Production of rice, the third most abundant grain crop in the
world behind wheat and corn (http://www.irri.org), generatesquantities of rice hulls as a by-product. Global production of
rice hulls is estimated at 139 million tonnes annually [1]. The
hulls, which are harvested with the grain and equal 20% of
harvested rice on a dry weight basis, are traditionally
considered a low-value or waste residue due to high lignin