briquettes, and can be hot or cold depending on its intended use. DRI can be produced from key two processes: gas-based DRI, which utilizes steam methane reformers, and coal-based DRI, which directly reacts lump iron ore with coal. While both methods are used, this blog will focus on gas-based DRI and the role of SMRs.
Optimizing Combustion Efficiency
Efficient combustion is critical for reducing emissions and increasing safety. Combustion requires three elements: fuel, oxygen, and heat. However, incomplete combustion can lead to the generation of combustibles such as carbon monoxide and hydrogen. To optimize combustion efficiency, excess oxygen levels need to be carefully controlled. By maintaining the appropriate excess air-to-fuel ratio, a safety margin is ensured while minimizing inefficiencies and emissions. Monitoring excess oxygen levels and combustibles allows for precise control and optimization of the combustion process.
Safe Monitoring of Tube Wall Temperature
In addition to combustion optimization, monitoring tube wall temperature is crucial for ensuring safety in SMRs. Thermal imaging technology enables the safe and continuous monitoring of tube wall temperature, providing early detection of any abnormal temperature rise that could indicate potential issues. By implementing effective monitoring systems, operators can prevent critical equipment failures, mitigate safety risks, and optimize process performance.
Combining Solutions for Increased Safety and Reduced Emission
The key to achieving decarbonization and safety in SMRs lies in the combination of combustion optimization and tube wall temperature monitoring. These two approaches work synergistically to increase safety, reduce emissions, and enhance process efficiency. By carefully managing excess oxygen levels and monitoring tube wall temperature, operators can strike a balance between safety margins and fuel consumption, resulting in optimized combustion and reduced environmental impact.
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