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Article: Solid–Liquid Phase Behaviors of Binary Mixtures of Various Partial Acylglycerols by Differential Scanning Calorimetry

Seniorita, Latifa / Minami, Eiji / Kawamoto, Haruo

European journal of lipid science and technology. 2022 Jan., v. 124, no. 1

2022

Abstract: Monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) are impurities in biodiesel and a major cause of precipitation. Understanding the behavior of such acylglycerols is essential for predicting biodiesel cold flow properties (CFPs). ... ...

Abstract	Monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) are impurities in biodiesel and a major cause of precipitation. Understanding the behavior of such acylglycerols is essential for predicting biodiesel cold flow properties (CFPs). The previous study on MAG/MAG binary mixtures shows that they tend to solidify by forming molecular compounds. In contrast, TAG/TAG mixtures, which have been studied extensively, are commonly eutectic or monotectic systems, in which each component solidifies separately. The present study focuses on binary mixtures of DAG/DAG and different acylglycerol pairs (MAG/DAG, TAG/MAG, and DAG/TAG), and determination of their solid–liquid phase behavior by differential scanning calorimetry. These mixtures are found to behave as eutectic or monotectic systems with no sign of compound formation. As DAG and TAG have lower contents than MAG in biodiesel and they are unlikely to form molecular compounds with MAG, it is suggested that DAG and TAG have little effect on the biodiesel CFPs. Practical Applications: Biodiesel has attracted much interest because its blending with conventional fossil diesel has become more standard with biofuel mandates. From an energy perspective, the solid–liquid phase behavior of acylglycerols will contribute to building prediction models for biodiesel CFPs.
Keywords	biodiesel ; cold ; diacylglycerols ; energy ; fossil fuels ; prediction ; technology ; triacylglycerols
Language	English
Dates of publication	2022-01
Publishing place	John Wiley & Sons, Ltd
Document type	Article
Note	JOURNAL ARTICLE
ZDB-ID	2003265-1
ISSN	1438-7697
ISSN	1438-7697
DOI	10.1002/ejlt.202100092
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Influence of Proteins on the Lignin Decomposition Behavior of Japanese Cedar (

Yao, Yilin / Takada, Masatsugu / Minami, Eiji / Kawamoto, Haruo

ACS omega

2022 Volume 7, Issue 42, Page(s) 37286–37292

Abstract: The effect of adding protein on the decomposition behavior of lignin in Japanese cedar under supercritical methanol conditions (270 °C/27 MPa) was studied. The Klason method was used to detect the lignin content in the insoluble residue following to a 30 ...

Abstract	The effect of adding protein on the decomposition behavior of lignin in Japanese cedar under supercritical methanol conditions (270 °C/27 MPa) was studied. The Klason method was used to detect the lignin content in the insoluble residue following to a 30 min treatment. Adding either an animal (bovine serum albumin) or plant (soy) protein enhanced delignification from 50 to 65% of the lignin-based wt %. This result was attributed to enhanced lignin depolymerization owing to inhibited lignin recondensation and/or the suppressed formation of polysaccharide-derived char via reactions between the protein and polysaccharides. Although the solubilization of lignin was promoted and the yield of lignin-derived low-molecular-weight compounds increased, the selectivity of major monomers such as coniferyl alcohol (CA) and γ-methylated CA decreased. The addition of proteins has a substantial impact on the decomposition behavior of cell wall components under supercritical methanol conditions. This information provides insights into the use of protein-rich lignocelluloses.
Language	English
Publishing date	2022-10-11
Publishing country	United States
Document type	Journal Article
ISSN	2470-1343
ISSN (online)	2470-1343
DOI	10.1021/acsomega.2c03716
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article: Location of uronic acid group in Japanese cedar and Japanese beech wood cell walls as evaluated by the influences of minerals on thermal reactivity

Wang, Jiawei / Minami, Eiji / Kawamoto, Haruo

Journal of wood science. 2021 Dec., v. 67, no. 1

2021

Abstract: The thermal reactivities of cellulose and hemicellulose are significantly different in cell walls when compared with isolated components and differ in Japanese cedar (softwood) and Japanese beech (hardwood). Uronic acid bound to xylan promotes the ... ...

Abstract	The thermal reactivities of cellulose and hemicellulose are significantly different in cell walls when compared with isolated components and differ in Japanese cedar (softwood) and Japanese beech (hardwood). Uronic acid bound to xylan promotes the thermal degradation of cellulose and hemicellulose, and its effect is different depending on the form of free acid (acting as an acid catalyst) or metal uronate (acting as a base catalyst). We evaluated the location of uronic acid in the cell wall by identifying the components affected by demineralization in pyrolysis of cedar and beech wood. The thermal reactivities of xylan and glucomannan in beech were changed by demineralization, but in cedar, glucomannan and cellulose reactivities were changed. Therefore, the location of uronic acid in the cell wall was established and differed between cedar and beech; close to glucomannan and xylan in beech, but close to glucomannan and cellulose in cedar. Such information is important for understanding the ultrastructure and pyrolysis behavior of softwood and hardwood cell walls.
Keywords	Cryptomeria japonica ; Fagus crenata ; catalysts ; cell walls ; cellulose ; glucomannans ; hardwood ; pyrolysis ; softwood ; ultrastructure ; uronic acids ; xylan
Language	English
Dates of publication	2021-12
Size	p. 3.
Publishing place	Springer Singapore
Document type	Article
ZDB-ID	1429032-7
ISSN	1435-0211
ISSN	1435-0211
DOI	10.1186/s10086-020-01936-6
Database	NAL-Catalogue (AGRICOLA)

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Article: Effect of delignification on thermal degradation reactivities of hemicellulose and cellulose in wood cell walls

Wang, Jiawei / Minami, Eiji / Asmadi, Mohd / Kawamoto, Haruo

Journal of wood science. 2021 Dec., v. 67, no. 1

2021

Abstract: The thermal degradation reactivities of cellulose and hemicellulose are substantially different in Japanese cedar (Cryptomeria japonica, a softwood) and Japanese beech (Fagus crenata, a hardwood). Uronic acid and its salts act as acid and base catalysts, ...

Abstract	The thermal degradation reactivities of cellulose and hemicellulose are substantially different in Japanese cedar (Cryptomeria japonica, a softwood) and Japanese beech (Fagus crenata, a hardwood). Uronic acid and its salts act as acid and base catalysts, respectively, and their specific placement in the cell walls has been considered a factor that influences degradation reactivity. In this study, the role of lignin in degradation reactivity was investigated using holocellulose prepared from cedar and beech woods. The thermal degradation reactivities of cellulose and hemicellulose in holocellulose were evaluated according to the recovery of hydrolyzable sugars from heat-treated samples and compared with those of wood samples. Results show that the reactivities of xylan and glucomannan in both woods became similar to those of the corresponding isolated samples when lignin was removed. By contrast, the cellulose in both woods became more reactive when lignin was removed, and the degradation could be separated into two modes depending on the reactivity. These results were analyzed in terms of the effect of lignin on the matrix of cell walls and the interaction between the matrix and surface molecules of cellulose microfibrils. Differential thermogravimetric curves of the holocellulose samples were obtained and explained in terms of the degradation of hemicellulose and cellulose. The reported findings will provide insights into the research fields of wood pyrolysis and cell wall ultrastructures.
Keywords	Cryptomeria japonica ; Fagus crenata ; cell walls ; cellulose ; cellulose microfibrils ; delignification ; glucomannans ; hardwood ; heat treatment ; lignin ; pyrolysis ; softwood ; thermogravimetry ; ultrastructure ; uronic acids ; xylan
Language	English
Dates of publication	2021-12
Size	p. 19.
Publishing place	Springer Singapore
Document type	Article
ZDB-ID	1429032-7
ISSN	1435-0211
ISSN	1435-0211
DOI	10.1186/s10086-021-01952-0
Database	NAL-Catalogue (AGRICOLA)

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Article: Thermal degradation of hemicellulose and cellulose in ball-milled cedar and beech wood

Wang, Jiawei / Minami, Eiji / Asmadi, Mohd / Kawamoto, Haruo

Journal of wood science. 2021 Dec., v. 67, no. 1

2021

Abstract: The thermal degradation reactivities of hemicellulose and cellulose in wood cell walls are significantly different from the thermal degradation behavior of the respective isolated components. Furthermore, the degradation of Japanese cedar (Cryptomeria ... ...

Abstract	The thermal degradation reactivities of hemicellulose and cellulose in wood cell walls are significantly different from the thermal degradation behavior of the respective isolated components. Furthermore, the degradation of Japanese cedar (Cryptomeria japonica, a softwood) is distinct from that of Japanese beech (Fagus crenata, a hardwood). Lignin and uronic acid are believed to play crucial roles in governing this behavior. In this study, the effects of ball milling for various durations of time on the degradation reactivities of cedar and beech woods were evaluated based on the recovery rates of hydrolyzable sugars from pyrolyzed wood samples. The applied ball-milling treatment cleaved the lignin β-ether bonds and reduced the crystallinity of cellulose, as determined by X-ray diffraction. Both xylan and glucomannan degraded in a similar temperature range, although the isolated components exhibited different reactivities because of the catalytic effect of uronic acid bound to the xylose chains. These observations can be explained by the more homogeneous distribution of uronic acid in the matrix of cell walls as a result of ball milling. As observed for holocelluloses, cellulose in the ball-milled woods degraded in two temperature ranges (below 320 °C and above); a significant amount of cellulose degraded in the lower temperature range, which significantly changed the shapes of the thermogravimetric curves. This report compares the results obtained for cedar and beech woods, and discusses them in terms of the thermal degradation of the matrix and cellulose microfibrils in wood cell walls and role of lignin. Such information is crucial for understanding the pyrolysis and heat treatment of wood.
Keywords	Cryptomeria japonica ; Fagus crenata ; X-ray diffraction ; cellulose ; cellulose microfibrils ; crystal structure ; glucomannans ; hardwood ; heat treatment ; lignin ; pyrolysis ; softwood ; temperature ; thermogravimetry ; uronic acids ; xylan ; xylose
Language	English
Dates of publication	2021-12
Size	p. 32.
Publishing place	Springer Singapore
Document type	Article
ZDB-ID	1429032-7
ISSN	1435-0211
ISSN	1435-0211
DOI	10.1186/s10086-021-01962-y
Database	NAL-Catalogue (AGRICOLA)

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Article: Solidification behavior of acylglycerols in fatty acid methyl esters and effects on the cold flow properties of biodiesel

Seniorita, Latifa / Minami, Eiji / Kawamoto, Haruo

The journal of the American Oil Chemists' Society. 2021 July, v. 98, no. 7

2021

Abstract: The formation of precipitates in biodiesel (comprising fatty acid methyl esters [FAMEs] obtained from plant oils) can lead to the clogging of fuel filters. Such precipitates are often caused by the solidification of acylglycerols (monoacylglycerols [MAGs] ...

Abstract	The formation of precipitates in biodiesel (comprising fatty acid methyl esters [FAMEs] obtained from plant oils) can lead to the clogging of fuel filters. Such precipitates are often caused by the solidification of acylglycerols (monoacylglycerols [MAGs], diacylglycerols [DAGs], and triacylglycerols [TAGs]) that have higher melting points than FAMEs. Based on our prior study on the solidification behavior of MAG/FAME binary mixtures, the present work investigated the behavior of various DAGs and TAGs combined with FAMEs. Differential scanning calorimetry was used to clarify the effects of acylglycerols on the cold‐flow properties of biodiesel. When DAGs and TAGs were added to FAMEs, the liquidus temperatures (above which the mixtures were completely liquid) increased steeply even at low concentrations. This same behavior was observed previously in trials with MAGs, indicating that all acylglycerols readily precipitate in combination with FAMEs. However, thermodynamic analyses established that the reasons for such precipitation were different for different compounds. MAGs precipitates because they contain two hydroxyl groups and therefore have a low affinity for FAMEs. In contrast, TAGs precipitates as a result of their high enthalpies of fusion (which in turn are caused by high molecular weights), while both factors affect the precipitation of DAGs. A non‐solid‐solution thermodynamic model that assumes a eutectic system was found to accurately predict the liquidus temperatures of binary and multicomponent mixtures containing various acylglycerols with FAMEs.
Keywords	biodiesel ; cold ; diacylglycerols ; enthalpy ; liquids ; monoacylglycerols ; solidification ; thermodynamic models ; triacylglycerols
Language	English
Dates of publication	2021-07
Size	p. 727-735.
Publishing place	John Wiley & Sons, Inc.
Document type	Article
Note	JOURNAL ARTICLE
ZDB-ID	240684-6
ISSN	1558-9331 ; 0003-021X
ISSN (online)	1558-9331
ISSN	0003-021X
DOI	10.1002/aocs.12492
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Hydroxymethylfurfural as an Intermediate of Cellulose Carbonization.

Nomura, Takashi / Minami, Eiji / Kawamoto, Haruo

ChemistryOpen

2021 Volume 10, Issue 6, Page(s) 609

Abstract: Invited for this month's cover is the group of Haruo Kawamoto at Kyoto University (Japan). The cover picture shows the carbonization pathway of cellulose via 5-hydroxymethylfurfural as an important intermediate. Thermochemical conversion is one of the ... ...

Abstract	Invited for this month's cover is the group of Haruo Kawamoto at Kyoto University (Japan). The cover picture shows the carbonization pathway of cellulose via 5-hydroxymethylfurfural as an important intermediate. Thermochemical conversion is one of the promising technologies to convert cellulose, which is the main component of lignocellulosic biomass, into biofuels and biochemicals. Understanding the molecular mechanism of thermal degradation of cellulose is important for developing efficient conversion techniques by controlling the reaction. Read the full text of their Full Paper at 10.1002/open.202000314.
Language	English
Publishing date	2021-05-28
Publishing country	Germany
Document type	Journal Article
ZDB-ID	2655605-4
ISSN	2191-1363 ; 2191-1363
ISSN (online)	2191-1363
ISSN	2191-1363
DOI	10.1002/open.202100115
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Topochemistry of the Delignification of Japanese Beech (

Takada, Masatsugu / Minami, Eiji / Kawamoto, Haruo

ACS omega

2021 Volume 6, Issue 32, Page(s) 20924–20930

Abstract: The topochemistry of Japanese beech ( ...

Abstract	The topochemistry of Japanese beech (
Language	English
Publishing date	2021-08-02
Publishing country	United States
Document type	Journal Article
ISSN	2470-1343
ISSN (online)	2470-1343
DOI	10.1021/acsomega.1c02345
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Hydroxymethylfurfural as an Intermediate of Cellulose Carbonization.

Nomura, Takashi / Minami, Eiji / Kawamoto, Haruo

ChemistryOpen

2021 Volume 10, Issue 6, Page(s) 610–617

Abstract: Hydrogen bond donor solvents such as aromatic solvents inhibit the secondary degradation of cellulose-derived primary pyrolysis products. In a previous study, we found that the formation of solid carbonized products was completely inhibited during ... ...

Abstract	Hydrogen bond donor solvents such as aromatic solvents inhibit the secondary degradation of cellulose-derived primary pyrolysis products. In a previous study, we found that the formation of solid carbonized products was completely inhibited during cellulose pyrolysis in aromatic solvents, with 5-hydroxymethylfurfural (5-HMF) recovered in certain yields instead. This indicated that 5-HMF is an intermediate in cellulose carbonization. To confirm this hypothesis, the thermal reactivity of 5-HMF was investigated. At 280 °C, pure 5-HMF polymerized into a hard glassy substance through OH group elimination, but further conversion was slow. When pyrolyzed in the presence of glycerol, a model of coexisting primary pyrolysis products from cellulose, a coupling reaction proceeded. Reactions characteristic of cellulose carbonization then occurred, including the formation of acidic groups and benzene-type structures in the solid products. These results confirmed the above hypothesis. The molecular mechanism of cellulose carbonization is discussed, focusing on the crystalline nature.
Language	English
Publishing date	2021-05-01
Publishing country	Germany
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2655605-4
ISSN	2191-1363 ; 2191-1363
ISSN (online)	2191-1363
ISSN	2191-1363
DOI	10.1002/open.202000314
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article: Carbonization of cellulose cell wall evaluated with ultraviolet microscopy

Nomura, Takashi / Minami, Eiji / Kawamoto, Haruo

RSC advances. 2020 Feb. 19, v. 10, no. 13

2020

Abstract: This is the first study of cellulose carbonization in the interior of cell walls. Cotton cellulose was pyrolyzed under nitrogen or in aromatic solvents (benzophenone, diphenyl sulfide, and 1,3-diphenoxybenzene) at 280 °C, and cross sections of the cell ... ...

Abstract	This is the first study of cellulose carbonization in the interior of cell walls. Cotton cellulose was pyrolyzed under nitrogen or in aromatic solvents (benzophenone, diphenyl sulfide, and 1,3-diphenoxybenzene) at 280 °C, and cross sections of the cell walls were examined using ultraviolet (UV) microscopy. After pyrolysis under nitrogen, UV absorption caused by carbonization appeared inside the cell walls. The absorptivity of the cell interiors was homogeneous and slightly lower than that of the cell surfaces. The UV spectra had maximal absorption at ca. 250 nm. The spectra of model compounds and Py-GC/MS analysis data suggested that furanic and polycyclic aromatic structures were present in the carbonized products. The use of aromatic solvents decreased the yields of solid carbonized products and the UV absorptivity, which remained homogeneous throughout the cross sections. The mechanism of cellulose carbonization in cell walls is discussed along with the influence of aromatic solvents.
Keywords	absorption ; absorptivity ; benzophenones ; carbonization ; cell walls ; cellulose ; cotton ; gas chromatography-mass spectrometry ; microscopy ; models ; nitrogen ; organic sulfur compounds ; pyrolysis ; solvents
Language	English
Dates of publication	2020-0219
Size	p. 7460-7467.
Publishing place	The Royal Society of Chemistry
Document type	Article
ISSN	2046-2069
DOI	10.1039/c9ra09435k
Database	NAL-Catalogue (AGRICOLA)

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