28-12-2012, 03:11 PM
ENERGY AUDIT IN SUGAR INDUSTRY A PASSPORT TO PROSPERITY
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ABSTRACT:
Energy audit is an important tool in transforming the fortunes of any organisation. This is
highly relevant to the sugar industry as it deals with a renewable energy source and
looked upon as rural power house. The scope for conservation is immense and if properly
harnessed can take the organisation to the path of prosperity. Energy audit becomes all
the more important in view of the energy conservation Act 2001 enacted by
Government of India and the proposed New provisions 18A(1), (2) & (3) to the Boiler
Amendment Bill – 2000 (Indian Boilers Act – 1923). A case study of the Energy audit of a
sugar factory that identified scope for saving more than Rs. 800 lakhs per annum is
illustrated as an example.
INTRODUCTION OF STATUTES FOR ENERGY CONSERVATION:
This paper is meant to highlight the importance of energy conservation to enhance the
viability of operations of sugar industry and also to prepare the industry to meet the
requirements of the proposed legislation as per Boiler amendment Bill – 2000 (Indian
Boilers Act – 1923), which envisages energy audit as mandatory in Industries.
The industrial sector in India is a major energy user accounting for more than 48% of the
commercial energy consumption in the country. The sector is becoming increasingly
energy intensive and to achieve self reliance besides looking at enhancing energy
production to meet the increasing demand, looking at ways and means of reducing the
energy requirements by improving the efficiencies of applications and operations is also
another positive way of meeting the challenge.
Taking the specific case of sugar industry there are wide variations in energy
consumption among different units using comparable technology. The energy saving
potential in sugar sector is estimated to be at least 30% of its present utilisation, making
the sector with the maximum potential in the country’s economy. The sector can easily
be termed as rural power houses and any conservation here will not only serve the cause
of national economy but also enhance the profitability and stability of the sector. This is
where the energy audit and energy norms become vital for the sugar sector as a whole.
Only to realize the potential of energy efficiency in the country, the government of India
enacted the Energy conservation act 2001 which came into force since 1st March 2001.
Under the provisions of this act, the Bureau of Energy Efficiency (BEE) has been
established with effect from 1st March 2002, to implement the provisions of the Energy
conservation act. The government of India has also been announcing fiscal incentives
for implementing energy conservation measures in all sectors.
ENERGY & SUGAR SECTOR:
In the light of the above developments, it has become the paramount need of the sugar
sector at present to become energy efficient for maximizing their profits as well as to
support the government, in their quest for additional energy resources. Any
augmentation from sugar sector will be a boon to any national economy as it will not be
at the expense of their fossil reserves. Therefore for every unit in the sugar sector, a self
introspection in the form of a detailed energy audit will do a world of good at this
juncture, without waiting for the intervention of statutes. In this context, sharing of
experience based on the energy audits carried out and the improvement made in some
of the sugar factories in our country will be very useful.
STEAM GENERATION:
At the outset the steam and power production areas will be highlighted before going
into the details of energy consumption areas. For steam production bagasse being the
only fuel, it is very important to ensure that uniform feed of the fuel of not exceeding 50%
moisture content is assured always to the boilers. More than 60% of the factories in India
work with Boiler systems of less than 20 kg/sq.cm pressure rating. Whatever may be the
operating parameters of the boilers, the need for maintaining the boilers in excellent
health to work at the rated efficiencies does not require over emphasis. Typically in a well
maintained boiler there is a variation of 0.8% in the efficiency of boiler for every
percentage of moisture variation in bagasse. A moisture level of 50% in bagasse is
generally taken as the benchmark as all the sugar mills as well as boiler manufacturers
adopt this for their designs. Though bagasse drying can improve boiler efficiency further,
it has to be carefully planned in the heat balance of the plant, while optimizing the
power cycle.
POWER GENERATION:
While dwelling on Energy audit, it will be relevant to highlight the importance of
improving productivity of bagasse. The foregoing discussions and case study have
established the fact that how moisture % in bagasse is a critical factor in enhancing the
productivity of bagasse in addition to efficient boiler conditions. Modern high efficiency
boilers of high pressure designs i.e. pressures upwards of 45kg/cm2 aim at an efficiency
of 70% plus for bagasse firing, and with these boilers productivity of bagasse is further
increased with the increase of operating pressures. Adopting higher pressure power
cycle will increase the power output from the same bagasse. For example 100 kg of
bagasse can produce the following power output.
RAW WATER:
Utilisation of raw water in the factory ranges from 75% to 110% on cane as against the
optimum of 25%. Two bore pumps of 30 kW capacity each, running at 70% loading
continuously operate for meeting the water requirement of the factory. In addition to this
2 more similar pumps continuously operate to meet the distillery’s requirements. The
enormous wastage of water and power in this area can be successfully controlled by
proper planning. There is potential to save at least 60 kW of power in this area, which will
save a wastage of about Rs.7.2 lakhs per annum.
Conclusion:
Energy audit is a very important tool in transforming the fortunes of any organisation.
Norms should be set and continuously reviewed during the course of operations, just as
any other financial or production or commercial parameters.
As seen in this write up, the huge potential for savings, if properly harnessed can take any
organisation to the path of prosperity. Particularly where cogeneration of power is
involved in a sugar industry, every unit of power saved and every ton of bagasse saved
adds to the additional revenue of the organisation.
Potential for energy conservation in sugar industry is immense because of the fast
developments that are taking place in the industry as well as the traditionally
conservative outlook of the Industry in India and their present status. This paper highlights
only a few important areas that has come to light during the audit of different factories.
There may be many more areas uncovered by this report typical to individual units. That
the potential for saving more than Rs.800 lakhs per annum in one factory has been
identified does not reflect that the same state of affairs will exist in all. It will be different in
different places and there are bound to be concern areas in all places if honestly looked
into, since no one could claim to have reached the state of perfection.