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Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations.

Bals B, Rogers C, Jin M, Balan V, Dale B - Biotechnol Biofuels (2010)

Bottom Line: All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars.Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomass Conversion Research Laboratory, Department of Chemical Engineering and Material Science, Michigan State University, Lansing, MI, USA.

ABSTRACT

Background: When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX) pretreatment on two harvest times (July and October) and ecotypes/locations (Cave-in-Rock (CIR) harvested in Michigan and Alamo harvested in Alabama) for switchgrass (Panicum virgatum).

Results: Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass) during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass). All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.

Conclusions: Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

No MeSH data available.


Box and whisker plot for sugar yields at varying enzyme loadings. Ammonia fibre expansion (AFEX) pretreatment was kept constant for each harvest (conditions listed in Table 2), and enzyme loadings were varied as stated in the text. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation, with samples collected after 72 h.
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Figure 2: Box and whisker plot for sugar yields at varying enzyme loadings. Ammonia fibre expansion (AFEX) pretreatment was kept constant for each harvest (conditions listed in Table 2), and enzyme loadings were varied as stated in the text. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation, with samples collected after 72 h.

Mentions: The response of glucose and xylose yields using different enzyme loadings is seen in Figure 2. In general, higher enzyme loadings led to greater sugar production, as expected. However, due to the high costs of enzymes, high enzyme loadings are unlikely to provide maximum economic benefit. As the material cost of enzymes is unknown, the economic optimal enzyme loading is currently unknown and will likely change with future research into enzyme combinations and production. Instead, the maximum sugar yields produced using at most 15 mg enzyme/kg biomass was used to determine optimal enzyme loadings. Using this constraint, optimal enzyme loadings and sugar yields are shown in Table 3.


Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations.

Bals B, Rogers C, Jin M, Balan V, Dale B - Biotechnol Biofuels (2010)

Box and whisker plot for sugar yields at varying enzyme loadings. Ammonia fibre expansion (AFEX) pretreatment was kept constant for each harvest (conditions listed in Table 2), and enzyme loadings were varied as stated in the text. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation, with samples collected after 72 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2823726&req=5

Figure 2: Box and whisker plot for sugar yields at varying enzyme loadings. Ammonia fibre expansion (AFEX) pretreatment was kept constant for each harvest (conditions listed in Table 2), and enzyme loadings were varied as stated in the text. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation, with samples collected after 72 h.
Mentions: The response of glucose and xylose yields using different enzyme loadings is seen in Figure 2. In general, higher enzyme loadings led to greater sugar production, as expected. However, due to the high costs of enzymes, high enzyme loadings are unlikely to provide maximum economic benefit. As the material cost of enzymes is unknown, the economic optimal enzyme loading is currently unknown and will likely change with future research into enzyme combinations and production. Instead, the maximum sugar yields produced using at most 15 mg enzyme/kg biomass was used to determine optimal enzyme loadings. Using this constraint, optimal enzyme loadings and sugar yields are shown in Table 3.

Bottom Line: All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars.Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomass Conversion Research Laboratory, Department of Chemical Engineering and Material Science, Michigan State University, Lansing, MI, USA.

ABSTRACT

Background: When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX) pretreatment on two harvest times (July and October) and ecotypes/locations (Cave-in-Rock (CIR) harvested in Michigan and Alamo harvested in Alabama) for switchgrass (Panicum virgatum).

Results: Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass) during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass). All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.

Conclusions: Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

No MeSH data available.