scholarly journals Chromatographic analysis of bio-oil formed in fast pyrolysis of lignocellulosic biomass

2020 ◽  
Vol 39 (1) ◽  
pp. 65-77
Author(s):  
Jacek Grams

AbstractFast pyrolysis of lignocellulosic biomass is one of the most promising methods of the production of renewable fuels. However, an optimization of the conditions of bio-oil production is not possible without comprehensive analysis of the composition of formed products. There are several methods for the determination of distribution of products formed during thermal decomposition of biomass with chromatography being the most versatile among them. Although, due to the complex structure of bio-oil (presence of hundreds chemical compounds with different chemical character), an interpretation of the obtained chromatograms is not an easy task. Therefore, the aim of this work is to present an application of different chromatographic methods to the analysis of the composition of the mixture of products formed in high temperature decomposition of lignocellulosic feedstock. It includes pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), two dimensional gas (GC x GC) or liquid chromatography (LC x LC) and initial fractionation of bio-oil components. Moreover, the problems connected with the analysis of bio-oils formed with the use of various fast pyrolysis reactors and capabilities of multivariate analysis are discussed.

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3474 ◽  
Author(s):  
Yichen Liu ◽  
James J. Leahy ◽  
Jacek Grams ◽  
Witold Kwapinski

Fast pyrolysis of Miscanthus, its hydrolysis residue and lignin were carried with a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) followed by online vapor catalytic upgrading with sulfated ZrO2, sulfated TiO2 and sulfated 60 wt.% ZrO2-TiO2. The most evident influence of the catalyst on the vapor phase composition was observed for aromatic hydrocarbons, light phenols and heavy phenols. A larger amount of light phenols was detected, especially when 60 wt.% ZrO2-TiO2 was present. Thus, a lower average molecular weight and lower viscosity of bio-oil could be obtained with this catalyst. Pyrolysis was also performed at different pressures of hydrogen. The pressure of H2 has a great effect on the overall yield and the composition of biomass vapors. The peak area percentages of both aromatic hydrocarbons and cyclo-alkanes are enhanced with the increasing of H2 pressure. The overall yields are higher with the addition of either H2 or sulfated catalysts. This is beneficial as phenols are valuable chemicals, thus, increasing the value of bio-oil. The results show that the hydrolysis residue has the potential to become a resource for phenol production.


2015 ◽  
Vol 3 (1) ◽  
pp. 18
Author(s):  
Anthonia E. Eseyin ◽  
El Barbary Hassan ◽  
Emad, M El-Giar

<p>Pyrolysis gas chromatography mass spectrometry (Py-GC/MS) studies were carried out on the Nigerian and US corn stalks at 500 °C. Analyses of the fast pyrolysis products showed that the Nigerian corn stalks produced more diverse compounds like: acetaldehyde, acetic acid methyl ester, 2,3-pentanedione, 1-hydroxy-2-butanone, butanedial, phenol and vanillin. On the other hand, the pyrolyzed US corn stalks produced compounds like: furfural, phenol, 2-methoxy, 2-methylbenzaldehyde, and 2-methoxy-4-vinylphenol which had significantly high peak area percentages. Few anhydrous sugars were detected in the pyrolysis products of both samples. Both samples were found to be good biomass for the production of bio-oil and chemicals. However, the Nigerian corn stalks seem to be more suitable for the production of bio-oil while the US corn stalks seem to be more suitable for the production of valuable chemicals.</p>


2020 ◽  
Vol 14 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Shuangxia Yang ◽  
Xiaodong Zhang ◽  
Feixia Yang ◽  
Baofeng Zhao ◽  
Lei Chen ◽  
...  

The objective of this study is to catalytically upgrade fast pyrolysis vapors of sawdust using various Fe-based catalysts for producing phenolic-rich bio-oil by analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique. A variety of parameters, including support characteristic, calcination temperature, pyrolysis temperature, as well as the catalyst-to-biomass ratio during the pyrolysis process were evaluated for their effects on product distribution of bio-oil. GC-MS analysis showed that compared to Fe–Mg and Fe–Al catalysts, the developed Fe–Ca catalyst significantly promoted the formation of phenols and its derivatives. The phenolic concentration declined with increasing calcination temperature and pyrolysis temperature, while increased monotonically along with increasing catalyst-to-biomass ratio. The phenolics concentration was high upto 81% (peak area) under optimum conditions of calcination temperature of 500 °C, pyrolysis temperature of 600 °C and catalyst-to-biomass ratio of 10. At higher catalyst-to-biomass ratio of 20, phenolics (88.03% in peak area) and hydrocarbons (including 7.86% of aromatics and 4.1% aliphatics) were the only two components that can be detected, with all the acids, aldehydes and ketones completely eliminated. This indicated the excellent capability of developed Fe–Ca catalyst in promoting the decomposition of lignin in biomass to generate phenolic compounds and meanwhile inhibiting the devolatilization of holocellulose.


2012 ◽  
Vol 26 (5) ◽  
pp. 2962-2967 ◽  
Author(s):  
Chih-Chiang Chang ◽  
Seng-Rung Wu ◽  
Chi-Cheng Lin ◽  
Hou-Peng Wan ◽  
Hom-Ti Lee

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 609 ◽  
Author(s):  
Dongyan Zhang ◽  
Yuyang Fan ◽  
Anqing Zheng ◽  
Zengli Zhao ◽  
Fengyun Wang ◽  
...  

Anhydrosugars, such as levoglucosan (LG), are high value-added chemicals which are mainly derived from fast pyrolysis of pure cellulose. However, fast pyrolysis of raw lignocellulosic biomass usually produces a very low amount of levoglucosan, since alkali and alkaline earth metals (AAEM) present in the ash can serve as the catalysts to inhibit the formation of levoglucosan through accelerating the pyranose ring-opening reactions. In this study, eucalyptus was impregnated with H2SO4 solutions with varying concentrations (0.25–1.25%). The characteristics of ash derived from raw and H2SO4-impregnated eucalyptus were characterized by X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). The pyrolysis behaviors of raw and H2SO4-impregnated eucalyptus were performed on the thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG analysis demonstrated that the H2SO4-impregnated eucalyptus produced less char than raw eucalyptus. Py-GC/MS analysis showed that even small amounts of H2SO4 can obviously improve the production of anhydrosugars and phenols and suppressed the formation of carboxylic acids, aldehydes, and ketones from fast pyrolysis of eucalyptus. The rank order of levoglucosan yield from raw and impregnated eucalyptus was raw < 1.25% H2SO4 < 1% H2SO4 < 0.75% H2SO4 < 0.25% H2SO4 < 0.5% H2SO4. The maximum yield of levoglucosan (21.3%) was obtained by fast pyrolysis of eucalyptus impregnated with 0.5% H2SO4, which was close to its theoretical yield based on the cellulose content. The results could be ascribed to that H2SO4 can react with AAEM (e.g., Na, K, Ca, and Mg) and lignin to form lignosulfonate, thus acting as an inhibitor to suppress the catalytic effects of AAEM during fast pyrolysis of eucalyptus.


2018 ◽  
Vol 37 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Ismail Cem Kantarli ◽  
Stylianos D Stefanidis ◽  
Konstantinos G Kalogiannis ◽  
Angelos A Lappas

The objective of this study was to examine the potential of poultry wastes to be used as feedstock in non-catalytic and catalytic fast pyrolysis processes, which is a continuation of our previous research on their conversion into biofuel via slow pyrolysis and hydrothermal conversion. Both poultry meal and poultry litter were examined, initially in a fixed bed bench-scale reactor using ZSM-5 and MgO as catalysts. Pyrolysis of poultry meal yielded high amounts of bio-oil, while pyrolysis of poultry litter yielded high amounts of solid residue owing to its high ash content. MgO was found to be more effective for the deoxygenation of bio-oil and reduction of undesirable compounds, by converting mainly the acids in the pyrolysis vapours of poultry meal into aliphatic hydrocarbons. ZSM-5 favoured the formation of both aromatic compounds and undesirable nitrogenous compounds. Overall, all bio-oil samples from the pyrolysis of poultry wastes contained relatively high amounts of nitrogen compared with bio-oils from lignocellulosic biomass, ca. 9 wt.% in the case of poultry meal and ca. 5–8 wt.% in the case of poultry litter. This was attributed to the high nitrogen content of the poultry wastes, unlike that of lignocellulosic biomass. Poultry meal yielded the highest amount of bio-oil and was selected as optimum feedstock to be scaled-up in a semi-pilot scale fluidised bed biomass pyrolysis unit with the ZSM-5 catalyst. Pyrolysis in the fluidised bed reactor was more efficient for deoxygenation of the bio-oil vapours, as evidenced from the lower oxygen content of the bio-oil.


GCB Bioenergy ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Stefanie Arnold ◽  
Karin Moss ◽  
Nicolaus Dahmen ◽  
Marius Henkel ◽  
Rudolf Hausmann

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