Interesting. In my country, we are charged 5 pence for every bag at the store. It's reduced waste by a huge amount, people keep the same bags and use them over and over again. But converting them into fuel is a better way of recycling them I guess!
No mention of the cost of conversion. They did mention the number of discarded bags, but didn't mention the expense of gathering them for recycling. Personally, I think an easier solution would be to run the combustible wastes through a shredder, then mix it at low percentage with the coal being burned in electric generating plants. Count on the pollution traps in the coal plant to clean up the exhaust stream.
The problem with just burning it with coal is that many coal plants are grandfathered in and their pollution controls are lacking for what they burn now.
The pyrolysis method they use can also process more than plastic bags. In theory, any organic material can be converted by the process. The USDA ARS is going to be field testing a mobile pyrolysis unit that will go farm to farm to process field waste.
Pyrolysis is an old process. It is the means by which coal tar is extracted from coal, leaving coke as a byproduct. In a sense distillation is a form of pyrolysis. Sometimes the vapors driven off by the heat form the desired product; sometimes the residue; sometimes both. The only thing I see new is the use of plastic bags and likely other plastics as the feedstock.