Rubber Seed Oil – an alternate fuel

Rubber Seed Oil – an alternate fuel

As a developing country, the fast depleting fuel resources are a cause of great concern to us. So exploring the feasibility of using any alternate fuel for automobiles can greatly contribute towards prolonging our available energy resources. The most critical threat is the scarcity of automobile fuels, which can deliver maximum efficiency and pollution free exhaust. As a result, the search for alternate fuel is guided not only by the limited resources of fossil fuels but also the pollution factor.

Research studies show that the Rubber seed oil can be used as an alternate fuel to diesel in combustion ignition engine.

Rubber seed oil

Rubber seed oil, which is highly yellow in colour, is a minor source of non-edible oil in India. The rubber seeds are passed through a standard nut mill and then filtered to make it clean enough.

Rubber seeds are harvested from rubber tree, which is sturdy quick growing and tall. Rubber is traditionally grown in the hinterlands of the south west coast of Kerala and

parts of Tamilnadu. Non-traditional areas where rubber is being cultivated includes North-eastern states, Karnataka, Goa, parts of Orissa, West Bengal, Madhya Pradesh, Andhra Pradesh and Maharastra. The fruits nature and ripen during July / September months are picked up every day during this seed fall season. Seeds can also be collected by harvesting fruits at yellow brown colour stage and breaking them. Each seed weighs about 6 gm. They possess hard brown coat having characteristic mottling.

Present uses

Rubber seed oil is used for making soaps and is a substitute for linseed oil in the paint manufacturing industry. Oxidised rubber seed oil is used as anti corrosive coatings, adhesives and resins coatings. Rubber seed oil with Sulphur produces a rubber compound named as factice.

Processing industry

For a long time, only small quantity of the rubber seeds produced in India were utilized for raising stock material or as seedlings for planting. Around 2000 small quantities of seeds were used for extracting oil. Later, this activity picked up gradually with Virudhunagar in Tamilnadu as the centre of effort. Originally, the collection of seeds was confined to Kanyakumari district and then it spread to Kerala also. These seeds are now collected from the rubber growing areas of the Tamilnadu, Kerala and Karnataka states.

The increase in price of non-edible oil after 1970 gave the necessary impetus to this industry. The rubber seed oil production industry is mainly concentrated in Tamilnadu and more particularly in and around Virudhunagar. The millers in Tamilnadu have been mainly processing groundnuts. These groundnut mills function after December while the rubber seed season in India is generally between July to September. As a result it is convenient for groundnut millers to process rubber seed during slack months. The climate condition of Tamilnadu is conducive for drying rubber seed prior to crushing. During July to September it rains heavily in west coast of India while it is dry in the inland districts of Tamilnadu enabling them to dry seeds in the sun.

A few units have also come up in Kerala in recent years. Some of the units processing Cashew kernel waste are located in and around Kollam. The market price of this oil at Tamilnadu is around Rs 25 per Kg.

Estimate of oil

The rubber seed contain an oily endo sperm. Generally 37% of the seed is shell and 63% kernel by weight. The oil content of air-dried kernel is about 47%. An estimated 45000 tones of rubber seed are produced during a normal year. Around 10% of the seeds are used in plantations. The oil content in the rubber seed is about 15% of the total weight of the seed. The annual production rubber seed oil is placed around 3500 tones.

Greater the percentage of carbon and hydrogen, better is the fuel in quality and calorific value since these two constituents are responsible for heat value. Nitrogen has no calorific value and hence its presence is undesirable. For a good fuel Sulphur content should be less so that formation of oxides of Sulphur is reduced leading to minimal pollution from exhaust and corrosive effects in engine parts. In case of rubber seed oil, greater percentage of carbon and hydrogen is advantageous for higher calorific value. Besides ash and moisture content is very low leaving no deposit and heat loss on account of this during combustion. Another added advantage of rubber seed oil is the oxygen content, which reduces emission of carbon monoxide and unburnt hydrocarbon from exhaust.

The inherent properties of rubber seed oil make it suitable for use in diesel engines, as an alternate fuel. Rubber seed oil can be used as a fuel in rural area for agricultural and irrigation equipments.

Development and utilization of plant based seed oils in Indian rural areas will definitely assist in extending our crude oil reserves beyond the expected period of availability.