Alkaline cupric oxide and nitrobenzene oxidation of Alcell® lignin

A solvolysis lignin has been oxidatively degraded using nitrobenzene and cupric oxide (CuO) as catalysts. The effects of reaction conditions on lignin conversion to identifiable low molecular weight liquid products were quantified. Optimal yields of vanillin and syringaldehyde of 2.2 wt % and 5.9 wt,% respectively were obtained using nitrobenzene at 180 degrees C and 2h, whereas both were less than 1 wt % when CuO was used at 225 degrees C and Ih, indicative of the milder oxidative power of CuO for this lignin. The higher total aldehyde yield from solvolysis lignin (8.2, wt %) than kraft lignin (5.1 wt %) when using nitrobenzene indicates it might be a better candidate for producing chemicals via oxidation.