It is not often when my professional and hobby life cross and meet, but that happened last night at my local American Chemical Society (ACS) meeting. The invited guest/speaker was from the USDA where she works on taking byproducts from ethanol production and making it into polymers.
The biggest source actually isn't any of the leftover raw materials but the yeast used to ferment the ethanol. They're taking the lactic acid, polymerizing it and using that already in plastic bottles. Next, they can take some of the pectin and other by products and break that down into a chemical class called polyvinyls (which PVC is a member). Finally they've been using enzymes (no cost difference to use yeast or bacteria yet) to take ethanol and covert that to polyethylene which is the basis for most platics on the market today. Some of these derivatives are already in use by the Department of Transportation/TSA screening machines.
The good news about this method is that it does have multiple pathways to get to the byproducts so it's not just an ethanol related process. It is nice that a "greener" way to make toys and a variety of things are on the horizon.