The Effect of Chemical Character of Ionic Liquids on Biomass Pre-Treatment and Posterior Enzymatic Hydrolysis

Ionic liquids have been recognised as interesting solvents applicable in the efficient lignocellulosic biomass valorisation, especially in the biomass fractionation into individual polymeric components or direct hydrolysis some of biomass fractions. Considering the chemical character of ionic liquids, two different approaches, paved the way for a fractionation of biomass. The first strategy integrated a pre-treatment, hydrolysis and conversion of biomass through the employment of hydrogen-bond acidic 1-ethyl-3-methyimidazolim hydrogen sulfate ionic liquid. The second one relied on the use of a three-step fractionation process with hydrogen-bond basic 1-ethyl-3-methylimidazolium acetate to produce high purity cellulose, hemicellulose and lignin fractions. The proposed approaches were scrutinised for wheat straw and eucalyptus residues. Those different biomasses allowed understanding that enzymatic hydrolysis yields are dependent on the crystallinity of pre-treated biomass. The use of acetate based ionic liquid allowed to change crystalline cellulose I to cellulose II and consequently enhanced glucan to glucose yield to 93.14.1 mol% and 82.91.2 mol% for wheat straw and eucalyptus, respectively. Whereas for hydrogen sulfate ionic liquid, the same enzymatic hydrolysis yields were 61.6  0.2 mol% for wheat straw and only 7.90.3 mol% for eucalyptus residues. These results demonstrate the importance of either ionic liquid character or biomass type on the efficient biomass processing.

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The Effect of the Chemical Character of Ionic Liquids on Biomass Pre-Treatment and Posterior Enzymatic Hydrolysis

Molecules ◽

10.3390/molecules24040808 ◽

2019 ◽

Vol 24 (4) ◽

pp. 808 ◽

Cited By ~ 12

Author(s):

Joana Bernardo ◽

Francisco Gírio ◽

Rafał Łukasik

Keyword(s):

Hydrogen Bond ◽

Ionic Liquid ◽

Ionic Liquids ◽

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Crystalline Cellulose ◽

Fractionation Process ◽

Hydrogen Sulphate ◽

Chemical Character ◽

Pre Treatment

Ionic liquids have been recognised as interesting solvents applicable in efficient lignocellulosic biomass valorisation, especially in biomass fractionation into individual polymeric components or direct hydrolysis of some biomass fractions. Considering the chemical character of ionic liquids, two different approaches paved the way for the fractionation of biomass. The first strategy integrated a pre-treatment, hydrolysis and conversion of biomass through the employment of hydrogen-bond acidic 1-ethyl-3-methyimidazolim hydrogen sulphate ionic liquid. The second strategy relied on the use of a three-step fractionation process with hydrogen-bond basic 1-ethyl-3-methylimidazolium acetate to produce high purity cellulose, hemicellulose and lignin fractions. The proposed approaches were scrutinised for wheat straw and eucalyptus residues. These different biomasses enabled an understanding that enzymatic hydrolysis yields are dependent on the crystallinity of the pre-treated biomass. The use of acetate based ionic liquid allowed crystalline cellulose I to change to cellulose II and consequently enhanced the glucan to glucose yield to 93.1 ± 4.1 mol% and 82.9 ± 1.2 mol% for wheat straw and eucalyptus, respectively. However, for hydrogen sulphate ionic liquid, the same enzymatic hydrolysis yields were 61.6 ± 0.2 mol% for wheat straw and only 7.9 ± 0.3 mol% for eucalyptus residues. These results demonstrate the importance of both ionic liquid character and biomass type for efficient biomass processing.

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Enzymatic hydrolysis of chicken viscera proteins in the presence of an ionic liquid as a strategy to improve the antioxidant properties of the hydrolysates

Revista dos Trabalhos de Iniciação Científica da UNICAMP ◽

10.20396/revpibic2620181367 ◽

2019 ◽

Author(s):

Vitor Geniselli da Silva ◽

Ruann Janser Soares de Castro

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Enzymatic Hydrolysis ◽

Antioxidant Activities ◽

Antioxidant Properties ◽

Protein Hydrolysates ◽

Tetramethylammonium Bromide ◽

Chicken Viscera ◽

Hydrolysis Of

Aiming to explore the use of ionic liquids (ILs) not yet described in the literature, this work evaluated the hydrolysis of proteins from chicken viscera using the protease Alcalase modified and unmodified by the IL tetramethylammonium bromide. The protein hydrolysates produced in the presence of the IL presented values of antioxidant activities 40% higher than the hydrolysates obtained without IL. In addition, with the presence of the IL, it was possible to obtain protein hydrolysates from chicken viscera with similar antioxidant activities, compared to the protein hydrolysates produced without IL, using 1/3 of the amount of enzyme.

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Hydrogen bond basicity of ionic liquids and molar entropy of hydration of salts as major descriptors in the formation of aqueous biphasic systems

Physical Chemistry Chemical Physics ◽

10.1039/c8cp01401a ◽

2018 ◽

Vol 20 (20) ◽

pp. 14234-14241 ◽

Cited By ~ 6

Author(s):

Helena Passos ◽

Teresa B. V. Dinis ◽

Ana Filipa M. Cláudio ◽

Mara G. Freire ◽

João A. P. Coutinho

Keyword(s):

Hydrogen Bond ◽

Ionic Liquid ◽

Ionic Liquids ◽

Predictive Model ◽

Aqueous Biphasic Systems ◽

Molar Entropy ◽

Liquid Salt ◽

Hydrogen Bond Basicity ◽

Aqueous Biphasic ◽

Biphasic Systems

A predictive model for ionic liquid/salt aqueous biphasic systems’ formation based on the hydrogen bond basicity of ionic liquids and molar entropy of hydration of salts.

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Design of a combined ionosolv-organosolv biomass fractionation process for biofuel production and high value-added lignin valorisation

Green Chemistry ◽

10.1039/d0gc01143f ◽

2020 ◽

Vol 22 (15) ◽

pp. 5161-5178

Author(s):

Meng Chen ◽

Francisco Malaret ◽

Anton E. J. Firth ◽

Pedro Verdía ◽

Aida R. Abouelela ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Value Added ◽

Biofuel Production ◽

Protic Ionic Liquids ◽

Fractionation Process ◽

Biomass Fractionation

IonoSolv pretreatment using protic ionic liquids has shown impressive biomass fractionation performance and ionic liquid recyclability.

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The effect of ionic liquid and superbase pre-treatment on the spring-back, set-recovery and Brinell hardness of surface-densified Scots pine

Holzforschung ◽

10.1515/hf-2019-0158 ◽

2020 ◽

Vol 74 (3) ◽

pp. 303-312 ◽

Cited By ~ 2

Author(s):

Benedikt Neyses ◽

Olov Karlsson ◽

Dick Sandberg

Keyword(s):

Ionic Liquid ◽

Scots Pine ◽

Brinell Hardness ◽

Wood Products ◽

Densified Wood ◽

Crystalline Cellulose ◽

Control Group ◽

Densification Process ◽

Spring Back ◽

Pre Treatment

AbstractCompressing the surface of sawn timber results in a substantial increase in hardness, and this opens up new market opportunities of using low-density timber species as the raw material for high-value wood products. Unfortunately, widespread commercialisation is hindered by the lack of an industrially viable surface densification process, the major obstacle being the set-recovery (SR) of the densified wood cells upon exposure to moisture. Our hypothesis is that partial dissolution of the crystalline cellulose during densification will largely prevent the SR of densified wood. We therefore evaluated the effect of ionic liquid (IL) or organic superbase pre-treatment on the elastic spring-back (SB), SR and Brinell hardness (HB) of surface-densified wood. Specimens of Scots pine were treated with solutions of ILs or superbases, and then densified in a hot press at temperatures between 200°C and 270°C. The SR was reduced from 90% for the control group to only about 10% for the treated materials. The treated and densified specimens exhibited a higher HB than their untreated and densified counterparts. The method presented in this study is a precursor to the development of a continuous densification process adapted for an open system. Further studies are needed to understand the underlying mechanisms of the pre-treatment.

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Biodiesel fromCitrullus colocynthisOil: Sulfonic-Ionic Liquid-Catalyzed Esterification of a Two-Step Process

The Scientific World JOURNAL ◽

10.1155/2014/540765 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Yasir Ali Elsheikh ◽

Faheem Hassan Akhtar

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Sulfonic Acid ◽

Molar Ratio ◽

Disulfonic Acid ◽

Hydrogen Sulfate ◽

Citrullus Colocynthis ◽

Step Process ◽

Acidic Catalyst ◽

Acidic Catalysts

Biodiesel was prepared fromCitrullus colocynthisoil (CCO) via a two-step process. The first esterification step was explored in two ionic liquids (ILs) with 1,3-disulfonic acid imidazolium hydrogen sulfate (DSIMHSO4) and 3-methyl-1-sulfonic acid imidazolium hydrogen sulfate (MSIMHSO4). Both ILs appeared to be good candidates to replace hazardous acidic catalyst due to their exceptional properties. However, the two sulfonic chains existing in DSIMHSO4were found to increase the acidity to the IL than the single sulfonic chain in MSIMHSO4. Based on the results, 3.6 wt% of DSIMHSO4, methanol/CCO molar ratio of 12 : 1, and 150°C offered a final FFA conversion of 95.4% within 105 min. A 98.2% was produced via second KOH-catalyzed step in 1.0%, 6 : 1 molar ratio, 600 rpm, and 60°C for 50 min. This new two-step catalyzed process could solve the corrosion and environmental problems associated with the current acidic catalysts.

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Ionic liquid pretreatment of stinging nettle stems and giant miscanthus for bioethanol production

Scientific Reports ◽

10.1038/s41598-021-97993-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Małgorzata Smuga-Kogut ◽

Daria Szymanowska-Powałowska ◽

Roksana Markiewicz ◽

Tomasz Piskier ◽

Tomasz Kogut

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Enzymatic Hydrolysis ◽

Raw Materials ◽

Compositional Analysis ◽

Energy System ◽

Alcohol Concentration ◽

Bioethanol Production ◽

Stinging Nettle ◽

Giant Miscanthus

AbstractProduction of ethanol from lignocellulosic biomass is considered the most promising proposition for developing a sustainable and carbon–neutral energy system. The use of renewable raw materials and variability of lignocellulosic feedstock generating hexose and pentose sugars also brings advantages of the most abundant, sustainable and non-food competitive biomass. Great attention is now paid to agricultural wastes and overgrowing plants as an alternative to fast-growing energetic crops. The presented study explores the use of stinging nettle stems, which have not been treated as a source of bioethanol. Apart from being considered a weed, stinging nettle is used in pharmacy or cosmetics, yet its stems are always a non-edible waste. Therefore, the aim was to evaluate the effectiveness of pretreatment using imidazolium- and ammonium-based ionic liquids, enzymatic hydrolysis, fermentation of stinging nettle stems, and comparison of such a process with giant miscanthus. Raw and ionic liquid-pretreated feedstocks of stinging nettle and miscanthus were subjected to compositional analysis and scanning electron microscopy to determine the pretreatment effect. Next, the same conditions of enzymatic hydrolysis and fermentation were applied to both crops to explore the stinging nettle stems potential in the area of bioethanol production. The study showed that the pretreatment of both stinging nettle and miscanthus with imidazolium acetates allowed for increased availability of the critical lignocellulosic fraction. The use of 1-butyl-3-methylimidazolium acetate in the pretreatment of stinging nettle allowed to obtain very high ethanol concentrations of 7.3 g L−1, with 7.0 g L−1 achieved for miscanthus. Results similar for both plants were obtained for 1-ethyl-3-buthylimidazolium acetate. Moreover, in the case of ammonium ionic liquids, even though they have comparable potential to dissolve cellulose, it was impossible to depolymerize lignocellulose and extract lignin. Furthermore, they did not improve the efficiency of the hydrolysis process, which in turn led to low alcohol concentration. Overall, from the presented results, it can be assumed that the stinging nettle stems are a very promising bioenergy crop.

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Imidazole Processing of Wheat Straw and Eucalyptus Residues—Comparison of Pre-Treatment Conditions and Their Influence on Enzymatic Hydrolysis

Molecules ◽

10.3390/molecules26247591 ◽

2021 ◽

Vol 26 (24) ◽

pp. 7591

Author(s):

Pedro M. A. Pereira ◽

Joana R. Bernardo ◽

Luisa Bivar Roseiro ◽

Francisco Gírio ◽

Rafał M. Łukasik

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Treatment Process ◽

Lignin Content ◽

Biomass Conversion ◽

Treatment Conditions ◽

Treatment Agent ◽

Pre Treatment ◽

Increasing Temperature ◽

Temperature Time

Biomass pre-treatment is a key step in achieving the economic competitiveness of biomass conversion. In the present work, an imidazole pre-treatment process was performed and evaluated using wheat straw and eucalyptus residues as model feedstocks for agriculture and forest-origin biomasses, respectively. Results showed that imidazole is an efficient pre-treatment agent; however, better results were obtained for wheat straw due to the recalcitrant behavior of eucalyptus residues. The temperature had a stronger effect than time on wheat straw pre-treatment but at 160 °C and 4 h, similar results were obtained for cellulose and hemicellulose content from both biomasses (ca. 54% and 24%, respectively). Lignin content in the pre-treated solid was higher for eucalyptus residues (16% vs. 4%), as expected. Enzymatic hydrolysis, applied to both biomasses after different pre-treatments, revealed that results improved with increasing temperature/time for wheat straw. However, these conditions had no influence on the results for eucalyptus residues, with very low glucan to glucose enzymatic hydrolysis yield (93% for wheat straw vs. 40% for eucalyptus residues). Imidazole can therefore be considered as a suitable solvent for herbaceous biomass pre-treatment.

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Use of Buckwheat Straw to Produce Ethyl Alcohol Using Ionic Liquids

Energies ◽

10.3390/en12102014 ◽

2019 ◽

Vol 12 (10) ◽

pp. 2014

Author(s):

Małgorzata Smuga-Kogut ◽

Leszek Bychto ◽

Bartosz Walendzik ◽

Judyta Cielecka-Piontek ◽

Roman Marecik ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Enzymatic Hydrolysis ◽

Alcoholic Fermentation ◽

Near Infrared ◽

Rapid Determination ◽

Raw Material ◽

Pls Regression ◽

Enzymatic Preparation ◽

Second Generation Bioethanol

Background: Common buckwheat (Fagopyrum esculentum Moench) is an annual spring-emerging crop that is classified among the dicotyledons, due to the manner of its cultivation, use, and chemical composition of seeds. The use of buckwheat straw for energy purposes—for example, for the production of second generation bioethanol—might enable its wider application and increase the cost-effectiveness of tillage. Methods: In this study, we examined the usability of buckwheat straw for the production of bioethanol. We pretreated the raw material with ionic liquids and subsequently performed enzymatic hydrolysis and alcoholic fermentation. The obtained chemometric data were analyzed using the Partial Least Squares (PLS) regression model. PLS regression in combination with spectral analysis within the near-infrared (NIR) spectrum allowed for the rapid determination of the amount of cellulose in the raw material and also provided information on the changes taking place in its structure. Results: We obtained good results for the combination of 1-ethyl-3-methylimidazolium acetate as the ionic liquid and Cellic CTec2 as the enzymatic preparation for the pretreatment of buckwheat straw. The highest concentration of glucose following 72 h of enzymatic hydrolysis was found to be around 5.5 g/dm3. The highest concentration of ethanol (3.31 g/dm3) was obtained with the combination of 1-butyl-3-methylimidazolium acetate for the pretreatment and cellulase from Trichoderma reesei for enzymatic hydrolysis. Conclusions: In summary, the efficiency of the fermentation process is strictly associated with the pool of available fermenting sugars, and it depends on the type of ionic liquid used during the pretreatment and on the enzymatic preparation. It is possible to obtain bioethanol from buckwheat straw using ionic liquid for pretreatment of the raw material prior to the enzymatic hydrolysis and alcoholic fermentation of the material.

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Lignin fate and characterization during ionic liquid biomass pretreatment for renewable chemicals and fuels production

Green Chemistry ◽

10.1039/c3gc42295j ◽

2014 ◽

Vol 16 (3) ◽

pp. 1236-1247 ◽

Cited By ~ 87

Author(s):

Noppadon Sathitsuksanoh ◽

Kevin M. Holtman ◽

Daniel J. Yelle ◽

Trevor Morgan ◽

Vitalie Stavila ◽

...

Keyword(s):

Ionic Liquid ◽

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Loblolly Pine ◽

Biomass Pretreatment ◽

Renewable Chemicals

The fate of lignin from wheat straw, Miscanthus, and Loblolly pine after pretreatment by a non-toxic and recyclable ionic liquid (IL), [C2mim][OAc], followed by enzymatic hydrolysis was investigated.

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