Organosolv pretreatment: an in-depth purview of mechanics of the system

Abstract

The concept of biorefinery has been advancing globally and organosolv pretreatment strategy has seen an upsurge in research due to its efficiency in removing the recalcitrant lignin and dissolution of cellulose. The high-performance organosolv system uses green solvents and its reusability contributes concurrently to the biorefinery sector and sustainability. The major advantage of the current system involves the continuous removal of lignin to enhance cellulose accessibility, thereby easing the later biorefinery steps, which were immensely restricted due to the recalcitrant lignin. The current system process can be further explored and enhanced via the amalgamation of new technologies, which is still a work in progress. Thus, the current review summarizes organosolv pretreatment and the range of solvents used, along with a detailed mechanistic approach that results in efficient pretreatment of LCB. The latest developments for designing high-performance pretreatment systems, their pitfalls, and advanced assessments such as Life Cycle Assessment along with Techno-Economic Assessment have also been deliberated to allow an insight into its diverse potential applicability towards a sustainable future. Graphical Abstract

Enhancing the Methane Yield of Salicornia spp. via Organosolv Fractionation as Part of a Halophyte Biorefinery Concept

“…During organosolv fractionation, lignin undergoes phase transitions between solid and liquid phases through depolymerization and repolymerization [35,36]. This results in structural changes in the lignin and the relocalization or deposition of lignin droplets on the cellulosic fiber surface [35][36][37]. Based on the findings of this study, this indicates that the fragments of lignin left on the cellulose-rich pulp surface after organosolv fractionation are presumably deposited on the pulp surface in such a way that minimally impedes microbial degradation.…”

Organosolv biorefinery: resource-based process optimisation, pilot technology scale-up and economics

“…141–143 The energy optimisation can also be achieved using alternative heating methods such as ultrasound, microwaves and electrical energy. 135 Moreover, the use of the spent liquor before the stage of solvent recovery, or the use of biphasic systems to extract the chemicals from the organic solvent used for the fractionation can be considered. 134 The use of the organosolv process in combination with other pre-treatments also has to be considered, such as ionsolv 20 and liquid hot water processes.…”

Conversion Characteristics of Chemical Constituents in Liriodendron tulipifera and Their Influences on Biomass Recalcitrance during Acid-Catalyzed Organosolv Pretreatment

“…Above 150℃, the precipitate yield slowly increased, and the xylose content in the precipitate disappeared at 170℃ (Table 5). It was theorized that the formation of an additional precipitate from lignin degradation rapidly decreased, and the precipitate that had already formed from lignin began to rapidly and regularly degrade into smaller fractions without condensation (Nair et al, 2023). As described in section 3.1.1., because of the lignin-carbohydrate complex of L. tulipifera, both Structural sugars (%) 3) Lignins (%) 3) Total (%) 3) Glucose Xylose Total Klason lignin Acid soluble lignin Total 120 0.9 ± 0.1 4.1 ± 0.3 2.6 ± 0.2 1.3 ± 0.1 3.8 ± 0.3 87.4 ± 0.9 1.6 ± 0.2 89.0 ± 0.9 92.8 ± 0.9 130 1.8 ± 0.2 8.5 ± 0.1 0.0 ± 0.0 1.8 ± 0.3 1.8 ± 0.3 88.8 ± 0.9 1.5 ± 0.3 90.3 ± 0.9 92.1 ± 0.9 140 3.0 ± 0.2 13.8 ± 0.5 0.0 ± 0.0 2.8 ± 0.2 2.8 ± 0.2 87.0 ± 1.3 1.8 ± 0.1 88.8 ± 1.3 91.6 ± 1.4 150 7.0 ± 0.1 32.3 ± 0.2 0.0 ± 0.0 2.2 ± 0.3 2.2 ± 0.3 86.7 ± 1.0 1.9 ± 0.4 88.7 ± 1.1 90.9 ± 1.1 160 9.0 ± 0.2 41.6 ± 0.2 0.0 ± 0.0 1.2 ± 0.1 1.2 ± 0.1 89.4 ± 1.7 1.7 ± 0.2 91.1 ± 1.7 92.3 ± 1.8 170 9.8 ± 0.2 45.3 ± 0.3 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 97.9 ± 1.6 2.1 ± 0.1 100.0 ± 1.6 100.0 ± 1.6 180 10.0 ± 0.1 46.0 ± 0.2 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 96.7 ± 1.9 3.1 ± 0.3 99.8 ± 2.0 99.8 ± 2.0 1) Yield (%) of the precipitates on the basis of 100 g initial oven-dried raw materials.…”