Upgrading low-boiling-fraction fast pyrolysis bio-oil using supercritical alcohol: Understanding alcohol participation, chemical composition, and energy efficiency

Jo, Heuntae; Prajitno, Hermawan; Zeb, Hassan; Kim, Jaehoon

doi:10.1016/j.enconman.2017.05.061

Cited by 48 publications

(17 citation statements)

References 52 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%

“…The increase in methanol activity may have led to higher mass losses due to the increased volatility of the product. In addition, self-decomposition of the alcohols in their supercritical state may contribute to some fractions of the gas products [14]. Table 2 summarises the results from the water content, heating value, pH and CHNS analysis.…”

Section: Product Yieldsmentioning

confidence: 99%

“…Compounds detected in the crude bio-oil include acetic acid, 2-methoxy-4-methyl-phenol, 1-(4-hydroxy-3-methoxyphenyl)-ethanone, and 4-Hydroxy-2-methoxycinnamaldehyde. Phenolic compounds, which can be produced from the degradation of lignin [14], exhibited the highest total area (%) (37.0%) in the raw bio-oil with compounds such as 2-methoxy-4-methyl-phenol and 2-methoxy-4-(1propenyl)-phenol, contributing to the high area (%). 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.…”

Section: Gc-ms Analysismentioning

confidence: 99%

“…Peng et al compared bio-oil upgrading in ethanol under conventional (100°C), sub-critical (238°C) and supercritical (260°C) conditions respectively and found operating under supercritical conditions was more effective for cracking the heavy components in the bio-oil compared to sub-critical conditions [13]. Jo et al used supercritical alcohol for bio-oil upgrading without a catalyst and external hydrogen to improve the economics of the upgrading process [14]. The study showed supercritical methanol was very effective in upgrading as it produced high bio-oil yield, decreased the acidity of the bio-oil and increased the heating value.…”

Section: Introductionmentioning

confidence: 99%

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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%

Section: Product Yieldsmentioning

confidence: 99%

Section: Gc-ms Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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.

View full text Add to dashboard Cite

show abstract

“…With increased pressure, hydrogen-bonds between ethanol molecules are more readily formed, which reduces the hydrogen donating ability as a solvent [41]. From control experiments using individual pure alcohols at 400 • C for 60 min, Jo et al [42] found the self-decomposition of methanol, ethanol, and isopropanol to be only 0.1%, 3.2%, and 4.8%, respectively. In solvothermal liquefaction experiments with ethanol, Bondesgaard et al [43] found only a slight formation of by-products below the critical temperature of ethanol but observed a sharp increase in the number of by-products (71 species) at 450 • C and a total ethanol decomposition of 4.86%.…”

Section: Ethanolmentioning

confidence: 99%

Use of Co-Solvents in Hydrothermal Liquefaction (HTL) of Microalgae

et al. 2019

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This study reviewed and summarized the literature regarding the use of alcohols during hydrothermal liquefaction (HTL) of algal biomass feedstocks. The use of both pure alcohols and alcohol-water co-solvents were considered. Based upon this review, laboratory experiments were conducted to investigate the impacts of different alcohol co-solvents (ethanol, isopropanol, ethylene glycol, and glycerol) on the HTL treatment of a specific saltwater microalga (Tetraselmis sp.) at two temperatures: 300 °C and 350 °C. Based on their performance, two co-solvents, isopropanol and ethylene glycol, were selected to explore the effects of varying solvent concentrations and reaction temperatures on product yields and biocrude properties. The type and amount of added alcohol did not significantly affect the biocrude yield or composition. Biocrude yields were in the range of 30–35%, while a nearly constant yield of 21% insoluble products was observed, largely resulting from ash constituents within the algal feedstock. The benefits of using alcohol co-solvents (especially isopropanol) were the reduced viscosity of the biocrude products and reduced rates of viscosity increase with biocrude aging. These effects were attributed mainly to the physical properties of the co-solvent mixtures (solubility, polarity, density, etc.) rather than chemical processes. Under the reaction conditions used, there was no evidence that the co-solvents participated in biocrude production by means of hydrogen donation or other chemical processes. Recovery and recycling of the co-solvent present various challenges, depending upon the type and amount of the co-solvent that is used. For example, glycol solvents are recovered nearly completely within the aqueous product stream, whereas simple alcohols are partitioned between the biocrude and aqueous product streams. In commercial applications, the slight benefits provided by the use of co-solvents must be balanced by the challenges of co-solvent recovery and recycling.

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Ethanol: A Promising Green Solvent for the Deconstruction of Lignocellulose

et al. 2018

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Growing energy demand, environmental impact, energy security issues, and rural economic development have encouraged the development of sustainable renewable fuels. Nonfood lignocellulosic biomass is a suitable source for sustainable energy because the biomass feedstocks are low cost, abundant, and carbon neutral. Recent thermochemical conversion studies are frequently directed at converting biomass into high-quality liquid fuel precursors or chemicals in a single step. Supercritical ethanol has been selected as a promising solvent medium to deconstruct lignocellulosic biomass because ethanol has extraordinary solubility towards lignocellulosic biomass and can be resourced from cellulosic ethanol facilities. This review provides a critical insight into both catalytic and noncatalytic strategies of lignocellulose deconstruction. In this context, the supercritical ethanol deconstruction pathways are thoroughly reviewed; GC-MS, 1D and 2D NMR spectroscopy, and elemental analysis strategies towards liquid biomass deconstruction products are also critically presented. This review aims to provide readers a broad and accurate roadmap of novel biomass to biofuel conversion techniques.

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Upgrading low-boiling-fraction fast pyrolysis bio-oil using supercritical alcohol: Understanding alcohol participation, chemical composition, and energy efficiency

Cited by 48 publications

References 52 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

Use of Co-Solvents in Hydrothermal Liquefaction (HTL) of Microalgae

Ethanol: A Promising Green Solvent for the Deconstruction of Lignocellulose

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