Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzy...Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzymes was selected as pretreatment for the production of ethanol from CGT.However,an increment in the ethanol production is necessary.To accomplish that,this research evaluated the effect of pretreating CGT using alkaline ultrasonication before a liquid hot water and ligninolytic enzymes pretreatments for ethanol production.Three NaOH concentrations(5%,10%,and 15%)were employed for the alkaline ultrasonication.Additionally,this work is one of the first applications of Fourier transform infrared(FT-IR)spectrum and principal component analysis(PCA)as fast methodology to identify the differences in the biomass after different types of pretreatments.Results:The three concentrations employed for the alkaline ultrasonication pretreatment produced ethanol yields and cellulose conversions higher than the experiment without NaOH.Furthermore,15%NaOH concentration achieved twofold increment yield versus the treatment without NaOH.The FT-IR spectrum confirmed modifications in the CGT structure in the different pretreatments.PCA was helpful to determine differences between the pretreated and un-pretreated biomass and to evaluate how the CGT structure changed after each treatment.Conclusions:The combination of alkali ultrasonication hydrolysis,liquid hot water,and ligninolytic enzymes using 15%of NaOH improved 35%the ethanol yield compared with the original treatment.Additionally,we demonstrated the use of PCA to identify the modifications in the biomass structure after different types of pretreatments and conditions.展开更多
In recent years bioethanol fuels derived from agricultural biomass resources or waste have been considered the cleanest liquid fuel alternative to fossil fuels.Ethanol consumption is expected to reach 11.2 billion gal...In recent years bioethanol fuels derived from agricultural biomass resources or waste have been considered the cleanest liquid fuel alternative to fossil fuels.Ethanol consumption is expected to reach 11.2 billion gallons by 2012.Sweet sorghum,grown in the Southeast and Midwest states in US,contains 14%-20%fermentable sugar and is an ideal feedstock,owing to its ease of fermentation by yeast.The objectives of this research were to perform kinetic studies to determine the factors that may affect the rates of sugar consumption and ethanol production during fermentation of two varieties of sweet sorghum juice,Variety 1(V-1)and Variety 2(V-2),and to optimize the fermentation efficiency and ethanol production by varying strategies to process the juice before fermentation.Kinetic parameters of fermentation provide total sugar consumption rate of 3.4 g/(L·h)for V-1 juice and 2.2 g/(L·h)for V-2 juice,with ethanol production rates of 1.8 g/(L·h)for V-1 juice and 1.6 g/(L·h)for V-2 juice.Maximum ethanol production(V/V)was 8.5%for V-1 and 9.2%for V-2;ethanol yield was 0.065 g of ethanol/g of V-1 juice and 0.072 g ethanol/g of V-2 juice.Even though V-2 has a higher ethanol yield than V-1,V-1 has faster consumption and production rates due to its lower initial glucose and sucrose proportions in the juice,relative to V-2.Fermentation efficiency is greater than 90%for frozen,autoclaved juice and 25%sugar content juice.The lowest fermentation efficiency(79%)was for 30%sugar-content juice.These results can be used to optimize processing conditions of sweet sorghum juice during fermentation.展开更多
文摘Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzymes was selected as pretreatment for the production of ethanol from CGT.However,an increment in the ethanol production is necessary.To accomplish that,this research evaluated the effect of pretreating CGT using alkaline ultrasonication before a liquid hot water and ligninolytic enzymes pretreatments for ethanol production.Three NaOH concentrations(5%,10%,and 15%)were employed for the alkaline ultrasonication.Additionally,this work is one of the first applications of Fourier transform infrared(FT-IR)spectrum and principal component analysis(PCA)as fast methodology to identify the differences in the biomass after different types of pretreatments.Results:The three concentrations employed for the alkaline ultrasonication pretreatment produced ethanol yields and cellulose conversions higher than the experiment without NaOH.Furthermore,15%NaOH concentration achieved twofold increment yield versus the treatment without NaOH.The FT-IR spectrum confirmed modifications in the CGT structure in the different pretreatments.PCA was helpful to determine differences between the pretreated and un-pretreated biomass and to evaluate how the CGT structure changed after each treatment.Conclusions:The combination of alkali ultrasonication hydrolysis,liquid hot water,and ligninolytic enzymes using 15%of NaOH improved 35%the ethanol yield compared with the original treatment.Additionally,we demonstrated the use of PCA to identify the modifications in the biomass structure after different types of pretreatments and conditions.
文摘In recent years bioethanol fuels derived from agricultural biomass resources or waste have been considered the cleanest liquid fuel alternative to fossil fuels.Ethanol consumption is expected to reach 11.2 billion gallons by 2012.Sweet sorghum,grown in the Southeast and Midwest states in US,contains 14%-20%fermentable sugar and is an ideal feedstock,owing to its ease of fermentation by yeast.The objectives of this research were to perform kinetic studies to determine the factors that may affect the rates of sugar consumption and ethanol production during fermentation of two varieties of sweet sorghum juice,Variety 1(V-1)and Variety 2(V-2),and to optimize the fermentation efficiency and ethanol production by varying strategies to process the juice before fermentation.Kinetic parameters of fermentation provide total sugar consumption rate of 3.4 g/(L·h)for V-1 juice and 2.2 g/(L·h)for V-2 juice,with ethanol production rates of 1.8 g/(L·h)for V-1 juice and 1.6 g/(L·h)for V-2 juice.Maximum ethanol production(V/V)was 8.5%for V-1 and 9.2%for V-2;ethanol yield was 0.065 g of ethanol/g of V-1 juice and 0.072 g ethanol/g of V-2 juice.Even though V-2 has a higher ethanol yield than V-1,V-1 has faster consumption and production rates due to its lower initial glucose and sucrose proportions in the juice,relative to V-2.Fermentation efficiency is greater than 90%for frozen,autoclaved juice and 25%sugar content juice.The lowest fermentation efficiency(79%)was for 30%sugar-content juice.These results can be used to optimize processing conditions of sweet sorghum juice during fermentation.
