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
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.
