Plant-based Marotti oil, widely used in alternative medicine such as Ayurveda, is emerging as an eco-friendly blend for diesel, according to studies conducted by Indian and Ethiopian researchers.
In terms of emissions, significant reductions in carbon monoxide (50 per cent to 29 per cent), unburned hydrocarbons (up to 26 per cent), and smoke opacity were observed during neat diesel operation, according to the research.
The performance and emission characteristics of a single-cylinder diesel engine running on Marotti oil biodiesel-diesel blends of 10–40 per cent were experimentally investigated. Marotti oil, also known as Chaulmoogra oil, is a non-edible traditional medicinal oil extracted from the seeds of the Marotti tree. It is used for treating skin diseases such as leprosy, eczema, psoriasis, and dandruff.
A medium-sized, semi-deciduous tree native to the Western Ghats in South India, Marotti extracts are also used in agriculture as a potent fertiliser and as a repellent for pests and insects.
The study, conducted by researchers from the National Institute of Technology Puducherry, Jeppiaar Engineering College Chennai, and Arba Minch University Ethiopia, was published in Scientific Reports, a peer-reviewed international journal, on April 24.
Researchers found that while brake thermal efficiency (BTE)—the ability of an engine to convert chemical energy into mechanical power—reduced by about 10 per cent, the engine’s fuel efficiency, or how effectively it converts fuel into useful shaft power, increased by about 20 per cent.
A decrease of 7.7 per cent in exhaust gas temperature also indicated better combustion stability at higher blend percentages. However, a slight increase in nitrogen oxide emissions was observed due to higher operating temperatures during biodiesel combustion, owing to its oxygenated properties, the study noted.
Biodiesel derived from non-edible feedstocks has attracted significant interest due to the growing need for cleaner alternative fuels. Marotti oil biodiesel is seen as a novel renewable fuel source that enables the use of non-arable land for cultivation and offers lower emissions compared to other non-edible fuel sources, the researchers said.
Diesel engines remain a preferred option for automotive transport, agriculture, and industrial applications due to their relatively low operating costs compared to other engines, the researchers observed. However, diesel combustion is associated with serious environmental and public health concerns.
In recent years, rising concerns over air pollution, global warming, and the depletion of fossil fuel resources have accelerated the global search for cleaner, sustainable fuels, leading to growing interest in bio-based alternatives that can improve engine performance while reducing harmful emissions by partially replacing petroleum diesel.
