Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydro...Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydrolysis and fermentation steps. This study focused on the steam explosion method as pretreatment. Therefore, different steam explosion severities were evaluated. The content of glucan, xylan and Klason lignin was examined. Xylan degraded with increasing severity from 412.7 g·kg-1 （untreated） to a minimum of 127.3 g-kg1 dry matter （190 ℃/30 min）. Glucan concentrations increased from 315.1 g·kg1 （untreated） to a maximum of 371.6 g·kg-1 dry matter （200 ℃/20 min）. For soluble lignin, an increase could be observed at rising severity, from 145.3 g·kg-l （untreated） to a maximum of 214.9 g·kg-1 dry matter （190 ℃/30 min）. Furthermore, the mass recovery was calculated. At harsher pretreatment conditions, a significant mass loss was observed, estimated by the ash content in the recovered dry matter. The lowest recovery rate was observed for SF = 4.13 （190 ℃/30 min） with 68.39%. The produced inhibitors were evaluated.展开更多
Biomass material as a source of fuel is difficult to handle, transport, store, and utilize in its original form. To overcome these challenges and make it suitable for energy prodution, the material must be pre-treated...Biomass material as a source of fuel is difficult to handle, transport, store, and utilize in its original form. To overcome these challenges and make it suitable for energy prodution, the material must be pre-treated. Biomass steam explosion is one of the promising pretreatment methods where moisture and hemicellulose are removed in order to improve biomass storage and fuel properties. This paper is aimed to model the suitability of pine saw dust for energy production through steam explosion process. The peak property method was used to determine the kinetic parameters. The model has shown that suitable operating conditions for steam explosion process to remove moisture and hemicellulose from pine sawdust. The temperature and pressure ranges attained in the current study are 260 -317 ℃ (533 -590 K), 4.7 -10.8 MPa, respectively.展开更多
Pelletization,a form of densification,increases bulk density and improves the convenience and accessibility of biomass feedstock due to the uniform shape and size.Pretreatment of biomass enhances the breakdown and acc...Pelletization,a form of densification,increases bulk density and improves the convenience and accessibility of biomass feedstock due to the uniform shape and size.Pretreatment of biomass enhances the breakdown and accessibility of the cross-linking lignin,which acts as a binding agent.In this study,pelletization of radio frequency-alkaline and steam explosion pretreated barley straw was performed.Three levels of temperature(70oC,80oC,and 90oC),five levels of the mass ratio of biomass to NaOH solution(1:4,1:5,1:6,1:7,and 1:8),one hour equilibration time,biomass screen size of 1.6 mm,1%NaOH concentration,and 20 min residence time in the radio frequency chamber were used for the radio frequency-alkaline pretreatment.Three levels of steam temperature(140oC,160oC,and 180oC),three levels of moisture content of 8%,30%,and 50%(mass fraction of total mass),and 5 min and 10 min exposure to steam were tested for the steam explosion pretreatment.The effects of both pretreatment methods were evaluated by pelletizing the pretreated and non-pretreated barley straw samples in a single pelleting unit.The pellet density,tensile strength,durability,dimensional stability,and color of the pellets were determined.Radio frequency-alkaline pretreatment with the use of 1%NaOH solution and a ratio of biomass:NaOH solution of 1:8 has significant effect(P<0.05)on the breakdown of the lignified matrix,resulting in pellets with superior physical characteristics.The steam exploded samples pretreated at higher temperatures(180ºC)and retention time of 10 min resulted into pellets with good physical qualities.展开更多
Processing and densification of agricultural biomass into high density and durable pellets are critical to facilitate handling,storage and transportation.Biomass pelleting experiments were designed to conduct single a...Processing and densification of agricultural biomass into high density and durable pellets are critical to facilitate handling,storage and transportation.Biomass pelleting experiments were designed to conduct single and pilot scale pelleting of non-treated and steam exploded barley,canola,oat and wheat straw grinds acquired from 6.4,3.2,1.6 and 0.8 mm hammer mill screen sizes at 10%moisture content(wb).Single-pelleting was performed by applying compression pressures of 31.6,63.2,94.7,and 138.9 MPa using a close-fit plunger die assembly(die length 135.3 mm and diameter of(6.30±0.5)mm).During pilot scale pelleting,customization of ground straw material was performed by adding steam exploded biomass in increments of 25%to non-treated ground straw for respective biomass at specific grind size.Ground straw samples were conditioned to 17.5%moisture content and 10%flaxseed oil was added to increase the bulk density and flowability of grinds,which resulted in the production of pellets.The quality of pellets from single pelleting experiments was ascertained by measuring their respective density and durability.In addition,the change in pellet density was measured after a storage period of one month to determine its dimensional stability.It was determined that applied pressure and pre-treatment were significant factors affecting the pellet density.Also,bigger grind sizes and lower applied pressures resulted in higher pellet relaxations(lower pellet densities)during storage of pellets.The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25%steam exploded straw at 0.8 mm.It was observed that the pellet bulk density and particle density are positively correlated.The density and durability of agricultural straw pellets significantly increased with decrease in hammer mill screen size from 1.6 mm to 0.8 mm.Customization of agricultural straw by adding 25%of steam exploded straw by weight is possible,but it did not improve pellet quality.In addition,durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption.展开更多
文摘Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydrolysis and fermentation steps. This study focused on the steam explosion method as pretreatment. Therefore, different steam explosion severities were evaluated. The content of glucan, xylan and Klason lignin was examined. Xylan degraded with increasing severity from 412.7 g·kg-1 （untreated） to a minimum of 127.3 g-kg1 dry matter （190 ℃/30 min）. Glucan concentrations increased from 315.1 g·kg1 （untreated） to a maximum of 371.6 g·kg-1 dry matter （200 ℃/20 min）. For soluble lignin, an increase could be observed at rising severity, from 145.3 g·kg-l （untreated） to a maximum of 214.9 g·kg-1 dry matter （190 ℃/30 min）. Furthermore, the mass recovery was calculated. At harsher pretreatment conditions, a significant mass loss was observed, estimated by the ash content in the recovered dry matter. The lowest recovery rate was observed for SF = 4.13 （190 ℃/30 min） with 68.39%. The produced inhibitors were evaluated.
文摘Biomass material as a source of fuel is difficult to handle, transport, store, and utilize in its original form. To overcome these challenges and make it suitable for energy prodution, the material must be pre-treated. Biomass steam explosion is one of the promising pretreatment methods where moisture and hemicellulose are removed in order to improve biomass storage and fuel properties. This paper is aimed to model the suitability of pine saw dust for energy production through steam explosion process. The peak property method was used to determine the kinetic parameters. The model has shown that suitable operating conditions for steam explosion process to remove moisture and hemicellulose from pine sawdust. The temperature and pressure ranges attained in the current study are 260 -317 ℃ (533 -590 K), 4.7 -10.8 MPa, respectively.
文摘Pelletization,a form of densification,increases bulk density and improves the convenience and accessibility of biomass feedstock due to the uniform shape and size.Pretreatment of biomass enhances the breakdown and accessibility of the cross-linking lignin,which acts as a binding agent.In this study,pelletization of radio frequency-alkaline and steam explosion pretreated barley straw was performed.Three levels of temperature(70oC,80oC,and 90oC),five levels of the mass ratio of biomass to NaOH solution(1:4,1:5,1:6,1:7,and 1:8),one hour equilibration time,biomass screen size of 1.6 mm,1%NaOH concentration,and 20 min residence time in the radio frequency chamber were used for the radio frequency-alkaline pretreatment.Three levels of steam temperature(140oC,160oC,and 180oC),three levels of moisture content of 8%,30%,and 50%(mass fraction of total mass),and 5 min and 10 min exposure to steam were tested for the steam explosion pretreatment.The effects of both pretreatment methods were evaluated by pelletizing the pretreated and non-pretreated barley straw samples in a single pelleting unit.The pellet density,tensile strength,durability,dimensional stability,and color of the pellets were determined.Radio frequency-alkaline pretreatment with the use of 1%NaOH solution and a ratio of biomass:NaOH solution of 1:8 has significant effect(P<0.05)on the breakdown of the lignified matrix,resulting in pellets with superior physical characteristics.The steam exploded samples pretreated at higher temperatures(180ºC)and retention time of 10 min resulted into pellets with good physical qualities.
文摘Processing and densification of agricultural biomass into high density and durable pellets are critical to facilitate handling,storage and transportation.Biomass pelleting experiments were designed to conduct single and pilot scale pelleting of non-treated and steam exploded barley,canola,oat and wheat straw grinds acquired from 6.4,3.2,1.6 and 0.8 mm hammer mill screen sizes at 10%moisture content(wb).Single-pelleting was performed by applying compression pressures of 31.6,63.2,94.7,and 138.9 MPa using a close-fit plunger die assembly(die length 135.3 mm and diameter of(6.30±0.5)mm).During pilot scale pelleting,customization of ground straw material was performed by adding steam exploded biomass in increments of 25%to non-treated ground straw for respective biomass at specific grind size.Ground straw samples were conditioned to 17.5%moisture content and 10%flaxseed oil was added to increase the bulk density and flowability of grinds,which resulted in the production of pellets.The quality of pellets from single pelleting experiments was ascertained by measuring their respective density and durability.In addition,the change in pellet density was measured after a storage period of one month to determine its dimensional stability.It was determined that applied pressure and pre-treatment were significant factors affecting the pellet density.Also,bigger grind sizes and lower applied pressures resulted in higher pellet relaxations(lower pellet densities)during storage of pellets.The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25%steam exploded straw at 0.8 mm.It was observed that the pellet bulk density and particle density are positively correlated.The density and durability of agricultural straw pellets significantly increased with decrease in hammer mill screen size from 1.6 mm to 0.8 mm.Customization of agricultural straw by adding 25%of steam exploded straw by weight is possible,but it did not improve pellet quality.In addition,durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption.
