Tag Archives: fermentable sugars

1099–1106 A.R.P.P. Weerasuriya Arachchige, L. Mezule and T. Juhna
Separation of reducing sugars from lignocellulosic hydrolysate: Membrane experiments & system dynamic modelling
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Separation of reducing sugars from lignocellulosic hydrolysate: Membrane experiments & system dynamic modelling

A.R.P.P. Weerasuriya Arachchige*, L. Mezule and T. Juhna

Riga Technical University, Faculty of Civil Engineering, Department of Water Science and Technology, Paula Valdena street 1-204/205, LV-1048 Riga, Latvia
*Correspondence: antonrayan@hotmail.com

Abstract:

Separation of fermentable sugars after hydrolysis of lignocellulosic biomass plays a vital role in second-generation biofuel production. Byproducts and solid fractions generated during pretreatment and hydrolysis can have adverse effects on fermentation efficiency. Previous studies have shown that a maximum of 40% (w/w) of sugar yield can be obtained by sequential UF and NF permeate recovery. This study aimed to introduce a multi-step membrane filtration process to recover fermentable sugars while removing inhibitory bi-products. Fermentable sugar recovery was investigated using a recirculation flow between various stages of separation. The experimental results demonstrated that by introducing NF permeate recirculation to the UF unit a sequential UF/NF system can achieve 60% (w/w%) recovery of reducing sugars. Based on the experimental results, a ‘Simultaneous ultrafiltration and nanofiltration model’ was developed using system dynamics. The model was used to predict the final sugar concentration and sugar yield using sugar permeability in each membrane as the dynamic variability. The model predicts that high sugar permeability (or selective permeability) through the ultrafiltration mostly affects the efficiency of the system, which still is a challenge.

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1427-1434 L. Mezule, M. Strods and B. Dalecka
Influence of Mechanical Pre–treatment on Fermentable Sugar Production from Lignocellulosic Biomass
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Influence of Mechanical Pre–treatment on Fermentable Sugar Production from Lignocellulosic Biomass

L. Mezule*, M. Strods and B. Dalecka

Riga Technical University, Faculty of Civil Engineering, Research Centre for Civil Engineering, Water Research Laboratory, Kipsalas 6a–263, LV–1048 Riga, Latvia *Correspondence: linda.mezule@rtu.lv

Abstract:

Mechanical pre-treatment of lignocellulosic biomass has been extensively applied in biofuel production despite its high energy requirements. To balance the consumed energy with the energy produced, careful selection and evaluation of pre-treatment parameters, equipment and desired outcome is needed. The study aims to determine optimal hay and barley straw biomass particle size in view of sugar yields, energy consumption and treatment time. The results show that there is no significant difference (p > 0.05) in sugar yields from hay biomass with particle sizes 0.25 mm, 1 mm and 10 mm. Energy requirements for the production of 1 kg of sugar from hay range from 1.8–10.7 MJ. At the same time barley straw proved to be inappropriate for sugar extraction due to low sugar yields (below 40 mg g-1 dry mass) and high energy consumption (18.5–76.2 MJ to produce 1 kg sugar). Thus, after the careful selection of biomass, mechanical pre-treatment followed by enzymatic hydrolysis can be an effective technique in biofuel production from biomass.

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287-293 B. Dalecka, M. Strods and L. Mezule
Production of fermentation feedstock from lignocellulosic biomass: applications of membrane separation
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Production of fermentation feedstock from lignocellulosic biomass: applications of membrane separation

B. Dalecka*, M. Strods and L. Mezule

Riga Technical University, Faculty of Civil Engineering, Department of Water Science and Technology, Azenes 16/20-263, LV1048 Riga, Latvia; *Correspondence: brigita.dalecka@gmail.com

Abstract:

The development of cost-efficient, highly productive technologies for fermentation feed production from lignocellulose biomass is still a challenge. In this paper, the production of fermentable sugars from lignocellulosic biomass using hydrolysis techniques with membrane separation systems is studied. The research was conducted on both a laboratory and pilot level to evaluate and optimize the efficiency of the proposed technology. The results demonstrated that UF and NF permeate recovery increased efficiency, and the highest sugar recovery rates were obtained when secondary waste recirculation was introduced after NF and UF, reaching an almost 40% yield from all produced sugars.

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