Bio Gas Project

BIO GAS 1. Energy Crisis Energy is a necessary concomitant of human existence. Although many sources of energy exist in nature, it is coal, electricity and fossil oil which have been commercially exploited for many useful purposes. This century has witnessed the phenomenal growth of various industries based on these energy sources. They have application in agricultural farms and have domestic use in one form or other. Fossil oil, in particular has played the most significant role in the growth of industry and agriculture, which would be recorded in the history of progress of human race in golden words. Whether it is flying in the air or speeding automobiles on the roads or heating and prime moving in the industry or petro-chemicals and fertilizers for farms or synthetics for daily use or cooking at home, all have been made possible by one single source - fossil oil. By now, it has penetrated so deep into the mechanism of human living that man is not prepared to accept the fact that this useful source of energy is not going to last very long. But that is the fact of life. Once fossil oil was available easily and at lower prices irrespective of its origin of supply. It has now been scarce and costly. The immediate effect of this is that the world is in a grip of inflation and rising prices. Today, energy crisis has mainly emerged from the fear that the boons of fossil oil may turn into a bane as the disappearance of fossil oil would compel the habits and practices of living of the society to change. That is the crisis and that is the compulsion for search alternate sources of energy. 2. Bio-Gas as one of the Alternate Renewable Sources of Energy It is evident that no single source of energy would be capable of replacing fossil oil completely which has diverse applications. On the other hand, dependence on fossil oil would have to be reduced at a faster pace so as to stretch its use for longer period and in critical sectors till some appropriate alternative energy sources preferably renewable ones are made available. Presently, the country is spending a fortune in importing fossil oil which can hardly be afforded for long on the face of developmental needs. Methane gas and more popularly known as bio-gas is one such alternate sources of energy which has been identified as a useful hydro-carbon with combustible qualities as that of other hydrocarbons. Though its calorific value is not high as some products of fossil oil and other energy sources, it can meet some needs of household and farms. Following table would provide an idea of comparative heat values and thermal efficiency of commonly used fuels in the household and farms. Table-1

Commonly used fuels Calorific values in Kilo calories Thermal efficiency

Bio-gas 4713/M3 60%

Dung cake 2093/Kg 11%

Firewood 4978/Kg 17.3%

Diesel (HSD) 10550/Kg 66%

Kerosene 10850/Kg 50%

Petrol 11100/Kg

These calorific values or heat values indicate that bio-gas can perform works similar to fossil oil in domestic cooking, lighting etc., with better efficiency depending upon the methane content in it. The bio-gas has also the potential for use in internal combustion engines used for pumping water etc. for which research and development works are in progress. Biogas, therefore, has a bright future as an alternate renewable source of energy for domestic and farm use. 3. Bio-Gas, its Production Process and Composition It would be useful to know what bio-gas is and what its properties are(i) Bio-gas: It mainly comprises of hydro-carbon which is combustible like any hydro-carbons and can produce heat and energy when burnt. The chemical formula of the hydro-carbon is CH4 where C stands for carbon and H for hydrogen and chemically the gas is termed as methane gas. The chemical formula of some other commonly used hydrocarbons derived from fossil oil viz. petrol, kerosene, diesel, etc. are C6H14, C9H20 and C16H34 respectively. Unlike these hydro-carbons which are derived from direct chemical processes, bio-gas is produced through a biochemical process in which some bacteria convert the biological wastes into useful bio-gas comprising methane through chemical interaction. Such methane gas is renewable through continuous feeding of biological wastes and which are available in plenty in rural areas in the country. Since the useful gas originates from biological process, it has been termed as bio-gas in which methane gas is the main constituent. (ii) Production Process: The process of bio-gas production is anaerobic in nature and takes place in two stages. The two stages have been termed as acid formation stage and methane formation stage. In the acid formation stage, the bio-degradable complex organic compounds of solids and cellulose presents in the waste materials are acted upon by a group of acid forming bacteria present in the dung and reduce them into organic acids, CO2, H2, NH4 and H2S. Since the organic acids are the main products in this stage, it is known as acid forming stage and this serves as the substrates for the production of methane by methanogenic bacteria. In the second stage, groups of methanogenic bacteria act upon the organic acids to produce methane gas and also reduce CO2 in the presence of H2 to form methane (CH4). At the end of the process the amount of oxygen demanding materials in the waste product is reduced to within the safe level for handling by human beings. There are four types of methano-genic bacteria; Methano-bacterium, Methano-spirillium, Methano-coccus and Methano-circina. These bacteria are oxygen sensitive and photo-sensitive and do not perform effectively in the presence of oxygen and light. Constituents The gas thus produced by the above process in a bio-gas plant does not contain pure methane and has several impurities. A typical composition of such gas obtained from the process is as follows: Table-2

Methane 60.0%

Carbondioxide 38.0%

Nitrogen 0.8%

Hydrogen 0.7%

Carbon-monoxide 0.2%

Oxygen 0.1%

Hydrogen Sulphide 0.2%

The calorific value of methane is 8400 kcal/ m3 and that of the above mixture is about 4713 Kcal/ m3. However, the bio-gas gives a useful heat of 3000 kcal/m3. If similar heat values are to be obtained from other sources of fuel, the equivalent quantities of those fuel have to be substantial as may be seen from Annexure-III. It is not the quantity which is so important but while bio-gas is renewable, others are not. 4. Scope of Bio-Gas Plants The basic feed material for, bio-gas plants in India has been considered to be cattle dung which is available in plenty. The estimated cattle population of 238 million in the country has the potential to produce about 1000 million tonnes of dung every year. According to an estimate (1977) of Khadi and Village Industries Commission (KVlC), bio-gas plants of average family size may provide energy equivalent to 5432 million liters of kerosene which in terms of current prices may cost well over Rs. 1000 crore per annum. Although, cattle dung has been recognized as the chief raw material for bio-gas plants, other materials like night-soil, poultry litter and agricultural wastes are also used where they are socially acceptable. In addition to combustible gas, the bio-gas plants would also be a source for conserving organic manure, rich in NPK. It is estimated that recoverable dung from 236 million cattle can add about 3.5 million tonnes of Nitrogen to the soil every year and for ensuring its conservation bio-gas plants can be very useful. The scope for bio-gas plants in India, therefore, is substantial if the benefits accruable from such plants are exploited by people living in rural areas. 5. Major Benefits of Installing Bio-Gas Plants It is estimated by the Govt. of India, Ministry of Energy, that alternative sources of energy like bio-gas plants, wind mills etc. may reduce the dependence on conventional sources of energy by about 20% by the turn of the century, provided promotional efforts are continued. Presently, the cooking media in rural areas consist of burning dung cake, fire-wood and to some extent kerosene where it is available easily. The installation of bio-gas plants would directly replace the use of above three and in saving them, following gains would be made: (i) Nearly 30% of available dung which is burnt and wasted would be recovered as bio-gas plants conserve the dung while producing bio-gas. Again, the dung after digestion in gas plant preserves more of NPK in the dung solids and cellulose which otherwise gets lost if heaped in the open. Table-3 Percent NPK

N P2O5 K2O

Bio-gas slurry 1.4 1.0 0.8

Farm Yard Manure (FYM) 0.5 0.2 0.5

Town Compost 1.5 1.0 1.5

The benefits derived from bio-gas plants in terms of manure and useful energy are illustrated at Annexure 1& II. The average NPK content of Farm Yard Manure (FYM) is about 0.5, 0.2 and 0.5 percent respectively and it may be

observed that biogas slurry is rich in NPK by more than four times than ordinary dung when converted into FYM. When the country is faced with shortage of fertilizers and has to spend enormous amounts for its import, the application of bio-gas slurry can replace the chemical fertilizers to a large extent. Bio-gas slurry or FYM not only adds NPK but it proves the soil porosity and texture. These are established benefits. (ii) Second major benefit is that rural people would gradually stop felling trees. Tree felling bas been identified as one of the major causes of soil erosion and worsening flood situation. Government has started massive afforestation programme to tackle the erosion and flood situation. Continued deforestation has been causing ecological imbalances in the environment in which we live. Bio-gas plants would be helpful in correcting this situation. (iii) In rural areas kerosene is used for lighting lantern and cooking in a limited way wherever kerosene supply has been made possible. Whatever quantity is used can be replaced by bio-gas as it can be used for lighting and cooking. This would reduce the dependence on fossil oil directly and in saving foreign exchange. (iv) Lastly, the most important social benefit would be that the dung being digested in the digester, there would be no open heap of dung to attract flies, insects and infections. The slurry from digesters can be transported to the farm forapplication in the soil, thus keeping the environment clean forinhabitation. Also, gas cooking would remove all the health hazards ofdung cake orfire wood cooking and would keep the woman folk free fromrespiratory and eye diseases which are prevalent in the villages.

6. History of Technological Development, Past Achievements, Future Programme and Role of Institutional Finance History of Technological Development The bio-gas technology is not new to India. Its experimentation started in 1940 when Dr. S.V. Desai after visiting Dadar sewage purification station at Bombay took up an experimental gas plant at Indian Agricultural Research Institute (IARI). The cattle dung fermentation followed next which was patented by Shri Jasbhai J Patel in 1951. However, the model had undergone several modifications and in 1954 the plant was named Gramlaxmi III. The same model has been propagated by KVIC in a nation wide programme since 1962. This KVIC model has stood the test of time although many institutions and individuals kept experimenting for better models and introduced several models but not good enough to completely replace the KVIC model. However, the late seventies saw the new Janata model where the difference in cost was about 20%. Even this model has not affected the popularity of KVIC model. It's designs etc. has been discussed later in this paper. Past Achievements and Future Programmes All along since 1962, KVIC was the sole agency forpromotion of bio-gas plants independent of government programme. The threat of oil embargo during the last Arab-Israel war in 1973 made the Government to include Biogas plants as alternative sources of energy to reduce the. dependence on fossil oil on its Vth Five Year Plan. The target set was one lakh gas plants for the plan period. However only 80,000 gas plants were reported to have been installed inspite ofthe fact that government provided 25-50% subsidy to the users. It was more vigorously pursued in the VI Five Year Plan with a target of 4 lakh gas plants. It is estimated that at the end ofVIPlan the achievement is no more than 45% of its target. The programme ofbio-gas plants are now covered under the National Biogas and Manure Management Programme (NBMMP) of Govt. of India, Ministry of Non Conventional Energy Sources. The NBMMP will be implemented with a physical target of 1.60 lakh biogas plants during FY 2003-2004. It can be noted from the above discussion that during last 21 years, the achievement has not, been appreciable. The government is now convinced that bio-gas plant technology is not a failure. However, social environment has to be more favorable for the speedier progress. For example, China has taken a rapid stride in the same field where the social environment is favorable to bio-gas technology. The Relevance of Chinese Experience A comparative study of India and China carried out by Centre for Application of Science & Technology to Rural Areas (ASTRA), Indian Institute of Science, Bangalore gives a striking revelation of the achievement of China in the field of bio-gas. India started the experimentation much earlier and actual programme started in 1967 where as China took to this technology only in 1970. Even after a late start, China over took India to reach anunbelievable target within a

short span of 7 years. However, with persistent efforts thereafter, the Indian programme got some fillip but there is still a long way to go to tap the potential. This can be observed from the following: Table-4 Year

Population of Bio-Gas Plants India

India China

1973 8,000 5,000

1980 80,000 72,00,000

1998 27,50,000 69,00,000

The achievement of China deserves all appreciation as they have managed to install so many numbers without much of cattle dung but with sources which are within easy reach. The daily feed in Chinese gas plants consists of 20 kgs. waste from four pigs, 4 kgs. waste from 5 humans, 6 kgs. of straw and poultry litters. All these are available with majority of Chinese families and so they have been successful in popularizing the gas plant, as feed was not a constraint. In India, rural population would perhaps not adopt such raw materials as their Chinese counterparts do. In our country. rural people are ready to handle cattle dung but not other raw materials and number of such families owning 4-5 cattle are not many. Only 20% of the household own 4-5 cattle. Unless the remaining rural families adopt

raw materials like Chinese have done, very limited success can be hoped. Chinese have followed the programme with all seriousness inspite of the fact that they are self-sufficient and exporter of fossil oil. When Chinese could take advance measures to counter the future energy crisis, we should be more vigilant in taking this programme seriously. However, a word of caution is added here that since large number of plants are failing in the field, sufficient care should be taken to select the type of plant and for sound construction. Role of Institutional Finance The responsibility for providing technical guidance, installation, supervision and also subsidy has been entrusted to KVIC and the states by the Government who have acquired sufficient experience due to their long association with the bio-gas programme. However, it has been observed that most of the plant users fail to raise their own contribution due to lack of resources. This made the financial institutions difficult to play its role in meeting the credit requirement. During the year 1974-75 the commercial banks entered the fray. The Government has now attached top priority to the bio-gas programme in which banks have a special role to play in making the programme successful. It is in this context that bank officials would have to acquaint themselves with the technology, operations, field problems, post installation maintenance and economical and social aspects of bio-gas plants and its programme so that formulation, appraising and processing of schemes become easier. 7. Main Features of the Bio-Gas Plant On the basis of the gas holder the present bio-gas plants are classified mainly into two groups -fixed dome type or floating drum type. Both the type of plants have the following functional components: (i) Digester : This is the fermentation tank and is built partially or fully underground. It is generally cylindrical in shape and made up of bricks and cement mortars. It holds the slurry within it for the period of digestion for which it is designed. (ii) Gas holder: This component is meant for holding the gas after it leaves the digester. It may be a floating drum or a fixed dome on the basis of which the plants are broadly classified. The gas connection is taken from the top of this holder to the gas burners or for any other purposes by suitable pipelines. The floating gas holder is made up of mild steel sheets and angle iron and is required to exert pressure of 10 cms of water in the gas dome masonry and exert a pressure upto 1m of water column on the gas. (iii) Slurry mixing tank: This is a tank in which the dung is mixed with water and fed to the digester through an inlet pipe. (iv) Outlet tank and slurry pit: An outlet tank is usually provided in a fixed dome type of plant from where slurry in directly taken to the field or to a slurry pit. In case of a floating drum plant, the slurry is taken to a pit where it can be dried or taken to the field for direct applications. 8. Broad Basis of Plant Design For designing a bio-gas plant, there is a need to match the gas requirement to the feed material available so that there is a continuity of gas production and supply without interruption. For this; it is useful to know the average requirement of gas for different uses, dung produced per day and average gas production per units of different feed materials. Some basic information on these aspects are furnished in annexure I to VI. The design of a plant may be determined in the following manner: (a) Bio-Gas requirement: Make use of Annexure IV to decide the total requirement of gas per day. If we take a case where gas requirement is 3 cum, further consideration of the design may be followed as observed in the following paragraphs: (b)Raw Material Requirement : To find out the quantity of equivalent dung for production of 3 cum gas refer Annexure - V. By dividing 3 cum by 0.04 cum. which is equivalent to 1 kg of dung it would reveal the total quantity of dung required for the purpose. In this case it is 3/0.04= 75 kgs. Thereafter, refer Annexure VI to know the number at

animals necessary to produce 75 kgs. of dung. (c) Digester Design : When dung is mixed with an equal quantity of water, it gives a slurry which has a specific gravity of 1.089. So the volume of slurry fed per day would be equal to (75 + 75)/ (1000 x 1.089) = 0.138m3 Therefore, for a 50 days retention plant, the volume of the digester has to be equivalent to 0.138 x 50 or 6.9 m3 say 7 m3. The recommendation of KVIC is to have a digester volume of 2.75 times the volume of gas produced per day. The commissions recommendation for the depth of the plant is between 4 to 6 m according to the size but for economical use of building materials, a depth to diameter ratio between 1.0 to 1.3 are considered ideal for all types of plants. In a floating drum plant, a continuous ledge is built into the digester at a depth 10 cm. shorter than the height of the gas drum to prevent the gas holder from going down when no gas is left in it. It helps in preventing the gas inlet being choked. It also guides the gas bubbles rising from the side of the plants into the gas bolder. In some plants slurry is fed at the bottom and removed at the top. When the digester diameter exceeds 1.6 m, a partition wall is provided in the digester to prevent short circuiting of slurry flow and increasing its retention period. Some standard dimensions of such floating drum plants are given at Annexure VII. In case of fixed dome plants, the volume of digester comes to between 1.5 times to 2.75 times the gas produced per day. Here, the higher the plant capacity, the lesser becomes the ratio of digester volume to gas produced per day. (d) Gas Holder Design: The design of a gas holder is influenced by the digester diameter and distribution of gas use during the day. For domestic plants, the gas holder capacity is kept at 60 per cent of a day's gas production and in case of laboratories, it is kept at 70 per cent of the day's gas production. In a floating drum plant, the gas holder diameter is 15 cm. less than the diameter of the digester and accordingly the other dimensions are decided. The gas holder can be given a rotary movement around its guide to break the scum formation at the top. In a fixed dome plant the dome angle is kept between 17° and 21° and it gives a pressure upto 100 cm. of water. Due to higher pressure, the diameter of gas pipelines can be reduced and the gas can be taken to greater distance. In this plant, care should be taken to provide and an earth pressure equivalent to 100 cm of water column from the top of the dome. Always use 'A' class bricks in the domes for better stability. (e) Inlet Tank : Before the dung is fed into the plant, it is mixed with water in a tank to give a solid content of 7.5 per cent to 10 per cent in the slurry. This tank also helps in removing grass and other floating materials from the raw materials to prevent excessive scum formation in the plant. This tank is connected to the digester by an asbestos cement pipe. The floor of the mixing tank is given a slope opposite to the direction of inlet pipe to help heavy inorganic solid particles to settle and get separated from the slurry. 9. Base Pre-requisites of Bio-Gas System (i) Land and Site: While selecting a site for a bio-gas plant, following aspects should be considered: (a) The land should be leveled and at a higher elevation than the surroundings to avoid runoff water. (b) Soil should not be too loose and should have a bearing strength of 2 kg/cm2 (c) It should be nearer to the intended place of gas use. (d) It should also be nearer to the cattle shed/ stable for easy handling of raw materials. (e) The water table should not be veryhigh. (f) Adequate supply of water should be there at the plant site. (g) The plant should get clear sunshine during most part of the day.

(h) The plant site should be well ventilated as methane mixed with oxygen is very explosive. (i) A minimum distance of 1.5m should be kept between the plant and any wall or foundation. (j) It should be away from any tree to make it free from failure due to root interference. (k) It should be at least 15m away from any well used for drinking water purpose. (l) There should be adequate space for construction of slurry pits. (ii) Feed for gas plants: The feed for gas plants in India mainly comprises of dung from cattle. Although, quantity of dung per cattle depends upon health, age, type and many other factors, it is generally believed that, average cattle yield is about 10 kg dung per day. On this presumption, the number of cattle required for various sizes of gas plants as has been recommended by KVIC can be taken from following table. Table-5 Requirement of cattle for various sizes of gas plants

Plant Size in M3 Minimum number of cattle required

2 3

3 4

4 6

6 10

8 15

25 45

However, it is advisable that assessment of dung and animal requirement may be made as per approach discussed in Sl. 8. (iii) Temperature: Temperature plays the most important role in the bio-gas production. The total amount of gas production from a fixed weight of organic waste is best when the temperature is within the messophillic range 25°C37°C and thermophillic range between 45°C-55°C. The gas yield is maximum in the thermophillic region and the period of digestion is also reduced. It takes about 55 days in messophillic range for digestion where as it takes about 7 days in thermophillic region. (iv) Hydrogen ion Concentration: pH of slurry in the digester should be maintained between 6.8 and 7.2 for optimum gas production and this can be accomplished by maintaining proper feeding rate. pH indicates the acidity and alkalinity of the feed mixture. Any excessiveness of acidity or alkalinity would affect gas production. There are a number of ways to correct the pH if the slurry becomes acidic or alkaline. (v) Agitation: Mechanical agitation of the scum layer and slight stirring of slurry improves gas production but violent stirring retards it. (vi) Solid Content: The solid content in the slurry should be maintained between 7.5 to 10 per cent for optimum gas production. (vii) Carbon to Nitrogen Ratio: A carbon to nitrogen ratio of 20: 1 to 30: 1 is found to be optimum for bio-gas production. Carbon to nitrogen ratio of various materials is given in Table - 6 as a guide so that the C: N. ratio of biogas feed mixture is kept at desired level. Table 6 Carbon to Nitrogen Ratio of various materials

Sr. No. Material Nitrogen Content (%) Ratio of Carbon to Nitrogen

1. Urine 15.18 8:1

2. Cow dung 1.7 25:1

3. Poultry manure 6.3 N.A.*

4. Night soil 5.5-6.5 8:1

5.

Annexure - I A tone of fresh cattle dung provides the following benefits through a Bio-Gas plant 1.

Manure *

1.1.

Fresh dung contains 80% moisture. One tonne of fresh dung gives 0.2 tonne of dry dung.

1.2.

One tonne of fresh dung gives 240 kg. of manure.

1.3.

Manure contains 1.6 % Nitrogen. One tonne of fresh dung gives 3.84 kg. of Nitrogen.

1.4.

Manure contains 1.55 % Phosphorous. One tonne of fresh dung gives 3.72 kg. of Phosphorous.

1.5.

Manure contains 1 % Potash, One tonne of fresh dung gives 2.4 kg. of potash.

1.6.

Fresh dung contains 16 % organic solids. Digestion in a bio-gas plant converts 40 % organic solids to gas. One tonne of fresh dung after digestion gives 96 kg, of Humus.

2.

Useful Energy **

ANNEXURE – II Potential of Bio-Gas Plants in the Country and in Village from Cow Dung 1.

Energy potential in the country

1.1.

22 x 106 animals in the country x 3.18 kg dry dung/day x collection efficiency = 5.38 x 108kg dry dung/day

1.2.

5.39 x 108 kg dry dung/day x 365 days/yr. = 1.967 x 1011 kg dry dung/yr. = 196 x 106 tonnes dry dung/yr.

1.3.

5.39 x 108 kg dry dung/day x 0.19m3 gas/kg dung = 1.02 x 108 m8 gas/day

1.4.

1.02 x 108m3gas/day x 4.698 K Wh/m3 kWh/day 4.791 x 108 kWh/day

1.5.

4.791 x 108 kWh/day x 365 day/yr. =175 million MWh/yr.

1.6. 1.02 x 108m3gas/day x 365 days/yr. x 62.00 x 102 kerosene per m3 gas. =23.08 billion litre kerosene

2.

Manure Potential in the Country per year

2.1.

196 x 106 tonnes dry dung/yr. x 1.2 tonnes manure/tonne dry dung = 235 x 106 tonnes manure/yr.

2.2.

236 x 106 tonnes manure/yr x 0.016 tonne N/tonne manure = 3.76 x 106 tonnes N/yr

2.3.

3.76 x 106 tonnes N/yr : 2.1 tonnee N/tonne naphtha =1.76 x 106 tonnes naptha /yr.

3.

Energy Potential in a Village. Considering overall collection of 100 kg. of dry dung per day in a village of 500 persons. 3.1100 kg. dry dung/day x 0.19m3 gas/kg dry dung x 4.698 kWh /m3 = 89.26kWh /day

4.

Manure Potential in the Village

4.1

109 kg. dry dung/day x 1.2 kg. N/kg manure/kg dry dung = 120 kg. manure/day

4.2 120 kg. manure/day x 0.016 kg N/kg manure.

=1.92 Kg. N/ day =700 kg. N/yr. 4.3 700 kg N/yr. x 5 kg. food grains/kgN = 3.5 tonnes food grains/yr. ANNEXURE – III Equivalent Quantity of Fuel for 1 m3 of Bio-Gas

Name of the fuel Kero-sene Fire-wood Cow-dung cakes Char-coal Soft coke Butane Furn-anceOil Coal gas Electricity

Equivalent quantities to 1 m3 of Biogas 0.620 3.474 kg 12.296 kg 1.458 kg 1.605 kg 0.433 kg 0.4171 1.177 m3 4.698 kWh

ANNEXURE -IV Bio-Gas Requirements

SL. No. Use Quantity require ment

1. Cookin g 336 430 1/ day / person

2. Gas Stove 330 1/ hr /5 cm burner

470 1/hr/10 cm burner

640 1/hr/15 cm burner

3.

All dimensions are in mm

Plant Size D

D2 L1 B1 F1 h1 h2 h3 h4 h5 h6 h7 R GATE

2 2750 2500 2370 850 610 580 680 765 810 680

ANNEXURE - VII B Dimensions of Floating Drum Type Bio-Gas Plants All dimensions in centimeters

Dimensio-ns Plant capacity ,m3

For 30 Days Retenti on Period For 40 Days Retenti on Period For 55 Days Retenti on Period

1 2 3 4 6 8 10 1 2 3 4 6 8

Cost Estimate for Bio-Gas Plants Model :

Capacity :

Sr. No. Item Quantity Rate/Unit Quantity Cost

1. Earth Work

2. Bricks

3. Cement

4. Sand

* The rates should be as per the State Government schedule of rates or approved district schedule of rates.

ANNEXURE -IX CHECK LIST Schemes for installation of Bio-Gas Plants (To be completed by the Senior 'Executive/Officer forwarding the Scheme) NOTE : Ticks in boxes to signify that the details of relevant information, as per are furnished in the scheme on the following aspects:

guidelines circulated by NABARD,

Arrang ements for procur ement of the equipm ent and supply to the benefic iaries.

14. Agenc y providi ng the technic al suppor t: Wheth er certific ate from the compet ent agency has been obtaine d regardi ng the technic al feasibil ity of the progra mme?

15. Availab ility of staff for technic al apprais

ANNEXURE - X Do's and Dont's for floating Drum Plant

Do not make slurry pit more than 0.9 mtr. (3 ft.) deep

19. Check the outlet pipe period ically during the summ er seaso n to avoid cloggi ng. 19. Do not allow the slurry to dry or cake at the end of the outlet pipe.

20. Repai nt the gas holder (if it is of

Annexure- XI Cost Benefit Analysis of KVIC Plant having an installed biogas generation capacity of 3 m³/day (Amt. Rs.)

a. Capital cost

Gas holder and frame 4500

Piping and stove 1750

Civil engineering construction (tank, inlet and outlet, etc.) 10000

Total 16250

b. Annual expenditure

The interest on investment @ 9% p.a. 1462.50

Depreciation on gas holder and frame @ 10% p.a. 450

Depreciation on piping and stove @ 5% p.a. 87.50

The net annual income of approximately Rs. 2300/- shows that the capital investment of Rs. 16250/- can be recouped in about seven years. There are also incidental advantages of hygienic improvement, the absence of smoke and soot in gas burning, convenience in burning, and the increased richness of manure.