Skip to Main content Skip to Navigation
Theses

Etude de la conversion de la biomasse en energie par un procédé hydrothermal de carbonisation - Caractérisation des produits issus des grignons d'olive

Abstract : Hydrothermal carbonization (HTC) allows pre-treating humid biomass in subcritical water (180-250°C) and at low pressures (10-40 bars) in the absence of air. This process produces a carbonaceous solid material called "hydro-char". The main aim of this work is to optimize the HTC process by studying the potential of hydro-char to produce energy. The studied biomass is a by-product of the olive oil industry called olive pomace containing water, residual oil, olive skin, olive pulp, and olive stones (with 70% moisture content). The moroccan olive pomace was first air-dried (DOP) and characterized. During the HTC process, the biomass is decomposed via dehydration and decarboxylation reactions. The obtained hydro-char has much less moisture and higher carbon contents than that of untreated DOP. Also, the hydro-char becomes poor in ashes by transferring them into the liquid phase. Hydro-chars have a higher HHV than that of peat and lignite. The results show that hydro-char mass yield and its properties depend on the process temperature especially. For a better analysis of the effect of operating conditions, a Design of Experiments Response Surface Methodology (DoE/RSM) approach was applied to optimize the HTC process. The DoE/RSM allows identifying a relationship between hydro-char properties and its mass yield and thermal combustion behavior. Response-surface plots show defined areas of production of hydro-char which allows tailoring hydro-char elaboration to a specific application. The process liquid from the HTC treatment of DOP shows a sensibility to operating conditions. The soluble carbon in the HTC liquid increases its polluting power and to decrease it two treatment process have been tested: evaporation and wet oxidation. Finally, the results show that the amount of water used for the hydrothermal treatment is the most influential factor on the energy balance of the HTC process.
Document type :
Theses
Complete list of metadatas

Cited literature [227 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02108223
Contributor : Abes Star :  Contact
Submitted on : Wednesday, April 24, 2019 - 9:40:07 AM
Last modification on : Thursday, March 5, 2020 - 6:49:48 PM

File

ayoub-missaoui_3946.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02108223, version 1

Collections

Citation

Ayoub Missaoui. Etude de la conversion de la biomasse en energie par un procédé hydrothermal de carbonisation - Caractérisation des produits issus des grignons d'olive. Autre. Université d'Orléans, 2018. Français. ⟨NNT : 2018ORLE2039⟩. ⟨tel-02108223⟩

Share

Metrics

Record views

499

Files downloads

4544