Research

Bio-diesel from Domba fruit ?

The Uva Wellassa University (UWU) is the first entrepreneurial university in Sri Lanka known as the Centre of Excellence for value addition. It fulfils the requirement of producing undergraduates with entrepreneurial skills much needed for the country.

Dulani Kuruppu

This is the eighth of a series of articles based on final year student research reports on value addition which will be useful for industrialists as well as readers. The objective of this series is to encourage and introduce the country’s future entrepreneurs to make industrialists and other relevant parties aware of potential businesses. Interested parties can contact the University for more details.

Dulani Kuruppu, an old girl of Nugegoda Anula Vidyalaya conducted a research to produce bio-diesel out of Domba herbal fruit for her degree program at the Uva Wellassa University.

A student with many talents from her school days she was impressed by a research done by one of her lecturers on a three wheeler driven using Domba oil. That made her to develop this project in the latter part with his guidance.

Degradation of polymeric components in bio-diesel fuel system

The worldwide demand for energy is ever increasing and bio-diesel is gaining momentum as an alternative renewable fuel against the ever shrinking fossil fuel reserves in the world.

However certain concerns must be addressed before manufacturers and the public fully accept it. There is a strong public opinion that the use of bio-diesel could harm the polymeric components in the diesel fuel system.

The purpose of this research is to investigate whether there is any degradation in polymeric components of the diesel fuel system of automobiles, such as the rubber fuel hose, with long-term use of bio-diesel.

Bio-diesel was made after base catalyzed transesterification of extracted pure Domba (Colophyllum inophyllum) oil. Blends of bio-diesel were made by mixing pure bio-diesel with fossil diesel.

Real fuel hose used in diesel automobiles and a garden rubber hose were treated with different blends of Bio-diesel, B100 (pure Bio-diesel), B80 (80 percent Bio-diesel 20 percent Fossil fuel), B60, B40, B20 and B00 (Fossil diesel) using a special set-up to mimic the actual diesel fuel system of automobiles.

A three-wheeler running on the Domba fruit oil extraction

Free test and post test internal diameter changes, weight changes and length changes were measured for rubber and real fuel hoses.

Internal surface observations were done under the magnification 4.0 A - 10 of a Stereo Microscope with a digital imaging system, before and after the treatment with bio-diesel blends.

Degree of degradation in garden rubber hose and in real fuel hose was assessed using a five point grading system and the analysis of data was done using Minitab statistical software.

Garden hose treated with blends over B80 underwent significant structural changes such as increase in diameter and weight loss while no significant structural changes were observed with real fuel hose.

No significant surface degradation occurred in the fuel hose used in the diesel automobiles with all the blends tested, since it has been treated with an oil resistant coating.

Conversely, garden rubber hose showed severe surface degradation with blends B100 and B80 while no significant degradation was observed with blends B20, B40 and B60.

Automobile fuel hose can be used with any blend of bio-diesel without any modification in existing diesel fuel system of all automobiles as an alternative to fossil diesel.

Extended abstract

Bio fuel has been around since the invention of the engine, but has not gained wide acceptance due to the relatively low cost and availability of fossil diesel fuel.

Considering the current world energy crisis, this may not be the case for long. Pressure is ever-increasing on identifying alternative renewable fuels such as Bio-diesel.

Bio-diesel can be made of plant oils derived from non-edible sources like Domba (Calophyllum inophyllum).

One of the main drivers for adoption of Bio-diesel is energy security. This means that a nation’s dependency on imported fossil fuel is reduced saving millions of dollars worth foreign currency.

However, certain concerns must be addressed before equipment owners, manufacturers and the public fully accept it. Mechanical reliability is the most notable concern. There is a strong public opinion that Bio-diesel when used in pure form, can soften and degrade parts of the fuel system, made of elastomers and natural rubber compounds (such as primary fuel hoses and fuel pump seals).

This study investigates possible degradation of polymeric components in Bio-diesel fuel system using a special set up to mimic the actual fuel system of diesel automobiles.

Materials and methods

Making Bio-diesel and blends

Pure Domba oil extracted from dried seeds was reacted with methanol in the presence of KOH. After base catalyzed transesterification bio-diesel was separated from Glycerol using a separated funnel.

Bio-diesel was mined with commercial fossil diesel to make different blends; B100 (pure bio-diesel), B80 (80 percent bio-diesel, 20 percent fossil fuel), B60, B40, B20 and B00 (pure commercial fossil diesel, control)

Set up to mimic fuel system of diesel automobiles

The set up was build to mimic the fuel system of diesel automobiles. Deferent blends of Bio-diesel blends were allowed to circulate at a fluid flow rate of 13.46 ml/sec using a submerged fuel pump - 2201 (Jsauto Trade Company, Mumbai).

Length, weight and internal diameter measurements

Length and internal diameter measurements before and after treatments with bio-diesel blends were taken using a digital Vernier Calliper 10101 (Pasco, USA). All weight measurements were taken with an Election Precision Balance 4100 (Citizen Scale, USA)

Internal surface observation

Internal surface observation of fuel hoses before and after treatments with bio-diesel blends was made under 4.0 A-10 magnification of a Stereo Microscope fitted with a digital camera. Images were analyzed using Digi Pro software. Forty data points were taken per each treated fuel hose and a five scale grading system was used to evaluate the degree of decay.

Statistical analysis

All the experiments were arranged in Completely Random Design (CRD) and the analysis of data was done by the Minitab statistical software. The fitted model was Linear Model.

Comparison between means and Standard Deviations with Coefficient of Variance for rubber hose pieces.