Comparison of sodium hydroxide and calcium hydroxide pretreatments of giant reed for enhanced enzymatic digestibility and methane production.

NaOH pretreatment with leachate reuse and Ca(OH) ₂ pretreatment were compared for improved enzymatic digestibility and biogas production from giant reed, a promising energy crop. The NaOH pretreatment with leachate reuse increased glucose yields during enzymatic hydrolysis by 2.6-fold, and methane yields during anaerobic digestion by 1.4- to 1.6-fold. However, NaOH pretreatment had a negative net benefit (i.e., revenue from increased energy production minus chemical cost). Pretreatment with 7-20% Ca(OH) ₂ not only improved glucose yield and methane yield by up to 2.3-fold and 1.4-fold, respectively, but also obtained a net benefit of $1.1-5.8/tonne dry biomass. Thus, Ca(OH) ₂ pretreatment was shown to be more feasible than NaOH pretreatment for biogas production from giant reed.
(Copyright © 2017 Elsevier Ltd. All rights reserved.)