Title of the project

Key words

Rice husk being an abundant agricultural residue in sub-Saharan Africa, its valorization for the production of silicon-based materials for several energy applications is an important issue for developing new production eco-technologies from local resources. This will be a breakthrough for the implementation of new industries meeting the sustainable development goals in the solar energy sector.

The major parameters involved in carbothermal reduction are the Si:C ratio in the material undergoing carbothermal reduction, a reducing environment and a sufficient temperature that can reach above 1500 °C. In order to reduce the energy costs of producing silicon-based materials, it is necessary to develop strategies to reduce the temperature and duration of the reaction. In addition, the control of the Si:C ratio in the material is another difficulty but strategies have been successfully developed by Schubert et al. through a gasification process [10].

Specific objectives:

·       Study the thermochemical transformation of rice husk by pyrolysis, gasification processes for the production of SiO₂/C composite materials with controlled Si:C ratio;

·       Study the carbothermal reduction for the production of Si or SiC based materials. This will include the search for optimal synthesis conditions to reduce the temperature and duration of the carbothermal reduction;

·       Define design factors for the carbothermal reduction process

·       Characterise the microstructure and chemical composition of the materials obtained and identify the materials of interest for the targeted applications;

·       Characterise and model the performance of the identified materials;

·       Carry out an economic study and a life cycle analysis of the most promising materials.

·       2. Schubert, P., Paganessi, J., Wilks, A., & Murray, M. (2012). Distributed Hydrogen Generation and Storage from Biomass. Materials Challenges in Alternative and Renewable Energy II, 105-14.

·       3. Liu, N., Huo, K., McDowell, M. et al. Rice husks as a sustainable source of nanostructured silicon for high performance Li-ion battery anodes. Sci Rep 3, 1919 (2013).

·       4. Marchal, Julien C., Krug III, David J., McDonnell, Patrick, et al. A low cost, low energy route to solar grade silicon from rice hull ash (RHA), a sustainable source. Green Chemistry, 2015, vol. 17, no 7, p. 3931-3940.

·       5. Ahmad, W., bahrani, M., Yang, Z. et al. Extraction of nano-silicon with activated carbons simultaneously from rice husk and their synergistic catalytic effect in counter electrodes of dye-sensitized solar cells. Sci Rep 6, 39314 (2016).

·       6. Chen, C. Y., Lin, C. I., et Chen, S. H. Kinetics of synthesis of silicon carbide by carbothermal reduction of silicon dioxide. British ceramic transactions, 2000, vol. 99, no 2, p. 57-62.

·       7. Lee, Hyun-Cheol, Dhage, Sanjay, Akhtar, M. Shaheer, et al. A simulation study on the direct carbothermal reduction of SiO2 for Si metal. Current Applied Physics, 2010, vol. 10, no 2, p. S218-S221.

·       8. Shatumbu T. Alweendo, Oluwagbenga T. Johnson, Mxolisi B. Shongwe, Frank P.L. Kavishe, Joseph O. Borode, Synthesis, Optimization and Characterization of Silicon Carbide (SiC) from Rice Husk, Procedia Manufacturing, Vol. 35, 2019, 962-967.

·       9. Li, Xiaoke, Guangyong Zeng, and Xinyu Lei. "The stability, optical properties and solar-thermal conversion performance of SiC-MWCNTs hybrid nanofluids for the direct absorption solar collector (DASC) application." Solar Energy Materials and Solar Cells 206 (2020): 110323.

·       10. Schubert, P.J., “System and method for controlling char in biomass reactors”, 3 Nov. 2011, US 20110266500

·       Literature survey of the parameters influencing the carbothermic reduction of SiO₂;

·       Study by thermogravimetric analysis of the pyrolysis and gasification of rice husk;

·       Study of the influence of pyrolysis and gasification parameters for the elaboration of SiO₂/C composites with controlled Si:C ratio;

·       Study by thermogravimetric analysis of the carbothermal reduction of SiO₂/C composites;

·       Definition of design factors of the carbothermal reduction process. Factors to consider might be (1) batch versus continuous operation; (2) seals and ports; (3) gas manifolds and pressure or vacuum requirements; (4) recover of solid materials and any post-processing which may be required; and (5) some consideration of power and control requirements.

·       Chemical (elemental analysis) and structural characterisation of the materials obtained (XRD, SEM, TEM, Raman);

·       Electrical characterisation (measurement of electrical conductivity/resistivity, carrier density (Hall effect), determination of carrier mobility, etc)

·       Study of the properties of use for the targeted applications in electronics and modelling;

·       Economic study and life cycle analysis of the most promising materials.

Expected results :

·       Optimal conditions of synthesis of both SiC or Si-based materials from rice husk are defined and the influence of parameters is determined;

·       Proper design factors are defined in view of a practical implementation of the technology

·       The silicon-based materials are characterised from a chemical and microstructural point of view;

·       The properties of use for the targeted applications are studied and modelled;

·       An economic study of the production of the materials is carried out;

·       A life cycle analysis of the most promising materials is carried out.

2. Laboratoire sur l'Énergie Solaire, Université de Lomé, Lomé, Togo

With possible mobility to the Richard G. Lugar Center for Renewable Energy, Indiana University-Purdue University Indianapolis, Indiana, USA

·       Pr Yendoubé LARE, Laboratoire sur l'Énergie Solaire, Université de Lomé, Lomé, Togo ;

·       Pr. Peter J. Schubert, Richard G. Lugar Center for Renewable Energy, Indiana University-Purdue University Indianapolis, Indiana, USA;

·       Pr. Igor OUEDROAGO, Laboratoire Energies Renouvelables et Efficacité Energétique (LabEREE), Institut International d'Ingénierie de l'Eau et de l'Environnement, Ouagadougou, Burkina Faso.

Starting date

Duration

·       Strong taste for experimentation and research;

·       Autonomous, dynamic, good interpersonal skills;

·       Fluency in English essential (minimum level required C1).

•   A letter of motivation;
•  A curriculum vitae;
•  A photocopy of the Master's degree or equivalent;
•  Photocopies of the Master's transcripts or equivalent;
•   The Master's thesis report.

Applications are made exclusively online at the following address:

 https://dev.2ie-edu.org/candidatures/formulaire/6

The deadline for applications is December 7, 2022 at 3:00 p.m. GMT.

No physical file or sent by email will be admissible.

For any information contact: Mrs. Nadège Obi KAM

Tel: (226) 25 49 28 00, Boxe 1531

E-mail: nadege.kam@2ie-edu.org