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Emissions Efficiency: Output Emissions

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Kids Fight Climate Change Team

Output emissions are the emissions produced by the manufacturing itself. Together, the cement and steel industries make up 15% of all greenhouse gas emissions, but there are new technologies that can combat that.


Output emissions are the direct, on-site emissions that arise due to industrial processes, such as generators, equipment, and chemical reactions, among others. They are different from process emissions because output emissions come directly from the equipment, instead of leakages.


The steel industry is responsible for 7% of the world's carbon dioxide emissions. That is because steel requires coke, the dirtiest fossil fuel. Coke makes up 85 to 90% of the steel industry's emissions. Removing coke from the reaction is imperative to cut down steel, and therefore industrial, emissions. Some European companies are working on replacing coke with hydrogen and electricity, moving towards a no-carbon future for steel.

Going Deeper:

In 2016, Vattenfield, SSAB, and LKAB (Swedish companies that are the leading iron ore producers of the EU) started a project called HYBRIT. HYBRIT's goal is to perfect a process to manufacture steel with limited or no carbon dioxide emissions/fossil fuel usage. The program is attempting to replace coke with hydrogen. Coke's role is that it helps break down the iron oxides, and other fossil fuels heat blast furnaces. Hydrogen would break down the iron oxides instead of coke, and, in HYBRIT's design, electricity would power the furnaces. A pilot for this program is expected to go online between 2021 and 2024, half funded by the Swedish Energy Agency.

Innovation like HYBRIT is an essential part of cutting down on industrial emissions. Industrial practices are so deeply ingrained in our society—they were the start of the  Industrial Revolution—making them hard and expensive to change. The HYBRIT project estimates that their steel will cost 20 to 30% more than normal steel when taking into account the cost of electricity versus coke. However, it is important to take into account that the world running out of fossil fuels, so soon coke and other fossil fuels will become much more expensive as they become scarce across the world.


The cement industry accounted for 8% of global emissions in 2016—2.2 billion tonnes of carbon dioxide. Cement is in a critical place in the economy; it is the key component of concrete, which is the basis of the world's infrastructure. Cement is often created from clinker, a key component that releases greenhouse gas emissions during its production. Clinker is the primary source of emissions from cement production. To cut down on emissions, we have to reduce clinker usage and develop innovative new ways to change how technology is used.

Going Deeper:

To produce clinker, the primary component of cement, carbon has to be removed from limestone by heating it in a kiln, which releases carbon dioxide. A major part of reducing emissions is reducing the amount of clinker. Right now, Indian companies are the only ones in the sector with significantly less clinker, mainly due to access to other waste such as fly ash or slag.

Currently available technologies can reduce emissions by 50%, according to the World Cement Association. However, these technologies are spreading too slowly to comply with the Paris Climate Agreement. To effectively cut down on emissions, these practices must be employed: the reduction of clinker usage through innovative practices; the efficient use of cement in processes, effectively cutting down on need (material efficiency); use of waste energy to power plants; and finally innovative technologies such as carbon capture and storage and new types of cement/binders.

While that is a long list, the cement industry is one of the most powerful industries in the world. Currently, it only gives 6% of revenue to research and development, on average, a small number. If innovation is given more attention, these goals can be met and a significant portion of the world's greenhouse gases can be cut


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