The Future of Biofuel

It must have been 40° C + outside, but when you spot this tree, it provide a nice green canopy and offer a cool, soothing welcome despite of the heat. Indian Beech tree, Karanj or Pongam tree (Millettia Pinnata/करंज) is an ever-green, moderated sized tree.

Pongam tree is very beautiful tree with attractive, showy, fragrant flowers; borne on racemes, are pink, light purple or white in colour. It attracts many small birds and butterflies like the Cerulean, Blue Tiger & Common Crows. They are considered good sources of pollen for honey bees. Many of these trees are just coming into bloom in the city. The flowers and new leaves generally appear together. When the trees are in flower the ground below them is usually carpeted with blooms. The flowers are used by gardeners as compost for plants requiring rich nutrients.

It is a very hardy tree and can adapt itself to varying conditions. Pongam tree can grow on most soil types ranging from stony to sandy to clayey, including Verticals. It does not do well on dry sands. It is highly tolerant of salinity and is an ideal candidate for saline soil reclamation. It is common along waterways or seashores, with its roots in fresh or salt water.

The tree is well suited to intense heat & sunlight and its dense network of lateral roots and its thick, long taproot make it drought-tolerant. The dense shade it provides slows the evaporation of surface water and its root nodules promote nitrogen fixation. Pongam tree is one of the few nitrogen fixing trees to produce seeds containing 30-40% oil.

The seeds has variety of uses. It yields thick reddish oil used for burning and for skin diseases as having bactericidal and anti-fungal properties. It also is very effective against white flies, mites and other sucking pests in all crops. In fact, almost every step in the life cycle of Pongam seeds results in a safe and useful product. Once the oil has been extracted from the seeds, the remaining seed-cake can be mixed with water and placed in an airtight environment where it ferments, producing a flammable gas and a slurry, which is a safe and highly effective organic fertilizer. The gas can be compressed and stored in small tanks for use as cooking fuel. (Biogas burns far cleaner than wood or cow dung, the traditional cooking fuels, and so causes fewer respiratory disorders.) Widespread use of gas for cooking could also help curb the rampant deforestation common to areas where wood is used as a primary fuel. The seed-cake has other uses as well.

Incorporation of leaves and the seed-cake into soils improves fertility. Dried leaves are used as an insect repellent in stored grains. The seed-cake, when applied to the soil, has pesticidal value, particularly against nematodes. Pongam tree is a fast growing tree which gives valuable fodder for livestock, especially in arid regions. They are also used as green manure. String and rope can be made from the bark fiber.

If that's not enough, the oil can also be used as Biodiesel in motor engines! Or rather, it is being used worldwide. Even in India, the Karnataka state transport department has operated buses on a diesel blended with 30% Pongam oil.

On a global scale, biofuels reduce the net emission of greenhouse gases, especially carbon dioxide. While it is true that any burning fuel releases carbon into the atmosphere, fossil fuels are composed of carbon previously stored below the earth’s surface in the form of oil, natural gas & coal, and as they burn they release a new load of carbon into the air. On the other hand, the carbon content of biofuels like Pongam oil has been taken directly from the atmosphere as the tree grows- on average, one hectare (2.47 acres) of Pongam tree absorbs 30 tons of carbon per year. Thus burning Pongam oil instead of fossil fuels has the overall effect of reducing carbon dioxide emissions by about 75% and carbon monoxide emissions by almost 50%. So planting Pongam tree may even help slow global warming.

The Pongam tree is easily raised from seeds. It is often planted in homesteads as a shade or ornamental tree and in avenue plantings along roadsides and canals. It is a preferred species for controlling soil erosion and binding sand dunes because of its thick long taproot and network of lateral roots.

In the traditional systems of medicines, Ayurveda and Unani, it is described that the tree possesses medicinal properties. Be it its root, bark, leaf, sap or flower. The tree is used as anti-inflammatory, anti-plasmodial, anti-hyperglycaemic, anti-lipidperoxidative, anti-diarrhoeal, anti-ulcer, anti-hyperammonic and antioxidant agent.

Pongam tree will do more than provide a steady source of biofuel; adult trees create shade and fix nitrogen in the soil, revitalizing scrubland into thriving fields from which farmers can maintain their livelihood.