Hemp fibers were treated with different pretreatments before being put into ionic liquid dissolved systems. NaOH,HCI,N,N-dimethylacetamide（ DMAc） solution and ultrasonic were utilized to activate fibers. Scanning el...Hemp fibers were treated with different pretreatments before being put into ionic liquid dissolved systems. NaOH,HCI,N,N-dimethylacetamide（ DMAc） solution and ultrasonic were utilized to activate fibers. Scanning electron microscopy（ SEM）,Fourier transform infrared spectroscopy（ FTIR） and X-ray diffraction（ XRD） were used to analyze the morphological and molecular structures of the fiber before and after activation for the comparative analysis. The pretreated fibers were dissolved and the dissolving process of fibers were observed until they were dissolved completely. Experimental studies found that NaOH solution made fibers crystal form change from cellulose Ⅰ to cellulose Ⅱ,and others didn＇t have this kind of change. By comparison,fibers treated by DMAc solution worked best, various methods which affected solubility could be sorted roughly as follows： DMAc ＆gt; ultrasonic ＆gt;HCI ＆gt; NaOH ＆gt; untreated.展开更多
The present research work aims to explore the potency of piranha solutions at the best-optimized concentrations,i.e.,40%and 30%to reduce the recalcitrant and heterogeneous structure of wheat straw,and the treated whea...The present research work aims to explore the potency of piranha solutions at the best-optimized concentrations,i.e.,40%and 30%to reduce the recalcitrant and heterogeneous structure of wheat straw,and the treated wheat straw was denoted as WS40 and WS30.The effect of pretreatment on wheat straw was determined by anaerobic digestion(AD)in a batch mode,followed by the analysis of soluble chemical oxygen demand(sCOD)and volatile fatty acids(VFAs).After pretreatment,the surface fibers shattered and detached,showing a distorted surface of wheat straw.An increase in the crystallinity of wheat straw after pretreatment was also observed due to the removal of amorphous cellulose and lignin.Enhancement in methane yield was obtained on the 9th day,which was 103±6.92 and 99.33±0.57 mL/d for WS40 and WS30,respectively.Displaced water measurement revealed that the pretreatment of wheat straw minimized the hydrolysis period by 14 days.It also improved the methane yield by 2.65(WS40)and 2.45(WS30)fold in comparison with the control which yielded 35.66 mL/d methane on the 23rd day.The modified Gompertz model(MGM),logistic function model(LFM)and transference function model(TFM)adequately described the degradation process and explained the kinetic behavior of the cumulative methane yield.Among the three models,MGM was found to fit best for the methane yield of WS40 and WS30.展开更多
文摘Hemp fibers were treated with different pretreatments before being put into ionic liquid dissolved systems. NaOH,HCI,N,N-dimethylacetamide（ DMAc） solution and ultrasonic were utilized to activate fibers. Scanning electron microscopy（ SEM）,Fourier transform infrared spectroscopy（ FTIR） and X-ray diffraction（ XRD） were used to analyze the morphological and molecular structures of the fiber before and after activation for the comparative analysis. The pretreated fibers were dissolved and the dissolving process of fibers were observed until they were dissolved completely. Experimental studies found that NaOH solution made fibers crystal form change from cellulose Ⅰ to cellulose Ⅱ,and others didn＇t have this kind of change. By comparison,fibers treated by DMAc solution worked best, various methods which affected solubility could be sorted roughly as follows： DMAc ＆gt; ultrasonic ＆gt;HCI ＆gt; NaOH ＆gt; untreated.
基金the financial support received from University Grant Commission(UGC),New Delhi,in the form of National Fellowship for Scheduled Caste Students(UGC-Ref.No.200510367941)。
文摘The present research work aims to explore the potency of piranha solutions at the best-optimized concentrations,i.e.,40%and 30%to reduce the recalcitrant and heterogeneous structure of wheat straw,and the treated wheat straw was denoted as WS40 and WS30.The effect of pretreatment on wheat straw was determined by anaerobic digestion(AD)in a batch mode,followed by the analysis of soluble chemical oxygen demand(sCOD)and volatile fatty acids(VFAs).After pretreatment,the surface fibers shattered and detached,showing a distorted surface of wheat straw.An increase in the crystallinity of wheat straw after pretreatment was also observed due to the removal of amorphous cellulose and lignin.Enhancement in methane yield was obtained on the 9th day,which was 103±6.92 and 99.33±0.57 mL/d for WS40 and WS30,respectively.Displaced water measurement revealed that the pretreatment of wheat straw minimized the hydrolysis period by 14 days.It also improved the methane yield by 2.65(WS40)and 2.45(WS30)fold in comparison with the control which yielded 35.66 mL/d methane on the 23rd day.The modified Gompertz model(MGM),logistic function model(LFM)and transference function model(TFM)adequately described the degradation process and explained the kinetic behavior of the cumulative methane yield.Among the three models,MGM was found to fit best for the methane yield of WS40 and WS30.
