Separation of Lignocellulosic Biomass Components by Alkali Pretreatment

Abstract

Traditional pretreatment methods have several disadvantages, including lower efficiency in terms of cellulose purity, high cost and incomplete separation of biomass components. Considering this, we compared different pretreatment processes and studied their effect on separation of biomass components. Effective delignification was achieved by alkali pretreatment with sodium hydroxide and ammonia. Among alkalis, sodium hydroxide treatment requires less severe process condition like lower concentration, temperature and pressure compared to ammonia pretreatment and produces enzyme amenable substrate, which made sodium hydroxide ideal for biomass pretreatment. Efforts were mounted to optimize sodium hydroxide pretreatment on wheat straw in terms of reaction temperature, reaction time and reagent concentration to produce enzymatically amenable substrate. The best experimental results were obtained when biomass was treated with 2% sodium hydroxide at 130°C for 30 minutes, which was found to extract lignin and significant amount of hemicellulose from biomass.

Low-energy extraction of lignocellulose nanofibers from fresh Musa basjoo pseudo-stem

“…A weak peak at 776 cm -1 in WRMA (Figure 2(a)), due to C-H out-of-plane deformation of lignin, was not found in the XRD patterns of LCNF-1h and LCNF-3h, indicating the hydrolysis of lignin with the NaOH treatment. The lignin wavenumber showed at 3343, 2891, 1600-1500, 1421, 1365, 1161 cm -1 in Figure 2 (a, b)-the data supported by Pereira et al [35].…”

“…These advantages render NaOH more environmentally friendly and highly valuable for biomass pre-treatment. It is advantageous due to its low-energy extraction, dilute concentrations, and normal air pressure[35].…”