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Improving carbohydrate recovery from...

Dou, Chang.

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Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar./
Author:	Dou, Chang.
Description:	86 p.
Notes:	Source: Masters Abstracts International, Volume: 52-04.
Contained By:	Masters Abstracts International52-04(E).
Subject:	Biochemistry. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1551022
ISBN:	9781303674341

Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar.
Dou, Chang.

Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar. - 86 p.

Source: Masters Abstracts International, Volume: 52-04.

Thesis (Master's)--University of Washington, 2013.

This item must not be sold to any third party vendors.

The presence of SO2 in steam pretreatment creates a series of problems in environmental protection, equipment corrosion, chemical catalysis and waste water treatment. Moreover, SO2 increases the pretreatment severity, resulting in more sugar degradation and increased inhibitor formation. In this study, hybrid poplar chips were steam exploded using 6 different conditions with or without the addition of SO2. The steaming temperature ranged from 190 °C to 212 °C, and the residence time ranged from 5 min to 10 min, resulting in a range of fermentation inhibitors, including furfural, 5-hydroxymethyl furfural (HMF), acetic acid and phenolic. It was found that certain concentration of inhibitors, particularly acetic acid, could promote the ethanol yield in hydrolysate fermentation, but always impairs the xylitol yield due to the acetyled xylan in hybrid poplar. At the lowest pretreatment severity condition at 205 °C, 10 minutes, without SO2, the best inhibitor concentration for ethanol yield and the highest overall sugar recovery following pretreatment were achieved. However, since no SO2 was applied, poor digestibility during enzymatic hydrolysis of cellulose reduced the post-hydrolysis sugar recovery. For that reason, mechanical refining was applied to the solid fractions and improved the enzymatic hydrolysis for solids pretreated at 205 °C for 10 minutes, without SO2 as much as 23 %. Similar improvements were observed for different enzyme loadings and solid consistencies. However, refining did not improve the hydrolyzability of solids pretreated at five other conditions. Reduced particle sizes were found to be correlated to increased sugar yields in enzymatic hydrolysis. Solids pretreated at 205 °C 10 minutes, without SO2 exhibited the largest size reduction after refining and correspondingly achieved the highest overall sugar recovery improvement after steam pretreatment and enzymatic hydrolysis. In general, refining can enable a catalyst free, low inhibitor concentration, high overall sugar recovery bioconversion system based on the steam pretreatment and enzymatic hydrolysis method.

ISBN: 9781303674341Subjects--Topical Terms:

518028
Biochemistry.

Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar.
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020 $a 9781303674341
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100 1 $a Dou, Chang. $3 3174847
245 1 0 $a Improving carbohydrate recovery from uncatalyzed steam pretreated hybrid poplar.
300 $a 86 p.
500 $a Source: Masters Abstracts International, Volume: 52-04.
500 $a Adviser: Renata Bura.
502 $a Thesis (Master's)--University of Washington, 2013.
506 $a This item must not be sold to any third party vendors.
506 $a This item must not be added to any third party search indexes.
520 $a The presence of SO2 in steam pretreatment creates a series of problems in environmental protection, equipment corrosion, chemical catalysis and waste water treatment. Moreover, SO2 increases the pretreatment severity, resulting in more sugar degradation and increased inhibitor formation. In this study, hybrid poplar chips were steam exploded using 6 different conditions with or without the addition of SO2. The steaming temperature ranged from 190 °C to 212 °C, and the residence time ranged from 5 min to 10 min, resulting in a range of fermentation inhibitors, including furfural, 5-hydroxymethyl furfural (HMF), acetic acid and phenolic. It was found that certain concentration of inhibitors, particularly acetic acid, could promote the ethanol yield in hydrolysate fermentation, but always impairs the xylitol yield due to the acetyled xylan in hybrid poplar. At the lowest pretreatment severity condition at 205 °C, 10 minutes, without SO2, the best inhibitor concentration for ethanol yield and the highest overall sugar recovery following pretreatment were achieved. However, since no SO2 was applied, poor digestibility during enzymatic hydrolysis of cellulose reduced the post-hydrolysis sugar recovery. For that reason, mechanical refining was applied to the solid fractions and improved the enzymatic hydrolysis for solids pretreated at 205 °C for 10 minutes, without SO2 as much as 23 %. Similar improvements were observed for different enzyme loadings and solid consistencies. However, refining did not improve the hydrolyzability of solids pretreated at five other conditions. Reduced particle sizes were found to be correlated to increased sugar yields in enzymatic hydrolysis. Solids pretreated at 205 °C 10 minutes, without SO2 exhibited the largest size reduction after refining and correspondingly achieved the highest overall sugar recovery improvement after steam pretreatment and enzymatic hydrolysis. In general, refining can enable a catalyst free, low inhibitor concentration, high overall sugar recovery bioconversion system based on the steam pretreatment and enzymatic hydrolysis method.
590 $a School code: 0250.
650 4 $a Biochemistry. $3 518028
650 4 $a Chemical engineering. $3 560457
650 4 $a Forestry. $3 895157
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710 2 $a University of Washington. $b Forest Resources. $3 2093012
773 0 $t Masters Abstracts International $g 52-04(E).
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793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1551022