Issue 05/2022

Automotive Category 10

Automotive Category 10 Years ago Published in bioplastics MAGAZINE Basics Plastics made from CO 2 Basics First plastics from CO 2 coming onto the market - and they can be biodegradable Basics Photosynthesis Metabolism Carbohydrates Fig. 2: The carbon cycle as occurring in nature (left) and the envisioned carbon cycle for the ‘CO 2 Economy’ (right). CO 2 CO 2 Bayer Material Science exhibited polyurethane blocks at ACHEMA, which were made from CO 2 polyols. CO 2 replaces some of the mineral oils used. Industrial manufacturing of foams for mattresses and insulating materials for fridges and buildings is due to start in 2015. Noteworthy is the fact that the CO 2 used by Bayer Material Science is captured at a lignite-fired power plant, thus contributing to lower greenhouse gas emissions. Implementing a CO 2 economy These examples, combined with the strong research efforts of different corporations and national research programs, are disclosing a future where we will probably be able to implement a real ‘CO 2 Economy’; where CO 2 will be seen as a valuable raw material rather than a necessary evil of our fossil-fuel based modern life style. Steps toward the implementation of such a vision are already in place. The concept of Artificial Photosynthesis (APS) is a remarkable example (Fig. 2). This field of chemical production is aiming to use either CO 2 recaptured from a fossil fuel combustion facility, or acquiring Artificial Photosynthesis By Fabrizio Sibilla Achim Raschka Michael Carus nova-Institute, Hürth, Germany Energy / Material Resources Industrial usage Thinking further ahead, in a future when propylene oxide will be produced from methanol reformed from CO 2 , PPC will be available derived 100% from recycled CO 2 , therefore making it very attractive for the final consumer. PPC is also a biodegradable polymer that shows good compostability properties. These properties, when combined with the 43% or 100% ‘Recycled CO 2 ’ can contribute to the development of a plastic industry that can aim at being sustainable in its three pillars (social, environmental, economy). Other big advantages of PPC are its thermoplastic behaviour similar to many existing plastics, its possibility to be combined with other polymers, and its use with fillers. Moreover, PPC does not require special tailor-made machines for its forming or extruding, hence this aspect contributes to make PPC a ‘ready to use’ alternative to many existing plastics. PPC is also a good softener for bioplastics: many biobased plastics, e.g. PLA and PHA, are originally too brittle and can therefore only be used in conjunction with additives in many applications. Now a new option is available which can cover an extended range of material characteristics through combinations of PPC with PLA or PHA. This keeps the material biodegradable and translucent, and it can be processed without any trouble using normal machinery. It must be pointed out that it is not easy to give an unambiguous classification to PPC, but it falls more into a grey area of definitions. As discussed above, it can be prepared either from CO 2 recovered from flue gases and conventional propylene oxide, and in this case although not definable as ‘bio-based’ CO 2 from the atmosphere together with water and sunlight to obtain what is often defined as ‘solar fuel’ - mainly methanol or methane. The word ‘fuel’ is used in a broad sense: it refers not only to fuel for transportation or electricity generation, but also to feedstocks for the chemicals and plastics industries. However research is also focused on other chemicals, such as, for example, the direct formation of formic acid. Efforts are in place to mimic the natural photosynthesis to such an extent that even glucose or other fermentable carbohydrates are foreseen as possible products. Keeping this in mind, a vision where carbohydrates, generated by APS, will be used in subsequent biotechnological fermentation to obtain almost any desired chemicals or bio-plastics (such as PLA, PHB and others) can become reality in a future that is nearer than expected. The Panasonic Corporation for example, released its first prototype of a working APS device (Fig. 3) that shows the same efficiency of photosynthetic plants and is able to produce formic acid from water, sunlight and CO 2 ; formic acid is a bulk chemical that is required in many industrial processes. H 3 C O propylene oxide it may still be attractive for its 43% by wt. of recycled CO 2 and its full biodegradability. It can in theory also be produced using CO 2 recovered from biomass combustion, thus being classified as 43% biomass-based (25% biobased according to the bio-based definition ASTM D6866). As already mentioned above, if propylene oxide could be produced from the oxidation of bio-based propylene, then it can be declared 57% biomass-based or 100% bio-based if CO 2 and propylene oxide are both bio-based. As more and more different plastics and chemicals in the future will be derived from recycled CO 2 they will need a new classification and definition such as ‘recycled CO 2 ’ in order not to bewilder the consumer. Polyethylene carbonate and polyols Polypropylene carbonate is not the only plastic that recently came onto the market. Other remarkable examples are the production of polyethylene carbonate (PEC) and polyurethanes from CO 2 . The company Novomer has a proprietary technology to obtain PEC from ethylene oxide and CO 2 , in a process similar to the production of PPC. PEC is 50% CO 2 by mass and can be used in a number of applications to replace and improve traditional petroleum based plastics currently on the market. PEC plastics exhibit excellent oxygen barrier properties that make it useful as a barrier layer for food packaging applications. PEC has a significantly improved environmental footprint compared to barrier resins ethylenevinyl alcohol (EVOH) and polyvinylidene chloride (PVDC) which are used as barrier layers. CH 3 O CO 2 C catalyst C arbon dioxide is one of the most discussed molecules in the popular press, due to its role as greenhouse gas (GHG) and the increase in temperature on our planet, a phenomenon known as global warming. Carbon dioxide is generally regarded as an inert molecule, as it is the final product of any combustion process, either chemical or biological in cellular metabolism (an average human body emits daily about 0.9 kg of CO 2 ). The abundance of CO 2 prompted scientists to think of it as a useful raw material for the synthesis of chemicals and plastics rather than as a mere emission waste. Traditionally CO 2 has been used in numerous applications, such as in the preparation of carbonated soft drinks, as an acidity regulator in the food industry, in the industrial preparation of synthetic urea, in fire extinguishers and many others. Today, as CO 2 originating from energy production, transport and industrial production continues to accumulate in the atmosphere, scientists and technologists are looking more closely at different alternatives to reduce flue-gas emissions and are exploring the possibility of using CO 2 as a direct feedstock for chemicals production, and first successful examples have already been achieved. The carbon cycle on our planet is able to recycle the CO 2 from the atmosphere back in the biosphere and it has maintained an almost constant level of CO 2 concentration over the last hundred thousand years. The carbon cycle fixes approx. 200 gigatonnes of CO 2 yearly while the anthropogenic CO 2 accounts for about 7 gigatonnes per year (3-4% of the CO 2 fixed in the carbon cycle). Even if this quantity looks small, we must bear in mind that this excess of CO 2 has been accumulating year after year in the atmosphere, and in fact we know that CO 2 concentration rose to almost 400 ppm from 280 ppm in the preindustrial era. In recent years different processes have been patented and are currently used to recover CO 2 from the flue-gases of coal, oil or natural gas, or from biomass power plants. The recovered CO 2 can be either stored in natural caves, used for 44 bioplastics MAGAZINE [05/12] Vol. 7 O O polypropylene carbonate n Enhanced Oil Recovery (EOR), or can be used as feedstock for the chemical industry. The availability of a high quantity of CO 2 triggered different research projects worldwide that are aimed at finding a high added value use for what otherwise is a pollutant. Plastics from CO 2 When it comes to the question of CO 2 and plastics there are many different strategies aiming at either obtaining plastics from molecules derived directly from CO 2 or using CO 2 in combination with monomers that could either be traditional fossil-based or bio-based chemicals. Moreover, the final plastics can be biodegradable or not, depending to their structures. Noteworthy among already existing CO 2 derived plastics are polypropylene carbonate, polyethylene carbonate, polyurethanes and many promising others that are still in the laboratories. dear readers Polypropylene carbonate Polypropylene carbonate (PPC) is the first remarkable example of a plastic that uses CO 2 in its preparation. PPC is obtained through alternated polymerization of CO 2 with PO (propylene oxide, C 3 H 6 O) (Fig. 1). The production of PPC worldwide is rising and this trend is not expected to change. Polypropylene carbonate (PPC) was first developed 40 years ago by Inoue, but is only now coming into its own. PPC is 43% CO 2 by mass, is biodegradable, shows high temperature stability, high elasticity and transparency, and a memory effect. These characteristics open up a wide range of applications for PPC, including countless uses as packaging film and foams, dispersions and softeners for brittle plastics. The North American companies Novomer and Empower Materials, the Norwegian firm Norner and SK Innovation from South Korea are some of those working to develop and produce PPC. Today PPC is a high quality plastic able to combine several advantages at the same time. Are plastics made from CO 2 to be considered as bioplastics? Not necessarily, I would say. If these plastics are in fact biodegradable they would fall under our definition of bioplastics (see our revised and extended ‘Glossary 3.0’ on page 50ff). And if such plastics are made from CO 2 that comes, via combustion or other chemical processes, from fossil based raw materials, we should at least avoid calling call them biobased. Nevertheless, I believe that the use of such CO 2 to make plastics (or other useful products) and so prevent, or at least delay, the CO 2 from entering the atmosphere, is a good approach in the sense of our overall objectives. It will certainly require further evaluation and even standardisation until CO 2 based plastics can/will be defined as a new (bio-) plastic class or category. Plastics produced from CO 2 , definitely one of the major topics in this issue of bioplastics MAGAZINE, is accompanied by further highlights. In several articles we report about biobased polyurethanes and elastomers and we present some articles about fibres and textile applications. In this issue we also present the five finalists for the 7 th Bioplastics Award. The number of entries was not as large as in previous years, however I doubt that the innovative power of this industry is Fig. 1: Route to PPC from CO 2 and propylene oxide CO 2 reduction bioplastics MAGAZINE [05/12] Vol. 7 45 Water oxidation by light energy water Carbon dioxide Oxygen Formic acid Metal catalyst Fig. 3: Panasonic scheme of its fully functioning artificial photosynthesis device (Courtesy of Panasonic Corporation). flagging. So we kindly ask all of you to keep your eyes open and report interesting innovations that have a significant market relevance whenever you see them. The 8 th Bioplastics Award is definitely coming. The 7 th ‘Bioplastics Oskar’ will be presented on November 6 th in Berlin at the European Bioplastics Conference. Until then, we hope you enjoy reading bioplastics MAGAZINE Sincerely yours Michael Thielen Follow us on twitter! www.twitter.com/bioplasticsmag Light source Nitride Semiconductor Be our friend on Facebook! www.facebook.com/bioplasticsmagazine 46 bioplastics MAGAZINE [05/12] Vol. 7 bioplastics MAGAZINE [05/12] Vol. 7 54 bioplastics MAGAZINE [05/22] Vol. 17

Automotive In September 2022, Alex Thielen, Editor of bioplastics MAGAZINE says: Already 10 years ago the topic of CO 2 -based plastics was featured in bioplastics MAGAZINE. And our very own Michael Thielen wrote in the editorial on page 3 whether or not they should be considered bioplastics. Back then we already made a clear distinction between bioplastics and CO 2 -based plastics, as they should only be considered bioplastics, if either the CO 2 comes from a biobased source or if they are biodegradable themselves. Now, 10 years later it should be more than obvious that we still agree with Michael’s statement about the usefulness of CO 2 -based plastics as we now have a separate segment that showcases topics related to CCU (Carbon capture and utilisation) or CO 2 -based plastic. Editorial However, the distinction is clear, CO 2 -based plastics tend to be a category of their own – some might also be bioplastics but many, or even most, are not. However, the waters around the definitions of (bio)plastics are already rather murky, or as Jan Ravenstijn said in What’s in a name, “ask ten people for the definition (of plastic) and you’ll get at least eight different answers” (see bM 03/22, p. 46). So instead of muddying these waters further it seems to make sense to sidestep the whole “what is and isn’t a plastic” discussion by looking at it from a different angle – where does the carbon come from? In any case, it is clear that the idea of CO 2 - based plastics is not new as even in 2012 we had articles about CO 2 -based polypropylene carbonate polyols, CO 2 -based polyurethanes, and a basics article about plastics made from CO 2 in general. The last one on this list was written by industry experts from the novainstitute that a couple of years ago founded the Renewable Carbon Initiative which focuses on the feedstock issue of the plastics crisis. The concept of renewable carbon creates a neat framework through which we can look at plastics, or plasticlike materials, through a new lens. At the end of the day, the goal is to move away from fossil-based plastics, we want to defossilise the industry (as it is quite impossible to decarbonise). To be clear defossilisation in that sense does not mean to avoid “fossil carbon”, but to avoid making plastics from newly extracted fossil resources. Some processes that fall under renewable carbon like advanced recycling (or any recycling for that matter) or CCU may have fossil carbon in it, yet are useful (though as a side note, CO 2 from direct air capture would technically count as bio due to its 12 C/ 14 C ratio). Again we can see how definitions of what might count as fossil can get in the way of solutions. And while some might not necessarily agree with the inclusion of CO 2 -based plastics in this, by now almost iconic publication that used to focus exclusively on bioplastics (as the name might have given away), we think that it is more important to look at proper solutions for the vast amount of challenges we as an industry face. I would be more than happy if bioplastics, both biobased and biodegradable, could solve all these problems, but as history has shown change can be slow and cumbersome even if it is so urgently necessary. Therefore it is my opinion that we need to use all the available tools to challenge and change the status quo. That includes CCU and yes that also includes advanced recycling technologies. There will be dead ends and false prophets that will try to sell their greenwashing as proper solutions, but that doesn’t make CO 2 -based and advanced recycling-based plastics the enemy – the enemy has always been misinformation and those that are keen to profit from false claims and straight out lies. Will this happen with CCU/CO 2 -based plastics? Probably, yes. Did this happen and is still happening with bioplastics? Sadly, yes. But if we even want to have a shot at solving these humongous issues we need more diverse solutions that tackle the issues from different sides. Divided we will fall, together we might succeed. Categroy tinyurl.com/ccu2012 3 bioplastics MAGAZINE [05/22] Vol. 17 55