Sunday 15 June 2008

Oil price rise for the good?

Oil price rise should be a reminder that we cannot continue to use petroleum products lavishly. Under the current rate of petroleum usage, the world reserves shall last for about 30 years only.

What is the solution?

Reduce the usage of petroleum products to the least possible. More emphasis should be given to explore renewable energy sources and should encourage more people to use non conventional energy sources. There will be international pressure to cut oil subsidies because of the subsidised oil prices in developing countries like China & India, the demand for petroleum is rapidly increasing. So better we act soon to utilise renewable energy sources.

How to reduce petroleum usage?

* Improve public transport system by introducing mass rapid transit systems and discouraging use of private vehicles.

* Reduce congestion on roads - maintain wider roads and good road surfaces.

* Use alternative sources of energy wherever petroleum products are used.

Biofuel is the buzzword now for renewable energy which can replace petroleum products. Biodiesel and ethanol can be mixed with existing fuels in vehicles and oil companies are promoting them to sustain their business further, whereas biogas or bio methane is found to be the cleanest among biofuels – considering the energy requirements (thereby pollution) for extracting the fuel from various sources.

Biogas – three birds in one shot

Biogas or bio-methane is produced through the anaerobic decomposition of organic materials by certain bacteria. A wide range of materials can be used as feedstock in biogas plants like municipal solid wastes & waste water, cellulose materials like parts of green plants (including aquatic weeds water hyacinth & duckweed), non edible oil cakes, starchy kitchen wastes, human & animal wastes, etc.

By reusing the wastes generated by people as an energy source, we will be saving a lot of resources and at the same time solving the menace of processing those wastes. Another added advantage is that we will able to reduce the green house gas emissions by trapping the biogas which would otherwise be lost from landfills. We can sell the carbon credits earned this way to companies who want to lower their carbon footprint.

Plastic wastes can also be reused as fuel. Plastics, being derived from petroleum, have the energy content similar to petroleum fuels and it also a good opportunity which can be explored.

Governments should ensure that the dependence on petroleum imports is at the minimum, by promoting renewable energy sources (not just for electricity generation) to the maximum extend. The people should be advised on the benefits to the current and future generations by using alternate sources.

Tuesday 13 May 2008

Biofuel: Duckweed Vs Soybean

Soybean and other edible crop produce being diverted to bio fuel projects are of great concern for the people around the world as the food prices are rocketing. In this context, it will be worth considering different species of weeds commonly called duckweeds, as they show great potential in this regard as replacement for soybean.

Duckweeds are small, fragile, free floating aquatic plants that grow ubiquitously on fresh or polluted water throughout the world. When conditions are ideal, it’s biomass can double every 1-2 days. The diluted slurry from biogas digesters was found to be a good medium for the growth of duckweed. Duckweeds were also being used by some farmers as a protein rich food supplement for cattle, poultry and fish. In aquaculture, it can assist in controlling the algae growth, which denies oxygen for fishes. Duckweed is eaten by people also, mainly in Thailand. Some of their species are being used for medicine is countries like China.


Advantages of duckweed compared to soybean

* Duckweeds are as good as or better than soybean as cattle, poultry, aquaculture feed.

* Duckweeds give many times more protein yield per hectare compared to soybean.

* Duckweed protein has higher concentrations of the essential amino acids, lysine and methionine, than most plant proteins and more closely resembles animal protein in that respect.

* Duckweeds can be grown in wastewater and can be harvested daily.


Another important use for duckweed is in waste processing. Duckweeds are being used in water treatment plants as they have the potential to purify both domestic and industrial wastewater that too at minimal cost of operation. They also help in recovering mineral nutrients which would otherwise be lost with the wastewater.

There is widespread research interest on generating bio-fuels from duckweeds. We have made advances in production of biogas from aquatic plants like water hyacinth and duckweeds can be easily harvested compared to algae or other aquatic plants. Until better techniques are developed for generating ethanol or biodiesel from duckweeds, generating biogas from duckweed will be the attractive utilisation (in fact biogas is being used in buses, cars and trains in Linköping, Sweden)

So I am envisioning decentralised waste treatment plants in which wastes (organic wastes & wastewater) are being fed into a biogas plant where the wastes are subjected to anaerobic decomposition resulting in odour free, germ free slurry plus of course methane gas. This slurry shall be fed to ponds where duckweeds are grown may be along with fish. Duckweeds should be harvested daily from the pond and shall be fed into biogas plant after pre-treatment.

References:

http://en.wikipedia.org/wiki/Duckweed
http://www.fao.org/ag/againfo/resources/documents/DW/Dw2.htm
http://www.cpcb.nic.in/News%20Letters/Archives/R&D%20for2003/pollutioncontrol.html
http://www.mobot.org/jwcross/duckweed/practical_duckweed.htm
http://www.naturia.per.sg/buloh/plants/duckweed.htm
http://www.herbvideos.com/globald.htm#Duckweed
http://www.carbon-connections.org/downloads/Biofuel%20from%20duckweed%20case%20study.pdf


Picture from http://www.fractalnature.com/duckweed.html

Tuesday 5 February 2008

Why not Biogas with LPG?

LPG shortage is bothering all the LPG consumers these days. Biogas systems using kitchen wastes can supplement the LPG in our households leading to the saving of at least half of LPG consumed. Families depending on LPG alone who may use a cylinder (14.2kg) a month can extend the cylinder usage for another month if the biogas is also utilised, which means that the investment on biogas can be paid back in about 3 years considering the subsidies also. If we add other feedstock like non-edible oil cakes along with kitchen waste we will get more biogas.

A domestic biogas system will cost about Rs.9,000 for a medium size family. If the Government can subsidise the biogas plants to such an extend that it is attractive for all households, it will be beneficial for the country in many ways. It may be noted that the Government is spending Rs.311 per cylinder as subsidy (The Hindu Feb 5, 2008) for domestic consumers. The various benefits are as follows.

• Can reduce the demand for LPG – saves fossil fuel, reduces dependence on imported petroleum thereby saving foreign exchange.

• Better solution for disposal of kitchen waste without stench – better environment, reduces the burden on the waste processing by Municipalities / Corporations.

• The slurry produced by the biogas plants is known to be good fertiliser – better for agriculture also.

• Utilisation of clean energy which might otherwise be lost.

Awareness should be created among the public on the economical and other benefits of domestic biogas plants.


Read also:

ARTI Biogas Plant: A compact digester for producing biogas from food waste
The Ashden Awards for Sustainable Energy | 2007 International Finalist: BIOTECH, India

Wednesday 2 January 2008

My Blog in Malayalam

I have created a new blog in Malayalam

http://keralanamaskar.blogspot.com/


Please visit and comment.
There was an error in this gadget