Exploiting the potential of underutilized African plants and agricultural wastes in biofuels production

This team will demonstrate that biofuels can be sustainable, by assessing the potential to convert diverse inedible biomass (e.g. underutilized plants) into biodiesel. In addition, the project will also target the production of high value biochemicals from such inedible biomass.

Keywords: Underutilized plants, Agricultural wastes, Biodiesel, Natural antioxidants, Catalytic upgraded biofuels

Thomas Kivevele

Thomas is currently working as a Senior Lecturer at the School of Materials, Energy, Water and Environmental Sciences (MEWES), Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha – Tanzania.

Jeremy Luterbacher

In 2014, Jeremy returned to EPFL as a Tenure-Track Assistant Professor and head of the Laboratory of Sustainable and Catalytic Processing.

Research project

Despite the vast potential of non-food plant-based biofuels, there are still exceedingly large data gaps in understanding their applicability in Africa. Presently, biofuels are largely produced from food-based oils, posing an existential threat to food security (food-versus-fuel debate). The goal of this project is to use vegetable oils from selected underutilized plants for biofuel production.

We will also produce significant amount of low-cost bio-based heterogeneous catalysts using selected agricultural wastes with significant amount of alkaline and alkaline earth metal oxides. The application of these catalysts will reduce the use of conventional homogeneous catalysts which are reported to be ineffective. On the other hand, biodiesel oxidizes during long-term storage, hence doping it with antioxidants is inevitable. Instability of biodiesel is one of the outstanding barriers towards its commercialization. Natural antioxidants extracted from plants and agricultural wastes with high phenolic contents are gaining attraction by researchers in the recent years. Synthetic antioxidants have been widely used in improving stability of biodiesels but they are expensive.

Furthermore, due to poor cold-flow properties and oxidation instability of biodiesel, catalytic upgrading of fatty acid esters through ketonization and aldol condensation is an ongoing research area in the context of improving the properties to diesel-like fuels or targeting high value applications such as aviation fuel. In this project, we intend to transform selected underutilized plants and agricultural wastes in Africa into “cash crops/wastes” for the production of biodiesels, low-cost heterogeneous catalysts, natural antioxidants, and catalytic upgraded biofuels.

Proposed Experimental set-up (transesterification process, purification of biodiesel/methyl ester and stability measurements)
Typical oxidation reaction of biodiesel: Oxidation of biodiesel starts with the removal of hydrogen from a carbon atom to produce a carbon free radical. If diatomic oxygen is present, as a result the subsequent reaction to form a peroxy radical is extremely fast. The peroxy free radical is not as reactive as the carbon free radical, but is sufficiently reactive to quickly abstract hydrogen from a carbon to form another carbon radical and a hydroperoxide (ROOH). The new carbon free radical can then react with diatomic oxygen to continue the propagation cycle. This chain reaction terminates when two free radicals react with each other to yield stable products like aldehydes, shorter chain carboxylic acids, and sediments.
 
Detailed chemistry of mixed fatty acids and cetic acid during the single step transformation to alkanes and aromatics over Cu/ZrO2 in the presence of H2

Publications / Science news

Poster presented at the symposium “Le Grand Rift Africain – À la confluence des Temps”, Collège de France, Paris 17-18 November, 2023 (CNRS). “Du mega au low-tech: Qu’est-ce qu’un système énergétique durable en Afrique de I’Est.”

Meeting at the Centre National de la Recherche Scientifique (CNRS) à l’Ecole des Hautes Études en Sciences Sociales (EHESS), 20 – 30 November 2023.


Biofuels workshop, October, 2023. Participants from EPFL (LPDC), EXAF-EPFL, Swiss Embassy, NM-AIST, Arusha Technical College, Tanzania Commission for Science and Technology (COSTECH), Tanzania Renewable Energy Association (TAREA) and Ministry of Energy.


September 2023: Competition organised in primary and secondary schools around Arusha, based on a project relating to biofuels.

Kariim, I., Park, J., Kazmic, W. W., Swai, H., Lee, I. & Kivevele, T. 2023. Solvothermal liquefaction of orange peels into biocrude: An experimental investigation of biocrude yield and energy compositional dependency on process variables, Bioresource Technology (ELSEVIER), 129928.


Kichonge, B. & Kivevele, T. (2023). Viability of Non-Edible Oilseed Plants and Agricultural Wastes as Feedstock for Biofuels Production: A Techno-economic Review from an African Perspective, Biofuels, Bioproducts and Biorefining (WILEY).


Kariim, I., Swai, H., & Kivevele, T. 2023. Bio-Oil Upgrading over ZSM-5 Catalyst: A Review of Catalyst Performance and Deactivation, International Journal of Energy Research (WILEY), Volume 2023 | Article ID 4776962 .


Kariim. I., Waidi D.y., Swai, H. & Kivevele, T. 2023. Catalytic hydrothermal liquefaction of orange peels into biocrude: An optimization approach by Central Composite Design, Journal of Analytical and Applied Pyrolysis (ELSEVIER).


Kahimbi, H., Kichonge, B. & Kivevele, T. 2023. The Potential of Underutilized Plant Resources and Agricultural Wastes for Enhancing Biodiesel Stability: The Role of Phenolic-Rich Natural Antioxidants, International Journal of Energy Research (WILEY), vol. 2023, Article ID 9389270, 30 pages, 2023.


Mahene, W. L., Kivevele, T., & Machunda, R. 2023. The role of textural properties and surface chemistry of activated carbon support in catalytic deoxygenation of triglycerides into renewable diesel. Catalysis Communications (ELSEVIER), 181, 106737.