’Wonder-Plant’ – To Reclaim Landfills and Get Fuel !

Out of thousands of unused and non-beneficial researches comes one which can give mankind the most needed solution. Recently read  one scientific publication from India on ” Phytoremediation “, which means using plants to recover a soil degraded by heavy metals, pesticides, harmful chemicals,  crude oil, methane  gas and landfill leachates. Will see shortly what is this ‘Wonder-Plant’.

Using different plants offers cost effective, nonintrusive and safe alternative to clean up soil. Different plants have been used depending upon their hardiness like Eucalyptus, vetiver grass and many more [1].  It is known that prairie grasses stimulate breakdown of petroleum products. Wildflowers were used to degrade hydrocarbons from an oil spill in Kuwait. Hybrid poplars can remove ammunition compounds such as TNT as well as high nitrates and pesticides [2]

The  mentioned article studies an indigenous hardy plant’s growth was studied in clean soil as well as municipal landfill soil to see the changes in both soil and plant.[3,4] Plants grew fast with more chlorophyll and heavy metal concentration in soil reduced largely. This is exciting. A rotten stinky landfill can be slowly reclaimed.  Several other studies are also being done to check different types of soil compositions on this plant but I find it a great solution for our exponentially increasing waste and number of landfills. This plant along with variety of grass and wild shrubs can degrade and reclaim landfills to a great extent. Other than being indigenous this hardy plant   is well suited to intense heat and sunlight and its dense network of lateral roots and thick, long taproot make it drought tolerant.  It needs very little care and cattle do not browse it. It tolerates a wide range of soil types including saline, alkaline, sandy, heavy clay and rocky soils and waterlogged soils.  Has all the general benefits of planting a green tree like cleaning the air, providing shade, check soil erosion and green manure.

 Showing plants growing in a soil from a landfill

Pongamia Pinnata (new name-Millettia pinnata  the indigenous ‘Wonder-Plant’ of India has been used for arid land reclamation for some time now. Greenleaf Energy conceived the idea of arid land reclamation in 2009 in response to the serious labour migration, drought, poverty, wasteland, unemployment in Bihar. The idea was to bring farmers back to lands which had gone bad and provide them with revenue generating farming. This was possible as the seed oil from Pongamia is used as a bio fuel. Selling it generates revenue or it can be used to power village for irrigation, making a village power self-sufficient.

A plant (seed) oil can be made into diesel by a process called trans-esterification (bio-diesel) or mixed as it is with petro-diesel (SVO-straight vegetable oil). Bio-diesel burns cleaner without harmful CO and SO2 gasses. Trans-esterification is  a process where unrefined oil is separated into clean oil and other constituents like Glycerol in the presence of a catalyst. This refined oil is used in generators, vehicles etc. Both eatable (soya, palm) and non-eatable (neem, mahua, pongamia) can be used for but preference is given to non-eatable ones.

Comparison of biodiesel and petro diesel emission properties.

Specification	Petro-diesel	Biodiesel
Engine modification	No change	No change in blends
Safety of storage	Risky since inflammable	Safe since high flash point
Combustion point (degree Celsius)	550C	1920C
Engine maintenance	Lubricant needed	Self lubricant
Exhaust gases	CO2 + CO + SO2 + NO2	CO2 + NO2
Kinematic viscosity (CentiStokes)	4.8 cSt	2.0-8.0 cSt
Calorific value (energy in joules)	48.1MJ/kg	38.86MJ/kg
Fuel price (2Q 2013)	Rs.48.00/ltr	Rs.58.00/ltr

Source: Courtesy Mr Srinivas Ghatty Tree Oils /Other

For most of us biofuel means Jatropha seed oil which is not an indigenous plant and has been brought from Mexico. Jatropha has given very little yield and has not been cost effective. We also don’t fully understand the pests and diseases that affect this plant and the way to treat them. It needs more care and investment than Pongamia plant and very little is known of their Phytoremediation properties.

One of the pioneers in this field is Tree Oil India Limited. Situated on the border of Karnataka state this plantation has around 3000 Pongamia trees.  According to Mr. Srinivas Ghatty the Managing Director who is into sustainable agroforestry for 12 years, the tree starts producing seeds after 5 years till its life span of about 100 years. Each tree on the average gives about 20 to 30 kilograms of pods per year and about 1.5 litres of oil can be extracted from about 5 kilograms of seed while cake and shell can be used as bio-fertilizer. That’s 27000 litres per year. Enough for a medium sized village’s power needs.

A very important aspect of   Pongamia bio-fuel plantation is that it  does not compete with drinking water or crop water resources as it needs very little water, making it an incredibly promising source of green fuel for vehicles and aviation. Additionally in the light of the current researches it would also not compete with agricultural land or decrease the food production since it can be grown on waste degraded lands. Many cities have planted it along roadsides too.  Pongamia also acts as an effective carbon sink, helping to safely store excess CO2 emissions through carbon sequestration. Pongamia is a Nitrogen fixing tree too. Different parts of it can be used in multiple ailments (mentioned in Charaka Sanhita too) and used in Ayurveda for long.

In a nut shell it has benefits in six broad categories of our life and our environment  . Phytoremediation, Carbon sequestration, Nitrogen balancing, Green fuel, Medicine and Employment

Few detailed uses are listed below

a) Pongamia is a high yield plant. Pongamia oil is not edible due to the presence of bitter flavonoids but has traditionally been used for lanterns, cooking stove fuel, medicines and so on.

b) The by-product of trans-esterification  process is glycerol having  multiple applications, including use in cosmetics and pharmaceuticals.

c) Pongamia seed oil  are rich in long-chain carbon compounds having oleic acid, palmitic acid, linoleic acid and others. These compounds can be used in soaps, detergents, lubricants, cosmetics, as an ointment for skin complaints, surfactants, inks, paint binders and plastics.

d) Pongamia leaves are natural pesticide and can be kept with stored grains or sprayed on crops.

e) Seed cake after oil extraction is a high nitrogen content fertilizer or “Green Manure”. It can also be fermented for ethanol production which  gives of  biogas for cooking.

f ) The bark has been used as a medicine and to produce paper pulp. Infact every part has some medicinal property.

It need not be a separate plantation as this plant can  be grown on the margins of roads and fields and in backyard gardens. This hardy tree not only provides shade from the harsh sun, but has so many other benefits. With the increasing global warming and depleting mineral oil sources, trees like the Pongamia that were always there could find a new use.

 

 

[1]Plant-Based Remediation Processes edited by Dharmendra K. Gupta, Springer 2013

[2] The Nature and Properties of Soils, 13th Edition: N.C. Brady, R.R. Weil, Prentice Hall, Upper Saddle River, NJ

Images

http://www.flowersofindia.net/catalog/slides/Pongam%20Tree.html

http://www.pongamiaplantations.com/botanical-overview.htm

 

 

• .