District-level biomass resource assessment: A case study of an Indian State West Bengal

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33 (2009) 137 – 143

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District-level biomass resource assessment: A case study of an Indian State West Bengal Subhrabaran Dasa,, Tushar Jashb a

Department of Economics, Assam University, Silchar 788011, Assam, India School of Energy Studies, Jadavpur University, Kolkata 700032, India

b

art i cle info

ab st rac t

Article history:

West Bengal is basically an agricultural-based state in India. Agriculture and forest residues

Received 30 August 2006

are the two main categories of biomass residues generated in West Bengal. Out of the total

Received in revised form

biomass residues generated in the state, about 79% comes from agriculture. In this paper,

19 March 2008

district-wise biomass residues generation and the potential for power generation from

Accepted 2 May 2008

surplus biomass, in the state, have been estimated. The study is based on a primary survey

Available online 1 July 2008

carried out in West Bengal. It has been estimated that about 2107 MW of power generation

Keywords:

is possible. & 2008 Elsevier Ltd. All rights reserved.

Biomass residue Resource assessment Power generation potential

1.

Introduction

The importance of district-wise biomass resource assessment studies in West Bengal is now very useful in the recent perspective because biomass energy is indisputable. Most of the people in West Bengal live in rural areas. About 72% of the total population in the state live in rural West Bengal [1]. The availability of an affordable energy supply is an important component in the upliftment of the quality of life of the vast rural population of the state. But there is a scarcity of energy supply in all sectors of the rural economy and for satisfying the demand for energy, the most important alternative is extraction of energy from biomass. In rural West Bengal, as in other parts of India, biomass energy is used inefficiently. Present biomass residues can be utilized more efficiently and a variety of approaches, new and old, are being adopted for using biomass energy. Although a number of biomass gasifier-based power plants, using mostly saw mill waste and rice husk, have been installed in the state during the last few years, but the Corresponding author. Tel.: +91 3842242357.

E-mail address: [email protected] (S. Das). 0961-9534/$ - see front matter & 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biombioe.2008.05.001

present installed capacity is still very low and the installations are mainly concentrated in two or three districts. Nonavailability of district-wise primary data on generation of different types of biomass residues is one of the major obstacles for efficient utilization of biomass for energy generation in the rural areas of the state. The present paper reports the estimation of district-wise biomass residues generation in West Bengal. The power generation potential from surplus biomass in the state have also been evaluated.

2.

West Bengal at a glance

West Bengal is situated in the eastern part of India. It is surrounded by Bangladesh on the east, Bihar and Jharkhand states on the west, Sikkim and Bhutan on the north and the Bay of Bengal on south. The state covers a geographical area of 8,694,673 ha, excluding Kolkata. The net cultivated area of land is 5,521,576 ha, and the area under forest is

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Table 1 – General details of West Bengal Geographical situation Latitude (North) Longitude (East) Total geographical area (ha) (excluding Kolkata) No. of districts No. of rural population No. of urban population No. of male populations No. of female populations Density of population (per km2) Sex ratio (per thousand male) Literacy rate (%) Net area under agricultural use (ha) Irrigated area (ha) Non-irrigated area (ha) Area of waste land (ha) Area of forest (ha) No. of rice mills No. of saw mills Installed capacity of power plants (MW) Electricity generation (MU) Electrified villages (%)

211290 –271130 851490 –881480 8,694,673 19 57,748,946 22,427,251 41,465,985 38,710,212 904 934 69.22 5,521,576 4,003,870 1,517,706 37,743 1,184,165 2119 1701 7309 27,808.2 81.0

Source: Economic Review 2002–2003, Government of West Bengal [1].

Table 2 – Classification of biomass residues used as energy sources Type of residue Agriculture

Forest Agro-industry

Name

Residue used as fuel

Paddy/rice Wheat Potato Sugar cane Sesame Rapeseed and mustard Moong, Arhar, Khesari Masoor Pulses Ground Nut Sunflower Turmeric Chilly Tea

Straw Straw Stalks T&L, trash Stalks Stalks

Stalks Stalks Stalks, shell Stalks Stalks Stalks Stick

Forestry

Wood

Saw mills Hullers Rice mills Jaggery units

Wood chips Rice husk Rice husk Bagasse

Stalks

Source: District-wise Biomass Resource Assessment Studies in West Bengal [2].

33 (2009) 137 – 143

1,184,165 ha, whereas the wasteland covers an area of 37743 ha (Table 1). Biomass residues generated in the state can be classified into three categories—agricultural residues, residues from biomass-based industries and forest residues (Table 2).

2.1.

Agricultural residues

Paddy, wheat, potato, pulses and oil seeds are the major crops cultivated in the state. Tea is also a major crop in North Bengal, especially in Darjeeling and Jalpaiguri districts. Paddy is cultivated in summer, autumn and winter season. There are three types of paddy cultivation—Aus from May to September, Aman from July to December and Boro from January to April. Potato and mustard are cultivated in Rabi season (winter). Cropping intensity in the Rabi season is more than half. Main crop residue generated in the state is paddy straw, which is mainly consumed as fodder. Minor crop residues generated in the state are wheat straw, potato stalks, cotton stalks, rapeseed and mustard stalks. These are used as supplementary domestic fuel. There are 19 districts in West Bengal, out of these only Kolkata district has no agricultural land. But in the remaining 18 districts, the main economic activities are based on agriculture. Most of the rural people in these districts are dependent on agricultural productions. Due to increase in demand for crops in the state, the cropping intensity of land has been increased over the years. The change in land utilization pattern over different periods of time is given in Table 3. It is observed from Table 3 that the net sown area have been increased and the area of uncultivated portion decreased over the years. Current fallow has an increasing trend whereas there is a marginal change in forest area. District-wise area of cultivation and also the forest area, in the state, have been tabulated in Table 4. There is a significant increase in agricultural production in the state during the last 15 years. The yield rates of principal crops and the index number of productivity of different crops over different periods of time are given in Tables 5 and 6, respectively. West Bengal is the largest producer of paddy in the country. Both Aus and Aman have a positive trend in yield rates but Boro has a decreasing trend over the years (Table 5). It is observed that both food grains and nonfood grains maintained a positive trend in agricultural productions (Table 6). District-wise annual generation of agricultural residues, in West Bengal, have been estimated and tabulated in Table 7. The residue to crop ratio (coefficient) have been estimated through direct farmer inquiries during the field survey [2]. The accuracy of the estimations have been validated through random sampling and then physically weighing of the residue and the respective crop during its harvesting season. Table 7 shows that paddy straw is the major crop residue generated in the state irrespective of all the districts, followed by wheat straw, rapeseed and mustard stalks, and potato stalks, respectively. Total agricultural residues generated in the state have been estimated as 29.55 mt a1.

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Table 3 – Land utilization over different periods of time (% of the total geographical area) Year

Net area sown

Current fallow

Forests

Area not available for cultivation

Other uncultivated land excluding current fallow

59.5 62.8 63 62.4 63.5

0.7 2.5 2.4 4.1 3.3

13.4 13.8 13.7 13.7 13.6

19.6 18.9 19.1 18.3 18.1

6.8 2 1.8 1.5 1.5

1985–1986 1995–1996 1999–2000 2000–2001 2001–2002

Source: Economic Review 2002–2003, Government of West Bengal [1].

Table 4 – District-wise area of cultivation and forest area in West Bengal (ha) District

Geographical area

Net area under cultivation

Forest area

Bankura Birbhum Burdwan Coochbehar Darjeeling Dinajpur (North) Dinajpur (South) Haora Hooghly Jalpaiguri Malda Midnapore (E and W) Mushidabad Nadia Puruliya 24 Paraganas (N) 24 Paraganas (S)

688,104 451,118 699,060 331,376 325,470 312,467 221,903 136,015 312,224 622,700 371,048 1,323,880 532,501 390,657 623,287 386,686 966,172

383,337 320,320 472,959 270,034 146,454 272,505 191,751 80,144 225,906 366,920 1675 859,903 406,449 306,859 335,833 277,231 381,859

148,351 16,030 22,511 3151 124,575 579 932 0 649 178,998 223,112 170,827 771 1216 87,600 0 426,300

West Bengal (excluding Kolkata)

8,694,673

5,521,576

1,184,165

Source: Economic Review 2002–2003, Government of West Bengal [1].

Table 5 – Yield rates of principal crops in West Bengal Yield rate (kg ha1)

Crop/year

Paddy Aus Aman Boro Wheat Total cereals Pulses Total food grains Oilseeds Potato

1998–1999

1999–2000

2000–2001

2001–2002

1743 1900 3393

1938 1992 3031

1736 1979 3240

2091 2374 3034

2117 2248 621 2197 769 21,023

2336 2237 661 2187 808 23,689

2485 2297 800 2231 953 25,606

2215 2490 703 2424 816 26,090

Source: Economic Review 2002–2003, Government of West Bengal [1].

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Table 6 – Index no. of productivity of different crops over different time periods in West Bengal Year

1985–1986 1990–1991 1995–1996 1998–1999 1999–2000 2000–2001 2001–2002

Food grains

Cereals

Pulses

Non-food grains

Oilseeds

Fiber

Plantation

Spices

Vegetables and misc.

128.1 146.2 164.8 185.8 184.5 187 204.1

127.4 143.7 160.5 181.1 179.8 183.4 199.7

120.5 121.5 127.9 119.5 128.9 153.2 136.5

114.2 146.9 164.8 163.9 172.8 174.8 175.6

130.4 182.7 151.8 157.3 164.6 195.4 166.2

129 142.7 143.3 156.9 161.5 157.7 176.4

117.8 108.5 116.8 133.7 117.7 122.4 126.5

102.5 105.2 108.1 109.3 111.3 118.3 118.8

119.1 140.9 150.3 130.2 146.5 157.1 161.5

Source: Economic Review 2002–2003, Government of West Bengal [1].

2.2.

Biomass-based industrial residues

The other important sources of biomass residue comes from agro-industries. The most important biomass-based industries are rice mills and saw mills. There are 2119 rice mills, 1701 saw mills and 36,000 numbers of rice hullers in the state. District-wise annual generation of biomass residues from rice mills and saw mills have been estimated and reported in Table 8.

2.3.

Forest residues

South 24 Paraganas, Jalpaiguri, united Midnapore, Bankura and Darjeeling districts have larger share of forestlands out of the total forest area in West Bengal (Table 4). There are two types of forests in the state. One is reserved or protected forests under the State Government and other is private owned forests or forests own by the villagelevel local bodies. In estimating the annual forest residues generation, the reserved forests have been excluded from this study. Only residues generated from the second type of forests and also from waste lands have been estimated and tabulated in Table 9 under the head ‘residues generated from non-forest lands’.

3. District-wise surplus biomass and power generation potential Based on the purpose of usage, biomass residues generated from all sources, in the state, have been categorized as ‘essential class’ and ‘non-essential class’ [2]. Biomass residues consumed as fodder, thatching and fencing materials and other socially significant nature are grouped under the essential class and the remaining under non-essential class. District-wise annual surplus biomass generation and their power generation potential have been estimated and given in Table 10. In Table 10, basic surplus of biomass residues have been estimated by deducting the essential class consumption from the total residues generation. Productive surplus stands for basic surplus less the 50% of biomass consumed as domestic fuel and biomass used

as green manure. Net surplus of biomass residues have been estimated by deducting the commercial and industrial consumption of biomass from the productive surplus. Biomass residues consuming commercial and industrial units in the state are rice mills (Par-boiled), solvent plants, jaggery, poultry farms, puffed rice units, and hotels. Power generation potential from surplus biomass have been estimated in assuming that the power plant would operate 7000 h in a year with a plant load factor of 75% and the average biomass consumption for 1 kWh of electricity generation is 1.5 kg [2]. It is observed from Table 10 that the potential for electricity generation from surplus biomass in the state is quite large. It is also observed that there is a considerable variation in power generation potential among the different districts. Major potential exists in Midnapore (162.18 MW), Murshidabad (106.28 MW), South 24 Paraganas (107.22 MW), Darjeeling (91.18 MW), Jalpaiguri (86.95 MW), Nadia (88.48 MW), Bankura (73.08 MW), Dinajpur North (75.4 MW). Coochbehar (70.5 MW) and Burdwan (70.52 MW) districts.

4.

Conclusions

West Bengal is mainly an agricultural-based state in India, where agricultural biomass residues are available in large quantities. The total biomass residue generation in the state is 37.35 mt a1. Agricultural residues constitute major share (79%) of the biomass residues generation. But there is a disparity on biomass generation among the 19 districts of the state. Midnapore, Murshidabad, South 24 Paraganas, Darjeeling, Jalpaiguri, Nadia, Bankura, Dinajpur North, Coochbehar and Burdwan districts have been identified as biomass resourceful areas. Total power generation potential from basic surplus biomass and net surplus biomass are about 2107 and 1197 MW, respectively, which could play an important role in energy generation to meet the demand for energy in the rural West Bengal. Biomass resourceful districts should get priorities in the future planning for exploitation of biomass residues for electricity generation in the state.

Table 7 – District-wise agricultural residues generation in West Bengal (103 t a1) Pulses

Moong

Masoor

Potato

Residue

Straw

Straw

Stalks

Stalks

Stalks

Stalks

Coefficient Bankura Birbhum Burdwan Coochbehar Darjeeling Dinajpur (N) Dinajpur (S) Haora Hoogly Jalpaiguri Malda Midnapore Murshidabad Nadia Puruliya 24 Pgs (N) 24 Pgs (S)

1.42 1980.00 1703.40 2751.10 751.57 75.80 1309.60 750.21 611.49 1635.60 957.54 817.32 5519.02 1569.10 1417.70 1037.00 1566.90 2046.10

1.45 16.03 93.37 16.11 69.61 9.187 236.88 33.89 0.616 1.156 38.59 167.83 24.76 434.7 176.3 8.41 31.63 3.458

1.01 0.04 0.1 0.01 16.36 1.42 13.65 4.95 0 0 6.16

1.0 0.02 0.26 0.65

1.72 0.38

0.22 0.011 2.83 29.98 9.472 53 22.31 5.26 2.92 1.534

26,499.45

1382.52

139.36

Total

0.064 0 0

0.25 0.68 0.10 1.28 0.13 0.00 0.00

0.07 4.26 0.61

0.05 22.2 13.66 60.86 39.34 16.61 42.12 12.85 15.09 39.18 45.21 2.23 98.36 8.72 5.31 1.29 8.172 3.098

43.04

3.31

6.19

434.30

0.29

0.00 0.03

0.01 0.24

0.62

Sugar cane T&L, trash 0.1 0.072 5.72 6.04

Tea Stick

1.0

Rapeseed, mustard Stalks

Sesame Stalks

Sun flower Stalks

Ground Nut Stalks,

1.65 16.23 52.22 60.17 9.65

1.85 17.50 1.41 5.21

2.58 0.00 0.02 0.02

1.64 0.37 0.50 3.49

1.80 14.58

0.00 0.00

2.33 11.79

72.02

144.83

72.02

76.68 32.54 0.76 10.38 17.40 51.34 25.87 84.21 92.15 0.61 50.00 5.63

0.16 61.79 4.03 16.72 1.03 7.51 2.29

585.83

134.02

0.28 0.00 0.00 5.95

0.15 39.66 1.15 10.65 0.91 1.76 0.34

6.32

73.10

0.04

Chilly

Turmeric

Stalks

Stalks

1.38

0.24 0.12 0.07 0.05

Total

6.36 5.27 0.49 0.00 12.36

0.43 0.97 0.49 0.17 0.02 0.79 0.11

2052.961 1871.460 2906.470 888.962 175.194 1679.368 835.006 632.784 1713.950 1214.949 1072.54 5781.420 2161.86 1748.14 1055.274 1673.944 2081.489

23.96

3.32

29545.771

0.73 2.76 2.43 0.15 0.44 0.57 0.40 0.91 2.39 2.85

0.08 0.07

Source: District-wise Biomass Resource Assessment Studies in West Bengal [2].

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Table 8 – District-wise biomass residues generation from major biomass-based industries (103 t a1) District

Rice husk from rice mills/hullers

Residues from saw mills

Total residues generation

Bankura Birbhum Burdwan Coochbehar Darjeeling Dinajpur (North) Dinajpur (South) Haora Hooghly Jalpaiguri Malda Midnapore (E and W) Murshidabad Nadia Puruliya 24 Paraganas (North) 24 Paraganas (South)

486.04 305.0 509.0 13.578 2.05 82.195 26.95 98.398 233.66 16.972 116.72 465.56 274.0 264.86 328.624 257.709 248.338

1.66 3.87 15.83 1.456 0 5.342 0.98 1.208 1.765 0.52 12.75 49.067 12.50 20.83 1.365 7.54 5.292

487.70 308.87 524.83 15.034 2.05 87.54 27.93 99.606 235.425 17.487 129.47 514..627 286.50 285.69 329.989 265.249 253.63

Total

3729.654

141.975

3871.629

Source: District-wise Biomass Resource Assessment Studies in West Bengal [2].

Table 9 – District-wise biomass residues generation from different sources (103 t a1) District

Bankura Birbhum Burdwan Coochbehar Darjeeling Dinajpur (North) Dinajpur (South) Haora Hoogly Jalpaiguri Malda Midnapore (E and W) Murshidabad Nadia Puruliya 24 Paraganas (N) 24 Paraganas (S) Total

Agricultural residues generation

Biomass based industrial residues

Residues generated from non-forest land

Total biomass residues generation

2052.961 1871.46 2906.47 888.962 175.194 1679.368

487.70 308.87 524.83 15.034 2.05 87.54

191.07 261.35 515.58 124.95 158.757 86.60

2731.731 2441.68 3946.88 1028.946 366.001 1853.508

835.006

27.93

79.36

942.296

632.784 1713.95 1214.95 1072.54 5781.42

99.606 235.425 17.487 129.47 514.627

95.94 140.50 142.84 295.74 388.78

828.33 2089.875 1375.277 1497.75 6684.827

2161.86 1748.14 1055.274 1673.944

286.50 285.69 329.989 265.249

485.57 361.85 111.144 236.92

2933.93 2395.68 1496.407 2176.113

2081.44

253.63

180.98

2561.05

29,545.723

3871.627

3932.931

37,350.281

Source: District-wise Biomass Resource Assessment Studies in West Bengal [2].

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Table 10 – District-wise surplus biomass residues and power generation potential in West Bengal Surplus biomass (103 t a1)

District

Power generation potential (MW)

Basic surplus

Productive surplus

Net surplus

Basic surplus

Productive surplus

Net surplus

Bankura Birbhum Burdwan Coochbehar Darjeeling Dinajpur (North) Dinajpur (South) Haora Hoogly Jalpaiguri Malda Midnapore (E and W) Murshidabad Nadia Puruliya 24 Paraganas (N) 24 Paraganas (S)

836.827 766.88 1420.90 857.303 1085.484 1041.053 510.948 205.718 436.821 1272.577 674.36 1919.583

581.889 581.83 1054.82 559.099 718.344 647.763 337.619 153.662 354.826 747.469 432.95 1459.384

575.485 299.85 555.35 555.27 718.111 593.583 312.292 149.004 348.017 684.791 316.13 1277.137

109.7 97.4 180.43 108.86 137.84 132.2 64.88 26.12 55.46 161.6 85.63 243.58

73.9 73.88 134.0 71.0 91.22 82.25 42.87 19.51 45.06 94.92 54.9 185.32

73.08 38.07 70.52 70.5 91.18 75.4 39.66 18.92 44.2 86.95 40.14 162.18

1683.58 1419.74 441.663 561.228 1431.025

1102.97 873.95 295.295 405.065 864.811

836.98 696.79 290.03 375.982 844.399

213.78 180.28 56.1 71.27 181.72

140.06 110.97 37.42 51.44 109.82

106.28 88.48 36.83 47.74 107.22

Total

16,565.69

11,171.656

9429.201

2106.85

1418.54

1197.35

Source: District-wise Biomass Resource Assessment Studies in West Bengal [2].

R E F E R E N C E S

[1] Economic review 2002–2003. Kolkata: Government of West Bengal; 2003.

[2] District-wise biomass resource assessment studies in West Bengal. Kolkata: Jadavpur University; 2005.