Hydrothermal carbonization of dried olive pomace: Energy potential and process performances

Missaoui, Ayoub; Bostyn, Stéphane; Belandria, Verónica; Cagnon, Benoı̂t; Sarh, Brahim; Gökalp, İskender

doi:10.1016/j.jaap.2017.09.022

Cited by 88 publications

(45 citation statements)

References 51 publications

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“…Olive pomace oil is reported in the literature as having a high content of oil and water (Barbanera et al, 2016;Missaoui et al, 2017). In the present work, the following results were obtained: 18 ± 2 wt.% lipid content; moisture content of 26.8 ± 0.2 wt.%…”

Section: Olive Pomace Oilsupporting

confidence: 70%

Recovery of by-Products From the Olive Oil Production and the Vegetable Oil Refining for Biodiesel Production

Cruz¹,

Costa²,

Almeida³

et al. 2018

Detritus

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The by-products acid oil from soapstock of vegetable oil refining and olive pomace oil were evaluated for biodiesel production. Enzymatic hydroesterification was studied to convert the acid oil (̴ 34 wt.% free fatty acids) into methyl esters; due to the low free fatty acid content of the fresh olive pomace oil (̴ 2 wt.%), alkaline transesterification was conducted. The results from the enzymatic hydrolysis (35˚C, 24 h, 200 rpm) showed a clear influence of enzyme concentration (0.1-5 wt.%, relative to oil) and water:oil ratio (1:0.25 and 1:0.5 w:w) towards free fatty acid production. After applying the best established conditions (3 wt.% of enzyme and 1:0.5 water: oil ratio, w:w), enzymatic esterification was performed (35˚C, 7 h, 200 rpm, 2 wt.% of enzyme and 2:1 molar ratio of methanol to acid). Hydroesterification led to a product with a methyl esters content of about 84 wt.% whereas the esterification alone allowed reaching only around 65 wt.%. The olive pomace oil was obtained from chemical extraction of fresh olive pomace (̴ 18 wt.% of oil). By performing direct alkaline transesterification (65˚C, 1 wt.% NaOH, 1 h and 6:1 molar ratio of methanol to oil) a product with a purity of 90 wt.% was obtained. The olive pomace storage in the air during 2 weeks led to an increase in the oil free fatty acid content of almost 2 fold showing the relevance of developing storage and conservation strategies to ensure a sustainable recovery of this by-product. Both by-products showed potential for biodiesel production.

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Section: Olive Pomace Oilsupporting

confidence: 70%

Recovery of by-Products From the Olive Oil Production and the Vegetable Oil Refining for Biodiesel Production

Cruz¹,

Costa²,

Almeida³

et al. 2018

Detritus

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“…The low value obtained in the present work resulted possibly from sampling in a different season of the year (where differences are frequently found in the acid value of the raw oil that is going to be refined) or due to variations in the process used to produce the acid oil from soapstock (by-product of refining), namely different mineral acid dosings (conventionally it is added to break the soaps). Olive pomace is reported in the literature as having a high content of oil and water depending upon the extraction process used to obtain the olive oil [18,23]. In the present work, the following results were obtained: 15 ± 2 wt.% of lipid content and a moisture content of 31 ± 1 wt.%.…”

Section: Characterization Of Feedstockssupporting

confidence: 61%

Monitoring Enzymatic Hydroesterification of Low-Cost Feedstocks by Fourier Transform InfraRed Spectroscopy

et al. 2019

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Enzymatic hydroesterification is a heterogeneous catalyzed process suitable for the conversion of low-cost feedstocks in biodiesel production, namely, because of its tolerance to high free fatty acid contents. The current study describes the use of Fourier transform infrared spectroscopy (FTIR) to monitor biodiesel production using enzymatic hydroesterification and, as raw materials, acid oil from soapstock and olive pomace oil. Acid oil (~34 wt.% FFA) and olive pomace oil (~50 wt.% FFA) were first hydrolyzed (35 °C, 24 h, 200 rpm, 3 wt.% of lipase from Thermomyces lanuginosus, and 1:0.5 water:oil ratio, w:w), and then enzymatic esterification was performed (35 °C, 7 h, 200 rpm, 2 wt.% of lipase from Thermomyces lanuginosus, and 2:1 molar ratio of methanol to acid). FTIR analyses were conducted on the products using a Jasco FT/IR-4100 with a scanning range of 4000–650 cm−1 at 4 cm−1 spectral resolution and 54 scans. For free fatty acid (FFA) quantification, the C=O band at 1708 cm–1 was used, corresponding to the carboxylic acid, whereas for fatty acid methyl ester (FAME) quantification, the peak corresponding to C=O at 1746 cm−1 was considered, which corresponded to the ester. The results were calibrated using volumetric titration and gas chromatography analyses, concerning FFA and FAME quantification, respectively. The best conditions for analysis were determined, and a calibration method was established. FTIR has shown to be a simple, fast, and clean technique suitable to monitor hydroesterification of low-cost feedstocks.

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“…Among different wet residual biomasses, agro-industrial wastes have received particular attention by HTC scientists due to their large production, high management and treatment costs, and the potential sanitary and pollution hazards deriving from their improper disposal. In particular, olive oil milling residues, olive pulp [16,29,30], olive stones, olive mill waste water [31], and their mixture [14] have been deeply investigated. Much less attention has been focused on the treatment of olive tree pruning residues [32].…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Carbonization Kinetics of Lignocellulosic Agro-Wastes: Experimental Data and Modeling

2019

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Olive trimmings (OT) were used as feedstock for an in-depth experimental study on the reaction kinetics controlling hydrothermal carbonization (HTC). OT were hydrothermally carbonized for a residence time τ of up to 8 h at temperatures between 180 and 250 °C to systematically investigate the chemical and energy properties changes of hydrochars during HTC. Additional experiments at 120 and 150 °C at τ = 0 h were carried out to analyze the heat-up transient phase required to reach the HTC set-point temperature. Furthermore, an original HTC reaction kinetics model was developed. The HTC reaction pathway was described through a lumped model, in which biomass is converted into solid (distinguished between primary and secondary char), liquid, and gaseous products. The kinetics model, written in MATLABTM, was used in best fitting routines with HTC experimental data obtained using OT and two other agro-wastes previously tested: grape marc and Opuntia Ficus Indica. The HTC kinetics model effectively predicts carbon distribution among HTC products versus time with the thermal transient phase included; it represents an effective tool for R&D in the HTC field. Importantly, both modeling and experimental data suggest that already during the heat-up phase, biomass greatly carbonizes, in particular at the highest temperature tested of 250 °C.

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Hydrothermal carbonization of dried olive pomace: Energy potential and process performances

Cited by 88 publications

References 51 publications

Recovery of by-Products From the Olive Oil Production and the Vegetable Oil Refining for Biodiesel Production

Recovery of by-Products From the Olive Oil Production and the Vegetable Oil Refining for Biodiesel Production

Monitoring Enzymatic Hydroesterification of Low-Cost Feedstocks by Fourier Transform InfraRed Spectroscopy

Hydrothermal Carbonization Kinetics of Lignocellulosic Agro-Wastes: Experimental Data and Modeling

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