Sodium hydroxide is one of the
most commonly used alkali-based pretreatment reagents that could
effectively remove lignin from lignocelluloses with little formation
of sugar degradation compounds and furan derivatives, but it’s less
satisfactory if applied to lignin-rich lignocelluloses (Li et al., 2014)
and the recovery of NaOH requires combustion of the black liquor
and followed by an expensive causticization process. Recently, alkalic
salts as weak bases, such as sodium carbonate (Na2CO3), sodium
phosphate dodecahydrate (Na3PO4), and sodium sulfide (Na2S) have
been reported as viable catalyst options for alkaline pretreatment
with the main advantages of recoverable and less corrosive