Mass balance and product carbon footprint (PCF)
Method
The CO2 footprint calculations available for all SKW Piesteritz products are based on the mass balancing of our production. This was adapted to the specifications of Fertilizer Europe and the international standard of the Greenhouse Gas Protocol. The system boundaries are shown in the following overview and correspond to the cradle-to-gate principle.
Figure 1: Material flow diagram of the core processes with system boundaries
A new process has been implemented at SKW Piesteritz to ensure that the carbon footprint of alpha products is correctly and completely balanced. The biomethane is fed into the natural gas grid at its production site. The methane that reaches the company via a pipeline is therefore a mixture of fossil and biogenic sources and cannot be differentiated or separated in terms of material. By using certificates, however, it is possible to allocate exactly how much biomethane is used in the processes. The certificates used comply with the guidelines of the German Energy Agency and the International Sustainability and Carbon Certification. A validated calculation method specifies how much biomethane must be used to reduce the CO2 footprint of a product by up to 90 percent. This means that the CO2 emissions of our alpha products only come from 10 percent fossil sources.
Figure 2: Process chain of alpha products
Independent audit
SKW Piesteritz has been driving forward scientific analyses for the life cycle assessment of products in accordance with the requirements of ISO 14040 and 14044 since 2012. In 2022, the methodology for calculating the carbon footprint of our products based on ISO 14067 was finally checked and certified by independent external auditors for the first time. In 2024, this was followed by the certification of our corporate footprint and, separately, the methodical further development of the product-related balance to the internationally established specifications of Fertilizers Europe.
A validation of the carbon footprint of alpha products was commissioned for the first time in 2024 and is to be re-verified annually in future. With the proof of conformity according to ISO 14067 and a mass balance according to ISO 22095, a fossil CO2 footprint reduced by up to 90 percent compared to conventionally manufactured products from SKW Piesteritz can thus be ensured and documented.