The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Guido Zacchi - One of the best experts on this subject based on the ideXlab platform.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for Biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand. Results The experiments were conducted in a reactor with a controlled temperature profile. The total dry matter content of the hydrolysate was up to 21.1% w/w, corresponding to a content of 15.5% w/w of water insoluble solids. The highest measured glucose yield, (18.3 g glucose per 100 g dry raw material), was obtained after DAH cycles of 3 min at 209°C and 6 min at 211°C with 1% H_2SO_4, which resulted in a total of 26.3 g solubilized C6 sugars per 100 g dry raw material. To estimate the remaining sugar potential, enzymatic Hydrolysis (EH) of the solid fraction was also performed. EH of the solid residue increased the total level of solubilized C6 sugars to a maximum of 35.5 g per 100 g dry raw material when DAH was performed as described above (3 min at 210°C and 2 min at 211°C with 1% H_2SO_4). Conclusion The dual-temperature DAH method did not yield decisively better results than the single-temperature, one-step DAH. When we compared the results with those of earlier studies, the Hydrolysis performance was better than with the one-step DAH but not as well as that of the two-step, single-temperature DAH. Additional enzymatic Hydrolysis resulted in lower levels of solubilized sugars compared with other studies on one-step DAH and two-step DAH followed by enzymatic Hydrolysis. A two-step steam pretreatment with EH gave rise to a considerably higher sugar yield in this study.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for Biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand. Results The experiments were conducted in a reactor with a controlled temperature profile. The total dry matter content of the hydrolysate was up to 21.1% w/w, corresponding to a content of 15.5% w/w of water insoluble solids. The highest measured glucose yield, (18.3 g glucose per 100 g dry raw material), was obtained after DAH cycles of 3 min at 209°C and 6 min at 211°C with 1% H_2SO_4, which resulted in a total of 26.3 g solubilized C6 sugars per 100 g dry raw material. To estimate the remaining sugar potential, enzymatic Hydrolysis (EH) of the solid fraction was also performed. EH of the solid residue increased the total level of solubilized C6 sugars to a maximum of 35.5 g per 100 g dry raw material when DAH was performed as described above (3 min at 210°C and 2 min at 211°C with 1% H_2SO_4). Conclusion The dual-temperature DAH method did not yield decisively better results than the single-temperature, one-step DAH. When we compared the results with those of earlier studies, the Hydrolysis performance was better than with the one-step DAH but not as well as that of the two-step, single-temperature DAH. Additional enzymatic Hydrolysis resulted in lower levels of solubilized sugars compared with other studies on one-step DAH and two-step DAH followed by enzymatic Hydrolysis. A two-step steam pretreatment with EH gave rise to a considerably higher sugar yield in this study.
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the influence of solid liquid separation techniques on the sugar yield in two step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for Biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
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The influence of solid/liquid separation techniques on the sugar yield in two-step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
Mats Galbe - One of the best experts on this subject based on the ideXlab platform.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for Biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand. Results The experiments were conducted in a reactor with a controlled temperature profile. The total dry matter content of the hydrolysate was up to 21.1% w/w, corresponding to a content of 15.5% w/w of water insoluble solids. The highest measured glucose yield, (18.3 g glucose per 100 g dry raw material), was obtained after DAH cycles of 3 min at 209°C and 6 min at 211°C with 1% H_2SO_4, which resulted in a total of 26.3 g solubilized C6 sugars per 100 g dry raw material. To estimate the remaining sugar potential, enzymatic Hydrolysis (EH) of the solid fraction was also performed. EH of the solid residue increased the total level of solubilized C6 sugars to a maximum of 35.5 g per 100 g dry raw material when DAH was performed as described above (3 min at 210°C and 2 min at 211°C with 1% H_2SO_4). Conclusion The dual-temperature DAH method did not yield decisively better results than the single-temperature, one-step DAH. When we compared the results with those of earlier studies, the Hydrolysis performance was better than with the one-step DAH but not as well as that of the two-step, single-temperature DAH. Additional enzymatic Hydrolysis resulted in lower levels of solubilized sugars compared with other studies on one-step DAH and two-step DAH followed by enzymatic Hydrolysis. A two-step steam pretreatment with EH gave rise to a considerably higher sugar yield in this study.
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Impact of dual temperature profile in Dilute Acid Hydrolysis of spruce for ethanol production
Biotechnology for Biofuels, 2010Co-Authors: Peter Bösch, Mats Galbe, Ola Wallberg, Elisabeth Joelsson, Guido ZacchiAbstract:Background The two-step Dilute Acid Hydrolysis (DAH) of softwood is costly in energy demands and capital costs. However, it has the advantage that Hydrolysis and subsequent removal of hemicellulose-derived sugars can be carried out under conditions of low severity, resulting in a reduction in the level of sugar degradation products during the more severe subsequent steps of cellulose Hydrolysis. In this paper, we discuss a single-step DAH method that incorporates a temperature profile at two levels. This profile should simulate the two-step process while removing its major disadvantage, that is, the washing step between the runs, which leads to increased energy demand. Results The experiments were conducted in a reactor with a controlled temperature profile. The total dry matter content of the hydrolysate was up to 21.1% w/w, corresponding to a content of 15.5% w/w of water insoluble solids. The highest measured glucose yield, (18.3 g glucose per 100 g dry raw material), was obtained after DAH cycles of 3 min at 209°C and 6 min at 211°C with 1% H_2SO_4, which resulted in a total of 26.3 g solubilized C6 sugars per 100 g dry raw material. To estimate the remaining sugar potential, enzymatic Hydrolysis (EH) of the solid fraction was also performed. EH of the solid residue increased the total level of solubilized C6 sugars to a maximum of 35.5 g per 100 g dry raw material when DAH was performed as described above (3 min at 210°C and 2 min at 211°C with 1% H_2SO_4). Conclusion The dual-temperature DAH method did not yield decisively better results than the single-temperature, one-step DAH. When we compared the results with those of earlier studies, the Hydrolysis performance was better than with the one-step DAH but not as well as that of the two-step, single-temperature DAH. Additional enzymatic Hydrolysis resulted in lower levels of solubilized sugars compared with other studies on one-step DAH and two-step DAH followed by enzymatic Hydrolysis. A two-step steam pretreatment with EH gave rise to a considerably higher sugar yield in this study.
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the influence of solid liquid separation techniques on the sugar yield in two step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for Biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
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The influence of solid/liquid separation techniques on the sugar yield in two-step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
V V N Kishore - One of the best experts on this subject based on the ideXlab platform.
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low severity Dilute Acid Hydrolysis of sweet sorghum bagasse
Applied Energy, 2013Co-Authors: Aditi Banerji, Malini Balakrishnan, V V N KishoreAbstract:Abstract Sweet sorghum is emerging as a promising energy crop in India, with potential for ethanol production both from the extracted juice and the bagasse residue. This work investigates the release of fermentable total sugars (TS) and formation of total degradation compounds (TDC) by Dilute sulphuric Acid Hydrolysis of sweet sorghum bagasse from the genotype SSV 84. Hydrolysis was conducted at moderate temperatures (100 °C and 121 °C). The effect of pretreatment severity (measured by the combined severity factor, CS), particle size and substrate loading on the hydrolysate composition was examined. The kinetics of xylose, acetic Acid and furfural formation was also studied. The maximum theoretical yield is 29.9 g C5 sugars/100 g bagasse on dry weight basis. Under the conditions of this study, 10% substrate loading in the CS range of 1.64–1.93 was optimal with C5 yield >22.3 g/100 g bagasse and efficiency (TS/TDC ratio) >8. Bagasse particle size reduction also resulted in a higher efficiency. SEM and FT-IR analysis of the solid residue confirmed disruption of the biomass structure and removal of functional groups associated with hemicelluloses and lignin. This study demonstrates that Acid Hydrolysis at moderate temperature has an advantage in terms of high sugars concentration vis-a-vis low degradation compounds formation.
Malini Balakrishnan - One of the best experts on this subject based on the ideXlab platform.
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low severity Dilute Acid Hydrolysis of sweet sorghum bagasse
Applied Energy, 2013Co-Authors: Aditi Banerji, Malini Balakrishnan, V V N KishoreAbstract:Abstract Sweet sorghum is emerging as a promising energy crop in India, with potential for ethanol production both from the extracted juice and the bagasse residue. This work investigates the release of fermentable total sugars (TS) and formation of total degradation compounds (TDC) by Dilute sulphuric Acid Hydrolysis of sweet sorghum bagasse from the genotype SSV 84. Hydrolysis was conducted at moderate temperatures (100 °C and 121 °C). The effect of pretreatment severity (measured by the combined severity factor, CS), particle size and substrate loading on the hydrolysate composition was examined. The kinetics of xylose, acetic Acid and furfural formation was also studied. The maximum theoretical yield is 29.9 g C5 sugars/100 g bagasse on dry weight basis. Under the conditions of this study, 10% substrate loading in the CS range of 1.64–1.93 was optimal with C5 yield >22.3 g/100 g bagasse and efficiency (TS/TDC ratio) >8. Bagasse particle size reduction also resulted in a higher efficiency. SEM and FT-IR analysis of the solid residue confirmed disruption of the biomass structure and removal of functional groups associated with hemicelluloses and lignin. This study demonstrates that Acid Hydrolysis at moderate temperature has an advantage in terms of high sugars concentration vis-a-vis low degradation compounds formation.
Sanam Monavari - One of the best experts on this subject based on the ideXlab platform.
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the influence of solid liquid separation techniques on the sugar yield in two step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for Biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
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The influence of solid/liquid separation techniques on the sugar yield in two-step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids.
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The influence of solid/liquid separation techniques on the sugar yield in two-step Dilute Acid Hydrolysis of softwood followed by enzymatic Hydrolysis
Biotechnology for Biofuels, 2009Co-Authors: Sanam Monavari, Mats Galbe, Guido ZacchiAbstract:Background Two-step Dilute Acid Hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic Hydrolysis, is considered to result in higher sugar yields than one-step Acid Hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step Dilute Acid Hydrolysis, with and without subsequent enzymatic digestion of the solids. Results Washing the material between the two Acid Hydrolysis steps, followed by enzymatic digestion, resulted in recovery of 96% of the mannose and 81% of the glucose (% of the theoretical) in the liquid fraction, regardless of the choice of dewatering method (pressing or vacuum filtration). Not washing the solids between the two Acid Hydrolysis steps led to elevated Acidity of the remaining solids during the second Hydrolysis step, which resulted in lower yields of mannose, 85% and 74% of the theoretical, for the pressed and vacuum-filtered slurry, respectively, due to sugar degradation. However, this increase in Acidity resulted in a higher glucose yield (94.2%) from pressed slurry than from filtered slurry (77.6%). Conclusion Pressing the washed material between the two Acid Hydrolysis steps had no significant negative effect on the sugar yields of the second Acid Hydrolysis step or on enzymatic Hydrolysis. Not washing the material resulted in a harsher second Acid Hydrolysis step, which caused greater degradation of the sugars during subsequent Acid Hydrolysis of the solids, particularly in case of the vacuum-filtered solids. However, pressing in combination with not washing the material between the two steps enhanced the sugar yield of the enzymatic digestion step. Hence, it is suggested that the unwashed slurry be pressed to as high a dry matter content as possible between the two Acid Hydrolysis stages in order to achieve high final sugar yields.