Two-stage, dilute sulfuric acid hydrolysis of wood : an investigation of fundamentals

Harris, John F.; Baker, Andrew J.; Conner, Anthony H.; Jeffries, Thomas W.; Minor, James L.; Pettersen, Roger C.; Scott, Ralph W.; Springer, E.L.; Wegner, Theodore H.; Zerbe, John I.

doi:10.2737/fpl-gtr-45

Cited by 60 publications

(74 citation statements)

References 10 publications

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“…It can be seen from the results presented in Table VI that acid dehusked wheat samples also produced more alcohol (over 19 LA/tonne or ~4%) than the original normal wheat samples. It is therefore possible that acid dehusking results in modification or degradation or hydrolysis, of cell wall materials or other non-starch polysaccharides (NSP) such as cellulose and hemicellulose materials 14,15 of barley, resulting not only in easier access to starch, but also better extraction of fermentable sugars (such as glucose) deriving from endosperm and the non-starch polysaccharides of these cell wall components 2 , resulting in the higher alcohol yield obtained from these cereals. These results, however, confirm that dehusking cereal grains will yield samples that will produce more alcohol than the original cereal.…”

Section: Processing Properties Of Malts Of Barley Acid De-husked Andmentioning

confidence: 99%

Performance of Husked, Acid Dehusked and Hull-less Barley and Malt in Relation to Alcohol Production

Agu

Bringhurst

Brosnan

2008

Journal of the Institute of Brewing

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J. Inst. Brew. 114(1), 62-68, 2008Studies carried out on normal husked barley, normal hull-less (naked) barley, acid dehusked barley and acid dehusked hull-less barley, as well as the malts derived from them, showed that when acid dehusked barley samples (obtained from either husked or hull-less barley), were processed using commercial enzyme preparations, they produced more alcohol when compared with the alcohol yield obtained from the barley samples from which the acid dehusked samples were derived. When the husked (Optic) control, acid dehusked and hull-less barley samples were malted, Optic control barley produced malt that gave higher dextrinising units (DU) and diastatic power (DP), whilst acid dehusked Optic and hull-less barley produced malts that gave similar DU results on day 5 of the germination time. When mashed, acid dehusked (Optic) barley malt produced wort that filtered faster than the wort obtained from the malt made from hull-less barley. This observation is very important because it shows that the husk of the barley is not the only factor that determines the filtration performance of the malted barley, since both the malt samples made from husked and acid dehusked barley had similar filtration rates on day 5 of the germination time. The slow filtration rate observed for the wort made from hull-less barley suggests that other factors play some role during the filtration of the mash made from hull-less barley malt. Although hull-less malt appeared to develop lower DU and DP enzyme activities, when compared with the values obtained for the Optic control, hull-less barley malted faster and produced optimum predicted spirit yield (PSY) at day 4 of the germination time. In contrast, the control husked Optic barley malt that had higher DU and DP produced equivalent (optimum) predicted spirit yield one day later at 5 days germination time. This is an advantage for hull-less barley, both in terms of time and energy saving during the malting of barley. Although the acid dehusked Optic barley produced more alcohol than the husked control when commercial enzyme preparation was used to process barley, it was surprising that when the derived malt was assessed, it gave a lower predicted spirit yield than the husked control, even though it produced a higher amount of hot water extract (HWE). The higher extract yield and lower predicted spirit yield obtained from the malt made from acid dehusked malt confirmed that high extract yield is not necessarily associated with high fermentable extract.

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Section: Processing Properties Of Malts Of Barley Acid De-husked Andmentioning

confidence: 99%

Performance of Husked, Acid Dehusked and Hull-less Barley and Malt in Relation to Alcohol Production

Agu

Bringhurst

Brosnan

2008

Journal of the Institute of Brewing

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“…[73][74][75][76][77] In one of the Renmatix® process embodiments where 0.2% H 2 SO 4 is used, approximately 90% yield of cellulose-soluble sugars is reported after 1 s at 510 K. 65 These conditions are similar to those reported by the two-stage process described by the Forest Products Laboratory (500 K, 35 s, 0.8 wt% H 2 SO 4 ) but with higher yields (88% vs. 50%). 52 The difference in yield could in part be due to the difference in solid content at the start of hydrolysis (4 wt% vs. 24% solids), which can significantly hinder yields.…”

Section: Degradation Products ð4þmentioning

confidence: 99%

“…Such a process was developed and run at pre-pilot plant scales (two batch reactors, with a capacity of 100 kg per run of initial biomass) in the 1980s at the Forest Products Laboratory in Madison, WI. 52 In this process, a first hydrolysis stage was employed at 440 K for 11 min in the presence of a 1.1 wt% H 2 SO 4 solution. The resulting slurry was washed to produce an initial hydrolysate solution containing 10 wt% sugars, representing 88% yield of the original xylose ( Table 1).…”

Section: Degradation Products ð2þmentioning

confidence: 99%

Targeted chemical upgrading of lignocellulosic biomass to platform molecules

2014

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This review presents an overview of the initial targeted chemical processing stages for conversion of lignocellulosic biomass to platform molecules that serve as intermediates for the production of carbonbased fuels and chemicals. We identify four classes of platform molecules that can be obtained in an initial chemical processing step: (i) sugars, (ii) dehydration products, (iii) polyols and (iv) lignin monomers. Special emphasis is placed on reporting and comparing parameters that affect process economics and/or sustainability, including product yields, amount of catalyst used, processing conditions, and product concentrations. We discuss the economic trade-offs associated with choices related to these parameters, depending on the product that is targeted. We also address the effects of real biomass on the ability to recover, recycle, and potentially regenerate catalysts and solvents used in the biomass conversion processes.

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“…The use of dilute sulfuric acid to totally hydrolyze the carbohydrates in lignocellulosic feedstocks for ethanol production was widely abandoned by 1990 due to the relatively low yields of glucose (50%-60%) as compared to potentially high yields (80%-95%) from enzymatic hydrolysis of cellulose (54)(55)(56). Even though kinetic modeling exercises conducted at NREL (57) suggested that yields as high as 88% could be obtained using a countercurrent reactor configuration, laboratory studies could only demonstrate total sugar yields (C 5 and C 6 sugars) of about 60% (56).…”

Section: Two-stage Countercurrent Pretreatmentmentioning

confidence: 99%