Frequently asked questions about BASF’s ChemCyclingTM project
About ChemCycling™ in general
ChemCycling™ is the name of a chemical recycling project launched by BASF with the aim to manufacture high-performance products from chemically recycled plastic waste on an industrial scale. BASF cooperates with technology partners who use a thermochemical process called pyrolysis to transform plastic waste into secondary raw material (pyrolysis oil). We can feed this oil into BASF’s production network (Verbund) at the beginning of the value chain, thereby saving fossil resources. The share of recycled material is allocated to products manufactured in the Verbund by using a third-party audited mass balance approach. The products which carry the name suffix “Ccycled™” have the exact same properties as those manufactured from fossil feedstock. Customers can therefore further process them in the same way as conventionally manufactured products and use them in demanding applications.
BASF is developing chemical recycling for use on industrial scale as it enables us to:
- Increase recycled content in high-performance products for applications with strict requirements on quality and hygiene
- Support our customers in achieving their recycling targets
- Recycle plastic waste for which no high-value recycling processes are established yet
- Turn plastic waste into feedstock for the chemical industry and thus contribute to a circular economy
- Replace fossil resources and save CO2 emissions against conventional plastics production
In mechanical recycling, the waste plastics (e.g. deposit PET bottles) are cleaned, melted down and reprocessed into granulate. Therefore, only clean single-stream waste is suitable for high-value mechanical recycling. Nevertheless, recycled plastics produced by mechanical recycling often do not achieve the same level of quality and purity as virgin plastics. This is because impurities remain in the recycled plastic and the properties of the plastics are changed during the use-phase and during re-processing. This can be problematic, for example, in food packaging.
In chemical recycling, the polymer chains of the plastics are chemically broken down into molecules that can be used as raw materials by the chemical industry (e.g., syngas, pyrolysis oil, monomers), which can then be used to make products with the same quality as those made from fossil resources. This means they can, for example, be used for medical applications or applications with food contact.
Chemical recycling can be used to recycle plastic waste for which there are currently no other high-quality recycling processes or insufficient capacities (e.g. mixed plastic waste, contaminated plastics and multi-layer packaging). Therefore, chemical recycling is a useful complementary process to mechanical recycling.
Usually, chemical recycling refers to technologies that break down long plastic polymer chains into their basic building blocks by chemical reactions. These secondary raw materials can then be used to replace fossil raw materials in chemical production. Commonly used methods in this regard are pyrolysis, in which plastics are converted into pyrolysis oil, and gasification, with which plastic waste is converted into syngas.
Another common method is the depolymerization of plastics, also known as solvolysis or re-monomerization. In this process, plastics are broken down into their monomers, from which the polymer can be rebuilt. The material obtained from depolymerization therefore re-enters the chemical value chain at a later stage than pyrolysis oil or syngas. However, this also means that single-stream plastic waste is required for this process. Suitable input materials are single plastics like polyamide (PA) or polyurethane (PUR).
There are also other technologies like hydrogenation. All technologies are needed to transform the linear plastic value chain into more circularity. BASF supports a technology-neutral definition of recycling.
We are focusing on pyrolysis because, one the one hand, it an extremely efficient process. Round about 70% of the plastic waste can be converted into secondary raw materials. Efficiency improvements can be expected during the next 10 years. The part of the waste that cannot be turned into raw material but is pyrolyzed into gas is used to generate almost all of the energy required for the process. The external thermal energy demand is very low (<1%, e.g. for start-up processes).
On the other hand, pyrolysis plants can be built in large numbers and distributed over a large area, so that long transport routes for plastic waste are not necessary. Since pyrolysis oil has a higher density than plastic waste, about half of the transport distances can be saved. In contrast to pyrolysis plants, gasification plants are built on a larger scale. Therefore, a few large gasification plants would mean that huge quantities of plastic waste would have to be transported over long distances.
In our ChemCycling™ project we are feeding pyrolysis oil derived from mixed plastic waste into our production network to manufacture new plastics based on a mass balance approach. By this, we are clearly closing the loop for plastics.
We are in line with the definition of recycling in the EU Waste Framework Directive.
This question can only be answered for each product in the relevant application. Some products could be redesigned without a loss of function, e.g. changes in the design of bottles with large sleeves of another material that will interfere with the sorting. (The IR scanner will incorrectly sort the bottle into the waste stream of the sleeve material.)
In other cases, this is more difficult. One example is multilayer packaging, which is often challenged for being non-recyclable with current methods. Nevertheless, it is difficult to imagine the packaging landscape without them, because their properties help to save resources and energy. The combination of different materials allows to make the overall packaging thinner, hence reducing resource consumption, waste amounts and shipping weight in the first place. In addition, they can, for example, keep food fresh for longer than alternative products due to tailor-made gas barrier properties, thus helping to avoid food waste.
To sum it up: substituting multilayer with mono-material is not generally feasible without increasing the amount of waste, and secondly compromising the performance of the packaging. Chemical recycling processes can be a solution to this target conflict and allow to recycle products and packaging where re-design is not possible or desirable.
ChemCycling is a complementary approach to mechanical recycling and can process plastic waste for which no high-value mechanical recycling is available, or capacities are missing, e.g. mixed plastic waste streams. However, the existing technologies for conversion of plastic waste into pyrolysis oil need to be further developed to ensure a reliable high quality of the secondary raw materials and to enable the conversion of a greater variety in quality of mixed plastic waste.
In general, an eco-efficiency assessment should be used to decide whether chemical recycling is the recycling method that makes the most environmental and economic sense. Plastic fractions that can be mechanically recycled and further processed into high quality recycled materials (e.g. PET bottles) should therefore continue to undergo mechanical recycling.
Chemical recycling is less appropriate for waste streams that do not contain enough hydrocarbons (i.e., the calorific value is low).
On the one hand, the existing technologies for conversion of plastic waste into pyrolysis oil need to be further developed and adapted to ensure a reliable high quality of the secondary raw materials. On the other hand, legislation will determine whether the technology will become established in the waste industry. The legislative framework of the EU builds on a technology-neutral definition of recycling and counts chemical recycling as a technology contributing e.g. towards the recycling targets of plastic packaging. Yet, it is up to the interpretation of individual member states how chemical recycling contributes to meeting their recycling targets. In Germany, for example, chemical recycling is not yet recognized as a process which contributes to fulfilling the plastic packaging waste recycling targets. It would be an important political signal to be able to contribute to the achievement of all recycling targets in Germany (as in other EU countries) also through chemical recycling. Similarly, incentives for recycled content should be applicable to all forms of recycling. Moreover, full acceptance of mass balance approaches is needed, both on EU and national level.
Although the legislative framework of the EU builds on a technology-neutral definition of recycling, it is up to the interpretation of each member state how chemical recycling contributes to achieving their recycling targets and whether chemically recycled plastic waste is exempt from this tax.
The first commercial products based on chemically recycled plastic waste are already on the market. For chemical recycling to develop its full potential, all players along the value chain must work together. This will determine how quickly production can be carried out on a large industrial scale.
In the 1990’s the focus was mainly on gasification plants. As these plants must be built on large scale they can only be operated economically if large quantities of waste are available within a small radius. As this was often not the case, these projects were stopped. Today, the focus lies on pyrolysis plants, which can be built on a smaller scale. This means many small plants can be built and distributed over a large area. This ensures that enough input material is available.
Moreover, customers show a much broader interest in using recycled raw materials today than they did in the 1990s. Many companies are feeling regulatory and public pressure to increase the share of recycled materials and therefore have set themselves the goal of using, for example, only packaging made from recycled materials in a few years’ time.
About the eco-efficiency of ChemCycling™
For plastics where there are large volumes of waste arising without significant impurities, such as PET from water bottles, mechanical recycling has a smaller carbon footprint than chemical recycling.
However, it is another story especially with mixed and contaminated plastics. It may be impossible or very inefficient to sort them for a high-value mechanical recycling or the recyclates cannot be reused in applications of the same quality. This means that they are often energetically recovered. In this case, chemical recycling is the better option.
A life cycle assessment (LCA) conducted by Sphera for BASF, which was reviewed by three independent experts, comes to the clear conclusion that pyrolysis of mixed plastic waste emits 50 percent less CO2 than its incineration. The study also showed that CO2 emissions are saved when manufacturing products based on pyrolysis oil under a mass balance approach instead of naphtha. The lower emission result from avoiding the incineration of mixed plastic waste by reusing it. Moreover, it concluded that manufacturing plastics via either pyrolysis or mechanical recycling results in comparable CO2 emissions. It was taken into account that the quality of chemically recycled products is similar to that of virgin material and that less input material needs to be sorted out compared with mechanical recycling.
At the end of life of a plastic product, the most eco-efficient solution should be chosen. Chemical recycling – like other recycling processes – should be evaluated based on scientific life cycle assessments (LCA).
The basic LCA for ChemCycling™ comprises three separate studies considering waste, product and plastic quality perspectives:
- Study 1 (Waste perspective): Comparison of CO2 emissions between pyrolysis and incineration of mixed plastic waste
- Study 2 (Product perspective): Comparison of CO2 emissions between plastics production from pyrolysis oil and naphtha
- Study 3 (Plastic quality perspective): Comparison of CO2 emissions between plastics made via chemical recycling and plastics made via mechanical recycling
- Where available, the LCA was calculated with high quality data from existing commercial plants. Please note that the basic LCA was not calculated with data of our partner Quantafuel.
- Remaining data gaps were modeled based on acknowledged databases or in case of the purification of pyrolysis oil on process design assumptions by BASF R&D.
- The study was calculated according to international accepted standards and critically reviewed by three independent experts.
- Panel decision: “…the LCA study followed the guidance of and is consistent with the international standards for Life Cycle Assessment (ISO 14040:2006 and ISO 14044:2006).”
The full LCA report and the statement of the critical reviewers can be downloaded here.
Further life cycle impact analysis (LCIA) categories were calculated, which are listed in the LCA analysis. According to this, the values for acidification and summer smog are higher for pyrolysis than for thermal recovery, due to the different credits for electricity production.
The various indicators of (eco-)toxicity potential are dominated by secondary and tertiary processes (e.g. electricity production and credits). Therefore, it is not possible to draw clear conclusions.
In case studies 2 and 3 of the LCA analysis, the entire life cycle was defined and considered – within the set boundaries of the system – including the steps mentioned above.
There, the impact of each energy type (electricity, thermal energy, mechanical energy, primary energy, secondary energy, regenerative energy, fossil energy, nuclear energy, energy saved, etc.) on the environment is assessed in Life Cycle Impact Assessments (LCIA). The LCA analysis (study 2) shows, for example, that the production of chemically recycled PE saves more than 2.3 metric tons of CO2 compared to the production of PE from crude oil. The lower emissions result from avoiding the incineration of the plastic waste.
The production of chemically recycled PE saves almost 40 percent of the energy raw materials compared to fossil production. In an LCA analysis, this is usually not displayed as energy demand, as the different types of energy must not be added together to form a figure.
The main difference between the assumptions for 2030 and the current status in 2020 is the electricity mix in Germany. The scenario for 2030 assumes that there will be a higher share of electricity from renewable sources in the German grid in 2030. For this reason, in the alternative scenario (incineration of MSWI (municipal waste) and RDF (refuse derived fuel)) fewer CO2 savings are to be credited for the use of plastics for energy generation.
Regarding the pyrolysis technology, the current state of the art was conservatively assumed, whereby in one scenario it was calculated what effect an improvement in yield would have. The results of both scenarios (energy mix 2020 and possible improvement of the pyrolysis yield) are presented in the LCA analysis.
About the pyrolysis technology
Pyrolysis is the thermochemical splitting of organic compounds. High temperatures (300-700°C) are used to break down the bonds in large molecules to create smaller molecules. In contrast to gasification and incineration, the pyrolysis reaction occurs solely under the influence of high temperatures and in the absence of oxygen. No additional chemicals are used in these processes.
BASF does not own a pyrolysis plant. The pyrolysis oil used to manufacture the pilot products was purchased from a pyrolysis oil producer. In October 2019, we announced a partnership with Quantafuel. Quantafuel is currently starting up a pyrolysis and purification plant with a nameplate capacity of approximately 16,000 tons per year in Skive, Denmark. BASF will have a right of first refusal to all pyrolysis oil and purified hydrocarbons from this plant for a minimum of four years.
Since 2020, BASF also has partnerships with Pyrum and New Energy. Both companies supply BASF with pyrolysis oil derived from waste tires.
The plant of the Norwegian start-up Quantafuel is located in Skive, Denmark and is currently in the start-up phase. The raw material which will be used is mixed post-consumer plastic waste, which would otherwise be energetically recovered. Quantafuel has signed agreements with Norwegian recycling companies Grønt Punkt Norge and Geminor to supply mixed plastic waste.
The Norwegian Environmental Agency (Miljødirektoratet) confirmed that the Quantafuel technology for chemical recycling qualifies as material recycling. However, even if Quantafuel is eligible to recycle plastic material suitable for recycling mechanically, the economics will not be sustainable. Only mixed plastic waste yielding close to zero or negative value also called “gate fee”, can sustain Quantafuel’s business case. Hence, plastic waste suitable for mechanically recycling with a market value normally ranging from 200 to 1,000 EUR per metric ton, will not be utilized.
Quantafuel has taken further steps to optimize their feedstock value chain, acquiring a 49% stake in the Norwegian mechanical recycler Replast. Replast will first sort out the mechanically recyclable plastics. The rest, which would usually be recovered thermally, will be converted to pyrolysis oil in Quantafuel’s plant, resulting in a very high overall recycling rate.
This depends on the waste fraction. When using the MK352 fraction – on the basis of which the LCA analysis was carried out – the impurity content (maximum 10%) must be sorted out. These impurities are energetically recovered (waste incineration plant or incineration as fuel substitute).
Background information: MK352 is a mixed plastic fraction according to the specifications of the Green Dot. Among other things, it contains used, completely empty, system-compatible articles made of plastics typical for packaging (PE, PP, PS), including secondary components such as closures, labels, etc.
There are different technologies available to produce pyrolysis oil out of plastic waste and there are different plastic waste streams. These prerequisites determine the resulting type of oil. One big challenge in scale-up is to ensure a reliable high quality of the secondary raw materials independent of the input material. Therefore, we are working closely together with our partners to improve the pyrolysis and purification process.
The technical documentation of our partner Quantafuel provides for a yield of 84%. After purification, these oils can be used directly in BASF's Production Verbund for the production of virgin-like plastics. The share of recycled raw material is allocated to certain sales products manufactured in the Verbund by using a third-party audited mass balance approach.
The calculations performed as part of the life cycle assessment (LCA) analysis, which are based on pyrolysis data from another company, were based on a conservative oil yield of 71%. This represents the lower value of the plants operating today, as pyrolysis technologies for plastic waste are not yet fully optimized.
The part of the waste that cannot be turned into raw material but is pyrolyzed into gas is used to generate the energy required for the process.
In general, we assume that in the long run only 1.4 metric tons of plastic waste will be needed to produce 1 metric ton of plastic. In our LCA study we have used higher mixed plastic waste inputs due to quality constraints of the German yellow bag (1.7 metric tons).
Different amounts of pyrolysis oil are required depending on the plastic being produced. The products manufactured as part of the ChemCycling™ project are certified according to several standards (a.o. ecoloop, REDcert2).
- Example HDPE: (High-density polyethylene): In the conservative basic calculation case, 2 metric tons of the input material MK 352 (according to the Green Dot specifications) are required to produce 1 metric ton of HDPE. In this case, the yield is 50%. With the design documents of Quantafuel the yield increases to 65%.
- Example Polyamide: Polyamide is a higher quality plastic. The yield is between 44% and 57%. It must be taken into account that mixed plastic waste, which would otherwise be incinerated, is used to produce virgin-like plastics that can be used without restriction for food contact or for safety-relevant components in the automotive, electrical and construction industries.
- As the composition of the waste input materials is not constant, the composition of the output materials also shows some variations.
- Raw materials for the production of new plastics: up to 84% (of which approx. 60% is middle distillate, 16% light distillate and 8% heavy distillate). All these products can and will be used in BASF's Verbund production to produce virgin-like plastics by using a mass balance approach.
- Other energetically used products: up to 10% ash and approx. 7-12% non-condensable pyrolysis gas. The internally generated pyrolysis gas covers the energy demand of the plant. The external thermal energy demand is very low (<1%, e.g. for start-up processes). The ash fraction is thermally utilized within the scope of the plant approval.
- Other materially used products/fuels: None
The kind of waste produced in chemical recycling depends on the input materials and the reaction conditions.
Organic materials are potentially converted to gas, oil, wax and tar. Oil and wax can be used as raw materials for chemical production. The gas is usually used for energy generation, whereby the resulting waste gases are thermally after-treated to avoid harmful emissions. The tar will be incinerated. The right choice of process conditions is crucial to minimize the generation of waste products.
Inorganic materials (e. g. metals or glass fibers) would have to be removed, as would halogens, flame retardants and, in many cases, PET. The removal could happen either before the pyrolysis step or by purification of the raw pyrolysis oil.
The ash fraction will be analyzed, and the goal is to find a reasonable use for the fraction. One way is to feed it to a cement kiln.
With the combination of pyrolysis, purification and subsequent conversion to chemical products, we have the possibility of removing harmful substances from the material cycle that would remain after mechanical recycling.
The pyrolysis plants from which we purchase the pyrolysis oils (e.g. Quantafuel, Denmark) are operated in the EU and are therefore approved according to the respective national laws. The examination by the authorities prior to approval ensures that there is no harm to people or the environment.
Before commissioning of the plant, the relevant approval processes have been completed. The approval documents for Quantafuel from the “Skive Municipality Technical Administration” (under Danish environmental legislation) specify the maximum concentration for emissions of a wide range of substances. There are also regulations for their monitoring.
Permit from the Danish Ministry of the Environment for Quantafuel’s plant in Skive, Denmark (in Danish).
The pyrolysis oil currently used in our ChemCycling™ project, together with the applied chemical processes for the conversion into final products, ensure that the safety and quality of those products are not impacted by POPs or other unwanted substances.
The pyrolysis oil we purchase from partner companies and feed into our syngas plant or steam cracker complies with the specifications of raw materials suitable for the chemical industry. Should the pyrolysis oil change due to a wider range of plastic waste used, we will have this topic on our agenda and will continue to develop our technology accordingly to ensure the safety and quality of final products.
About products and markets
We would like to target customers in various value chains who place importance in high-value products or in demanding packaging made of recycled materials. Many companies are feeling regulatory and public pressure to increase the share of recycled materials and therefore have set a goal of using only packaging made from recycled materials in a few years’ time.
The pyrolysis oil will be used along with fossil raw materials to manufacture basic products (drop-in). Should a customer select a Ccycled™ product, the proportion of recycled feedstock to be used is calculated based on the formulation. The required fossil raw materials are then exchanged for recycled raw materials at the beginning of production. The recycled content will then be allocated to the sales product via a mass balance approach. The allocation process is certified via a third-party audit. This concept is similar to the approach used for “green” electricity.
In 2018/2019, BASF has developed pilot products with customers from various industries. The first customer products produced in the ChemCycling™ project include mozzarella cheese packaging, refrigerator components and insulation boxes. The products were produced on a pilot scale and tested by the customers for the corresponding applications.
In 2020, packaging were the first commercial products that have been launched by customers.
BASF is clearly aiming for material recovery and not for energetic use of the pyrolysis oil. Waste to fuel may have a value to reduce the use of fossil fuels in transport or to improve plastics waste management in countries with little infrastructure. However, it diverts materials from the materials circle, and is therefore a one-time effect. Future use of the resource is not possible. Fractions which are used energetically are not classified as chemically recycled products.