scholarly journals Is Steam Explosion a Promising Pretreatment for Acid Hydrolysis of Lignocellulosic Biomass?

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1626
Author(s):  
David Steinbach ◽  
Andrea Kruse ◽  
Jörg Sauer ◽  
Jonas Storz
Keyword(s):  
Acid Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Steam Explosion ◽  
Complex Structure ◽  
Beech Wood ◽  
Soluble Sugars ◽  
Water Soluble ◽  
Special Importance ◽  
Hydrolysis Of ◽  
Subsequent Acid

For the production of sugars and biobased platform chemicals from lignocellulosic biomass, the hydrolysis of cellulose and hemicelluloses to water-soluble sugars is a crucial step. As the complex structure of lignocellulosic biomass hinders an efficient hydrolysis via acid hydrolysis, a suitable pretreatment strategy is of special importance. The pretreatment steam explosion was intended to increase the accessibility of the cellulose fibers so that the subsequent acid hydrolysis of the cellulose to glucose would take place in a shorter time. Steam explosion pretreatment was performed with beech wood chips at varying severities with different reaction times (25–34 min) and maximum temperatures (186–223 °C). However, the subsequent acid hydrolysis step of steam-exploded residue was performed at constant settings at 180 °C with diluted sulfuric acid. The concentration profiles of the main water-soluble hydrolysis products were recorded. We showed in this study that the defibration of the macrofibrils in the lignocellulose structure during steam explosion does not lead to an increased rate of cellulose hydrolysis. So, steam explosion is not a suitable pretreatment for acid hydrolysis of hardwood lignocellulosic biomass.

Understanding the slowdown of whole slurry hydrolysis of steam pretreated lignocellulosic woody biomass catalyzed by an up-to-date enzyme cocktail

2018 ◽  
Vol 2 (5) ◽  
pp. 1048-1056 ◽  
Author(s):  
Rui Zhai ◽  
Jinguang Hu ◽  
Jack N. Saddler
Keyword(s):  
Lignocellulosic Biomass ◽  
Enzyme Activities ◽  
Woody Biomass ◽  
Water Soluble ◽  
Enzyme Cocktail ◽  
Key Enzyme ◽  
Whole Slurry ◽  
Hydrolysis Of ◽  
Soluble Components

The key enzyme activities were selectively inhibited and/or deactivated by water-soluble components derived from pretreated lignocellulosic biomass.

Acid hydrolysis of O-acetyl-galactoglucomannan in a continuous tube reactor: a new approach to sugar monomer production

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 187-194 ◽  
Author(s):  
Andrea Pérez Nebreda ◽  
Henrik Grénman ◽  
Päivi Mäki-Arvela ◽  
Kari Eränen ◽  
Jarl Hemming ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Continuous Production ◽  
Product Distribution ◽  
Water Soluble ◽  
Continuous Reactor ◽  
New Approach ◽  
Tube Reactor ◽  
Soluble Polysaccharide ◽  
Hydrolysis Of ◽  
Laminar Flow Model

Abstract Hemicellulose O-acetyl-galactoglucomannan (GGM) is the main noncellulosic water-soluble polysaccharide in the coniferous softwood Norway spruce, consisting of anhydro-galactose, -glucose, and -mannose. Acid hydrolysis of GGM has been studied in a continuous tube reactor to obtain these sugars under industrially relevant conditions. The reaction was performed under atmospheric pressure at 90°C and 95°C, and hydrochloric acid (HCl) served as catalyst. The influence of the reaction parameters, such as acid concentration (pH), temperature, concentration of the substrate, as well as catalyst and reactant flow rates, has been studied on the conversion efficiency and product distribution. Continuous production of monomeric sugars was achieved without formation of low-molecular by-products. The GGM conversion was high with HCl as catalyst, at 95°C, and a pH of 0.3. The main hydrolysis products were mannose, glucose, and galactose monomers. Minor amounts of sugar dimers were detected among the products. The experimental results are described with a laminar flow model for the continuous reactor.

Hydrophilicity and acid hydrolysis of water-soluble antibacterial iron(II) Schiff base complexes in binary aqueous solvents

2013 ◽  
Vol 83 (12) ◽  
pp. 2460-2464 ◽  
Author(s):  
Ali M. Shaker ◽  
Lobna A. E. Nassr ◽  
Mohamed S. S. Adam ◽  
Ibrahim M. A. Mohamed
Keyword(s):  
Schiff Base ◽  
Acid Hydrolysis ◽  
Water Soluble ◽  
Schiff Base Complexes ◽  
Hydrolysis Of

Thermal rearrangement of functionalized 1,2-divinylcyclopropane systems. A convenient synthesis of substituted 4-cyclohepten-1-ones

1986 ◽  
Vol 64 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Edward Piers ◽  
Max S. Burmeister ◽  
Hans-Ulrich Reissig
Keyword(s):  
Acid Hydrolysis ◽  
The Other ◽  
Thermal Rearrangement ◽  
Enol Ethers ◽  
Acyl Chlorides ◽  
Silyl Ethers ◽  
Convenient Synthesis ◽  
Enol Silyl Ethers ◽  
Hydrolysis Of ◽  
Subsequent Acid

Reaction of the acyl chlorides 14–21 with lithium (phenylthio)(cis-2-vinylcyclopropyl)cuprate (2) provided the ketones 22–29. Compounds 22–25, upon treatment with i-Pr2NLi-Me3SiCl, were converted cleanly into the enol silyl ethers 30–33, which gave the 1,4-cycloheptadienes 34–37 upon thermolysis (100–110 °C). Acid hydrolysis of the latter materials produced the corresponding 4-cyclohepten-1-ones 38–41. However, subjection of the cis-2-vinylcyclopropyl ketones 26–29 to i-Pr2NLi-t-BuMe2SiCl afforded, in each case, a mixture of isomeric enol ethers (26 → 42 + 44 (1:1); 27 → 43 + 45 (1:9); 28 → 56 + 58 (1:1); 29 → 57 + 59 (4:1)). Thermolysis (150–175 °C) of these mixtures, followed by acid hydrolysis of the resultant products, gave the 4-cyclohepten-1-ones 54, 55, 64, and 65, admixed with the corresponding 3-methylenecyclopentenes 52, 53, 62, and 63. On the other hand, treatment of the trans-2-vinylcyclopropyl ketones 70–74 with i-Pr2NLi–t-BuMe2SiCl provided exclusively or predominantly the enol ethers 75–79. Thermolysis (230 °C) of the latter materials and subsequent acid hydrolysis of the resultant products 80, 50, 51, 60, and 61 afforded the 4-cyclopenten-1-ones 38, 54, 55, 64, and 65.

THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: III. A GALACTOMANNAN FROM TRICHOPHYTON INTERDIGITALE

1964 ◽  
Vol 42 (12) ◽  
pp. 2862-2871 ◽  
Author(s):  
F. Blank ◽  
M. B. Perry
Keyword(s):  
Formic Acid ◽  
Acid Hydrolysis ◽  
Copper Complex ◽  
Periodate Oxidation ◽  
Water Soluble ◽  
Mild Acid Hydrolysis ◽  
Trichophyton Interdigitale ◽  
Soluble Polysaccharide ◽  
Hydrolysis Of ◽  
Mild Acid

The water-soluble polysaccharide preparation from Trichophytoninterdigitale was fractionated to give two distinct galactomannans and a glucan. A galactomannan isolated via its insoluble copper complex had [α]D +75° (water) and was composed of D-galactose (12%) and D-mannose (88%). On periodate oxidation, the galactomannan consumed 1.73 mole periodate and released 0.67 mole formic acid and 0.12 mole formaldehyde per anhydrohexose unit. Hydrolysis of the methylated galactomannan gave 2,3,5,6-tetra-O-methyl-D-galactose (1 part), 2,3,4,6-tetra-O-methyl-D-mannose (1 part), 2,3,4-tri-O-methyl-D-mannose (4 parts), and3,4-di-O-methyl-D-mannose (2 parts). Mild acid hydrolysis of the galactomannan removed all the galactose residues, leaving a mannan having [α]D +84° (water) whose structure was analyzed by periodate oxidation and methylation techniques.

The production of D-xylose by enzymatic hydrolysis of agricultural wastes

2002 ◽  
Vol 45 (12) ◽  
pp. 97-102 ◽  
Author(s):  
C.H. Cho ◽  
M. Hatsu ◽  
K. Takamizawa
Keyword(s):  
Enzymatic Hydrolysis ◽  
Acid Hydrolysis ◽  
Sunflower Seed ◽  
Steam Explosion ◽  
Agricultural Wastes ◽  
Rhizomucor Pusillus ◽  
Enzyme Solution ◽  
Penicillium Sp ◽  
Hydrolysis Of ◽  
Mixed Crude

Agricultural wastes, rich in D-xylose content, were hydrolyzed using the mixed crude enzymes produced by Penicillium sp. AHT-1 and Rhizomucor pusillus HHT-1. Shells of pistachio, peanut, walnut, chestnut, barley brans and sunflower seed peels, were used as raw or pretreated forms. Pretreatment was performed by milling or steam explosion. Enzymatic hydrolysis after steam explosion was more effective than milling processing. More than 13 g of D-xylose was produced from 100 g of milled pistachio shells, walnut shells, sunflower seed peels and peanut shells (less than 0.5 mm size) by the action of mixed enzyme solutions. A maximum of 36 g of D-xylose was produced from 100 g of milled pistachio shells when mixed enzyme solution, containing 3,000 U and 33 U per g of substrate with xylanase and β-xyosidase activities, respectively, was applied. The ratio of the enzymatic hydrolysis as compared to acid hydrolysis in this finding was 100%.

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