The ground-breaking Envion Oil Generator (EOG) gave its first public performance at the Montgomery County Solid Waste Transfer Station in Derwood, Maryland recently. The EOG can be fed almost any petroleum-based waste plastic and will convert it into synthetic light to medium oil for less than USD$10 per barrel. As with crude oil, the synthetic oil can then be processed into commercial fuels or even back into plastic.
Both a saint and a sinner, plastic has touched almost every part of modern life. It's everywhere - we live in homes built using it, we eat and drink from it or with it, we drive encased in it, we walk wearing it, we are entertained by it, this article was typed using keys made from it. It has made our lives easier and we have become utterly dependent on it. But it's this very usefulness - 20 times more plastic is produced today than 50 years ago, some 260 million tons globally - that is behind plastic's biggest problem. What do you do with it when it's reached the end of its useful life?
Until relatively recently, our disposable Western mindset would tell us to simply throw the snapped plastic fork or the empty plastic bottle out with the rubbish. Although most of us have now been whipped up into a recycling frenzy, an awful lot of plastic still ends up as waste. In the US it is estimated that less than 4 percent of plastic waste is recycled (2 millions tons, leaving about 46 million tons to be disposed of in other ways).
Whether it's incinerated (which produces hazardous emissions and toxic ash) or buried in landfill (where various toxic chemicals are released during the slow degradation of plastics) or dumped at sea (that accounts for millions of tons of hazardous floating garbage, such as the Great Pacific Garbage Patch) - humans, animals and the environment suffer as a result.
Energy capture
Given that an awful lot of the plastic we use every day is derived from fossil fuels such as gas and oil and as such contains huge amounts of stored energy which simply goes to waste when it's thrown away, wouldn't it be great if we could capture all of this energy and re-use it?
That's essentially what Envion (a portmanteau of environment and vision) says its EOG does. A reactor converts waste plastic feedstock into oil through low temperature thermal cracking in a vacuum, extracting the hydrocarbons embedded in petroleum-based plastic waste without the use of a catalyst. Roughly around 62 percent of what goes into the unit is successfully converted into oil.
Interestingly, the EOG makes use of some of the by-products of the conversion process to power the unit. Vent gas is recycled to provide electricity and excess oil residue is transformed into emulsified heavy oil.
When Gizmag asked about other by-products, Envion's Todd Makurath told us: "There are three byproducts of the EOG operation: oxygen, carbon dioxide and ash. First it should noted that the EOG is actually carbon negative as an oil producer. That being said, we are an environmentally-focused company and aren't satisfied with just beating the average. The CO2 released by the EOG is minimal and well-within all EPA guidelines," said Makurath.
"The ash that is produced is the result of the use of our sludge dryer. We try to contain and reuse whatever we can in the system and as sludge is produced within the EOG it is fed into the sludge dryer where any excess or residual oil is extracted and fed back into the system to increase efficiency, and what is leftover is microwaved to produce a non-hazardous ash. There are no gaseous emissions from the sludge dryer. When all is said and done, the ash generally equates to less than 5 percent by weight of what was processed by the machine."
Each Envion unit is assembled on a single mobile base platform with dimensions 47ft x 13ft (14.3m x 4m) and is capable of processing up to 10,000 tons of plastic waste annually, producing three to five barrels of refined (99 percent sediment-free) petroleum product per ton of plastic waste (that's over one million gallons of oil per year per unit). Scaling up the unit merely involves adding more reactors, not whole systems.
Unlike current recycling methods, where mixing different kinds of plastic is a big no-no, the EOG has an 'all plastic is welcome' policy, no segregation here! Polyethylene terephthalate (PET); high and low density polyethylenes (HDPE and LDPE); polyvinyl chloride (PVC); polypropylene (PP) and polystyrene (PS) as well as several other plastic materials, such as GPPS, EPS, HIPS, and PA, can all be converted to oil by the unit.
The company estimates that its solution would have been able to accept and process between 60-80 percent of the total plastic waste thrown away in the U.S. in 2007 (based on EPA statistics).
At the recent launch in Maryland, company founder Michael S Han commented: "The Envion Oil Generator provides a revolutionary solution to the problem of plastic waste by transforming it from an environmental hazard into a sustainable, renewable energy source."
After 15 years in development, the EOG is now ready for deployment throughout the U.S. and beyond but Envion isn't planning to stop there. Its research and development boffins are currently looking into applying the conversion technology to other types of petroleum-based waste products, such as vehicle tires.
The good, the bad and...
The good - re-using the millions of tons of plastic waste instead of burying, dumping or burning it is undoubtedly a good thing. With processing costs of less than USD$30 per ton compared to other methods in excess of USD$200 per ton, it's a cheaper way of managing plastic waste, too.
The bad - the end product is oil which means that all the environmental consequences associated with it are likely to continue for some time to come.
The last great oil shock in the late 1970s fueled some wonderful ideas for alternatives to polluting power but as the distress died away, so did the ideas. The realization that oil reserves are finite, that some day soon oil production will come to an end, has finally started to hit home. A great innovation in itself, it would be a great shame if the widespread application of the Envion technology put a premature end to the increasingly numerous clean-power innovations that are regularly showcased on Gizmag's pages.
The following video shows the EOG in action:
