The port of Rotterdam , The Netherlands . Photo courtesy by Outokumpu .
Carbon footprint comparison – duplex stainless steels vs competing materials
The green transition in the process industry sector calls for greener raw materials and production processes with greener process equipment to reduce greenhouse gas emissions towards zero .
By Claes Tigerstrand , Outokumpu
Renewable energy production , from the refining of battery metals to biofuel production , hydrogen production and storage , carbon capture , plastic recycling , etc , calls for new material solutions . This transition brings demanding process environments which often operate at high ( or low ) temperatures and pressures , making the material selection more complicated . Hence , stronger , more corrosion resistant materials with a lower carbon footprint are now in demand . The challenge is how an engineering company or a materials engineer working on a large investment project can compare the carbon footprint of various material solutions and draw unbiased conclusions about their performance . The author of this article has extensive experience in stainless steel and represents a stainless steel manufacturer with a strong green profile . Lots of improvements are being made to reduce emissions in stainless manufacturing , but how do these compare to other materials ? I have less knowledge of the competing materials , but can I identify similar data for them to enable a comparison ? Let ’ s find out . Let ’ s start with the toolbox . A life cycle assessment ( LCA ) study can be used for this task . This method quantifies various types of emissions , where the global warming potential ( GWP ) – carbon dioxide equivalents ( CO2e ) is the most sought . See Figure 1 for a complete assessment spanning the entire product life cycle ( cradle to grave ) from the extraction of resources through production , use , disposal , and potential recycling . The LCA methodology is standardised , mainly through ISO 14040 and ISO 14044 .
Life cycle assessment There are four main steps to follow in an LCA : 1 . Define scope and boundary conditions ,
2 . Emission data collection ( Life cycle inventory ), 3 . Emission calculation for the different stages of the product life cycle , 4 . Validation of results . Collecting emission data is not easy . Where can you find carbon emission data for materials ? How reliable is the data ? Can data be compared ? Are they derived using the same systematics ? How do we ensure that we are comparing ‘ apples to apples ’ and not ‘ apples to oranges ’? Extensive knowledge and experience are required in both production processes and material properties , as well as environmental assessments . ‘ Trustworthy ’ carbon footprint data can be found from three primary sources : 1 ) Environmental Product Declarations ( EPD ), 2 ) Product Carbon Footprints ( PCF ), and 3 ) Verified databases . Third-party verified databases are trusted sources used for all types of LCA calculations , including EPDs and PCFs .
Environmental Product Declarations ( EPD ) The building and construction sector is at the forefront of developing and putting EPDs into practice . An EPD is a third-party verified report according to ISO 14025 , which declares various
32 Stainless Steel World April 2025 www . stainless-steel-world . net