scholarly journals Effect of Liquid Hot Water Pretreatment on Hydrolysates Composition and Methane Yield of Rice Processing Residue

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3254
Author(s):  
Lisbet Mailin López González ◽  
Monika Heiermann

Lignocellulosic rice processing residue was pretreated in liquid hot water (LHW) at three different temperatures (140, 160, and 180 °C) and two pretreatment times (10 and 20 min) in order to assess its effects on hydrolysates composition, matrix structural changes and methane yield. The concentrations of acetic acid, 5-hydroxymethylfurfural and furfural increased with pretreatment severity (log Ro). The maximum methane yield (276 L kg−1 VS) was achieved under pretreatment conditions of 180 °C for 20 min, with a 63% increase compared to untreated biomass. Structural changes resulted in a slight removal of silica on the upper portion of rice husks, visible predominantly at maximum severity. However, the outer epidermis was kept well organized. The results indicate, at severities 2.48 ≤ log Ro ≤ 3.66, a significant potential for the use of LHW to improve methane production from rice processing residue.

Fuel ◽  
2008 ◽  
Vol 87 (17-18) ◽  
pp. 3640-3647 ◽  
Author(s):  
J.A. Pérez ◽  
I. Ballesteros ◽  
M. Ballesteros ◽  
F. Sáez ◽  
M.J. Negro ◽  
...  

2014 ◽  
Vol 472 ◽  
pp. 774-779 ◽  
Author(s):  
Hong Dan Zhang ◽  
Shu Bin Wu

Liquid hot water pretreatment, as an initial step in an alternative use of lignocellulosic biomass to produce fermentable sugar, was performed in this study. The effect of pretreatment temperature range from 160 to 200 °C on the hemicellulose degradation (the yields of glucose and xylose, as well as inhibitors) and cellulose enzymatic digestibility were evaluated. The results indicated that the maximum xylose yields (combined 2.23 g xylose and 13.20 g xylo-oligosaccharides per 100g raw material) in prehydrolysate liquid were obtained at 180 °C. The untreated and pretreated solid residues were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fourier transform infrared spectroscopy (FT-IR). The results showed that liquid hot water pretreatment removed a large number of hemicellulose and resulted in enriched cellulose and lignin content in the pretreated residues. Due to the effective removal of hemicellulose, the maximum glucose yield in enzyme hydrolyzate reached 37.27 g per 100 g raw material (after the pretreatment temperature of 200°C), representing 90.13% of glucose in the sugarcane bagasse.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1640
Author(s):  
M.A. Martín-Lara ◽  
L. Chica-Redecillas ◽  
A. Pérez ◽  
G. Blázquez ◽  
G. Garcia-Garcia ◽  
...  

In this work, liquid hot water pretreatment (autohydrolysis) was used to improve enzymatic hydrolysis of a commonly consumed vegetable waste in Spain, Italian green pepper, to finally produce fermentable sugars. Firstly, the effect of temperature and contact time on sugar recovery during pretreatment (in insoluble solid and liquid fraction) was studied in detail. Then, enzymatic hydrolysis using commercial cellulase was performed with the insoluble solid resulting from pretreatment. The objective was to compare results with and without pretreatment. The results showed that the pretreatment step was effective to facilitate the sugars release in enzymatic hydrolysis, increasing the global sugar yield. This was especially notable when pretreatment was carried out at 180 °C for 40 min for glucose yields. In these conditions a global glucose yield of 61.02% was obtained. In addition, very low concentrations of phenolic compounds (ranging from 69.12 to 82.24 mg/L) were found in the liquid fraction from enzymatic hydrolysis, decreasing the possibility of fermentation inhibition produced by these components. Results showed that Italian green pepper is an interesting feedstock to obtain free sugars and prevent the enormous quantity of this food waste discarded annually.


2020 ◽  
Vol 12 (21) ◽  
pp. 8935 ◽  
Author(s):  
George Dimitrellos ◽  
Gerasimos Lyberatos ◽  
Georgia Antonopoulou

The effect of liquid hot water (LHW) pretreatment with or without acid addition (A-LHW) on the production of hydrogen—through dark fermentation (DF)—and methane—through anaerobic digestion (AD)—using three different lignocellulosic biomass types (sunflower straw (SS), grass lawn (GL), and poplar sawdust (PS)) was investigated. Both pretreatment methods led to hemicellulose degradation, but A-LHW resulted in the release of more potential inhibitors (furans and acids) than the LHW pretreatment. Biological hydrogen production (BHP) of the cellulose-rich solid fractions obtained after LHW and A-LHW pretreatment was enhanced compared to the untreated substrates. Due to the release of inhibitory compounds, LHW pretreatment led to higher biochemical methane potential (BMP) than A-LHW pretreatment when both separated fractions (liquid and solid) obtained after pretreatments were used for AD. The recovered energy in the form of methane with LHW pretreatment was 8.4, 12.5, and 7.5 MJ/kg total solids (TS) for SS, GL, and PS, respectively.


2005 ◽  
Vol 125 (2) ◽  
pp. 077-098 ◽  
Author(s):  
Nathan S. Mosier ◽  
Richard Hendrickson ◽  
Mark Brewer ◽  
Nancy Ho ◽  
Miroslav Sedlak ◽  
...  

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