Singapore’s plastic recycling conundrum: Could bioplastics hold the key?

Singapore, often touted for its proactive commitment to sustainability and green initiatives, has a plastic recycling problem. In the past year, the nation generated over one million tonnes of plastic waste, but only 6%, roughly 57,000 tonnes, were recycled. This dismal recycling rate underscores a pressing issue that is unobvious yet pervasive, demanding urgent attention and propositions of solutions.

Plastic recycling in Singapore

In Singapore, plastic waste typically faces one of two outcomes: recycling or incineration. By the country’s definition, effective plastic recycling starts with categorizing plastics into seven distinct groups, including:

1. Polyethylene terephthalate (PET)
2. High-density polyethylene (HDPE)
3. Polyvinyl chloride (PVC)
4. Low-density polyethylene (LDPE)
5. Polypropylene (PP)
6. Polystyrene (PS)
7. Other plastics, including polycarbonates (PC)

These groups are segmented based on their unique properties, in particular melting points as it is an important consideration when processing and recycling plastic.

There are four key stages to plastic recycling:

1. Sorting: Plastics are sorted based on their classification before processing.
2. Crushing and blending: Plastics are crushed into smaller fragments and blended to form a consistent, homogenous mixture.
3. Melting and forming: The blended mixture is melted and passed through a screen to create strands of plastic.
4. Pelletization: These plastic strands are cut into pellets, which can be used to create new products.

Challenges in Singapore’s plastic recycling practices

While some countries have mandated the separation of recyclables into paper, plastic, and metal, Singapore has instead adopted a commingled system, allowing residents to deposit recyclables of any type into blue recycling bins situated islandwide.

In a reply to Singaporean politician Murali Pillai, who had probed into the efficacy of the commingled system, Grace Fu, Singapore’s minister for sustainability and the environment, emphasized that the commingled system has been adopted to simplify recycling for residents, aiming to enhance cost-effectiveness and reduce carbon footprints.

However, while the commingled system offers convenience, it also presents significant challenges. One of its most pressing issues is the resultant high contamination rate of approximately 40%. Contamination occurs when non-recyclable waste, contaminated recyclables, or reusable items are incorrectly placed into recycling bins. When these items are mixed with recyclables within bins, they are difficult to filter out and may result in cross-contamination. This often results in the entire pool of materials getting incinerated, defeating the original purpose

Additionally, Singapore’s land constraints have compelled the country to export a substantial portion of its plastic waste to other nations for recycling. According to CNA, around 92% of Singapore’s plastic waste is exported, mainly to Malaysia, while China and Vietnam also import some of Singapore’s plastic waste.

However, the landscape of plastic waste management in these recipient countries is gradually changing. China has already implemented an import ban on plastics, while Malaysia and Vietnam are imposing stricter regulations on the quantity they are willing to accept.

For Singapore, establishing recycling plants on home ground is challenging due to its limited land area and high population density. The low economies of scale result in recycled pellets being produced at a cost higher than new plastic pellets. This underscores the complexities of plastic recycling and the need for innovative solutions to address the issue effectively.

How bioplastics could solve the problem

In the endeavor to address the issue of plastic waste, bioplastics have emerged as a possible solution. Bioplastics are generally bio-based, which means they are sourced from biomass—organic materials from plants and animals. They offer a sustainable alternative to traditional plastics, and can fall under either one of three classifications:

• Non-biodegradable, and fully or partially bio-based.
• Biodegradable, and petroleum-based.
• Biodegradable, and fully or partially bio-based.

However, biodegradability can be a confusing concept as most materials will eventually biodegrade to some extent, according to Daniel Carraway, co-founder and CEO of RWDC Industries, a Singapore-based biodegradable material producer. Instead, Carraway emphasizes the need to differentiate materials based on multiple factors: bio-based nature, biodegradability, and compostability.

“The issue with bioplastics is that they can be just as harmful to the environment and human health and safety as petroleum-based plastics,” Carraway said.

For bioplastics to be sustainably produced, the right materials have to be selected. For example, RWDC Industries has developed a biopolymer known as polyhydroxyalkanoate (PHA). Unlike traditional plastics, PHA is biodegradable and derived from waste materials such as cooking oil and olive oil extraction byproducts. These are materials that would otherwise be unfit for human use and likely disposed of as waste.

In natural settings such as soil, freshwater, or marine water, PHA can biodegrade relatively quickly. PHA is also compostable. Composting is the process by which organic materials, including food waste, are decomposed by bacteria and microorganisms, transforming them into nutrient-rich compost. According to Carraway, PHAs can be composted in facilities together with food waste, grass trimmings, and other compostable materials.

However, composting is not a widely adopted practice in Singapore. Initiatives like Project Black Gold are working diligently to change that, having launched composting trials in three neighborhoods to encourage the local community to compost their food scraps.

Singapore is home to over 1,900 community gardens situated in various housing estates. These community gardens have the potential to not only support but also benefit from composting practices.

However, to fully reap the benefits of alternative solutions such as RWDC’s PHA, a broader transformation is necessary within Singapore’s context. For one, although PHA is biodegradable and compostable, integrating its usage without modifying the commingled recycling system is likely to lead to PHA being inadvertently processed within the existing recycling stream, ultimately getting incinerated due to pervasive contamination issues.

Thus, to fully realize the potential of PHA in Singapore, education and dialogue will be pivotal. “There’s a strong recognition of the necessity for these materials [such as PHA], and we collaborate with a diverse range of global brand owners to assist them in achieving their goals. This strong interest is driven by the human health and safety concerns associated with traditional plastics,” Carraway said.

RWDC serves customers in North America, Europe, and Southeast Asia, with notable interest from the food service and packaging sectors in these regions. While the PHA industry is still in its early stages, Carraway shares that the firm is operating at a pre-commercial demonstration scale. At this stage, it has generated substantial quantities of material to assist its clients in their endeavors to validate and commercialize its products. The company’s ongoing focus is on establishing commercial production facilities to realize this objective on a larger scale.

According to Carraway, it may take another three to five years before PHA becomes commonplace globally. As the industry continues to evolve and expand, alternative solutions like PHA offer a beacon of hope in the global quest for sustainability.