scholarly journals Effects of Pretreatment with Ionic Liquids on Cellulose Hydrolysis under Hydrothermal Conditions

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3572 ◽  
Author(s):  
Toshitaka Funazukuri ◽  
Shingo Ozawa
Keyword(s):  
Ionic Liquids ◽  
Filter Paper ◽  
Biomass Conversion ◽  
Batch Reactor ◽  
Cellulose Hydrolysis ◽  
Reaction Rates ◽  
Crystalline Cellulose ◽  
Hydrothermal Conditions ◽  
Imidazolium Chloride ◽  
Product Yields

Hydrothermal hydrolysis in hot pressurized liquid water (HPLW) is attractive for biomass conversion into valuable products because it achieves high reaction rates without catalysts and additives. The hydrothermal hydrolysis of high crystalline cellulose requires higher reaction temperature than polysaccharides having low crystallinity. It can be expected to increase the reaction rate or decrease temperature by decreasing the crystallinity. In the present study ashless filter paper as a fibrous pure cellulose sample was pretreated with ionic liquids (ILs) such as imidazolium chloride ILs containing alkyl side chains ranging from two to six carbons, and with an aqueous solution of bis(ethylenediamine ammonium) copper (BEDC). Herein, the pretreatment with ILs was to regenerate filter paper: dissolving in ILs at 373 K for 120 min or in an aqueous BEDC solution at room temperature, precipitating by adding water, washing the solid, and then drying. Subsequently, the pretreated filter paper samples were hydrolyzed at 533 K and 5.0 MPa in HPLW in a small semi-batch reactor, and the effects of the pretreatment with ILs or BEDC on reaction rates and product yields were examined. While the crystallinity indexes with all ILs and BEDC after the pretreatments decreased to 44 to 47 from the original sample of 87, the reaction rates and product yields were significantly affected by the IL species. At 533 K and 5.0 MPa, the dissolution rate with [AMIM][Cl] was nine times as fast as that for untreated sample.

The Expression In Vitro and Application on Cellulose Degradation of LeEXP2

2011 ◽  
Vol 183-185 ◽  
pp. 790-794 ◽  
Author(s):  
Yuan Yuan Ma ◽  
Xin Wang ◽  
Han Ze Wang ◽  
Kun Zhang ◽  
Min Hua Zhang
Keyword(s):  
Filter Paper ◽  
Plant Cell Wall ◽  
Cellulose Degradation ◽  
Biomass Conversion ◽  
Cellulose Hydrolysis ◽  
Cellulosic Biomass ◽  
Functional Study ◽  
Extracellular Medium ◽  
Yeast Strains

Cellulosic ethanol has become a hotspot in recent years. However, its crystal structure makes the efficiency of cellulosic degradation by cellulase very low. Traditional ways to disrupt of connection between microfiber consumes a deal of energy and would pollute the environment as well. Plant expansin is known to loosen the plant cell wall, and might provide a synergistic effect on the activities of cellulase. Whereas, the expression level of expansin in plants has been a limit to the functional study and application in cellulose degradation. Thus, it is essential to screen expansin proteins for biomass deconstruction and express them effectively in vitro. Therefore, we cloned expansin gene LeEXP2 from tomato leaves and obtained recombinant Pichia yeast strains integrated with LeEXP2 gene. When incubated in the same culture condition, recombinant strains can secrete the LeEXP2 protein to extracellular medium, while wild-type strain cannot. Preliminary cellulose degradation experiment confirmed that the secreted protein had synergistic the effect of cellulose hydrolysis by cellulase. The experiments of extension strength of filter-paper strips shows that LeEXP2 has a texture-loosening effect on the filter paper, which might make cellulase prone to access cellulose. Above data suggests that LeEXP2 could be expressed effectively in vitro and might become a kind of potential biochemical agent applied in cellulosic biomass conversion for bioenergy production.

scholarly journals Hydrolysis of Cellulose by Soluble Clostridium Thermocellum and Acidothermus Cellulolyticus Cellulases

2018 ◽  
Vol 1 (1) ◽  
pp. 5-19
Author(s):  
Phillip Brumm ◽  
Phillip Brumm ◽  
Dan Xie ◽  
Dan Xie ◽  
Larry Allen ◽  
...  
Keyword(s):  
Filter Paper ◽  
Clostridium Thermocellum ◽  
Cellulose Degradation ◽  
Cellulase Activity ◽  
Cellulose Hydrolysis ◽  
Reducing Sugar ◽  
Crystalline Cellulose ◽  
Amorphous Cellulose ◽  
Highly Active ◽  
The Individual

The goal of this work was to clone, express, characterize and assemble a set of soluble thermostablecellulases capable of significantly degrading cellulose. We successfully cloned, expressed, and purified eleven Clostridium thermocellum (Cthe) cellulases and eight Acidothermuscellulolyticus(Acel) cellulases. The performance of the nineteen enzymes was evaluated on crystalline (filter paper) and amorphous (PASC) cellulose. Hydrolysis products generated from these two substrates were converted to glucose using beta-glucosidase and the glucose formed was determined enzymatically. Ten of the eleven Cthe enzymes were highly active on amorphous cellulose. The individual enzymes all produced <10% reducing sugar equivalents from filter paper. Combinations of Cthe cellulases gave higher conversions, with the combination of CelE, CelI, CelG, and CelK converting 34% of the crystalline cellulose. All eight Acel cellulases showed endo-cellulase activity and were highly active on PASC. Only Acel_0615 produced more than 10% reducing sugar equivalents from filter paper, and a combination of six Acel cellulases produced 32% conversion. Acel_0617, a GH48 exo-cellulase, and Acel_0619, a GH12 endo-cellulase, synergistically stimulated cellulose degradation by the combination of Cthe cellulases to almost 80%. Addition of both Acel enzymes to the Cthe enzyme mix did not further stimulate hydrolysis. Cthe CelG and CelI stimulated cellulose degradation by the combination of Acel cellulases to 66%.

Densities, viscosities and refractive indices of 1-alkyl-3-propanenitrile imidazolium chloride ionic liquids

2012 ◽  
Vol 50 (2) ◽  
pp. 152-160 ◽  
Author(s):  
Abobakr K. Ziyada ◽  
Cecilia D. Wilfred ◽  
Thanapalan Murugesan
Keyword(s):  
Ionic Liquids ◽  
Refractive Indices ◽  
Imidazolium Chloride

scholarly journals Experiments and Computational Research of Biomass Pyrolysis in a Cylindrical Reactor

2021 ◽  
Vol 64 (1) ◽  
pp. 51-64
Author(s):  
A. V. Mitrofanov ◽  
V. E. Mizonov ◽  
S. V. Vasilevich ◽  
M. V. Malko
Keyword(s):  
Biomass Conversion ◽  
Batch Reactor ◽  
Beech Wood ◽  
Electrical Heating ◽  
Difference Approximation ◽  
Radial Coordinate ◽  
Internal Diameter ◽  
Biomass Pyrolysis ◽  
Ideal Mixing ◽  
Cylindrical Reactor

The article features an experimental study of thermally thin biomass samples (beech wood particles 17×8×6 mm) pyrolysis in a laboratory scale batch reactor. The reactor was a cylindrical steel body with internal diameter of 200 mm and height of 500 mm. The temperature of a lateral surface of the cylinder during the experiment was being kept constant (550 °C) due to electrical heating. The initial loading of the apparatus was about 4 kg with moisture content of about 14 % by weight. During the experiment, the temperature values of the material being pyrolyzed were recorded at two points of the radial coordinate, viz. at the wall of the apparatus and on its axis. A one-dimensional numerical model of the nonstationary process of biomass conversion (heat and mass transfer in combination with the Avrami – Erofeev reaction model) has been proposed and verified. The reactor is represented as a set of a countable number of cylindrical layers, considered as cells (representative meso-volumes) with an ideal mixing of the properties inside. The cylindrical surfaces that form cells are considered to be isothermal. The size of the cells is chosen to be sufficiently large in comparison with the individual particles of the layer, which makes it possible to consider the temperature field inside the cell volume as monotonic. The evolution of the temperature distribution over the radius of a cylindrical reactor is determined on the basis of a difference approximation of the process of non-stationary thermal conductivity. The calculated forecasts and experimental data showed a good agreement, which indicates the adequacy of the developed mathematical model of pyrolysis and makes it possible to recommend it for engineering calculations of biomass pyrolysis. This model can also be useful in improving the understanding of the basic physical and chemical processes occurring in the conditions of biomass pyrolysis.

Conversion of biomass model compound under hydrothermal conditions using batch reactor

Fuel ◽  
2009 ◽  
Vol 88 (9) ◽  
pp. 1656-1664 ◽  
Author(s):  
Wahyudiono ◽  
Mitsuru Sasaki ◽  
Motonobu Goto
Keyword(s):  
Model Compound ◽  
Batch Reactor ◽  
Hydrothermal Conditions

Synthesis of 1,8-dioxo-octahydro-xanthene and tetrahydrobenzo[b]pyran derivatives promoted by two bis-imidazolium-based ionic liquids

2021 ◽  
Vol 08 ◽  
Author(s):  
Maryam Shirzad ◽  
Mitra Nasiri ◽  
Nader Daneshvar ◽  
Farhad Shirini ◽  
Hassan Tajik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Knoevenagel Condensation ◽  
Reaction Rates ◽  
Xanthene Derivatives ◽  
Acidic Ionic Liquids ◽  
Dicationic Ionic Liquids ◽  
Acidic Nature ◽  
Work Up ◽  
Reaction Media

Aim and objective: In this work, we have prepared two bis-dicationic ionic liquids with the same cationic core (Bis-imidazole) and different counter-anions using sulfuric acid and perchloric acids. After that, the efficiency and ability of these compounds as catalysts were investigated and compared in the promotion of Knoevenagel condensation and synthesis of benzo[b]pyran derivatives to see the effect of the anionic counter-part in the reaction. Material and method: In a 25 mL round-bottomed flask, a mixture of aldehyde (1.0 mmol), 1,3-cyclodicarbonyl (2.0 mmol) and the desired amount of the mentioned acidic ionic liquids was heated at 90°C in the absence of solvent (Reaction A) or In a 25 mL round-bottomed flask, a mixture of aldehyde (1.0 mmol), 1,3-cyclodicarbonyl (1.0 mmol), malononitrile, (1.1 mmol) and optimized amounts of the ionic liquid in water (3.0 mL) was heated at 80°C (Reaction B) for the appropriated time. After the completion of the reactions which were monitored by TLC (n-hexane: EtOAc; 3:1), 10 mL of water was added and the mixture was stirred for 2 minutes. Then, the products were separated by filtration and were washed several times with water. After drying, the pure products were obtained while there was no need to further. Results: Comparison of the obtained results from both of the ionic liquids revealed that [H2-Bisim][HSO4]2 because of its more acidic structure had a more catalytic activity for the preparation of 1,8-dioxo-octahydro-xanthene derivatives but [H2-Bisim][ClO4]2 was relatively more efficient for the synthesis of tetrahydrobenzo[b]pyran derivatives since the stronger acidic nature of [H2-Bisim][HSO4]2 may prevent the simple activation of malononitrile in the reaction media. Conclusion: In this study, we have introduced efficient methods for the synthesis of 1,8-dioxo-octahydro-xanthene and tetrahydrobenzo[b]pyran derivatives in the presence of catalytic amounts of [H2-Bisim][ClO4]2 and [H2-Bisim][HSO4]2 These methods have several advantages such as ease of preparation and handling of the catalysts, high reaction rates, excellent yields, eco-friendly procedures and simple work-up.

scholarly journals Current Developments in Lignocellulosic Biomass Conversion into Biofuels Using Nanobiotechology Approach

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5300
Author(s):  
Mamata Singhvi ◽  
Beom Soo Kim
Keyword(s):  
Lignocellulosic Biomass ◽  
Enzyme Immobilization ◽  
Enzyme Stability ◽  
Biomass Conversion ◽  
Cost Effective ◽  
Reaction Rates ◽  
Biofuel Production ◽  
Potential Strategy ◽  
Lignocellulosic Biomass Conversion ◽  
Review Current

The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the costliest part of the biomass conversion process. Even though acid/enzyme catalysts are usually being used for LB hydrolysis, enzyme immobilization has been recognized as a potential strategy nowadays. The use of nanobiocatalysts increases hydrolytic efficiency and enzyme stability. Furthermore, biocatalyst/enzyme immobilization on magnetic nanoparticles enables easy recovery and reuse of enzymes. Hence, the exploitation of nanobiocatalysts for LB to biofuel conversion will aid in developing a lucrative and sustainable approach. With this perspective, the effects of nanobiocatalysts on LB to biofuel production were reviewed here. Several traits, such as switching the chemical processes using nanomaterials, enzyme immobilization on nanoparticles for higher reaction rates, recycling ability and toxicity effects on microbial cells, were highlighted in this review. Current developments and viability of nanobiocatalysts as a promising option for enhanced LB conversion into the biofuel process were also emphasized. Mostly, this would help in emerging eco-friendly, proficient, and cost-effective biofuel technology.

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