What exactly happens when plants burn? The question is likely among the oldest pondered by humanity, and yet it’s drawing newfound attention in the context of how biomass might be productively transformed into a sustainable source of bulk chemical feedstock in place of petroleum. Though chemists have a reasonable grasp of the web of reactions underlying combustion, the source of certain nonvolatile compounds in the product stream—particularly those that enter the gas phase—remains uncertain. Teixeira et al. combine high-speed photography of heated cellulose with extensive theoretical fluid modeling to uncover a plausible mechanism for ejection of this product class. Specifically, they put forward a process termed reactive boiling ejection, whereby bubbles form and then rapidly collapse in a short-lived molten cellulose phase. The collapse expels streams of aerosols that contain nonvolatile material. They argue that a deeper understanding of this process should lead to more control over product distributions.
SOURCE : SCIENCE MAGAZINE VOL 333