Hawaii – The Great Pacific Garbage Patch Opportunity

Picture of trash in the pacific ocean

By: T. Jeffersonian

Hawaii sits at the center of swirling ocean currents, just east of the Great Pacific Garbage Patch. The Great Pacific Garbage Patch, also described as the Pacific Trash Vortex, is a garbage patch in the central North Pacific Ocean.  The collection of plastic and floating trash originates from the Pacific Rim, including countries in Asia, North America, and South America.  It is divided into two areas, the Eastern Garbage Patch between Hawaii and California, and the Western Garbage Patch extending eastward from Japan to the Hawaiian Islands.  

Humans produce 420 million tons of plastic annually, and as much as 14 million tons of plastic enter the ocean. Despite the common public perception of the patch existing as giant islands of floating garbage, its low density prevents detection by satellite imagery, or even by casual boaters or divers in the area. This is because the patch is a widely dispersed area consisting primarily of suspended fingernail-sized or smaller bits of plastic, often microscopic, particles in the upper water column known as microplastics. 

Hawaii’s shorelines catch plastic from all over the world, some of the garbage is decades old.  Once hailed as a wonder-material, plastic is now a reviled pollutant found on every corner of the planet and even deep inside our own bodies. Hawaii’s remarkable wildlife has been particularly hard hit. Across the islands, marine wildlife agents continue to find humpback whales ensnared in abandoned fishing nets and turtles hooked on plastic bags, while fishermen routinely haul in catches of fish with plastic-filled bodies.  Reef fish, commonly eaten by local fishermen, are often the most likely to consume microplastic, but the contamination does not stop there. Many of those reef fish are eaten by larger fish, such as tuna, which absorb the plastics into their fatty tissues. With a culture that celebrates fresh fish and raw dishes such as poke, many Hawaiians rightly fear the growing health repercussions associated with ingested microplastics. 

Places like Hawaii will continue to bear the brunt of the planet’s plastic dependency. Hawaii’s own efforts to push back on rampant plastics consumption have been among the United States’ boldest.  In 2015, it became the first state in the United States to ban plastic bags at grocery stores. Maui and the Big Island banned polystyrene containers. Honolulu, in December 2019 passed one of the most restrictive plastic bans in the United States, prohibiting all single-use plastic food containers, including straws and utensils, as well as Styrofoam.  The Coronavirus pandemic however has brought with it a renewed and even greater global dependency on single use plastics including gloves, masks, dishes, cups, and utensils.  Plastics are essential for creating a barrier against nasty viruses, bacteria, and parasites, which is important during disasters such as the Coronavirus.  Therefore, the tragic and undeniable fact about plastics is that they will never go away.  

Hawaii must begin to see the Great Pacific Garbage Patch as an opportunity to diversify and make its post-pandemic economy much more resilient.  A circular product life cycle for plastic ocean garbage must be created in Hawaii.  The physical features that make plastic useful also make it difficult to recycle and hard to replace in our manufacturing chain.  We linearly dispose of plastics in unsustainable ways — 91 percent of plastics are not recycled.  Most people believe that plastics recycling is severely restricted: that only a few types can be recycled at all. This is unsurprising.

Technologically, all plastic polymers are 100 percent recyclable. Some of them have the perfect cradle-to-cradle lifecycle: they can be used again and again to produce the same goods. Some plastics can be reused just as they are by shredding them into flakes, melting, and then reusing the materials in new molds.  To help repurpose plastic waste, scientists and inventors are creating novel uses for plastics that would otherwise end up in the trash, or alternatives to the most wasteful plastic products that we use today.  With a seemingly endless supply of material floating just off its shores and while facing both an affordable housing shortage and a rising climate change danger, Hawaii’s post pandemic diversified economy must incorporate and industrialize these novel concepts.  

One novel opportunity to use unrecyclable plastic waste is as fuel in the manufacturing of cement.  Manufacturing cement involves heating limestone in large furnaces at temperatures of 1,450 degrees Celsius until it liquifies. The fuel widely used to create cement is coal, of which cement factories burn half a billion tons every year around the planet. Some of this vast quantity of coal could be replaced by non-recyclable plastics. The Japanese company Blest Corporation already sells a portable machine to convert domestic plastic waste into fuel in a simple, affordable way.  

Another opportunity to reuse plastic garbage is seen in construction materials.  Plastics are strong, durable, waterproof, lightweight, easy to mold, and recyclable – all key properties for construction materials.  Any plastic waste can already be shredded and used as filler for asphalt roads, which Hawaii will need plenty of as sea levels rise and erode our coastal roads. Existing initiatives are also promising as well for using plastic garbage to create construction blocks, but these initiatives are not yet reproducible on an industrial scale.  Initiatives include a range of prospective building materials using a mix of virgin and recycled plastics – colored PET (polyethylene terephthalate) bottles, polypropylene, polyethylene – and other local waste-stream materials, such as hemp, sawdust, concrete waste and red mud.  Researchers are adjusting the properties of the available materials and then recombining them through the Rotational Molding process.  Rotomolding is a plastics molding technology which is ideal for making hollow articles.  It is a casting technic but unlike most other plastics processes there is no pressure involved. Molds for the process are relatively inexpensive as they do not have to withstand pressure and therefore relatively short production runs can be made very economically.  

Rotomolding is already used to make a very diverse range of products. The process offers product designers exceptional freedom as just about any shape can be produced. There is almost no limit to the size of moldings and there are literally thousands of construction applications alone.  Researchers intend to maximize the use of garbage plastics in each rotomolded construction block. Blocks made of 25 percent recycled plastics have already performed extremely well in mechanical tests with blocks made of 50-100 percent reused plastics currently undergoing testing.  Researchers are already thinking about the aesthetics of the blocks. Blends of recycled mixed-color plastics usually end up with a grey or black color which would be bad for beat absorption in tropical areas such as Hawaii. To enable color, blends of virgin or recycled plastics overlay the main bulk of the repurposed plastic blocks.