scholarly journals Organosolv Fractionation of Birch Sawdust: Establishing a Lignin-First Biorefinery

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6754
Author(s):  
Maxwel Monção ◽  
Kateřina Hrůzová ◽  
Ulrika Rova ◽  
Leonidas Matsakas ◽  
Paul Christakopoulos

The use of residual biomass for bioconversions makes it possible to decrease the output of fossil-based chemicals and pursue a greener economy. While the use of lignocellulosic material as sustainable feedstock has been tried at pilot scale, industrial production is not yet economically feasible, requiring further technology and feedstock optimization. The aim of this study was to examine the feasibility of replacing woodchips with residual sawdust in biorefinery applications. Woodchips can be used in value-added processes such as paper pulp production, whereas sawdust is currently used mainly for combustion. The main advantages of sawdust are its large supply and a particle size sufficiently small for the pretreatment process. Whereas, the main challenge is the higher complexity of the lignocellulosic biomass, as it can contain small amounts of bark and cambium. Here, we studied the fractionation of birch sawdust by organosolv pretreatment at two different temperatures and for two different durations. We evaluated the efficiency of fractionation into the three main fractions: lignin, cellulose, and hemicellulose. The cellulose content in pretreated biomass was as high as 69.2%, which was nearly double the amount in untreated biomass. The obtained lignin was of high purity, with a maximum 4.5% of contaminating sugars. Subsequent evaluation of the susceptibility of pretreated solids to enzymatic saccharification revealed glucose yields ranging from 75% to 90% after 48 h but reaching 100.0% under the best conditions. In summary, birch sawdust can be successfully utilized as a feedstock for organosolv fractionation and replace woodchips to simplify and lower the costs of biorefinery processes.

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 626
Author(s):  
Siti Hajar Mohamed ◽  
Md. Sohrab Hossain ◽  
Mohamad Haafiz Mohamad Kassim ◽  
Mardiana Idayu Ahmad ◽  
Fatehah Mohd Omar ◽  
...  

There is an interest in the sustainable utilization of waste cotton cloths because of their enormous volume of generation and high cellulose content. Waste cotton cloths generated are disposed of in a landfill, which causes environmental pollution and leads to the waste of useful resources. In the present study, cellulose nanocrystals (CNCs) were isolated from waste cotton cloths collected from a landfill. The waste cotton cloths collected from the landfill were sterilized and cleaned using supercritical CO2 (scCO2) technology. The cellulose was extracted from scCO2-treated waste cotton cloths using alkaline pulping and bleaching processes. Subsequently, the CNCs were isolated using the H2SO4 hydrolysis of cellulose. The isolated CNCs were analyzed to determine the morphological, chemical, thermal, and physical properties with various analytical methods, including attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy-filtered transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the isolated CNCs had a needle-like structure with a length and diameter of 10–30 and 2–6 nm, respectively, and an aspect ratio of 5–15, respectively. Additionally, the isolated CNCs had a high crystallinity index with a good thermal stability. The findings of the present study revealed the potential of recycling waste cotton cloths to produce a value-added product.


Author(s):  
Tan M. Le ◽  
Uyen P. N. Tran ◽  
Yen H. P. Duong ◽  
Quan D. Nguyen ◽  
Viet T. Tran ◽  
...  
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1127
Author(s):  
Júnia Alves-Ferreira ◽  
Ana Lourenço ◽  
Francisca Morgado ◽  
Luís C. Duarte ◽  
Luísa B. Roseiro ◽  
...  

Residues of Cistus ladanifer obtained after commercial steam distillation for essential oil production were evaluated to produce cellulose enriched solids and added-value lignin-derived compounds. The delignification of extracted (CLRext) and extracted and hydrothermally pretreated biomass (CLRtreat) was studied using two organosolv processes, ethanol/water mixtures (EO), and alkali-catalyzed glycerol (AGO), and by an alkali (sodium hydroxide) process (ASP) under different reaction conditions. The phenolic composition of soluble lignin was determined by capillary zone electrophoresis and by Py-GC/MS, which was also used to establish the monomeric composition of both the delignified solids and isolated lignin. The enzymatic saccharification of the delignified solids was also evaluated. The ASP (4% NaOH, 2 h) lead to both the highest delignification and enzymatic saccharification (87% and 79%, respectively). A delignification of 76% and enzymatic hydrolysis yields of 72% were obtained for AGO (4% NaOH) while EO processes led to lower delignification (maximum lignin removal 29%). The residual lignin in the delignified solids were enriched in G- and H-units, with S-units being preferentially removed. The main phenolics present in the ASP and AGO liquors were vanillic acid and epicatechin, while gallic acid was the main phenolic in the EO liquors. The results showed that C. ladanifer residues can be a biomass source for the production of lignin-derivatives and glucan-rich solids to be further used in bioconversion processes.


2020 ◽  
pp. 152808372097062
Author(s):  
Muhammad Yameen Solangi ◽  
Umair Aftab ◽  
Muhammad Ishaque ◽  
Aqeel Bhutto ◽  
Ayman Nafady ◽  
...  

Solid polymer electrolytes (SPEs) are the best choice to replace liquid electrolytes in supercapacitors, fuel cells, solar cells and batteries. The main challenge in this filed is the ionic conductivity and thermal stability of SPEs which is still not up to mark, therefore more investigations are needed to address these issues. In this study, PVA/salt based SPEs was fabricated using both solution cast and electro-spinning methods to probe the effect of different salts such as (NaCl, KCl and KI) and their concentrations on the ionic conductivity. Scanning electron microscopy (SEM) x and Fourier Transform Infra-Red (FTIR) have been employed to study the morphology as well as the different functional groups of SPEs, respectively. It was noted that small addition of NaCl, KCl and KI salts in SPEs dramatically increased the ionic conductivity to 5.95×10−6, 5.31×10−6 and 4.83×10−6 S/cm, respectively. Importantly, the SPEs obtained with NaCl via electro-spinning have higher ionic conductivity (5.95×10−6 S/cm) than their casted SPEs (1.87×10−6 S/cm). Thermal stability was also studied at two different temperatures i.e. 80 °C and 100 °C. The weight loss percentage of electrospun SPEs have zero percent weight loss than the solution based SPEs. The combined results clearly indicated that the nature of salt, concentration and fabrication process play a vital role in the ionic conductivity. Also, the NaCl salt with low molecular weight at low concentrations shows an enhanced ionic conductivity.


Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 609 ◽  
Author(s):  
Dongyan Zhang ◽  
Yuyang Fan ◽  
Anqing Zheng ◽  
Zengli Zhao ◽  
Fengyun Wang ◽  
...  

Anhydrosugars, such as levoglucosan (LG), are high value-added chemicals which are mainly derived from fast pyrolysis of pure cellulose. However, fast pyrolysis of raw lignocellulosic biomass usually produces a very low amount of levoglucosan, since alkali and alkaline earth metals (AAEM) present in the ash can serve as the catalysts to inhibit the formation of levoglucosan through accelerating the pyranose ring-opening reactions. In this study, eucalyptus was impregnated with H2SO4 solutions with varying concentrations (0.25–1.25%). The characteristics of ash derived from raw and H2SO4-impregnated eucalyptus were characterized by X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). The pyrolysis behaviors of raw and H2SO4-impregnated eucalyptus were performed on the thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG analysis demonstrated that the H2SO4-impregnated eucalyptus produced less char than raw eucalyptus. Py-GC/MS analysis showed that even small amounts of H2SO4 can obviously improve the production of anhydrosugars and phenols and suppressed the formation of carboxylic acids, aldehydes, and ketones from fast pyrolysis of eucalyptus. The rank order of levoglucosan yield from raw and impregnated eucalyptus was raw < 1.25% H2SO4 < 1% H2SO4 < 0.75% H2SO4 < 0.25% H2SO4 < 0.5% H2SO4. The maximum yield of levoglucosan (21.3%) was obtained by fast pyrolysis of eucalyptus impregnated with 0.5% H2SO4, which was close to its theoretical yield based on the cellulose content. The results could be ascribed to that H2SO4 can react with AAEM (e.g., Na, K, Ca, and Mg) and lignin to form lignosulfonate, thus acting as an inhibitor to suppress the catalytic effects of AAEM during fast pyrolysis of eucalyptus.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Kaixuan Huang ◽  
Lalitendu Das ◽  
Jianming Guo ◽  
Yong Xu

Abstract Background Poplars are considered suitable dedicated energy crops, with abundant cellulose and hemicellulose, and huge surplus biomass potential in China. Xylan, the major hemicellulosic component, contributes to the structural stability of wood and represents a tremendous quantity of biobased chemicals for fuel production. Monomeric xylose conversion to value-added chemicals such as furfural, xylitol, and xylonic acid could greatly improve the economics of pulp-paper industry and biorefinery. Acetic acid (HAc) is used as a friendly and recyclable selective catalyst amenable to xylan degradation and xylooligosaccharides production from lignocellulosic materials. However, HAc catalyst usually works much feebly at inert woods than agricultural straws. In this study, effects of different iron species in HAc media on poplar xylan degradation were systematically compared, and a preferable Fe3+-assisted HAc hydrolysis process was proposed for comparable xylose-hydrolysate recovery (XHR) and enzymatic saccharification of cellulose. Results In presence of 6.5% HAc with 0.17–0.25 wt% Fe3+, xylose yield ranged between 72.5 and 73.9%. Additionally, pretreatment was effective in poplar delignification, with a lignin yield falling between 38.6 and 42.5%. Under similar conditions, saccharification efficiency varied between 60.3 and 65.9%. Starting with 100 g poplar biomass, a total amount of 12.7–12.8 g of xylose and 18.8–22.8 g of glucose were harvested from liquid streams during the whole process of Fe3+-HAc hydrolysis coupled with enzymatic saccharification. Furthermore, the enhancement mechanism of Fe3+ coupled with HAc was investigated after proof-of-concept experiments. Beechwood xylan and xylose were treated under the same condition as poplar sawdust fractionation, giving understanding of the effect of catalysts on the hydrolysis pathway from wood xylan to xylose and furfural by Fe3+-HAc. Conclusions The Fe3+-assisted HAc hydrolysis process was demonstrated as an effective approach to the wood xylose and other monosaccharides production. Synergistic effect of Lewis acid site and aqueous acetic acid provided a promising strategy for catalytic valorization of poplar biomass.


2022 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Malinee Sriariyanun ◽  
Nichaphat Kitiborwornkul ◽  
Prapakorn Tantayotai ◽  
Kittipong Rattanaporn ◽  
Pau-Loke Show

Ionic liquid (IL) pretreatment of lignocellulose is an efficient method for the enhancement of enzymatic saccharification. However, the remaining residues of ILs deactivate cellulase, therefore making intensive biomass washing after pretreatment necessary. This study aimed to develop the one-pot process combining IL pretreatment and enzymatic saccharification by using low-toxic choline acetate ([Ch][OAc]) and IL-tolerant bacterial cellulases. Crude cellulases produced from saline soil inhabited Bacillus sp. CBD2 and Brevibacillus sp. CBD3 were tested under the influence of 0.5–2.0 M [Ch][OAc], which showed that their activities retained at more than 95%. However, [Ch][OAc] had toxicity to CBD2 and CBD3 cultures, in which only 32.85% and 12.88% were alive at 0.5 M [Ch][OAc]. Based on the specific enzyme activities, the sugar amounts produced from one-pot processes using 1 mg of CBD2 and CBD3 were higher than that of Celluclast 1.5 L by 2.0 and 4.5 times, respectively, suggesting their potential for further application in the biorefining process of value-added products.


Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2221
Author(s):  
Adila Fazliyana Aili Hamzah ◽  
Muhammad Hazwan Hamzah ◽  
Hasfalina Che Man ◽  
Nur Syakina Jamali ◽  
Shamsul Izhar Siajam ◽  
...  

Pineapple waste accounts for a significant part of waste accumulated in landfill which will further contribute to the release of greenhouse gases. With the rising pineapple demands worldwide, the abundance of pineapple waste and its disposal techniques are a major concern. Exploiting the pineapple waste into valuable products could be the most sustainable way of managing these residues due to their useful properties and compositions. In this review, we concentrated on producing useful products from on-farm pineapple waste and processing waste. Bioenergy is the most suitable option for green energy to encounter the increasing demand for renewable energy and promotes sustainable development for agricultural waste. The presence of protease enzyme in pineapple waste makes it a suitable raw material for bromelain production. The high cellulose content present in pineapple waste has a potential for the production of cellulose nanocrystals, biodegradable packaging and bio-adsorbent, and can potentially be applied in the polymer, food and textile industries. Other than that, it is also a suitable substrate for the production of wine, vinegar and organic acid due to its high sugar content, especially from the peel wastes. The potentials of bioenergy production through biofuels (bioethanol, biobutanol and biodiesel) and biogas (biomethane and biohydrogen) were also assessed. The commercial use of pineapples is also highlighted. Despite the opportunities, future perspectives and challenges concerning pineapple waste utilisation to value-added goods were also addressed. Pineapple waste conversions have shown to reduce waste generation, and the products derived from the conversion would support the waste-to-wealth concept.


2020 ◽  
Author(s):  
Yafeng Ye ◽  
Shuoxun Wang ◽  
Kun Wu ◽  
Yan Ren ◽  
Hongrui Jiang ◽  
...  

Abstract Background: Cellulose synthase (CESA) mutants have potential use in straw processing due to their lower cellulose content, but almost all of the mutants exhibit defective phenotypes in plant growth and development. Balancing normal plant growth with reduced cellulose content remains a challenge, as cellulose content and normal plant growth are typically negatively correlated with one another. Result: Here, the rice (Oryza sativa) semi-dominant brittle culm (sdbc) mutant Sdbc1, which harbors a substitution (D387N) at the first conserved aspartic acid residue of OsCESA9, exhibits lower cellulose content and reduced secondary wall thickness as well as enhanced biomass enzymatic saccharification compared with the wild type (WT). Further experiments indicated that the OsCESA9D387N mutation may compete with the wild-type OsCESA9 for interacting with OsCESA4 and OsCESA7, further forming non-functional or partially functional CSCs. The OsCESA9/OsCESA9D387N heterozygous plants increase salt tolerance through scavenging and detoxification of ROS and indirectly affecting related gene expression. They also improve rice straw return to the field due to their brittle culms and lower cellulose content without any negative effects in grain yield and lodging. Conclusion: Hence, manipulation of OsCESA9D387N can provide the perspective of the rice straw for biofuels and bioproducts due to its improved enzymatic saccharification.


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