Based on renewable feedstock and comprised of biodegradable materials, bioplastics are becoming increasingly popular as an alternative to traditional, petroleum-based plastic products. Not only can bioplastics help to eliminate the need to consume fossil resources and reduce greenhouse gas emissions, but they can also contribute to a more efficient and sustainable waste management system. Read on to learn more about the impact that bioplastics can have on various methods of waste management.
Prevention and reduction
In order to stop waste before it starts, manufacturing processes and materials must be able to minimize the use of resources in production and maximize the functionality and durability of the resulting product. Bioplastics have proven to be very successful in these efforts, with products becoming increasingly stronger (and thus longer lasting), as well as lighter and thinner (and thus containing less waste, which must eventually be disposed of in some manner).
Like their conventional counterparts, bioplastic products are easily reused. Everything from bottles manufactured from biobased PET (or polyethylene terephthalate, a very common clear plastic) to shopping bags made of starches or biobased PE (polyethylene, which is derived from bioethanol) or PLA (polylactic acid, which is derived from fermented starch) can be reused multiple times over the course of their potentially long life spans.
For both biobased and conventional plastic products, a number of factors—including product design, material composition, and cost effectiveness—are used to determine whether or not recycling is a potential waste management option. In general, products that are easiest to recycle do not involve complex material blends and are easily sorted into recyclable materials. Examples of such products include shopping bags or other large surface films, large hollow containers like bottles or clamshell packaging, and construction materials such as window frames.
Fortunately, the biobased versions of PE and PET, which are becoming more widely used in bioplastic production, are chemically and physically identical to their petroleum-based equivalents. This means that bioplastics can be easily handled by established recycling streams and facilities, and they do not require the creation of any special infrastructure or new processes in order to be properly managed.
For other types of bioplastics that are not recyclable under existing streams, experts estimate that new, separate streams for these materials will be created as soon as the commercial market for such products has grown sufficiently to cover the necessary investment in their disposal technology. Recycling feasibility tests for biobased PLA, for example, are currently ongoing in Belgium, Germany, and the US.
The fact that some bioplastics are biodegradable or compostable is a huge benefit to the waste management industry in that it increases the available options for such products’ end-of-life treatment.
An especially important feature of biodegradable and compostable plastics is that they can be composted even when mixed with biowaste. Compostable take-out containers from a restaurant provide a clear example of this benefit. When a container has been soiled by food and organic matter, mechanical recycling is no longer a feasible option, either for the plastic container or for the biowaste. However, if a container is biodegradable, it can be composted together with the biowaste, thus diverting both products from the landfill and contributing to the creation of more valuable compost.
However, it is important to note that not all bioplastics are biodegradable or compostable. Some, like biobased PE, can be mechanically—but not organically—recycled. In order to address the common confusion surrounding which types of bioplastic are and are not suitable for organic recycling, many countries and regulatory bodies are adopting clear labeling protocols for “compostable” products.
Feedstock and energy recovery
Due to technical difficulties or economic viability, mechanical recycling for bioplastics (and conventional plastics) is not always available. Fortunately, there are still several waste management options suitable for bioplastics that do not simply involve sending them to a landfill.
One is the recovery of plastic waste for use as a secondary raw material in certain industrial processes, such as concrete or steel production. Both bioplastics and conventional plastics are suitable for this waste management method, which can be a convenient way to handle mixed materials, as it is not very sensitive to contaminants. Another option, which can also use mixed materials and does not discriminate between biobased and conventional plastics, is gasification, a technique which applies heat to mixed waste (including both types of plastic as well as municipal waste) to produce syngas, which can then be used for electricity or fuel production, or further distilled into ethanol and methanol.
Finally, it is also possible to simply incinerate plastic waste to produce heat and energy. Due to their high calorific value, plastics are often an excellent substitute for coal or heating fuel. Again, biobased and conventional plastics are treated identically in this energy recovery process. However, bioplastics offer the additional—and significant—advantage of allowing renewable energy to be obtained from the biogenic carbon.