The International Sustainability and Carbon Certification (ISCC+) mass balance approach represents a transformative method for the production of bio-based and bio-circular materials, enabling sustainable production without the need for separate processing facilities. This innovative framework allows manufacturers to utilize renewable and fossil feedstocks in shared production lines, offering a practical solution to the physical inseparability of mass flows in complex industrial processes such as oil refining. By integrating materials like vegetable oils, used cooking oils, animal fats, and naphtha, ISCC+ ensures precise accounting of renewable contributions, promoting transparency and sustainability in polymer manufacturing.
Mass Balance Approach of ISCC+:
The mass balance approach follows a simple principle: every unit of raw material that enters a facility must be accounted for either in a product or as waste. Essentially, the mass balance approach is a calculatory method. The advantage is that only one production line is required to produce bio-based materials. This is particularly beneficial in conversion facilities where raw materials, such as vegetable oil and naphtha, are combined to produce a single product or a range of products. In situations like an oil refinery (as illustrated in Scheme 1, top row), it is often impossible to physically separate mass flows.
Scheme 1 (top row) outlines the production of bio-based and bio-circular materials by TotalEnergies. In the production process, vegetable oils (1), used cooking oils (2), animal fats (3), and naphtha (4) are all utilized, but in varying ratios. All these raw materials are combined in the manufacturing process. Although the mass flows cannot be physically separated, it is known how much of each raw material was used and how much final material can be produced from the respective raw materials. To calculate the mass balance, the amounts of renewable resources (1+2+3) are summed up to determine the amount of final material with a biogenic feedstock. The remaining material can then only be attributed to the fossil feedstock.
ISCC+ certified bio-based materials undergo the same basic production steps as commonly used PE, PP, and PS. Ultimately, they are produced from ethylene, propylene, and styrene. As mentioned earlier, the only distinction lies in the feedstock and the mass balance approach. There are no differences in quality or processing compared to standard polyolefin materials from TotalEnergies.
The ISCC+ mass balance approach provides a robust foundation for advancing sustainability in the polymer industry. By enabling the co-processing of renewable and fossil feedstocks while maintaining quality and efficiency, this method bridges current production realities with the industry’s vision for a sustainable future. However, it is crucial to recognize that this approach is merely one step on the journey toward a fully bio-based plastics economy. Each incremental innovation, such as adopting the mass balance method, brings us closer to this goal, but further advancements are necessary to completely phase out fossil-based plastics. As the demand for sustainable solutions grows, the polymer industry must continue to innovate and invest in transformative technologies, paving the way for a circular and environmentally responsible future.
