The effect of the neutralizing capacity of cellulosic materials on the kinetics of cellulose dilute acid hydrolysis

Liu

2011

JIPB

146

The overall goal of this work was to develop a saccharification method for the production of third generation biofuel (i.e. bioethanol) using feedstock of the invasive marine macroalga Gracilaria salicornia. Under optimum conditions (120• C and 2% sulfuric acid for 30 min), dilute acid hydrolysis of the homogenized invasive plants yielded a low concentration of glucose (4.1 mM or 4.3 g glucose/kg fresh algal biomass). However, two-stage hydrolysis of the homogenates (combination of dilute acid hydrolysis with enzymatic hydrolysis) produced 13.8 g of glucose from one kilogram of fresh algal feedstock. Batch fermentation analysis produced 79.1 g EtOH from one kilogram of dried invasive algal feedstock using the ethanologenic strain Escherichia coli KO11. Furthermore, ethanol production kinetics indicated that the invasive algal feedstock contained different types of sugar, including C 5 -sugar. This study represents the first report on third generation biofuel production from invasive macroalgae, suggesting that there is great potential for the production of renewable energy using marine invasive biomass. Wang X, Liu X, Wang G (2011) Two-stage hydrolysis of invasive algal feedstock for ethanol fermentation.

Section: Resultsmentioning

confidence: 99%

Two‐stage Hydrolysis of Invasive Algal Feedstock for Ethanol Fermentation^F

Liu

2011

JIPB

146

“…However, excess H ? ions from a strong acid can cause further degradation of sugars and formation of furan derivatives, organic acids, and phenolic compounds that are inhibitors to fermentation microbes [17,24]. Furan derivatives were formed upon the degradation of sugars, organic acids were released from the degradation of hemicelluloses side-groups, and phenolic compounds were released from lignin [23,[25][26][27].…”

Section: Acid Hydrolysismentioning

confidence: 99%

Production of lactic acid and ethanol by Rhizopus oryzae integrated with cassava pulp hydrolysis

Thongchul

Navankasattusas

Yang

2009

Bioprocess Biosyst Eng

Cassava pulp was hydrolyzed with acids or enzymes. A high glucose concentration (>100 g/L) was obtained from the hydrolysis with 1 N HCl at 121 degrees C, 15 min or with cellulase and amylases. While a high glucose yield (>0.85 g/g dry pulp) was obtained from the hydrolysis with HCl, enzymatic hydrolysis yielded only 0.4 g glucose/g dry pulp. These hydrolysates were used as the carbon source in fermentation by Rhizopus oryzae NRRL395. R. oryzae could not grow in media containing the hydrolysates treated with 1.5 N H2SO4 or 2 NH3PO4, but no significant growth inhibition was found with the hydrolysates from HCl (1 N) and enzyme treatments. Higher ethanol yield and productivity were observed from fermentation with the hydrolysates when compared with those from fermentation with glucose in which lactic acid was the main product. This was because the extra organic nitrogen in the hydrolysates promoted cell growth and ethanol production.

“…It is usual to use simplified models to determine the kinetic of hydrolysis of lignocelluloses material. The models proposed in the literature use irreversible pseudohomogeneous first-order reactions (Malester et al, 1988(Malester et al, , 1992Orozco et al, 2007;Aguilar et al, 2002;Lenihan et al, 2010) as follows:…”

Section: Kinetic Modelingmentioning

confidence: 99%

Kinetic modeling of concentrated acid hydrolysis of walnut green skin

Arastehnodeh¹,

Ardjmand²,

Shykholeslami³

et al. 2012

Afr. J. Biotechnol.

The overall goal of this experiment was to detect whether kinetic modeling can explain effects of temperature, acid concentration, time and solid contents on the production of glucose by concentrated acid hydrolysis of walnut green skin. For this purpose, sulfuric acid concentration of 20, 40 and 60% (w/w), processing temperature of 65, 80 and 90°C, reaction time of 120, 180 and 240 min and solid content of 5, 10 and 15% (w/w) were used as hydrolysis conditions. High performance liquid chromatography (HPLC) was used to analyze the products. The process was modeled by first-order irreversible reaction in series and kinetic constant, relating reaction time to glucose released. To relate temperature with kinetic constant and calculate activation energy, Arrhenius equation was employed. Optimal conditions occurred at 40% H 2 SO 4 , 90°C and 15% solid content for 285 min, which yielded a solution with 10.72 g glucose/L. In these conditions, 45% of the cellulose was hydrolyzed.