Investigation on the esterification by using supercritical ethanol for bio-oil upgrading

Zhang, Qing; Xu, Ying; Li, Yuping; Wang, Zhihui; Zhang, Qi; Ma, Longlong; He, Minghong; Li, Kai

doi:10.1016/j.apenergy.2014.12.063

Cited by 45 publications

(19 citation statements)

References 30 publications

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“…Although the percentage of peak area does not represent the actual content of the compound, it is a strong indication that the crude bio-oil contains a large amount of phenolic compounds. The presence of the phenolic compounds in the crude bio-oil and after the reactions is consistent with the results reported by other researchers [10,14,36,37].…”

Section: Gc-ms Analysissupporting

confidence: 92%

Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions

Omar

Alsamaq

Yang

et al. 2019

Front. Chem. Sci. Eng.

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The work studied a non-catalytic upgrading of fast pyrolysis bio-oil by blending under supercritical conditions using methanol, ethanol and isopropanol as solvent and hydrogen donor. Characterisation of the bio-oil and the upgraded bio-oils was carried out including moisture content, elemental content, pH, heating value, gas chromatography-mass spectrometry (GCMS), Fourier transform infrared radiation, 13 C nuclear magnetic resonance spectroscopy, and thermogravimetric analysis to evaluate the effects of blending and supercritical reactions. The GCMS analysis indicated that the supercritical methanol reaction removed the acids in the bio-oil consequently the pH increased from 2.39 in the crude bio-oil to 4.04 after the supercritical methanol reaction. The ester contents increased by 87.49% after the supercritical methanol reaction indicating ester formation could be the major deacidification mechanism for reducing the acidity of the bio-oil and improving its pH value. Simply blending crude bio-oil with isopropanol was effective in increasing the C and H content, reducing the O content and increasing the heating value to 27.55 from 17.51 MJ$kg-1 in the crude bio-oil. After the supercritical isopropanol reaction, the heating value of the liquid product slightly further increased to 28.85 MJ$kg-1 .

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Section: Gc-ms Analysissupporting

confidence: 92%

Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions

Omar

Alsamaq

Yang

et al. 2019

Front. Chem. Sci. Eng.

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“…Recently, alcohols have been utilized as an alternative solvent in the liquefaction of various types of biomass, including cellulose, lignin, sewage sludge, and microalgae, due to their advantages with better solubility of organic intermediates, hydrogen donor properties, and easier separation due to their low boiling points [50][51][52][53][54][55][56][57][58][59]. Compared to water, alcohols such as methanol and ethanol have much lower critical temperatures and pressures.…”

Section: Mesoporous Silicate Materials Containing Zirconium Have Highmentioning

confidence: 99%

Mechanistic insights into the production of methyl lactate by catalytic conversion of carbohydrates on mesoporous Zr-SBA-15

Yang

Tian

et al. 2016

Journal of Catalysis

114

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The as-synthesized Zr-SBA-15 catalysts with tunable mesoporous structures showed excellent catalytic performance for the conversion of carbohydrates to methyl lactate in a "onepot" process using near-critical methanol or methanol-water mixture as the solvents. The effects of reaction conditions, including temperature, reaction time, and catalyst loading amount, on the conversions of carbohydrates and the yields of methyl lactate were investigated. The high yields of methyl lactate, up to 41 % and 44%, were produced from pentose and hexose, respectively, in the near-critical methanol at 240°C. Moreover, the Si/Zr ratio of the Zr-SBA-15 catalysts profoundly affected the Lewis acidity and therefore the catalytic activity and selectivity to methyl lactate in the conversion of carbohydrates. The pore size of the Zr-SBA-15 catalysts, tuned by the synthesis temperature, strongly affected the formation of solid residues. The key intermediates such as glyceraldehyde, glycolaldehyde, and pyruvaldehyde were used as probe reactants to understand the mechanism. The role of the Zr-SBA-15 catalyst in the aldol-and retro-aldol condensation, isomerization, and Cannizzaro reactions of carbohydrates and their derivatives was discussed. Furthermore, 28% and 27% yields of methyl lactate were obtained from cellulose and starch, respectively, in methanol-water mixture (5 wt% water and 95 wt% methanol) at 240°C. The Zr-SBA-15 catalyst was relatively stable in short term without regeneration.

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“…The sulfonic acid groups present in the structure of H-LS can catalyze esterification reactions [27]. Esterification reactions are favored for enhancement of the oil quality as carboxylic acids groups decrease the stability of the oil [28]. Guaiacol was the primary monomeric product identified from degradation of lignin in the EG medium, corresponding to selectivity of 5.8 and 2.6 wt.% in the oil phases from non-catalytic and catalytic conditions, respectively.…”

Section: Characterization Of the Products And Comparison Between Etohmentioning

confidence: 99%

Solvothermal Conversion of Lignosulfonate Assisted by Ni Catalyst: Investigation of the Role of Ethanol and Ethylene Glycol as Solvents

et al. 2018

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In this study, reductive solvolysis of lignosulfonate using Ni-based catalysts in ethylene glycol (EG) and ethanol (EtOH) at 250 °C was investigated. The liquefied fractions, regarded as oil, were carefully analyzed using size-exclusion chromatography (SEC) and gas chromatography–mass spectrometry with flame ionization detection (GC-MS-FID). The oil yields from catalytic conversion in EtOH and EG were similar, being 31 and 32 wt.%, respectively. The oil fractions from depolymerization in EtOH had lower molecular weight compared to the oil products in EG, indicating a higher degree of degradation of liquefied products in EtOH. On the other hand, EG showed superior activity in inhibiting condensation reactions; 16 and 46 wt.% tetrahydrofuran (THF) soluble and THF insoluble solid fractions were obtained from conversion in EtOH, while those numbers in EG were 45 and 23 wt.%, respectively. The Ni-based catalyst was introduced to provide active sites for hydrogenation of lignosulfonate fragments released into the solvent. The presence of NiS in the spent catalyst, formed from reaction between Ni and sulfur in the lignosulfonate, was confirmed. The sulfur content in the oil obtained in EtOH was 0.38 wt.%, which in comparison to lignosulfonate with 3.1 wt.% sulfur, indicated a high level of desulfurization.

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Investigation on the esterification by using supercritical ethanol for bio-oil upgrading

Cited by 45 publications

References 30 publications

Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions

Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions

Mechanistic insights into the production of methyl lactate by catalytic conversion of carbohydrates on mesoporous Zr-SBA-15

Solvothermal Conversion of Lignosulfonate Assisted by Ni Catalyst: Investigation of the Role of Ethanol and Ethylene Glycol as Solvents

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