The effects of screw elements on enzymatic digestibility of corncobs after pretreatment in a twin-screw extruder

Zheng, Jian; Choo, Kim; Rehmann, Lars

doi:10.1016/j.biombioe.2015.01.022

Cited by 25 publications

(16 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… Levoglucosan concentrations were obtained after water extraction; the yields are expressed as mole levoglucosan per mole of glucan of the respective biomass (38.80 wt% in corn cobs [ 66 ] and 37.00 wt% in switchgrass [ 67 ]) …”

Section: Resultsmentioning

confidence: 99%

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

Luque

Oudenhoven

Westerhof

et al. 2016

Biotechnol Biofuels

Self Cite

View full text Add to dashboard Cite

BackgroundOne of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when compared to dried distillers grains (DDG), the main by-product of corn ethanol. Fast pyrolysis is an alternative thermal conversion technology for processing biomass. It has recently been optimized to produce a stream rich in levoglucosan, a fermentable glucose precursor for biofuel production. Additional product streams might be of value to the petrochemical industry. However, biomass heterogeneity is known to impact the composition of pyrolytic product streams, as a complex mixture of aromatic compounds is recovered with the sugars, interfering with subsequent fermentation. The present study investigates the feasibility of fast pyrolysis to produce fermentable pyrolytic glucose from two abundant lignocellulosic biomass sources in Ontario, switchgrass (potential energy crop) and corn cobs (by-product of corn industry).ResultsDemineralization of biomass removes catalytic centers and increases the levoglucosan yield during pyrolysis. The ash content of biomass was significantly decreased by 82–90% in corn cobs when demineralized with acetic or nitric acid, respectively. In switchgrass, a reduction of only 50% for both acids could be achieved. Conversely, levoglucosan production increased 9- and 14-fold in corn cobs when rinsed with acetic and nitric acid, respectively, and increased 11-fold in switchgrass regardless of the acid used. After pyrolysis, different configurations for upgrading the pyrolytic sugars were assessed and the presence of potentially inhibitory compounds was approximated at each step as double integral of the UV spectrum signal of an HPLC assay. The results showed that water extraction followed by acid hydrolysis and solvent extraction was the best upgrading strategy. Ethanol yields achieved based on initial cellulose fraction were 27.8% in switchgrass and 27.0% in corn cobs.ConclusionsThis study demonstrates that ethanol production from switchgrass and corn cobs is possible following a combined thermochemical and fermentative biorefinery approach, with ethanol yields comparable to results in conventional pretreatments and fermentation processes. The feedstock-independent fermentation ability can easily be assessed with a simple assay.

show abstract

Section: Resultsmentioning

confidence: 99%

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

Luque

Oudenhoven

Westerhof

et al. 2016

Biotechnol Biofuels

Self Cite

View full text Add to dashboard Cite

show abstract

“…As previously discussed, lignin is profoundly affected by temperature and can undergo structural modifications. In the previous study by Zheng et al, 2015, the action of reverse screw induces high local temperatures that reached transition temperature of lignin. Although it was fixed at 75°C, the outcome was lignin blocking pores and lower enzyme digestibility.…”

Section: Enzymatic Hydrolysismentioning

confidence: 87%

“…The results exhibit that lignin fraction can undergo physico-chemical modifications such as re-condensation and formation of pseudo-lignin with carbohydrates occasioned by the temperature and pressure employed. In extrusion pretreatment, the effect of reverse screw elements on corncobs produced lignin re-distribution at the fiber surface, thus, blocking pores (Zheng et al, 2015). In the three studies mentioned, droplets of lignin on the biomass surface were observed by SEM.…”

Section: Tablementioning

confidence: 99%

“…This is associated to the mechanical and chemical actions. The conveying and kneading screws have proven to increase porosity of biomass and reduce of particle size, promoting the enzyme action (Zheng et al, 2015). Using alkaline extrusion, pretreated biomass exposes higher amount of non-crystalline cellulose at the surface, producing higher conversion of carbohydrates than sole alkali pretreated biomass (Khatri et al, 2018).…”

Section: Enzymatic Hydrolysismentioning

confidence: 99%

See 1 more Smart Citation

Influence of temperature and soda concentration in a thermo-mechano-chemical pretreatment for bioethanol production from sweet corn co-products

Lopez

Rigal

et al. 2019

Industrial Crops and Products

View full text Add to dashboard Cite

show abstract

“…Pre-treatment effects on lignocellulosic content could be explained by the structural modifications evidenced in Figure 1. In addition, there was also chemical modifications, such as the condensation and fusion of lignin or the grouping of pseudo-lignin by the mixture of carbohydrates formed in the fragmentation of hemicellulose [29]. These effects could explain the observed increase of lignin content and the decrease of hemicellulose content.…”

Section: Effect Of Pre-treatments On Lignocellulosic Components Contentmentioning

confidence: 99%

Pre-treatments applied to rice husk enzymatic hydrolysis: effect on structure, lignocellulosic components, and glucose production kinetics

Aredo¹,

Rojas²,

Pagador³

et al. 2020

Proceedings of the 18th LACCEI International Multi-Conference for Engineering, Education, and Technology: Engineering, Integrat

View full text Add to dashboard Cite

Freezing (-20 °C, 12h) and alkaline (NaOH 8%) pretreatments were applied individually and combined in rice husk (Oryza sativa L.) before their hydrolysis with cellulase (EC: 3.2.1.4.). The effects on structural modifications, lignin content, cellulose, hemicellulose content and glucose production were evaluated. In addition, the glucose production kinetics were described by using the Peleg model. The homogenous rice husk (1 g) with and without pretreatments was hydrolysed with 150 U of Cellulase in 10 ml of acetate for 60 h (37 °C, pH 5.5, 100 rpm). As results, the SEM images evidenced porous microstructures with less agglomeration generated by all pre-treatments, which were intensified by the combined pretreatment. This pre-treatment allowed to obtain higher cellulose (62.51 ± 0.3 %) content. Besides, the glucose content after pretreatments increased. The Peleg model parameters from glucose production kinetics during enzymatic hydrolysis were related to initial glucose content (G0), glucose production rate (1/k1) and maximum glucose yield (1/k2). After enzymatic hydrolysis process, compared to control glucose yield (0.359 ± 0.002 g G/g rice husk), this was 27%, 71% and 88% higher for freezing, alkaline and combined pre-treatments respectively.

show abstract

The effects of screw elements on enzymatic digestibility of corncobs after pretreatment in a twin-screw extruder

Cited by 25 publications

References 44 publications

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

Influence of temperature and soda concentration in a thermo-mechano-chemical pretreatment for bioethanol production from sweet corn co-products

Pre-treatments applied to rice husk enzymatic hydrolysis: effect on structure, lignocellulosic components, and glucose production kinetics

Contact Info

Product

Resources

About