Pyrolysis: A New Option for Plastic Waste

We are on the verge of turning our plastic waste into fuel through pyrolysis. This is an exciting development since our current best options for plastic waste, recycling, landfilling and incinerating are only partial, stop-gap answers to our waste problem.

Recycling – We recycle only 9% of our plastic waste, and this figure is dropping since China stopped importing our scrap this year. We can only recycle plastic waste if there’s a market for it, and nobody wants used, low-value chip bags, forks or strawberry containers. PET (water bottles) and HDPE (milk jugs) have a good domestic market, but these aren’t infinitely recycled into new water bottles and milk jugs; they’re down-cycled into fabric. Once the fabric’s useful life is over it’s garbage.

Landfills – Most of our plastic scrap ends up in landfills, but landfills are filling up and big cities don’t have room to build more. New York City sends trash to a landfill 600 miles away. A landfill  600-miles away is still better than the open dumps in developing countries. If plastic waste is brought to an open dump (the “if” is big in countries with spotty waste pick-up) the waste may still leak out into the environment and end up in the ocean.

Incineration – Burning plastic waste does make it go away, but at a high price. It produces toxic dioxin, mercury and lead. Greenhouse gases released during incineration exacerbate another problem we’re trying to fix, global warming. Incinerators are called “Waste to Energy” plants, but energy is just a small byproduct of incineration. Plastic waste has a high energy value, but this is mixed in with soggy trash that doesn’t burn easily.

Finally there is a new option to deal with our plastic waste. Pyrolysis turns plastic, which is made from petroleum, back into petroleum. In pyrolysis, plastic is heated under pressure to around 500 degrees C in a sealed system with no oxygen. This produces gases, liquid oil and char. The gases, like methane and propane are used to heat the plastic and create electricity. The liquid oil can be refined into a number of different fuels and sold. Char is a solid, high-carbon material that can be used for fuel, road construction or landfilled. Pyrolysis does not require intensive sorting and washing of plastic waste like recycling does, and it can use unwanted, low-value plastic waste for feedstock. The resulting oil has a low sulfur content which burns cleanly, lubricates well and emits less greenhouse gas.

There are small-scale pyrolysis plants in the United States, the UK and Japan, each with slightly different processes and end products. RES Polyflow will open the first commercial-scale pyrolysis facility in the US in 2019. The Indiana facility will convert 100,000 tons of co-mingled, low-value plastic waste into 18 million gallons of ultra low sulfur diesel and 5 million gallons of industrial wax each year, thus reducing our dependance on fossil fuels. Reports also claim that pyrolysis is economically feasible.

The BlueTube community is watching with eager anticipation! Our plastic waste problem hasn’t been solved yet, so remember to reduce, recycle and reuse. Reuse your plastic bags by adding them to the BlueTube at your beach. Make it easy for everyone to grab a bag, pick up trash and throw it away so we can all keep plastic out of our ocean and off our beaches. If your favorite shore doesn’t have a BlueTube, it should!