Compostable plastic that’s made from plants is not a novelty. The manufacturing process is rather involved. It requires land and fertilizer to grow the plants, mainly corn, then the necessary ingredients need to be extracted from the plant, then additional chemical/biological processes are required that involve energy input. Currently to make a pound of widely used compostable plastic, polylactic acid (PLA) requires 25.5 megajoules of energy, same as burning 118 60-watt lightbulbs for one hour. To make a pound of not yet so popular compostable plastic, polyhydroxyalkanoate (PHA) requires the amount of energy equal to burning 170 60-watt bulbs for an hour.

So the present way of making compostable plastic is still involved and costly, it requires land, fertilizer, plants, additional processing and energy.

But in 2005 researchers at Washington State University developed a method for producing compostable material containing high levels of PHA from paper mill waste products, municipal waste and biodiesel waste. In addition, the fermentation process does not require any special equipment, but the existing wastewater treatment facilities and better yet, no additional energy input.

Apparently this research poses high hopes, since this thermoplastic can be used in a number of conventional applications. Based on the latest information that I was able to find, the research is ongoing. Grants of nearly $450K were pending from National Science Foundation and Idaho State Board of Education for 2008-09.

I can’t wait to know more. Wouldn’t it be awesome to produce compostable plastic from waste without complex equipment and energy input?

Reference: “Wastewater treatment generates PHA plastic.” Industrial Bioprocessing (Nov 25, 2005)

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