1. PROJECT
ESTIMATION OF BIOMASS RESOURSES IN
DIFFERENT VILLAGES OF W.B AND BIHAR.
1. INTRODUCTION :Biomass has always been an important energy source for the country considering the benefits it
offers. It is renewable, widely available, carbon-neutral and has the potential to provide
significant employment in the rural areas. Biomass is also capable of providing firm energy.
About 32% of the total primary energy use in the country is still derived from biomass and more
than 70% of the country’s population depends upon it for its energy needs. Ministry of New and
Renewable Energy has realised the potential and role of biomass energy in the Indian context
and hence has initiated a number of programmes for promotion of efficient technologies for its
use in various sectors of the economy to ensure derivation of maximum benefits Biomass power
generation in India is an industry that attracts investments of over Rs.600 crores every year,
generating more than 5000 million units of electricity and yearly employment of more than 10
million man-days in the rural areas. For efficient utilization of biomass, bagasse based
cogeneration in sugar mills and biomass power generation have been taken up under biomass
power and cogeneration programme.
Biomass power & cogeneration programme is implemented with the main objective of
promoting technologies for optimum use of country’s biomass resources for grid power
generation. Biomass materials used for power generation include bagasse, rice husk, straw,
cotton stalk, coconut shells, soya husk, de-oiled cakes, coffee waste, jute wastes, groundnut
shells, saw dust etc.
With the largest rural population in the world, India is facing a huge electrification challenge.
Today, 64.5% of India is electrified, with an electrification rate of 93.1% in urban settings but
only 52.5% in rural areas. This has been achieved mainly through grid extension or small-scale
renewable energy systems. Strong political will and sufficient funds have, since the beginning of
the 11th Five-Year Plan, accelerated the speed of electrification.
But India is currently faced with insufficient electricity generating capacity, which is
seriously hindering the implementation of future rural electrification programmes and
undermining their viability.
2. At the present status of our country, un electrified households are very high in Bihar,
Jharkhand, and Orissa, UP, NE, West Bengal, and Chattisgarh.
In this thesis I have tried to give electricity for few hours to the village through Biogas by
using the raw materials (like, cow dung, house waste, paddy straw etc.) from that certain village.
The generation of electricity through biogas is cheaper than other mode of electricity
generation. After an initial investment in the system, there is no need to spend money on fuel.
On the other hand, in these types of energy generation we can get clean energy. This energy
generation process is also eco friendly than any other mode of energy generation technique.
In this thesis I have tried to give electricity for almost 3 or 4 hours to each house of two
villages namely, Ramnagar (Hooghly District) of West Bengal and Behea (Bhojpur District) of
Bihar.
For electrification of these two villages I have used Biogas!!
2. Status of Rural Electrification in West Bengal & Bihar
The economy of a developing country depends on growth in industry, agriculture, service,
information & technology and infrastructure sector. The major input required for the growth of
these sectors is power or electricity. Power also plays an important role in social sectors such as
health and education. At present power has become an essential requirement for all walks of the
life.
A village was considered to be electrified if the electricity is being used within its revenue area
for any purpose whatsoever prior to October 1997. After October 1997, the definition of
electrified village was modified and it stated that a village should be classified as electrified if
the electricity is being used in the inhabited locality, within its revenue area for any purpose
whatsoever. These two definitions of electrified village were so vague that if even one household
uses electricity or within inhabited locality electricity used for any purpose irrespective of
number of users exist in the village than village used to consider as electrified.
In reality, the electrification of villages, which had been carried out as per definitions stated
above, did not serve any purpose and did not contribute to any betterment of rural people who
constitute more than 70 percent of total population.
3. “A village is termed as electrified provided
Number of households electrified should be at least 10% of the total number of
households in the village.
Electricity is provided to public places like schools, Panchayat offices, health centers,
dispensaries, community centers, etc. and
Basic infrastructure such as distribution transformers and distribution lines are provided
in the inhabited locality as well as the dalit basti/hamlet where it exists. (For
electrification through non-conventional energy sources a distribution transformer may
not be necessary)”
With implementation of this definition, the number of un-electrified villages has increased. To
judge the ground situation, the data of Census of India, 2003, which provides the data on source
of lighting (i.e. electricity, kerosene, solar energy, and other oils, any other as source of lighting)
used at household level by villages, can be used.
From 2003 census data, one can estimate the number of un-electrified villages which does not
meet the criterion of at least 10 % of total number of households electrified in the village. This
estimated number of un-electrified villages is likely to increase if all the three criterions are
applied.
Table showing Rural Electrification of West Bengal and Bihar
State
Total no. of
No. of unelectrified
households in
households in
villages
villages
West Bengal
11161870
8899353
79.7
Bihar
12660007
12010504
94.9
Source: Ministry of Power, Courtesy: Powerline 2/2005
% unelectrified
4. 2.1 Rural Households Electrification (as per 2001 census)
Total No. of rural households : 111,61,870
Households electrified : 22,62,517
%age of electrified rural households : 20.27%
2.2 Village Electrification in West Bengal
Total No. of inhabited villages : 37910
No. of villages reported as electrified : 32271
%age of Villages Electrified : 84%
In West Bengal, out of 37910 villages there were 2275 villages where none of the households
had the access to electricity and 3,791 villages having less than 10% of households using
electricity. Thus as per present definition, in 2001, there were 6066 un-electrified villages in the
state accounting for 16 % of total villages.
2.3 Rural Household Electrification (as per 2001 census)
Total no. of rural households : 126,60,007
Households electrified : 6,49,503
%age of electrified rural households : 5.13%
2.4 Village Electrification in Bihar
Total No. of inhabited villages: 67513
No. of villages reported as electrified : 48280
%age of village electrification : 71.5
In Bihar, out of 67513 villages there were 17317 villages where none of the households had the
access to electricity and 1924 villages having less than 10% of households using electricity. Thus
as per present definition, in 2001, there were 19241 un-electrified villages in the state accounting
for 28.5 % of total villages.
5. To solve this problem of unelectrified households of villages in West Bengal and Bihar, an
attempt has been made the estimate of electrification through Biogas resources.
3. Electrification of Village through Biogas
The data is analysed by using various parameters such as size of village, percentage of electrified
households in the village etc. To know about the present scenario/status of electrification the data
can be updated at village level and can be monitored efficiently and effectively. The present
status of electrification of villages and households is also provided in above chapters for
convenience of user of this report.
I hope that this paper may provide inputs to planners to prepare the strategy to achieve the goals
at various levels and to provide electricity to more number of villages and households in more
economical way.
3.1 Estimate of Electricity generation from biomass in Village Ramnagar
(Hooghly)
The number of houses in Ramnagar = 2000(approx)
In each house there are 2 no. of cow (Avg)
Each cow is giving 9kg – 10kg cow dung. (Avg)
Therefore,
From each house we are getting 18 – 20kg cow dung
From each house we are getting 900gm – 1 kg house waste.
From each house we are getting Paddy straw according to season
From each house we are getting Paddy straw according to season
In Ramnagar village total area 4500 Ekar, within this area 3000 Ekar is used for Paddy.
Now,
1 Ekar = 3 bigha
3000 Ekar = 3000 * 3 bigha = 9000 bigha
6. We are getting Boro Paddy 14 mon (Avg) from one bigha as per details given by villagers who
is cultivating Paddy in their fields.
From total Ramnagar village within these 4 months we are getting
= 9000 * 14 mon Paddy
= 126000 mon Paddy
And we know,
1 mon = 40 kg
i.e. 126000 mon = 126000*40kg
= 5040000 kg
And From 100 kg Paddy we are getting 40 kg straw (after threshing the Paddy)
Than, From 1 kg Paddy we are getting
= 40/100 kg Straw
So From 5040000 kg Paddy we are getting
= 40*5040000/100
= 2016000 kg straw
= 2016 ton straw.
From September to October (2 months) – Kalma Paddy
From Ramnagar village we are getting Kalma Paddy 8 mon (Avg) from 1 bigha.
Therefore, From total village we are getting
= 8*9000 mon
= 72000 mon
= 72000*40 kg (1 mon = 40 kg)
= 2880000 kg
And From 100 kg Paddy we are getting 40 kg straw (after threshing the Paddy)
Than, From 1 kg Paddy we are getting
= 40/100 kg Straw
So From 2880000 kg Paddy we are getting
7. = 2880000*40/100
= 1152000 kg straw
= 1152 ton straw
From February to April (3 months) – Aman Paddy
From Ramnagar village we are getting Aman Paddy 10 mon (avg) from 1 bigha
Therefore, From total village we are getting
= 10*9000 mon
= 90000 mon
= 90000*40 kg (1 mon = 40 kg)
= 3600000 kg
And From, 100 kg Paddy we are getting 40 kg straw (after threshing the Paddy)
Than From 1 kg Paddy we are getting
= 40/100 kg straw
So From 3600000 kg Paddy we are getting
= 40*3600000/100 kg straw
= 1440000 kg straw
= 1440 ton straw
In Ramnagar village total no. of houses 2000 (approx)
We are getting Raw materials of Biogas (Per day) –
1. Cow dung (2000*18) kg/day
= 36000 kg/day
= 36 ton/day (Avg)
2. House waste (1*2000) kg/day
= 2000 kg/day
= 2 ton /day (approx)
3. Paddy straw From May to August (4 months)
We are getting Paddy straw
= 2016 ton
4 months = 4*30 days =120 days
So we are getting Paddy straw
8. = 2016/120 ton/day
= 16.8 ton/day
= 17 ton/day (approx)
4. Paddy straw From September to October (2 months)
We are getting Paddy straw = 1152 ton
2 months = 2*30 days = 60 days
So we are getting Paddy straw
= 1152/60 ton/day
= 19.2 ton/day
= 19 ton/day (approx)
5. Paddy straw From Febraury to April (3 months)
We are getting Paddy straw = 1440 ton
3 months = 3*30days = 90 days
So we are getting Paddy straw
= 1440/90 ton/day
= 16 ton/day (approx)
Now, from (May- August)
Total feed stalks (Cow dung, House waste, Paddy straw)
= (36 +2+17) ton/day
= 55 ton/day
BIOGAS
55 ton/day (feed stalks)
↑
—————————→ DIGESTOR —————→ Digested (waste)
From, (Sep-Oct)
Total feed stalks (Cow dung, House waste, Paddy straw)
= (36+2+19) ton/day
= 57 ton/day
From, (Feb-April)
9. Total feed stalks (Cow dung, House waste, Paddy straw)
= (36+2+16) ton/day
= 54 ton/day
From, (Nov-Jan)
Total feed stalks (Cow dung, House waste, Paddy straw)
= (36+2) ton/day
= 38 ton/day
1. Now From –May to August
Total feed stalks = 55 ton/day
Type
Quantity
*Sp. Gas quantity Generated Gas
(ton/day)
(Normal m3/ton)
(m3/day)
1.Cow dung
36
43
1548
2. House waste
2
270
540
3. Boro Paddy
17
277
4709
* This specific values are got from Biomass Gasification Industry
Therefore Total Generated Gas = (1548+540+4709) m3/day = 6797 m3/day
2. From – September to October
Total feed stalks = 57 ton/day
Type
Sp. Gas quantity
Generated Gas
(ton/day)
1. Cow dung
Quantity
(Normal m3/day)
(m3/day)
36
43
1548
2. House waste
2
270
540
3. Kalma Paddy
19
277
5263
Total Generated gas = (1548+540+5263) m3/day = 7351 m3/day
3. From –February to April
10. Total feed stalks = 54 ton/day
Type
Sp. Gas quantity
Generated Gas
(ton/day)
1. Cow dung
Quantity
(Normal m3/day)
(m3/day)
36
43
1548
2. House waste
2
270
540
3.Aman Paddy
16
277
4432
Total Generated Gas = (1548+540+4432) m3/day = 6520 m3/day
4. From – November to January
Total feed stalks = 38 ton/day
Type
2. House waste
Sp. Gas quantity
Generated Gas
(ton/day)
1. Cow dung
Quantity
(Normal m3/day)
(m3/day)
36
43
1548
2
270
540
Note: There is no cultivation of Paddy between Novembers to January in Ramnagar village
Hooghly (data collected through door to door visit in village).
Total Generated Gas = (1548+540) m3/day = 2088 m3/day
From (1m3) Biogas we can get (2kWh) Electricity
1. During May to August:
1 m3 Biogas = 2kWh Electricity
: 6797 m3 Biogas = (6797*2) kWh/day
= 13594 kWh/day
Therefore per house will get 13594/2000 kwh/day
= 6.797kwh/day
= 7kwh/day (approx.)
Now, 7kWh=7000watt h=4.8*60 watt*24 hour
11. Therefore, each house will get 5 no. of 60 watt bulb for 24 hours.
2.
During September to October:
1 m3 Biogas = 2kWh Electricity
: 7351 m3 Biogas = (7351*2) kWh/day
= 14702 kWh/day
Therefore per house will get 14702/2000 kwh/day
= 7.3kwh/day
Now, 7.3 kWh=7300 watt h=5*60watt*24 hour
Therefore, each house will get 5 no. of 60 watt bulb for 24 hours.
3.
During November to January
1 m3 Biogas = 2kWh Electricity
: 2088 m3 Biogas = (2088*2) kWh/day
= 4176 kWh/day
Therefore per house will get 4176/2000kWh/day
= 2.088 kWh/day
Now, 2.088kWh=2088watt h=1.45*60watt*24hour
Therefore, each house will get 1 no. of 60 watt bulb for 24 hours.
4.
During February to April
1 m3 Biogas = 2 kWh Electricity
: 6520 m3 Biogas = (6520*2) kWh/day
= 13040 kWh/day
Therefore per house will get 13040/2000kWh/day
= 6.52kWh/day
Now, 6.52kWh=6520watt h=4.5*60watt*24hour
Therefore, each house will get 4 no. of 60 watt bulb for 24 hours.
12. 3.2 Estimate of Electricity generation from biomass in Village Behea
(Bhojpur, Bihar)
The number of houses in Behea = 1500(approx)
In each house there are 2 no. of cow (Avg)
Each cow is giving 9kg – 10kg cow dung. (Avg)
There fore,
From each house we are getting 18 – 20kg cow dung.
From each house we are getting 900gm – 1 kg house waste.
From each house we are getting Corn stalk according to season
From January to May (5 months) – Maize
In Behea village total area 4500 Ekar, within this area 3000 Ekar is used for Maize.
Now,
1 Ekar = 3 bigha
3000 Ekar = 3000 * 3 bigha = 9000 bigha
From 1 bigha Field cultivation we are getting
= 25 Quintals Maize (Approx)
= 2500 kg (1 Quintal = 100kg)
And from 1 kg Maize we are getting
= 450 grms Corn stalk (Agricultural waste, after threshing the Maize)
So from 2500 kg Maize we are getting
= 2500*450 grms
= 1125000 grms Corn stalk
= 1125 kg Corn stalk
Now, from 1 bigha we are getting 1125 kg Corn stalk
= 1.125 ton Corn stalk
Therefore from 9000 bigha we are getting
= 9000*1.125 ton Corn stalk
= 10125 ton Corn stalk
From June to September (4 months) – Paddy
13. In Behea village we are getting Paddy 15 mon (Avg) from 1 bigha.
Therefore, From total village we are getting
= 15*9000 mon
= 135000 mon
= 135000*40 kg (we already know 1 mon = 40 kg)
= 5400000 kg
And From 100 kg Paddy we are getting 40 kg straw (after threshing the Paddy)
Than, From 1 kg Paddy we are getting
= 40/100 kg Straw
So From 5400000 kg Paddy we are getting
= 5400000*40/100
= 2160000 kg straw
= 2160 ton straw
From October to December (3 moths) – other cultivation on fields
In this period mostly villagers are growing or Harvesting different crops like potatos, onions,
garlic, carrot, reddish, ginger e.t.c as weather is suitable for these types of cultivations.
(According to data collected from Behea village by door to door visit)
In Behea village total no. of houses 1500 (approx)
We are getting Raw materials of Biogas (Per day) –
1. Cow dung (1500*20) kg/day
= 30000 kg/day
= 30 ton/day (Avg)
2. House waste (1*1500) kg/day
= 1500 kg/day
= 1.5 ton /day (approx)
3. Paddy straw From June to September (4 months)
We are getting Paddy straw
= 2160 ton straw
& we know 4 months = 4*30 days =120 days
So we are getting Paddy straw
= 2160/120 ton/day
14. = 18 ton/day
= 18 ton/day (approx)
4. Corn stalk From January to May (5 months)
We are getting Corn stalk
= 10125 ton
And 6 month = 6*30 days = 180 days
So we are getting in these 6 months
= 10125/180 ton/day
= 56.25 ton/day Corn stalk
= 56 ton/day Corn stalk
Now, From January to May
Total feed stalks (Cow dung, House waste, Corn stalk, Paddy straw)
= (30 +1.5+56) ton/day
= 87.5 ton/day = 88 ton/day (approx)
BIOGAS
88 ton/day (feed stalks)
↑
—————————→ DIGESTOR —————→ Digested (waste)
Total feed stalks = 88 ton/day
Type
Quantity
Sp. Gas quantity
Generated Gas
(ton/day)
(Normal m3/ton)
(m3/day)
1.Cow dung
30
43
1290
2. House waste
1.5
270
405
3. Corn stalk
56
275
15400
Therefore total Generated Gas = (1290+405+15400) m3/day = 17095 m3/day
Now from June to September
Total feed stalks (Cow dung, House waste, Corn Stalk, Paddy straw)
= (30 +1.5+12) ton/day
15. = 43.5 ton/day = 44 ton/day (approx)
Type
Quantity
(ton/day)
Sp. Gas quantity
3
(Normal m /ton)
Generated Gas
(m3/day)
1.Cow dung
30
43
1290
2. House waste
1.5
270
405
3. Paddy
12
277
3324
Therefore total Generated Gas = (1290+405+3324) m3/day = 5019 m3/day
Now from October to December
Total feed stalks (Cow dung, House waste, Corn Stalk, Paddy straw)
= (30 + 1.5) ton/day
= 31.5 ton/day = 32 ton/day approx
Type
Quantity
Sp. Gas quantity
Generated Gas
(ton/day)
(Normal m3/day)
(m3/day)
1. Cow dung
30
43
1290
2. House waste
1.5
270
405
Therefore total Generated Gas = (1290+405) m3/day = 1695 m3/day
From (1m3) Biogas we can get (2kWh) Electricity
1. From January to May
1 m3 Biogas = 2kWh Electricity
: 17095 m3 Biogas = (17095*2) kWh/day
= 34190 kWh/day
Therefore per house will get 34190/1500 kWh/day
= 22.797kWh/day
= 23 kWh/day (Approx.)
Now, 23kWh = 23000watt h = 15*60 watt*24 hour
16. Therefore, each house will get 15 no. of 60 watt bulb for 24 hours. Or 9 no. of 100 watt bulbs for
24 hours (Approx)
2. From June to September
1 m3 Biogas = 2kWh Electricity
: 5019 m3 Biogas = (5019*2) kWh/day
= 10038 kWh/day
Therefore per house will get 10038/1500 kWh/day
= 6.692 kWh/day
= 7 kWh/day (Approx.)
Now, 7kWh = 7000watt h = 4.8*60 watt*24 hour
Therefore, each house will get 5 no. of 60 watt bulb for 24 hours. Or 3 no. of 100 watt bulbs for
24 hours (Approx)
3. From October to December
1 m3 Biogas = 2kWh Electricity
: 1695 m3 Biogas = (1695*2) kWh/day
= 3390 kWh/day
Therefore per house will get 3390/1500 kWh/day
= 2.26 kWh/day
= 2 kWh/day (Approx.)
Now, 2kWh =2000watt h = 1*60 watt*24 hour (Approx)
Therefore, each house will get 1 no. of 60 watt bulb for 24 hours. Or may not be get because
Efficiency of Electricity through Biogas is only about 90 %.
17. 4. Utilities
4.1
POTENTIAL
The current availability of biomass in India is estimated at about 500 millions metric tones per
year. Studies sponsored by the Ministry has estimated surplus biomass availability at about 120
– 150 million metric tones per annum covering agricultural and forestry residues corresponding
to a potential of about 18,000 MW. This apart, about 5000 MW additional power could be
generated through bagasse based cogeneration in the country’s 550 Sugar mills, if these sugar
mills were to adopt technically and economically optimal levels of cogeneration for extracting
power from the bagasse produced by them
4.2 TECHNOLOGY
4.2.1
Combustion
The thermo chemical processes for conversion of biomass to useful products involve
combustion, gasification or pyrolysis. The most commonly used route is combustion. The
advantage is that the technology used is similar to that of a thermal plant based on coal, except
for the boiler. The cycle used is the conventional ranking cycle with biomass being burnt in high
pressure boiler to generate steam and operating a turbine with generated steam. The net power
cycle efficiencies that can be achieved are about 23-25%. The exhaust of the steam turbine can
either be fully condensed to produce power, or used partly or fully for another useful heating
activity. The latter mode is called cogeneration. In India, cogeneration route finds application
mainly in industries.
10MW Gaya Biomass Based Power Plant - Bihar - Construction Project
18. 4.2.2 Cogeneration In Sugar Mills
Sugar industry has been traditionally practicing cogeneration by using bagasse as a fuel. With
the advancement in the technology for generation and utilization of steam at high temperature
and pressure, sugar industry can produce electricity and steam for their own requirements. It
can also produce significant surplus electricity for sale to the grid using same quantity of
bagasse. For example, if steam generation temperature/pressure is raised from 400oC/33 bar to
485oC/66 bar, more than 80 KWh of additional electricity can be produced for each ton of cane
crushed. The sale of surplus power generated through optimum cogeneration would help a sugar
mill to improve its viability, apart from adding to the power generation capacity of the country.
30 MW Bagasse Cogen project at a Sugar Mill in Bihar
19. 5. Instrument Needed for a Biomass Plant
5.1 Boilers
A number of large manufacturers have established capabilities for manufacturing spreader
stoker fired, traveling grate/dumping grate boilers; atmospheric pressure fluidized bed boilers
and circulating fluidized bed boilers.
Due to recent upsurge of interest in co-generation for surplus power, leading
manufacturers are further upgrading their capabilities for high efficiency boilers.
5.2
Steam Turbines
Almost all combinations – condensing, single extraction/double extraction condensing, back
pressure, etc. are now being manufactured in the country with full after sales services. The
efficiencies of turbines now being offered are comparable to the best in the world.
5.3 Gasifiers
A gasifier is a piece of equipment that burns organic fuel in an oxygen-starved environment. This
produces carbon monoxide, hydrogen and methane, and small amounts of other organic
products. The carbon monoxide, hydrogen and methane are the main components that are
subsequently oxidized as fuel to produce heat.
Stokers can burn many types of fuels individually or in combination. Some operate similar to a
gasifier with a deep bed of fuel on the grate. The bed can be burned in a low oxygen environment
with undergrate air. Overfire air completes the combustion higher in the furnace. The advantage
is a reserve of fuel in the boiler, ready to pick up an increase in steam demand. A rapid decrease
in steam demand is attained by reducing undergrate air and fuel under controlled conditions.
5.4 Contaminants, Emissions
Contaminants such as potassium, sodium, chlorides, silica and phosphorus can create havoc in a
boiler without proper design and chemistry. Variation in fuel type, fuel quality, season and
moisture will create operational issues.
Sodium, potassium and phosphorus can cause slagging due to the reduction in the ash melting
point. Chlorides from salts or plastics can cause corrosion, slagging and hydrogen chloride
20. emissions. Silica may cause slagging and erosion. Sulfur produces sulfur dioxide emissions,
sulfur trioxide emissions and cold end corrosion.
It is recommended to analyze the fuel ash for low fusion point and mix fuels or add materials
such as lime to mitigate sticky ash. Sootblowers in specific boiler areas may be required to keep
heat transfer surfaces clean. Where possible, contaminants should be removed from the fuel.
How are emissions kept under control for sulfur oxides, NOx, carbon monoxide, volatile organic
compounds, particulates and possibly other emissions?
Sulfur dioxide can be reduced internally with lime addition in fluidized bed boilers and
circulating fluidized bed boilers. Otherwise backend equipment is needed using lime in a wet
scrubber, or a spray dryer absorber with a baghouse.
5.5 Unit Operations
The above factors illustrate that biomass feed preparation is very important and forms an integral
part of the briquetting process.
The unit operations of the piston press and the screw press are similar except where the latest
development in screw press technology has been adopted, i.e., where a preheating system has
been incorporated to preheat the raw material for briquetting to give better performance
commercially and economically to suit local conditions. In the present piston press operating
briquetting plants, the biomass is briquetted after pre-processing the raw material but no
preheating is carried out.
Depending upon the type of biomass, three processes are generally required involving the
following steps.
A. Sieving - Drying - Preheating - Densification - Cooling - Packing
B. Sieving - Crushing - Preheating - Densification - Cooling - Packing
C. Drying - Crushing - Preheating - Densification - Cooling – Packing
5.6 Material Processing Equipment
5.6.1 Raw material storage
All biomass feeds are relatively very light with bulk densities ranging from 0.05 to 0.18 g/cc (50
to 180 kg/m³). Because of their bulky nature these are normally stored in the open. Where the
location lies in heavy rain fall region, these should be stored in ground level bins which can be
covered by heavy waterproof sheets or alternative, a side open shed could be provided.
21. Depending upon the availability of supply, feed material for a 15 days to 3 months period should
be stored at the plant site. It should be stored in a manner that the heaps are naturally aerated
and heavy wind effects are minimised. About 3-4 sq. meter open space is needed to store one
tonne of material.
5.6.2 Inclined screw feeder/Elevator
The function of this screw is to feed the material from ground level to either the top feed end of
a vibratory screen or the hammer mill.A standard enclosed screw conveyor or elevator made in
M.S. is most suitable for this operation.It can be custom built by numerous vendors. It should
preferably have variable speed so that.its capacity can be varied to match the capacity of related
equipment.
5.6.3 Hammer mills
Basically, hammer mills are bought out items and are supplied complete with a pneumatic
conveying discharge cyclone, a blower and dust separators by many vendors. Most of these
vendors have pilot plant facilities to test new materials and then recommend an appropriate
machine complete with rpm and power ratings of the motor. Typical prices for hammer mill cum
conveying systems of capacity 1500 kg/hr, as quoted by manufacturers in India complete with
cyclone, blower and dust collector, range from Rs.3.5 to 6 lac per system.
5.6.4 Dryers & Flash Dryers
All biomass materials are amenable to drying by flash driers with or without disintegration. Even
though biomass materials are heat sensitive these can be satisfactorily dried at relatively high
temperature because of short drying time. Most of the moisture is removed either in a
disintegrater or at the entry point of the feed into the gas stream. Entry temperature of gases
upto 300-400 °C can be conveniently employed even though the decomposition temperature
of most biomass materials is between 250-350 °C. One precaution that must be taken
is that sparks must not be allowed to proceed along with flue gases before gases are mixed with
feed material.
5.6.5 Intermediate storage bin
5.6.6 Main distribution screw feeder
5.6.7 Return feeder
22. 5.6.8 Briquette Cutter
To cut the briquettes to the desired length there are two technological options.
One option is to provide an automatic circular cutter which will cut the hot extrudant into
uniform lengths with smooth ends before these cut briquettes are allowed to fall on a cooling
conveyor.
5.6.9 Cooling Conveyor
5.6.10Fumes Exhaust System
5.6.11 Preheater
A preheater has become an important and integral component of the screw press briquetting
technology for agro-residues like rice husk etc. Experience gained during testing has shown that
the technology is feasible only with preheating of biomass. Therefore, it is imperative that the
unit should be properly designed so as to obtain the desired heating result and a trouble-free
and smooth operation. This section deals with the design parameters and operational aspects
of this equipment.
5.6.12 Furnace
Briquettes, along with some fresh raw biomass (mostly sieve oversized feed), are burnt along
with air. A part of the heat produced is transferred to the preheaters and flue gases, in case
required, are used for drying of feed in component . All the components require electrical
energy inputs in order to carry out their operations but these inputs are not taken into
consideration for a material and energy balance.
23. 6 COST ANALYSIS
Electrical Power Input
Power ratings of motors for 1.5 TPH of plant having two machines to produce 65 mm size
briquettes from materials like rice husk, groundnut shells and cow dig are given in Table 6.2.
Total power installed is 215 hp or 163 kW. With a utilization factor of 0.7, the power input into
the plant is 114 kW. Assuming a 1.5 T/hr production rate, the electrical power input amounts to
76.2 kWh per tonne. However, during smooth briquetting operations, the die heaters are not in
use for most of the time.
Cost
(Lakhs)
One
Two
One
One
Motor
Power
Rating(hp)
2
50
15
2
One
3
1.00
One
Two
Two
2
6
114
1.00
2.00
24.00
One
3
2.00
Equipment
Number
Screw Feeder
Hammer Mill
Dryer
Silo With
Feeder
Main Screw
Conveyor
Return Feeder
Pre-heater
Machines with
heaters
Cooling
Conveyor
Furnace
Fluid System
Fume Exhaust
Auxiliaries
One
One
One
15
5
2
15
219
0.50
4.00
4.00
2.00
1.25
3.00
0.75
45
TOTAL
Assuming energy inputs for one tonne of briquettes having 4200 x 10³ Kcal of intrinsic energy
as:
Electrical = 76.2 kWh or 65,500 Kcal
Thermal = 20 x 4200 = 84,000 Kcal
The percentage of electrical energy input in briquetting = 1.5
in addition to thermal input = 2.0
24. Manpower Requirements
Plant supervisor :One
Shift technicians: Three (1 for each shift)
Welder and maintenance technician: One
Electrician: One
Semi skilled machine operators :Three (1 in each shift)
Labourers:
For feeding raw material
For storing briquettes
Six (2 each shift)
Six (2 each shift)
Accountant cum store keeper One
Typist/data operator
One
Watchman (optional)
Casual labour
Two (preferably resident)
As and when required
The above listed staff are only indicative and actual deployment will-depend on the specific
location of the plant and degree of automation incorporated into the plant. For example,
deployment of a small size loader would change the staffing pattern. If the feed is regularly
produced by a main agro- industry, such as coffee curing or rice mills, a small feeding bin will
eliminate the need for labourers feeding the raw material. All these functions have to be carefully
considered in a project feasibility report and each report is highly site specific.
7.ECONOMIC ANALYSIS OF BRIQUETTING
7.1. Typical Cost Analysis
A typical cost analysis with materials which are available in dry form and do not therefore
require drying but do need grinding prior to briquetting is given below. The potential types of
biomass under this category are rice husk, coffee husk and groundnut shells.
Capacity
Basis:
Two machines each 750 kg/hr
Production capacity = 1.5 T/hr (20 hrs/day operation)
Operating days per year
300
Operating hours per year
6000
Capacity utilization
85%
Raw material
8000 TPY
Moisture losses
350 TPY
Briquettes produced
7650 TPY
Briquettes consumed (Dryer)
600 TPY
Saleable production
7050 TPY
25. lnfrastructural facilities
Power
Land area
Operational shed area
Briquetting storage
(covered area)
150 KW
3000 m²
240 m²
250 m²
Investments
Installed cost of plant &
machinery (based on 9.0 lac
for each machine)
Land
Building
Total investment
Working capital
52.0
3.0
4.2
59.2
7.5
Cost of production
cost
(Rs./tonne)
Power
Manpower
Water
Maintenance (including consumables)
Administrative overheads
Depreciation (Plant 10% Building 5%)
Subtotal
Financial cost
136.70
67.50
8.00
76.70
43.00
74.10
406.00
91.50
Cost of production
497.50 = Rs. 500/- per tone
Overall cost of production per year
Rs. 38.25 lac
Profitability
Basis:
Cost of raw material =
Net sale price of briquettes =
Total sales
(1450 x 7050)
Production cost
(500 x 7650)
Raw material
(500 x 8000)
Gross profit before taxes
Pay-back period
Rs. 500/- per tonne
Rs. 1450/- per tone
Rs.(lac)
102.22
38.25
40.00
23.97
2.5 years
26. The above analysis is based on a screw press costing Rs.9.0 lat. Plants with less than two
machines are not recommended. However, plants with more machines will definitely have better
profitability and advantages of scale of operation can be derived.
8.CONCLUSIONS
Bio-energy contribution to the total primary energy consumption in India is over 27%. Indeed,
this is the case for many other countries, because biomass is used in a significant way in rural
areas in many countries. However, the contribution of biomass to power production is much
smaller than this - currently, biomass comprises only about 2650 MW of installed capacity, out
of a total of about 172000 MW of total electricity installed capacity in the country (May 2011).
India is the pioneer in biomass gasification based power production. While gasification as a
technology has been prevalent elsewhere in the world, India pioneered the use of biomass
gasification for power production. As a result, prominent Indian solution providers in biomass
gasification are implementing their solutions in other parts of the world.
It is however expected the biomass gasifiers and biogas units will be functioning at full technical
potential by the time the project draws to a close in 2012. This will sufficiently increase the
carbon emissions saved from biomass power and biogas in the project area.
The activities arising as a result of the project have thus led to a positive impact on the
environment. It is inevitable that the carbon mitigation potential of the project is much higher
than is currently indicated. If all the indicators are working at their full technical potential and
the local community is given full support, the carbon mitigation benefits of the projects will be
significantly higher.
The importance of monitoring annual CO2 benefits must also be highlighted as this provides an
incentive to sustain use of the biogas units and power plants. Furthermore, is becomes crucial to set
targets for the beginning and end of each year so as to promote sustainable use of resources.
27. 9. REFERENCES
1. Reed, T.B., Trefek, G, and Diaz, L., Biomass densification energy requirements
in thermal conversion solid wastes and biomass, American Chemical Society
2. Google Search Engine
3. Power System J.B.Gupta
4. Industrial Biomass Energy Consumption and Electricity Net Generation by
Industry
5. Website Of Government of India
Ministry of New and Renewable Energy