Skip to Main content Skip to Navigation
Theses

Modelling, optimisation and scale up of a lab scale biomass solar gasifier

Abstract : The present thesis proposes to study a novel spouted bed solar reactor for biomass thermochemical gasification from laboratory to industrial scale by combining numerical simulations and lab-scale experimentations. The main objective is to provide new insights into the reactor operation in order to improve its performance, flexibility and industrial integration. A multiphysics numerical model of the reactor was developed using the Fluent© software for the simulation of solar steam gasification of wood particles. The model takes into account the two-phase solid/gas flow using the DPM (Discrete Phase Modelling) approach in interaction with radiation and chemistry. An experimental validation step at 1200°C showed Cold Gas Efficiencies higher than 1 thanks to the efficient valorization of solar energy and a Carbon Conversion Efficiency approaching 80%. The simulations provided key information on the particles solar conversion within the solar cavity and allowed to identify paths for improving the conversion. The use of inert bed materials as a heat transfer medium inside the cavity appeared judicious. This solution was examined both numerically using a granular Eulerian approach, and experimentally at 1200°C and 1300°C. A maximum relative improvement of the carbon conversion efficiency by 8% was this way achieved. The variability of solar energy is one of the critical obstacles hindering the scale-up of the technology. In order to ensure a continuous syngas production whatever the solar resource, the solar reactor was hybridized thanks to partial feedstock oxy-combustion. The study showed that the injection of a controlled amount of O2 is a relevant solution to overcome solar energy variability and to control the reactor temperature. A dynamic 0D model was then developed to predict the temperature and syngas production evolution at MWth scale according to two heating modes: solar-only and hybrid solar-combustion. Annual simulations were subsequently performed to predict reactor performance, reactants consumption and gas production volumes. These data were used to analyze the technical and economic feasibility of the process for the industrial production of hydrogen.
Document type :
Theses
Complete list of metadata

https://tel.archives-ouvertes.fr/tel-03426059
Contributor : ABES STAR :  Contact
Submitted on : Friday, November 12, 2021 - 1:01:14 AM
Last modification on : Friday, March 25, 2022 - 9:43:16 AM
Long-term archiving on: : Sunday, February 13, 2022 - 6:11:48 PM

File

BOUJJAT_2020_archivage.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-03426059, version 1

Collections

Citation

Houssame Boujjat. Modelling, optimisation and scale up of a lab scale biomass solar gasifier. Biotechnology. Université Grenoble Alpes [2020-..], 2020. English. ⟨NNT : 2020GRALI049⟩. ⟨tel-03426059⟩

Share

Metrics

Record views

171

Files downloads

52