The main culprit in the cinnamon powder is actually derived from tree bark and contains cellulose, an undigestible fiber capable of producing a strong inflammatory response in lung tissue, leading to long term wheezing and a chronic cough, potentially placing patients at further risk for bouts of pneumonitis or even aspiration pneumonia.
Meanwhile, the US Forest Service has been deriving cellulose nanocrystals from wood pulp extract to create a material that's stronger than Kevlar and carbon fiber.
Cellulose fuel production would require a consistant base product so it would become necessary to secure massive amounts of plant fiber to ensure uninterrupted production.