Relative Merits of Hydrolysis Schemes
Acid hydrolysis is fast and much simpler than enzymatic
hydrolysis. Yields tended to be only about 50% of theoretical, but better
process design is leading to upwards of 80%.
Drawbacks:
-
byproducts (rearranged sugar
structures) ferment badly and may hinder glucose fermentation
-
messy inorganic waste, mostly from neutralization
of acid
Enzymatic hydrolysis can approach 100% of theoretical
yield but in several days compared to minutes for acidic hydrolysis.
Drawbacks:
up to 10% of biomass feedstock is needed for fermentation that produces
enzymes
making of enzymes and hydrolysis step both easily contaminated, thus very
good aseptic, expensive equipment and techniques required.