Production of(fuel) Diesel From Non-Recyclable Waste Plastics

Thermal technique makes clean crude replacement from mixed plastic waste. 

Waste plastic could become a more valuable commodity after developing a process that turns mixed plastic waste into a hydrocarbon-based product. 

This is the assessment of Adrian Haworth, sales and marketing director of Recycling Technologies. This company has developed WarwickFBR, a recycling system that converts mixed plastic waste (MPW) into PlaxOil, a heavy fuel alternative that can be sold or used in localised on-demand combined heat and power (CHP) plants.

Haworth explained that its WarwickFBR system produces the PlaxOil following pyrolysis of MPW. To do this, the system first shreds and dries the MPW. It then injects blended product into a fluidised bed where the long hydrocarbon chains in the polymers are broken down by pyrolysis - a multi-step process in which organic materials are decomposed by heat in the absence of oxygen - to form an energy-rich gas. This gas is then filtered to remove contamination, cooled and condensed to provide PlaxOil.

“Pyrolysis is a fairly simple process, it starts by drying plastics to be processed. They are then shredded into smaller pieces and heated in a thermal chamber. The melted plastic is continually heated until it boils and produces vapours. The vapour is passed into cooling pipes and distilled into a liquid chemically identical to regular fuel.”

The art of refining liquid hydrocarbons (crude oil) into diesel, gasoline, and fuel oils was commercially scaled decades ago. Unfortunately, refineries are technologically limited to accepting only a narrow range of liquid hydrocarbons with specific properties and minimal contaminates. Hydrocarbon streams that fall outside of accepted refinery standards have traditionally been landfilled or melted into products of low value. Unrecyclable, hydrocarbon-based waste is a significant environmental problem increasing every year. According to the Environmental Protection Agency’s 2010 Facts and Figures report, over 92% of waste plastic is not recycled. With a growth rate of approximately 8% per year, a critical need for a viable and environmentally sound, general-purpose hydrocarbon-based recycling process exists. 

The barriers and challenges are so significant that previous attempts to refine waste plastics into fuel resulted in unviable batch-based machines producing low-value, unstable mixed fuels. However, for three years, JBI, Inc. (“JBI”) has broken through these barriers and has designed and built a viable commercial-scale continuous refinery capable of processing a wide range of hydrocarbon-based waste into ASTM specification fuels. 

Research and testing of scale-up through 1-gallon, 3000 gallon, multi-kiln, and 40 ton/day processors in a plant in Niagara Falls, NY. Technical challenges encountered and lessons learned during process development will be explained in detail. 

In 2009, our technology was “molecularly audited” by IsleChem, LLC (“IsleChem”) of Grand Island, NY. In 2012, SAIC Energy, Environment & Infrastructure, LLC (“SAIC”). Numerous sources of waste plastic and users of the resulting fuel products conducted extensive audits of the technology, process, and plant. However, this technology can be applied to other waste hydrocarbon-based materials such as contaminated monomers, waste oils, lubricants and other composite waste streams.

Plastic Fuel

All around the globe, companies and individuals are starting to produce fuel from waste plastic. As only 8% of waste plastic is recycled in the US, 15% in Western Europe, and much less in developing countries, this reuse of plastic could potentially keep enormous amounts of plastic out of landfills and out of the oceans. Over 500 billion pounds of new plastic is manufactured each year, and roughly 33% of that is single-use and thrown away. As so little plastic is recycled, we need to reframe plastic waste as an underused resource vs landfill destined. If all plastic waste made it into the dump, it would indeed be mined in the future, but currently, all plastic waste does not make it into our landfills. The United Nations estimates plastic accounts for four-fifths of the accumulated garbage in the world’s oceans. We need to stop polluting our oceans with plastic before it is too late and start collecting all plastics suitable for this new fairly simple technology, a technology that is available now.

Image via: coastalcare.org

The technology is not overly complicated; plastics are shredded and then heated in an oxygen-free chamber (known as pyrolysis) to about 400 degrees celsius. As the plastics boil, gas is separated out and often reused to fuel the machine itself. The fuel is then distilled and filtered. Because the entire process takes place inside a vacuum and the plastic is melted - not burned, minimal to no resultant toxins are released into the air, as all the gases and or sludge are reused to fuel the machine.

 

For this technology, the type of plastic you convert to fuel is essential. If you burn pure hydrocarbons, such as polyethene (PE) and polypropylene (PP), you will produce a fuel that burns pretty clean. But burn PVC and large amounts of chlorine will corrode the reactor and pollute the environment. Burning PETE releases oxygen into the oxygen-deprived chamber, thereby slowing the processing, and PETE recycles efficiently at recycling centres, so it is best to recycle PETE traditionally. HDPE (jugs) and LDPE (bags and films) are polyethene, so usable as fuel as well, just slightly more polluting as a thicker, heavier fuel is created. But additional processing can turn even HDPE into clean diesel.

 Source (Plastic To Fuel • Insteading)

“Polyethylene and polypropylene are pure hydrocarbons, only they are arranged in long chains. If you chop those chains into shorter ones, you get oil, if you chop them even shorter, you get diesel, and if you chop them again, you get gasoline and eventually burnable gas.” 

www.energeticforum.com

In Niagara Falls, NY, John Bordynuik’s ‘Plastic Eating Monster’ can even vaporise thick HDPE plastic into a cleaner-burning number 2 fuel. Put plastic in one end of the machine, and out the other end comes diesel, petroleum distillate, light naphtha and gases such as methane, ethane, butane and propane. The machine accepts unwashed, unsorted waste plastics, composites and commingled materials and returns about 1 gallon of fuel from 8.3 pounds of plastic. And the processor uses its off-gases as fuel, therefore using minimal energy to run the machine. John currently has two massive steel processors up and running, with financing secured for three more to be built shortly. 

In the Philippines, Poly-Green Technology and Resources Inc. was started by Jayme Navarro whose sister asked him to come up with a way to recycle plastic bags. A plant is being built that will produce 5,000 kilos of fuel per day. www.polygreen.com.ph 

Cynar in the UK likes to call their product ‘End of Life Plastic to Diesel’ or ELPD. Their technology converts mixed Waste Plastics into synthetic fuels that are cleaner, low in sulphur and in the case of the diesel, a higher cetane than generic diesel fuel. They have a plant running in Ireland , with another to open in Bristol, UK in January and many more in the planning stage. Each Cynar plant can process up to 20 tons of End of Life Plastic per day, producing 5,000 gallons (19,000 litres) of high quality liquid fuels at a conversion rate of 95%.

Cynar will be supplying Jeremy Rowsell, a British insurance industry executive who lives in Australia, with all the plastic waste fuel he needs to fly a single-engine Cessna from Sydney to London this winter. Fuel will be in place at about 10 locations along the 10,500-mile route. The solo journey dubbed ‘On Wings of Waste’ is intended to heighten awareness of this new fuel.

Of course, it would be best if widespread environmentally friendly plastics were in use, but in the meantime, recycling existing plastics into fuel would keep the plastics out of our waterways. This process is also excellent for difficult to recycle PP and PE plastics like bottle caps, appliance plastics, nursery planters and dirty plastics such as meat wrappings. This process is not suitable for PVC or polystyrene (styrofoam). This technology could also reduce carting issues, as companies that deal with plastic waste could build mini-burners on location. 

Companies:

Japan. Sells International: e-n-ergy.com

UK: Cynar produces a synthetic fuel suitable for all internal combustion engines: cynarplc.com

Washington, DC: www.envion.com
Boosts easy installation, high efficiency, no second-time pollution.
The plant converts 6,000 tons of plastic into nearly a million barrels yearly.

Circle Pines, MN and International:  polymerenergy.com
They have a modular unit that produces 775 litres of fuel for every ton of plastic waste processing. System capacity is rated at 185 tons per month.

New York/Canada: JBI, Inc. www.plastic2oil.com
20-ton processor, 4,000 lbs. of plastic feedstock per machine per hour.

Philippines: www.polygreen.com.ph
5,000 kilos of fuel per day

Hong Kong: Ecotech Recycling Social Enterprise
A prototype machine can process three tons of plastic waste into 1,000 litres of fuel oil per day.

Las Vegas, NV: general@quadraprojects.net

 

Resources:

UNEP Policy Brief on Plastic Waste: unep.org.pdf

Northeastern University turns plastic waste into energy to drive generators: phys.org

DIY for under $800.: energeticforum.com

Peswiki Plastic and Energy page: peswiki.com
This homemade device converts around 25 kg of shredded plastic into 24 litres of diesel in 4 hours. www.emuprim.lv