Plastics are derived from crude oil, and thus inherently incorporate carbon. In addition, plastics pose significant disposal problems and other post-life management challenges.
Compared to oil-based plastics, bioplastics have a lower carbon footprint as they are derived from renewable and bio resources. In addition, some of them are biodegradable. Bioplastics are thus both a low carbon and low pollution alternative.
About 2.5 million tons of bioplastics are produced every year, with about 50% of it being biodegradable bioplastics. Bioplastics currently however constitute a small percentage of the 350 million tons per year plastics market, but the 2020-2030 period could see significant growth in this sector.
Biodegradable plastics are dominated by PLA, which is produced from sources such as corn. Starch-based bioplastics (PHA and PHB) are the other prominent biodegradable bioplastics category. Durable bioplastics come in the form of BioPET, BioPE, Bio-polyurethane and bio-based polyamide (nylon).
Technologies are emerging to make bioplastics perform as well as their equivalent fossil plastic counterparts. However, two challenges remain: One, the standards and benchmarks for bioplastics are still evolving and the end user segment is thus not fully confident of using bioplastics for many large-applications. Two, the cost of many bioplastic resins are much higher than their comparable or equivalent conventional plastic resins (about 3x in 2020).
For the 2020-2030 period, innovations in bioplastics and biopolymers can expected around bio-based plastics for enhancing the performance of many types of biodegradable bioplastics, industrial bioplastics & biopolymers, a focus on bio-PET & bio-based foodware, biodegradable polymer additives, and enhancing the recycling infrastructure for bioplastics.
Switching from petroleum and other conventional materials to biomass as raw material could result in significant decarbonization. While bioplastics are the most prominent product in this transformation, they are not the only significant one. In fact, there could be others such as bio-based construction materials that have an equal - or even higher - decarbonization potential compared to bioplastics.
Focussing on plastics, for instance, across their business lifecycle, plastics account for about 3.8% of total global greenhouse gas emissions, close to 2 billion tons CO2 equivalent per year (60% of this in upstream production, 25% in conversion and 15% in end of life - incineration). While their bio-based plastic replacements or substitutes will also have a carbon footprint owing to emissions from their manufacturing processes, the per unit carbon footprint will be significantly lower than that for the fossil plastic owing to their bio origin.
Considering another prominent example, using timber instead of concrete for building and construction could potentially reduce construction related emissions significantly, as trees absorb CO2 over their lifetime and therefore act as carbon sinks. If well-maintained, sustainably sourced timber structures can effectively stock CO2 for as long as the material is intact, possibly to be reused and maintained beyond the lifetime of an initial building. Similar reasoning goes for the use of wood and bamboo products for green roofs and façades, and for earth and cementitious materials reinforced with bio-based fibers. Interestingly, some studies observed that these bio-based materials can act not only to reduce embodied carbon and energy but also to provide better thermal conditions with less energy consumption at operational stage to the buildings, which can also be considered climate adaptation strategies.
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Bio-based Materials Decarbonization Avenue
