The effect of ethanol as a homogeneous catalyst on the reaction kinetics of hydrothermal liquefaction of lipids

Chacón-Parra, Andrés; Lewis, David M.; Eyk, Philip J. van

doi:10.1016/j.cej.2021.128832

Cited by 14 publications

(18 citation statements)

References 36 publications

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“…A lower reaction temperature and longer residence time have a positive effect on the desired lower boiling point fraction while reducing the high boiling point fraction. 29 Finally, the combustible nonvolatile matter (at 600 °C with air) presented a relatively similar trend to the solid phase yields, as shown in Figure 4b. The glucose mass ratio had the largest influence, followed by the reaction temperature.…”

Section: Bulk Product Phase Yields and The Primarymentioning

confidence: 55%

“…The centered point values for temperature and reaction time were defined based on previous studies' results with the same system, and each experiment was duplicated to quantify the average of product yield reported. 29 2.3. Product Recovery and Separation.…”

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

“…After centrifugation of these ethanol rinse samples, 1 mL of biocrude in ethanol was transferred to chromatography vials for analysis. 29 Product separation was accomplished in a two-step filtration process. The recovered products containing aqueous, solid, and crude products were vortexed and filtered using a Buchner funnel (Whatman's Ashless Grade 42 filter paper) to separate the aqueous (oil-free) phase.…”

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

“…Boiling point fractions were calculated from the weight loss over defined temperature ranges of (80−180 °C), (180−300 °C), and (300−600 °C). 8,11,14,29,48 2.5. Kinetic Modeling.…”

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

“…The reaction constants (k) were optimized using the lsqcurvefit function by minimizing the squared norm of the residual function. 11,29 The error bars represent the standard deviation of the experimental data. 49…”

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

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Elucidating the Maillard Reaction Mechanism in the Hydrothermal Liquefaction of Binary Model Compound Mixtures and Spirulina

Chacón-Parra

Hall

Lewis

et al. 2022

ACS Sustainable Chem. Eng.

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Hydrothermal liquefaction (HTL) transforms wet biomass and biowaste feedstock into water-insoluble biocrude and valuable water-soluble organic products. HTL takes advantage of the exceptional properties of water near the critical point to break bio-macromolecule linkages, and as a reaction medium, subcritical water ions allow the reaction and recondensation of intermediates into various structures and product phases. Among the different reaction mechanisms involved in the hydrothermal conversion, the synergetic interaction between protein and carbohydrate intermediates, known as the Maillard reactions, can boost the renewable biocrude yield up to 25% higher than solely free fatty acid hydrolysis from lipids. However, the reaction mechanisms and the effect of biomass composition are not fully understood. In this study, the Maillard reactions have been investigated with a central composite design to validate the impact of mass ratio (carbohydrate/protein) over temperature and residence time, via product response analysis, including product yields, boiling point distribution, aqueous tests, elemental, and chemical compositions. Then, the gas chromatography−mass spectrometry data is used to propose a potential pathway, followed by levulinic acid from carbohydrates as a candidate, to produce proline via Maillard interactions before amino acid condensation into piperazinediones and reduction into pyrazines among other complex degradations. The understanding of Maillard interactions under HTL conditions could lead to more robust compositional models, and the present results showed that a protein-to-carbohydrate mass ratio 2:1 would maximize the volatile fraction, elemental carbon, and higher heating value in the renewable crude, with a 90−95% of the maximum crude yield being obtained. The HTL experiments were run with glucose and soy protein as model compounds and spirulina in a batch reactor at 300 °C temperature, 20 min residence time, and 50% mass ratio as a central point, with an alpha (α) of 20 °C, at 10 min, and a 25% mass ratio.

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Section: Bulk Product Phase Yields and The Primarymentioning

confidence: 55%

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

“…Boiling point fractions were calculated from the weight loss over defined temperature ranges of (80−180 °C), (180−300 °C), and (300−600 °C). 8,11,14,29,48 2.5. Kinetic Modeling.…”

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

Section: Design Of Experiments and The Reactor Systemmentioning

confidence: 99%

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