Microwave-assisted Alkali Pre-treatment of Wheat Straw and its Enzymatic Hydrolysis

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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Impact of mixed feedstock of wheat straw, willow and Miscanthus on enzymatic hydrolysis and inhibitor production after microwave hydrothermal pre-treatment in Europe

Biofuels ◽

10.1080/17597269.2021.1894782 ◽

2021 ◽

pp. 1-8

Author(s):

Kamaljit Moirangthem ◽

Darren Greetham ◽

Jim Craigon ◽

Gregory Tucker

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Microwave Hydrothermal ◽

Mixed Feedstock ◽

Pre Treatment

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

10.20944/preprints201902.0037.v1 ◽

2019 ◽

Author(s):

Joana R. Bernardo ◽

Francisco M. Girio ◽

Rafal Lukasik

Keyword(s):

Hydrogen Bond ◽

Ionic Liquid ◽

Ionic Liquids ◽

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Crystalline Cellulose ◽

Hydrogen Sulfate ◽

Fractionation Process ◽

Chemical Character ◽

Pre Treatment

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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Optimisation of enzymatic saccharification of wheat straw pre-treated with sodium hydroxide

Scientific Reports ◽

10.1038/s41598-021-02693-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zhiquan Wang ◽

Suqing Wu ◽

Chunzhen Fan ◽

Xiangyong Zheng ◽

Wei Zhang ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Treatment Time ◽

Solid Content ◽

Reducing Sugar ◽

Sugar Yield ◽

Experimental Result ◽

Enzyme Loading ◽

Hydrolysis Time ◽

Pre Treatment

AbstractTo enhance the reducing sugar yield in enzymatic hydrolysis, various factors (NaOH concentration, solid content and pre-treatment time) that affect the pre-treatment process were investigated and evaluated based on the reducing sugar yield of the subsequent enzymatic hydrolysis. The enzymatic hydrolysis was based on the cellulase from Trichoderma reesi ATCC 26921, the optimum NaOH pre-treatment conditions were an NaOH concentration of 1.0% (w/w), a solid content of 5.0% (w/v) and a pre-treatment time of 60 min. Various parameters that affect the enzymatic hydrolysis of wheat straw, including the solid content, enzyme loading, pH and hydrolysis time, were investigated and optimized through a Box–Behnken design and response surface methodology. The predicted optimum conditions for enzymatic hydrolysis were a solid content of 8.0% (w/v), an enzyme loading of 35 FPU/g substrate, a temperature of 50 °C, a pH of 5.3 and a hydrolysis time of 96 h. The experimental result showed that the maximum reducing sugar yield was 60.73% (53.35% higher than the wheat straw without NaOH pre-treatment), which is in accordance with the predicted conditions.

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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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Investigation of Acid and Enzyme Wheat Straw Hydrolysis for Obtaining Polysaccharides

Oriental Journal Of Chemistry ◽

10.13005/ojc/350237 ◽

2019 ◽

Vol 35 (2) ◽

pp. 766-772

Author(s):

Zhaksylyk Baumanuly Makhatov ◽

Bakhytzhan Shilmirzaevich Kedelbayev ◽

Madina Dzhakashyeva ◽

Amina Daulbai ◽

Bibilgul Zaydullayevna Doltayeva ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Plant Biomass ◽

Raw Materials ◽

Low Cost ◽

Economic Feasibility ◽

Aspergillus Awamori ◽

Processing Plant ◽

Pre Treatment ◽

Hydrolysis Of

The processes of acid and enzymatic hydrolysis of wheat straw in the presence of the strain Aspergillus awamori F-RKM 0719 has been studied. Enzymatic hydrolysis is the most promising method of processing plant biomass. When carrying out the enzymatic hydrolysis of cellulosic materials, the yield of sugars reaches less than 20% of the theoretically possible yield. Overcoming the physico-chemical barriers that hamper the availability of cellulose for enzymes is an important issue, the solution of which is directly related to the search for low-cost pre-treatment methods for raw materials. The effectiveness of this process determines the yield of the target product in the process of enzymatic hydrolysis of cellulose and the economic feasibility of the entire technology as a whole.

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