What are the environmental impacts of alternative raw materials?

Consumers usually believe that plastic packaging is sustainable if it has been made from recycled or renewable raw materials. But there are even more ways to manufacture packaging materials that are sustainable. An interesting approach is the mass balance method.

This method that’s used in the chemical industry inputs recycled or bio-based raw materials right at the start of production and then computationally allocates them to the end products. The method works in the same way as green electricity: Consumers with contracts with utilities that supply green electricity also don’t know whether the electricity consumed in their own households was generated directly from sources of renewable energy. But the decision does generally help increase the share of ecologically generated electricity within the overall grid. Mass balancing in plastics manufacturing similarly allows the quantities of recycled raw materials used to be allocated to specific products. Although the approach is complex, the computational principle delivers benefits because it makes it possible to reduce the use of fossil raw materials and cut greenhouse gas emissions – while the end products’ properties and qualities remain the same. There are also no differences in the further processing and the products subjected to mass balancing can be recycled like conventional plastics at the end of their life cycles.

Such chemical multinationals as BASF have already been using the mass-balancing method for years. The Ludwigshafen-based company has also broken new ground in the development of a biomass-balancing method that may be applied to the use of renewable raw materials in the chemicals industry. This approach allows fossil raw materials to be replaced not only with recycled raw materials but also with renewable raw materials within BASF’s production network.

But what are the environmental impacts of the different alternative raw materials used to replace or supplement fossil resources within the production process? To understand the impact within the entire life cycle, BASF joined forces with Südpack and Sphera to conduct a study that examined the effects using a mozzarella packaging as an example. Various alternative raw materials were used for the production of food-grade plastics and assigned to these on the basis of a certified mass-balancing approach. BASF’s Ultramid Ccycled polyamide, which is produced from chemically recycled raw materials, and Ultramid BMBcert, which is produced from renewable raw materials, were examined, each in combination with polyethylene. The study compared the flexible multilayer packaging manufactured in this way with the same packaging that used fossil raw materials in its production. The company also investigated a type of rigid-tray packaging that was made with fossil raw materials.

The packaging format plays an important role where environmental compatibility is concerned: Compared with flexible multilayer packaging, rigid hard-shell packaging, which consists of a mono-polypropylene cup combined with a multilayer lidding film, has the highest potential environmental impact in almost all categories. Flexible packaging requires significantly fewer raw materials, which also means that less packaging waste is generated. BASF reported that the results above all illustrated that the use of flexible multilayer packaging that was manufactured with a high proportion of chemically recycled or renewable raw materials has a significantly lower impact on the environment, particularly as a result of the reduction in CO2 emissions. Various technical and methodological scenarios were also highlighted for the life-cycle assessment study, including the use of green electricity and chemical or mechanical recycling at the end of the packaging’s life cycle.

BASF and partners had already produced prototype packaging for mozzarella from chemically recycled polyamide and polyethylene in 2019. The 100%-recycled share was computationally assigned to both plastics using the certified mass-balancing method. BASF supplied chemically recycled polyamide and Borealis provided sustainably produced polyethylene for the pilot project and Südpack used these materials to produce a multilayer film that was processed into specially sealed mozzarella packaging for the Zott dairy.