FOCUS ON SUSTAINABILITY
19
Carbon Footprint Study Exemplary Results
160,000 km | Reference Vehicle : Volkswagen iD . 3 ( 15.2 kWh / 100 km ) | Grid Mix | Scrap Flow : Cut-Off
Today
Stefan Lindner at the roundtable discussion .
GWP [ kg CO 2 -eq ]
20
Production Phase
Carbon Footprint Study Exemplary Results
800 700 600 500 400 300 200 100
0
“ Of the three stainless steels , Forta H-Series is a new generation of nickel-free , fully austenitic , manganese-chromium alloyed grade that was developed for safety-critical structural vehicle components . With a yield strength in the order of Rp0.2 ≥ 1000 MPa in the temper-rolled condition , and in combination with high elongation to fracture , it opens new opportunities in lightweight engineering and design . The material also has very high energy absorption in the event of an impact . The other two stainless steels were standard 1.4301 , a widely used chromium-nickel steel with a 2H finish and the same material produced via the Circle Green route ,” explained Lindner .
The ‘ use ’ phase
Use Phase
The final stage of the investigation was to evaluate the carbon footprint of the materials in the ‘ use ’ phase . This was based on the reference vehicle for the battery tray with energy storage of 58kWh , lifetime mileage of 160,000km and energy consumption of 15.2kWh / 100km . Two scenarios were considered : the current situation and a future more circular economy with a higher level of scrap reuse .
Net Recycling Credit
Overall
160,000 km | Reference Vehicle : Volkswagen iD . 3 ( 15.2 kWh / 100 km ) | Grid Mix | Scrap Flow : Cut-Off
165.38
267.40
26.52
406.25
138.34
189.60
+ 29.9 % + 112.8 %
15.16
312.77
106.92
604.90
Steel Variant Stainless Steel Variant ( 1.4301 2H Standard ) Aluminium Variant
Production Phase Use Phase
Net Recycling Credit Overall
46.39
Today
665.44
“ The current situation considers a relatively low level of recycling . It is interesting to note that stainless steel offers a carbon footprint saving of 29.9 % against carbon steel . But even more significant is that it also shows a reduction of 112.8 % against aluminium ,” highlighted Lindner .
“ This result is contrary to initial expectations as it would be anticipated that the light weight of aluminium would yield a high improvement in energy efficiency over both steel types . This is indeed true , as aluminium has a lower carbon footprint in the use case . However , because aluminium is produced using very energy-intensive processes , it has a very high carbon footprint in production . And its contribution to energy efficiency in use does not come close to compensating for this , even over a 160,000km vehicle life ,” he continued .
“ It was also interesting to compare the results when using the three types of stainless steel . As expected , the use cases of all three are identical . Forta 800 does show a higher carbon footprint in the production phase . It might be possible to offset this by making full use of its highstrength and energy absorbing properties to redesign components to achieve a lower weight . This could then be reflected in an improved figure for the use case .
“ Using Circle Green offers a 9.4 % reduction in overall carbon footprint against the regular 1.4301 stainless steel ,” Lindner concluded , highlighting the results of the Outokumpu / FKA study during the roundtable .
Outokumpu Circle Green ® stainless steel has a carbon footprint down to 7 % of the global average , according to Outokumpu .
ISMR October 2024 | ismr . net | 91