The global push for carbon neutrality has brought a wave of change to the manufacturing industry. The steel sector, in particular, is a major focus as it accounts for a significant portion of greenhouse gas (GHG) emissions. However, the challenge of reducing emissions extends beyond steel to include other essential materials like aluminum and zinc in die-casting and forging processes.

This post will explore the GHG emissions from steel forging and aluminum/zinc die-casting, and suggest practical ways to reduce them, paving the way for a more sustainable future in manufacturing.

Steel Forging: The Heat-Intensive Process of Carbon Emissions

Steel forging is a process where a red-hot steel block is hammered into a desired shape. The primary source of GHG emissions in this process is the heating furnace. To heat the steel to over 1,200°C, companies rely on fossil fuels like liquefied natural gas (LNG) or liquefied petroleum gas (LPG), which release a significant amount of carbon.

The amount of GHGs produced by a forging plant depends on several factors:

• Fuel Efficiency: Less efficient furnaces consume more fuel and emit more GHGs.
• Operating Time: Longer furnace operation leads to higher fuel consumption.
• Production Volume: Increased output requires more heating time, which in turn increases emissions.

For these reasons, steel forging companies must prioritize process efficiency and fuel conversion to reduce their carbon footprint.

Aluminum & Zinc Die-Casting: The Melting Point

Die-casting is a casting technique where molten metal is poured into a mold to create a product. It’s widely used for automotive parts and electronic casings. The main source of GHG emissions here is the melting furnace. Aluminum needs to be heated to about 700°C and zinc to about 420°C, so the energy consumed by the melting process accounts for a large portion of the overall emissions.

To reduce GHGs in die-casting, improving the efficiency of the melting furnace is key. The ‘carbon footprint of raw materials’ is also an important consideration. Since aluminum production is highly energy-intensive, using low-carbon aluminum produced with renewable energy can be an effective strategy for emission reduction.

Practical Solutions for GHG Reduction: A Blend of Technology and Strategy

For the forging and casting industries, cutting GHG emissions is no longer optional. The following core strategies can help achieve effective carbon reduction:

1. Improve Energy Efficiency

• Upgrade Furnaces: Replace old furnaces with modern, high-efficiency models that drastically cut fuel consumption.
• Implement Waste Heat Recovery: Reusing the high-temperature heat generated during the process can lead to significant energy savings.

2. Switch Fuel Sources

• Transition to Hydrogen: Replacing LNG/LPG with hydrogen can lead to “zero” carbon emissions. While hydrogen-based steelmaking is a well-known concept, its application in forging and casting is also being explored.
• Introduce Electric Furnaces: Using induction heating electric furnaces instead of fossil fuel-based ones can reduce direct carbon emissions. However, this is only a true carbon reduction if the electricity is sourced from renewables.

3. Enhance Resource Efficiency

• Increase Recycling Rates: Reducing waste and increasing the recycling of aluminum and zinc scrap is one of the most effective ways to lower emissions from raw material production.
• Adopt Lightweight and High-Strength Materials: Developing materials that are stronger with less mass can optimize production and reduce the overall material needed per product.

The future of manufacturing in South Korea depends on its commitment to carbon neutrality. If the steel, aluminum, and zinc industries embrace proactive technological development and process improvements, they will not only contribute to a sustainable future but also enhance their global competitiveness.