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Waste to Energy -
Electricity Generation
Through Rice Husk
I ndia
consumes around 3.4 per cent of global energy, which makes it the
world’s sixth largest consumer of energy. The electrification rate in
India is around 64.5 per cent. However, about 35.5 per cent of the
Indian population still does not have safe access to electricity.
Therefore, there a need is felt to search for decentralised and
renewable energy-based options to meet the rural energy needs in a
sustainable way.
The Indian government has now become active for production of safe and
green energy, with specific emphasis on Clean Development Mechanism (CDM).
For this, the Ministry of Non-Conventional Energy Sources, later renamed
as the Ministry of New and Renewable Energy (MNES), has also been set
up. The ministry has put forward many policies for effective
implementation and utilisation of renewable energy technologies in
India. Some of them are Jawaharlal Nehru National Solar Mission of
National Action Plan on Climate Change (NAPCC), Rajiv Gandhi Grameen
Vidhyutikaran Yojana (RGGVY), National Electricity Policy (NEP), The
Integrated Energy Policy of India and the National Biogas and Manure
Management Programme (NBMMP) etc1.
The renewable energy resources address the global warming and pollution
issues because these resources lead to the reduction in carbon
emissions. Non renewable energy fuels include diesel, natural gas,
kerosene, wood and coal. These non-renewable resources are expensive and
lead to the pollution in the atmosphere. Also, the continuous
exploitation of these non-renewable resources will sooner lead to the
depletion of these resources very soon. In fact different forms of
renewable energy provide safe and sustainable access to the green
energy. The carbon emissions are also negligible with no limitation for
consumption of renewable resources. The renewable energy market in India
is pegged at US$600 million, growing at 15 per cent per annum. The
Government’s renewable energy target by 2030 is 200 Gigawatts, which is
estimated to require US$200 billion in capital investment. Currently,
3.5 per cent of the installed capacity is in the renewable sector,
producing 3700 MW2.
The threat of global warming and climate change due to excessive use of
fossil fuels has increased the urgency of finding environmentally benign
ways of generating energy. India is blessed with an abundance of
non-depleting and environment-friendly renewable energy resources, such
as solar, wind, biomass, hydro-geothermal and cogeneration. Among all of
the renewable energy sources, biomass is in abundance, diversified and
readily exploitable resource. In India, among the renewable energy
options, Bio-energy technologies have been promoted to meet the rural
electricity needs of domestic, agricultural pumping and rural industrial
(such as enterprise development) activities.
Biomass For Energy
Production
The resources used for energy production should be non-conventional. The
comparison for various other resources is given below:
1. Solar energy is expensive, around Rs 400 per watt is required for its
installation;
2. Wind energy is not available everywhere; it can be established at the
place far from birds reach and wind flow and direction is good;
3. Hydro power plant is not feasible at all places because it requires
downstream availability of water. Also it requires high cost of
establishment.
4. Energy production through Biomass is a cheaper and easily available
solution. The establishments can be done from small communities at the
village level to large populated urban communities.
Rice Husk Biomass
Characteristics
India is the second largest producer of rice, which accounts for about
80 per cent of the total production in the world. In 2008 the world
paddy production was 661 million tonnes and consequently 132 million
tonnes of rice husk were also produced. Rice husk is one of the
alternative fuels because of its high potential and environmental
benefits. Rice is cultivated in almost every region of India; where
ample amount of water is available. Husk is the residue left after
processing rice husk in the mills, which accounts for approximately 20
per cent of the total rice husk produced. Hence, a large amount of rice
husk is left with no use. This husk is either dumped and brings a waste
disposal and methane emissions problem. Moreover, the inhalation of the
low density rice husk can cause it to be air-borne easily leading to the
breathing problems. However, rice husk is a waste, but still can be used
to solve many problems related with the waste. It can be used as an
additive in cement industries, for fertilisation in the fields and also
for chicken incubation in the poultry farms. However, these methods can
not solve the large scale of waste disposal problem. Hence, a proper
utilisation of husk for energy production can significantly resolve the
problem of waste disposal along with the energy loss. In fact the rice
husk can be converted into a useful form of energy to meet the thermal
and mechanical energy requirement for the mills themselves.
Rice husk can be converted into a useful form of energy to meet the
thermal and mechanical energy requirement of the mills itself because of
its high calorific value. Hence, the proper utilisation of husk into the
production of energy helps in minimising the waste disposal and
emissions problem.
Energy Production
Through Rice Husk
Conventionally, after paddy rice is processed, a huge quantity of
biomass is left as a residue in the form of rice husks. This rice husk,
when used in efficient gasification or combustion systems, has a
considerable potential to generate energy. The utilisation of rice husk
for power generation can even replace existing diesel consumption in the
rice mills for rice production. In this process of gasification, the
biomass (rice husk) is burned in control manner to produce a particular
cocktail of gases, called as the producer gas. This gas is a mixture of
carbon monoxide, nitrogen, hydrogen, carbon dioxide and a little bit of
methane. Producer gas is a combustible gas. Hence this gas is fed into a
gas engine, which drives an alternator to produce electricity. The
proper utilisation of waste into energy production has been explained by
a case study given below:
Case Study: Rice
Husk Power Plant, Bihar
After paddy rice is processed, a huge quantity of biomass is left as a
residue in form of rice husks. This rice husk, when used in efficient
gasification or combustion systems, has a considerable potential to
generate energy. This successful effort has been put forward by Husk
Power Systems (HPS), a rice husk based company with a goal to provide
affordable, reliable and environmentally sustainable energy to rural
India. They use husk as the fuel to generate electricity. Today, HPS has
installed 57 plants across 250 villages of Bihar and Uttar Pradesh.
These rice husk power plants are “mini power-plants” with the installed
capacity of 35-100 kW. HPS has planned to install 6000 plants by 2014,
which would provide electricity to around six million people. The HPS
initiative saves 42,000 litres of kerosene and 18,000 litres of diesel
per year. About 300 kg of rice husk is used as a raw material to
generate around 40 kilowatt of energy, which is sufficient to supply
energy to 500 households for 6-12 hours per day. Generally, electricity
is supplied to domestic and commercial consumers for fixed 6 - 8 hours a
day. The residual waste from the plant is also used in making incense
sticks, rubber and manure. For each Megawatt of power generated, about
5800 tonnes of carbon dioxide emission reductions can be achieved every
year.
q
Kavita
Syal
ksyal@devalt.org
Refrences
1 http://www.mnre.gov.in/
2 http://www.india-reports.com/default. aspx
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