Polymeren, waaronder plastics, kennen we allemaal uit ons dagelijks leven. Van de plastic draagtas tot computeronderdelen en kopjes. Allemaal worden deze polymeren vervaardigd uit aardolie en afgeleide producten. De producten zijn zeer nuttig en breed toepasbaar, mede door de gunstige eigenschappen zoals warmteweerbaarheid, stevigheid en waterdichtheid. Daarentegen kennen polymeren ook een keerzijde, zoals het niet of moeilijk afbreekbaar zijn in de natuurlijke omgeving en de nadelen van het gebruik van fossiele bronnen: hun eindigheid en de ongecontroleerde emissie van broeikasgassen die verband houdt met klimaatverandering. Dit is een zichtbaar probleem bij onder meer De Plasticsoep, waar geen of beperkte afbraak plaatsvindt van plastics in de oceaan. De zoektocht naar alternatieven is daarom volop aan de gang.
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For the future circular economy, renewable carbon feedstocks manifest considerable promise for synthesizing sustainable and biodegradable polyhydroxyalkanoate (PHA). In this study, 16 wt% and 30 wt% PHA (cell dry weight) are respectively produced by thermophilic Caldimonas thermodepolymerans from beechwood xylan and wheat arabinoxylan as the sole carbon source. Moreover, an in silico study of the potential xylan-degrading proteins was conducted using proteome sequencing and CAZyme specialized bioinformatic tools. This study demonstrates the feasibility of utilizing complex polysaccharide substrates for PHA biosynthesis, thereby potentially eliminate additional processing steps and reducing overall production costs for sustainable plastic.
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Bioplastics are gaining interest as an alternative to fossil-based plastics. In addition, biodegradable bioplastics may yield biogas after their use, giving an additional benefit. However, the biodegradability time in international norms (35 days) far exceeds processing times in anaerobic digestion facilities (21 days). As the bioplastic packaging does not indicate the actual biodegradability, it is important to understand the time required to biodegrade bioplastic if it ends up in the anaerobic digestion facility along with other organic waste. For this work, cellulose bioplastic film and polylactic acid (PLA) coffee capsules were digested anaerobically at 55 ℃ for 21 days and 35 days, which are the retention times for industrial digestors and as set by international norms, respectively. Different sizes of bioplastics were examined for this work. Bioplastic film produced more biogas than bioplastic coffee capsules. The biodegradability of bioplastic was calculated based on theoretical biogas production. With an increase in retention time, biogas production, as well as biodegradability of bioplastic, increased. The biodegradability was less than 50% at the end of 35 days for both bioplastics, suggesting that complete degradation was not achieved, and thus, the bioplastic would not be suitable for use in biogas digesters currently in use.
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Plastic products are currently been critically reviewed due to the growing awareness on the related problems, such as the “plastic soup”. EU has introduced a ban for a number of single-use consumer products and fossil-based polymers coming in force in 2021. The list of banned products are expected to be extended, for example for single-use, non-compostable plastics in horticulture and agriculture. Therefore, it is crucial to develop sustainable, biodegradable alternatives. A significant amount of research has been performed on biobased polymers. However, plastics are made from a polymer mixed with other materials, additives, which are essential for the plastics production and performance. Development of biodegradable solutions for these additives is lacking, but is urgently needed. Biocarbon (Biochar), is a high-carbon, fine-grained residue that is produced through pyrolysis processes. This natural product is currently used to produce energy, but the recent research indicate that it has a great potential in enhancing biopolymer properties. The biocarbon-biopolymer composite could provide a much needed fully biodegradable solution. This would be especially interesting in agricultural and horticultural applications, since biocarbon has been found to be effective at retaining water and water-soluble nutrients and to increase micro-organism activity in soil. Biocarbon-biocomposite may also be used for other markets, where biodegradability is essential, including packaging and disposable consumer articles. The BioADD consortium consists of 9 industrial partners, a branch organization and 3 research partners. The partner companies form a complementary team, including biomass providers, pyrolysis technology manufacturers and companies producing products to the relevant markets of horticulture, agriculture and packaging. For each of the companies the successful result from the project will lead to concrete business opportunities. The support of Avans, University of Groningen and Eindhoven University of Technology is essential in developing the know-how and the first product development making the innovation possible.
Lectoraat Circular Plastics zoekt partners voor onderzoek naar de biologische kringloop van kunststoffen. Hierdoor is zij in contact gekomen met WUR en betrokken geraakt bij de NWO aanvraag ‘Microbial Recycling of Biodegradable Plastics’. Middels dit voorstel gaat een haalbaarheidsonderzoek uitgevoerd worden naar de organische fractie van kunststof verpakkingsafval voor bedrijven. Bij deze aanvraag zijn ChainCraft en Better Future Factory betrokken. De onderzoeksvraag is of de organische fractie van kunststof verpakkingsafval geschikt gemaakt kan worden voor het procedé van ChainCraft om vetzuren te maken e/o er biopolymeren uit de organische fractie gemaakt kunnen worden voor 3D printer toepassingen van Better Future Factory. De uitkomst van het onderzoek moet inzicht geven of waarde creëren uit de organische fractie voor ChainCraft en Better Future Factory haalbaar is.
It is known that several bacteria in sewage treatment plants can produce attractive quantities of biodegradable polymers within their cell walls (up to 80% of the cell weight). These polymers may consist of polyhydroxyalkanoates (PHA), a bioplastic which exhibits interesting characteristics like excellent biodegradation, low melting point and good environmental footprint. PHA bioplastics or PHBV are still quite expensive because cumbersome downstream processing steps of the PHAcontaining bacteria are needed before PHA can be applied in products. In this proposal, the consortium investigates the possibilities for eliminating these expensive and environmentally intensive purification steps, and as a result contribute to speeding up the up-take of PHA production of residual streams by the market. The objective of the project is to investigate the possibilities of direct extrusion of PHAcontaining bacteria and the application opportunities of the extruded PHA. The consortium of experienced partners (Paques Biomaterials, MAAN Group, Ecoras and CoEBBE) will investigate and test the extrusion of different types of PHA-containing biomass, and analyse the products on composition, appearance and mechanical properties. Moreover, the direct extrusion process will be evaluated and compared with conventional PHA extraction and subsequent extrusion. The expected result will be a proof of principle and provide an operational window for the application of direct extrusion with PHA-containing biomass produced using waste streams, either used as such or in blends with purified PHA. Both the opportunities of the direct extrusion process itself as well as the application opportunities of the extruded PHA will be mapped. If the new process leads to a cheaper, more environmentally friendly produced and applicable PHA, the proof of principle developed by the consortium could be the first step in a larger scale development that could help speeding up the implementation of the technology for PHA production from residual streams in the market.
