A critical review of analytical methods in pretreatment of lignocelluloses: Composition, imaging, and crystallinity

Abstract

Lignocelluloses are widely investigated as renewable substrates to produce biofuels, e.g., ethanol, methane, hydrogen, and butanol, as well as chemicals such as citric acid, lactic acid, and xanthan gum. However, lignocelluloses have a recalcitrance structure to resist microbial and enzymatic attacks; therefore, many physical, thermal, chemical, and biological pretreatment methods have been developed to open up their structure. The efficiency of these pretreatments was studied using a variety of analytical methods that address their image, composition, crystallinity, degree of polymerization, enzyme adsorption/desorption, and accessibility. This paper presents a critical review of the first three categories of these methods as well as their constraints in various applications. The advantages, drawbacks, approaches, practical details, and some points that should be considered in the experimental methods to reach reliable and promising conclusions are also discussed.

Comparison of the Thermal Degradation Properties of Crystalline and Amorphous Cellulose, as well as Treated Lignocellulosic Biomass

“…Both phenomena were strongly related to the increase in the enzymatic digestibility of lignocellulose. Generally, the main component analysis (the detergent method) and XRD analysis have been used to evaluate pretreatment procedures for enzymatic hydrolysis (Mosier et al 2005;Inoue et al 2008;Hideno et al 2009;Karimi and Taherzadeh 2016). However, the main component analysis cannot analyze the denaturing of macromolecules because the analyzed sample is fully hydrolyzed to the monomers by sulfuric acid.…”

Review on the current status of polymer degradation: a microbial approach

“…Pretreatments were employed in milling, acid, alkali and other treatments (Karimi and Taherzadeh 2016). Some cellulase genes (9, 45, GH5 family gene) were reported in insects belonging to the taxa Crustacea, Gastropoda and Annelida (Cragg et al 2015).…”

Batch and continuous biogenic hydrogen fermentation of acid pretreated de-oiled jatropha waste (DJW) hydrolysate

“…A sorption isotherm is generally plotted as volume (V) against P/P 0 , where P is the absolute pressure and P 0 is the saturation vapor pressure. 31 3.3.5 FT-IR analysis. So far, our experience of BET analysis indicates that there are very many organic species in the raw sample.…”