As the freshwater scarcity crisis deepens worldwide, efforts are being made to find innovative solutions to meet growing needs without depleting limited resources. On one Omani farm, the story of a small tree irrigated with sewage water began, hoping that its seeds would provide a solution to the future of energy.

Dr. Ahmed Al-Busaidi, a researcher at the College of Agricultural and Marine Sciences, together with student Nibras Al-Shakili, examined the potential of the Jatropha tree to produce biofuel. The tree can grow in extreme conditions and produce seeds rich in oils that can be converted into biodiesel.

They addressed two questions: Does irrigating the Jatropha tree with treated sewage water affect the quality of its seeds? Is treated wastewater as efficient as fresh water for this purpose?

An experiment was conducted by dividing the plants into two groups – one irrigated with fresh water and the other with treated wastewater. During the study, the researchers were not only observing the growth of the trees, but also exploring the potential of their seeds to produce sustainable fuel.

As harvest time approached, the most exciting part of the research began. The seeds were carefully prepared, washed, dried and ground with hexane to extract their oil using ultrasound technology.

From seeds to fuel: After oil extraction with hexane and separation through distillation, the oil was converted into biodiesel by adding methanol and chemical catalysts. Not only was fuel produced, but the by-product, glycerin, was used to manufacture soaps and creams of various scents, while the seed residue was employed as organic fertiliser.

Results: The study found that the type of water used for irrigation did not affect the growth of the trees or seed production. The seeds also had an oil content of more than 60 percent. The extracted fuel was highly efficient when compared to fossil diesel, having a higher cetane number (i.e., 53 versus 40 for conventional diesel) and a higher flash point of 175 °C. When testing the biodiesel on an agricultural machine, the researchers found it worked efficiently without any malfunctions, thus demonstrating its practical feasibility.

Economic and environmental implications: This study presents a pioneering model that supports environmental and economic sustainability. Growing the Jatropha tree and irrigating it with treated wastewater is an ideal solution for desert environments. The extracted oil can also be used to operate machines and engines, while reducing dependence on fossil fuels.

In addition, the study showcased the potential of the Jatropha plant to absorb large amounts of carbon dioxide, which contributes to improving air quality and reducing carbon emissions. It also opens new horizons for using Jatropha leaves and seeds in many industries, including for the manufacture of organic fertilisers, glycerin and creams, which will provide sustainable commercial opportunities.

Towards achieving Oman Vision 2040: This research is in line with the sustainable development objectives of Oman Vision 2040, especially in terms of the theme of sustainable environment which focuses on promoting renewable energy at affordable prices. Through these efforts, the Sultanate of Oman confirms its commitment to finding innovative smart solutions that address energy and water challenges, thus contributing to building a sustainable future for all.

Dr. Ahmed Al-Busaidi – College of Agricultural and Marine Sciences