scholarly journals Effects of water pretreatment on properties of pellets made from beech particles

2021 ◽  
Vol 75 (1) ◽  
pp. 39-51
Author(s):  
Jasmina Popovic ◽  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Ana Prahin ◽  
Vladimir Dodevski ◽  
...  

Particles of beech wood were treated with hot water at the temperature of 150 oC, during 60 min, prior to the pelleting process. The applied hot water pretreatment affected the chemical composition and heating value of particles. Two groups of pellets, designated as PT 10 and PT 20, were produced from treated beech particles, with the moisture content of particles being 10.5 and 20.5 %, respectively. Pellets from nontreated beech particles (PNT) served as controls to assess the hot water pretreatment effects on the pellet properties. Both, the applied pretreatment, and the particle moisture content, affected properties of the obtained pellets. The heating value of PT 10 ad PT 20 pellets has increased for ~6 and 1 %, respectively. The mineral (ash) content in treated pellets decreased for about 24 % in comparison to that in PNT pellets. In addition, the bulk (apparent) density of pellets has increased for 21 % (PT 10) and 10 % (PT 20), as a consequence of the hot water pretreatment of particles. The specific density of PT 10 pellets was for 16 % higher, while the equilibrium moisture content (after conditioning at RH 68 % and 20.1?C) was for about 32 % lower in comparison to the respective properties of PNT pellets.

2021 ◽  
Author(s):  
CI Chemistry International

For the production of ethanol from pretreated lignocellulose biomass play a paramount role in facilitating the conversion of cellulose into glucose in the hydrolysis step. Therefore, this study is focused on the effect of hot water pretreatment on the chemical composition (cellulose and lignin) of highland bamboo of Ethiopia. The chemical composition of highland bamboo showed 46.76% (w/w) cellulose, 25.27% (w/w) lignin, 12.18% (w/w) hemicellulose, 3.77% (w/w) ash, 12.23% (w/w) hot-water extractive and 3.93% (w/w) ethanol-toluene extractives. The effect of hot water pretreatment was observed after the biomass was treated in the autoclave at 121, 128 and 135 oC with 5, 10, and 15 min pretreatment time with distilled water. The best pretreatment method was selected based on the pretreatment method which maximized the cellulose content and minimized the lignin content. Based on the selected pretreatment method a higher cellulose content of 52.44% and lower lignin content of 27.85% was achieved at 128 oC temperature and 10 min pretreatment time.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.


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.


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

2016 ◽  
Vol 216 ◽  
pp. 706-713 ◽  
Author(s):  
Sun Min Kim ◽  
Bruce S. Dien ◽  
M.E. Tumbleson ◽  
Kent D. Rausch ◽  
Vijay Singh

2018 ◽  
Vol 7 (1) ◽  
pp. 43
Author(s):  
Willem Kurniawan Lombu ◽  
Ni Wayan Wisaniyasa ◽  
AAI. Sri Wiadnyani

This study aims to determine the difference of characteristic and starch digestibility of germinated and ungerminated flour. This study used randomized complete design (RCD) three repeated. The corn germinated for 36 hours. Corn germinated flour and ungerminated flour were evaluated directly of the chemical composition of the flour content, moisture content, ash content, protein, fat, carbohydrates, fiber, starch content and starch digestibility. The results showed the corn germinated flour has increased of moisture content from 9.66% into 10.38%, increased of protein into 7.22% into 8.45%, increased of fiber content from 2.28% into 2.79% and increased of starch digestibility from 57.04% into 62.43%. While were the decreased fat content from 5.17% into 4.76%, decreased of carbohydrate from 75.41% into 73.89% and decreased of starch content from 76.10% into 69.40%. The treatmented has no effect for the flour content decreased from 41.40% into 40.36% and ash content decreased from 2.52% into 2.51%. Germinated increased starch digestibility and changed the character of corn flour.


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.


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