In terms of environmental impact, biodiesel fuel is nicer than “ordinary” diesel. Meanwhile, styrofoam is a nasty, non-biodegradable packaging material. Now, like a scene from Back to the Future made real, scientists have discovered that dissolving styrofoam in biodiesel actually makes for a better fuel–and it gets rid of the styrofoam totally.
You can recycle pretty much every form of plastic, but styrofoam or polystyrene–used in packaging, and to make take-away cups for hot drinks–is tricky. It’s so bulky and cheap that it’s simply not economical to recycle the stuff. Which is what makes the new technique of disposing of the material in biodiesel particularly interesting. The trick has been researched by Song-Charng Kong of Iowa State University, who found that a polystyrene cup will dissolve pretty much instantly in biodiesel, like “a snowflake in water.” The resulting plastic-enhanced fuel results in increased power output from a diesel engine by up to 5%. The research shows that this is due to the new fuel’s higher viscosity–it simply pushes up the pressure inside the fuel-injection system, and thus increases the engine’s efficiency.
Nature tends to balance things out, of course–the experimentally-fueled engine kicked out more soot, carbon monoxide and nitrous oxide in its exhaust. Increased carbon particulates and monoxides have a negative impact on health, while nitrous oxide reacts in the atmosphere and sunlight to form ozone which is damaging to plants and animals when present at low-altitudes. And while that all sounds very bad, it looks like redesigning the engine’s fuel injection system to create a better fuel-burn from the new mix could reduce the emission levels back down to more acceptable figures.
So it’s possible that disposing of polystyrene in biodiesel, rather than land-fills, is a “killing two birds with one stone” maneuver. It’s notable, too, that the plastic dissolves a whole lot better in normal petroleum-based diesel–and that suggests it may also be possible to increase the power output of conventional diesel engines, which could reduce their fuel consumption. That’s not a long-term solution, but perhaps a decent alternative while we await long-haul electric vehicles.