Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carboh...Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carbohydrates in oat husks into furfural through hydrothermal pretreatment using various phosphate-based catalysts,including H_(3)PO_(4),NH_(4)H_(2)PO_(4),NaH_(2)PO_(4),KH_(2)PO_(4),K_(2)HPO_(4) and K_(3)PO_(4) as catalyst.The catalysts’effectiveness in promoting furfural production was evaluated under identical hydrothermal conditions(treatment time for 60 min at a constant temperature of 170℃ and a catalyst amount).Continuous water steam was used to strip furfural from the reaction zone and minimize its degradation.Results indicated that H_(3)PO_(4) was the most effective catalyst,achieving a furfural yield of 13.99 wt.%,which corresponds to approximately 57%of the theoretical yield.NH4H2PO4 also showed moderate effectiveness,while sodium and potassium phosphate salts were significantly less effective.A scanning electron microscope analysis shows that catalysts with lower pH may disrupt the oat husks external layer thus providing a higher C5 carbohydrates conversion rate into furfural.The chemical complexity of oat husk contributes to side reactions between its carbohydrates and lignin during the hydrothermal treatment.This results in an increase in acid-insoluble lignin and inorganic matter in the oat husk lignocellulosic residue,which can reduce the effectiveness of further cellulose saccharification by enzymatic hydrolysis.展开更多
Instead of the traditional linear model of taking,making,and disposing,the circular bio-economy promotes a regenerative approach.Although there is potential to create valuable products like betulin,lupeol,and suberini...Instead of the traditional linear model of taking,making,and disposing,the circular bio-economy promotes a regenerative approach.Although there is potential to create valuable products like betulin,lupeol,and suberinic acids(SA)from outer birch bark,many industries,such as plywood and pulp,often choose to incinerate substan-tial amounts of leftover birch bark to meet their energy needs.This highlights the importance of obtaining valu-able products from wood.The objective of this study was to examine various fractions of SA and assess their potential for wood impregnation.The fractions included SA potassium salts in ethanol(SAK-EtOH)and water(SAK-H2O),SA suspension in water(SAS-H2O)and dried SA,which was subsequently diluted in ethanol(DSA-EtOH).There is significant potential for utilizing SA in wood treatment formulations as a sustainable alternative to harmful petroleum-derived chemicals.This approach not only addresses environmental concerns but also enhances the functionality of wood in construction applications,such as improving impregnation for moisture and fungal protection.Among the solutions tested,the ethanol solution of SA,specifically DSA-EtOH,showed the highest weight percent gain(WPG)and the greatest leaching resistance.GPC analysis showed that SA salts in ethanol(SAK-EtOH)and water(SAK-H2O)predominantly consist of low molecular fractions and each process(acidification and drying)reduces the low molecular content in the sample.This suggests that SA polymerizes after drying,making it necessary to dissolve it in ethanol to meet the requirements for impregnation.Further opti-mization,including adjustments in the concentration of the SA ethanol solution and the curing temperature,is essential to identify the optimal conditions for more in-depth impregnation studies.展开更多
Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained ...Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained through a depolymerization process in an alkaline medium and used as a binder due to their adhesive properties.The aim of this study was to develop the SA-containing binder and identify suitable pressing conditions to produce plywood that meets the shear strength requirements of the EN 314-2 standard 3rd moisture resistance class for bonding quality,ensuring durability in unprotected exterior conditions(shear strength≥1 N/mm^(2)).The raw BOB material was modified by extraction,milling,and fractionation,and the depolymerization methodology was enhanced by additional sieving to improve the adhesive properties of the obtained binders.Several analytical methods were used to characterize the feedstock and the binders.Higher heating value was used to assess the pure outer bark content of BOB.GC-MS and GPC were used to describe the monomeric and oligomeric composition of binders.TGA was used to describe the biopolymeric composition and DSC was used to determine the thermal behavior of the binders.As a result,successful modification of feedstock(extracted BOB,milled through 2 mm sieve,1-2 mm fraction used)and its depolymerization process(implementing the separation of coarse ligno-carbohydrate particles by 1 mm mesh sieve)was employed to obtain a binder for which suitable hot-pressing parameters were determined−200℃for 5 min at 1.8 MPa.Consequently,plywood with shear strength of 1.26±0.18 N/mm^(2),which adheres to the EN 314-2 standards 3rd moisture resistance class,was obtained.展开更多
基金funded by the Latvian State Institute of Wood Chemistry Bioeconomic Research Grant No.09-24 titled“Selective Valorization of Lignocellulosic Biomass(SeVaLi)”.
文摘Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carbohydrates in oat husks into furfural through hydrothermal pretreatment using various phosphate-based catalysts,including H_(3)PO_(4),NH_(4)H_(2)PO_(4),NaH_(2)PO_(4),KH_(2)PO_(4),K_(2)HPO_(4) and K_(3)PO_(4) as catalyst.The catalysts’effectiveness in promoting furfural production was evaluated under identical hydrothermal conditions(treatment time for 60 min at a constant temperature of 170℃ and a catalyst amount).Continuous water steam was used to strip furfural from the reaction zone and minimize its degradation.Results indicated that H_(3)PO_(4) was the most effective catalyst,achieving a furfural yield of 13.99 wt.%,which corresponds to approximately 57%of the theoretical yield.NH4H2PO4 also showed moderate effectiveness,while sodium and potassium phosphate salts were significantly less effective.A scanning electron microscope analysis shows that catalysts with lower pH may disrupt the oat husks external layer thus providing a higher C5 carbohydrates conversion rate into furfural.The chemical complexity of oat husk contributes to side reactions between its carbohydrates and lignin during the hydrothermal treatment.This results in an increase in acid-insoluble lignin and inorganic matter in the oat husk lignocellulosic residue,which can reduce the effectiveness of further cellulose saccharification by enzymatic hydrolysis.
基金supported according to contract No.5.1.1.2.i.0/1/22/A/CFLA/007 between“Forest Sector Competence Centre of Latvia”Ltd.the Central Finance and Contracting Agency which dated 20th January of 2023.
文摘Instead of the traditional linear model of taking,making,and disposing,the circular bio-economy promotes a regenerative approach.Although there is potential to create valuable products like betulin,lupeol,and suberinic acids(SA)from outer birch bark,many industries,such as plywood and pulp,often choose to incinerate substan-tial amounts of leftover birch bark to meet their energy needs.This highlights the importance of obtaining valu-able products from wood.The objective of this study was to examine various fractions of SA and assess their potential for wood impregnation.The fractions included SA potassium salts in ethanol(SAK-EtOH)and water(SAK-H2O),SA suspension in water(SAS-H2O)and dried SA,which was subsequently diluted in ethanol(DSA-EtOH).There is significant potential for utilizing SA in wood treatment formulations as a sustainable alternative to harmful petroleum-derived chemicals.This approach not only addresses environmental concerns but also enhances the functionality of wood in construction applications,such as improving impregnation for moisture and fungal protection.Among the solutions tested,the ethanol solution of SA,specifically DSA-EtOH,showed the highest weight percent gain(WPG)and the greatest leaching resistance.GPC analysis showed that SA salts in ethanol(SAK-EtOH)and water(SAK-H2O)predominantly consist of low molecular fractions and each process(acidification and drying)reduces the low molecular content in the sample.This suggests that SA polymerizes after drying,making it necessary to dissolve it in ethanol to meet the requirements for impregnation.Further opti-mization,including adjustments in the concentration of the SA ethanol solution and the curing temperature,is essential to identify the optimal conditions for more in-depth impregnation studies.
基金supported according to contract No.5.1.1.2.i.0/1/22/A/CFLA/007 between“Forest Sector Competence Centre of Latvia”Ltd.,and the Central Finance and Contracting Agency which dated 20th January of 2023.
文摘Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained through a depolymerization process in an alkaline medium and used as a binder due to their adhesive properties.The aim of this study was to develop the SA-containing binder and identify suitable pressing conditions to produce plywood that meets the shear strength requirements of the EN 314-2 standard 3rd moisture resistance class for bonding quality,ensuring durability in unprotected exterior conditions(shear strength≥1 N/mm^(2)).The raw BOB material was modified by extraction,milling,and fractionation,and the depolymerization methodology was enhanced by additional sieving to improve the adhesive properties of the obtained binders.Several analytical methods were used to characterize the feedstock and the binders.Higher heating value was used to assess the pure outer bark content of BOB.GC-MS and GPC were used to describe the monomeric and oligomeric composition of binders.TGA was used to describe the biopolymeric composition and DSC was used to determine the thermal behavior of the binders.As a result,successful modification of feedstock(extracted BOB,milled through 2 mm sieve,1-2 mm fraction used)and its depolymerization process(implementing the separation of coarse ligno-carbohydrate particles by 1 mm mesh sieve)was employed to obtain a binder for which suitable hot-pressing parameters were determined−200℃for 5 min at 1.8 MPa.Consequently,plywood with shear strength of 1.26±0.18 N/mm^(2),which adheres to the EN 314-2 standards 3rd moisture resistance class,was obtained.
