Fast depletion of fossil fuels, rapid increase in the prices of petroleum products and harmful exhaust emissions from the engine jointly created renewed interest among researchers to find the suitable alternative fuels. The interest in using Hibiscus species (Hibiscus cannabinus and Hibiscus sabdariffa) as feedstock's for the production of bio-diesel is rapidly growing. The properties of the crop and its oil have persuaded investors and policy makers consider these two plants as substitute for

more »

... ossil fuels to reduce greenhouse gas emissions. The literature survey shows that two Hibiscus species plants are wildly growing hardy species in arid and semi-arid regions of the country on degraded soils having low fertility and moisture. The seeds of these plants contain 21-25% oil. It is found that physical and chemical properties of Hibiscus cannabinus and Hibiscus sabdariffa oil and biodiesel are very close to fossil diesel. In this study, the oil has been converted to biodiesel by the well-known transesterification process and used it to diesel engine (CI engine) for performance evaluation. Performance tests was conducted on a single cylinder four-stroke water-cooled compression ignition engine connected to an eddy current dynamometer with different percentage of Hibiscus cannabinus and Hibiscus sabdariffa biodiesel blended with diesel. The performance and combustion characteristics of blends were evaluated at variable loads at constant rate speed and results were finally compared with the diesel. The authors hereby conclude that Hibiscus cannabinus and Hibiscus sabdariffa oil biodiesel can be used as an alternative fuel in the blending form.