Research shows how cellulose breaks down to create bio-oils

Using facilities at the Pittsburgh Supercomputing Center, NC State chemical and biomolecular engineer Dr Phillip Westmoreland and doctoral student Vikram Seshadri calculate what is occurring at the molecular level when wood is heated to high temperatures in the absence of oxygen — a decomposition process called pyrolysis.

Much of the energy that can be extracted from wood exists in the cellulose found in cell walls. Cellulose itself is a stiff, rod-like substance consisting of chains of a specific type of a simple sugar called glucose.

A paper that appears in the Journal of Physical Chemistry A describes a mechanism for glucose decomposition when heated. The mechanism is somewhat surprising, Westmoreland said in a statement, because it reveals how water molecules and the glucose itself can trigger this decomposition.

‘The calculations in the paper show that although the decomposition products and rates differ in glucose and cellulose, the various elementary steps appear to be the same but altered in their relative importance to each other,’ Westmoreland said.

Knowing the specifics of the decomposition process will allow researchers to make predictions about the ease of extracting energy from different types of wood from various soil types.

The researchers are now conducting experiments to verify their calculations.