Kenbim Domestic Biogas Construction Training Kenya 2009.docx
2009KENBIM DOMESTIC BIOGASCONSTRUCTION TRAININGMANUAL FOR MASONSKENDBIPKENYA NATIONAL FEDERATION OFAGRICULTURAL PRODUCERS9/8/20091
TABLE OF CONTENTSi) Chapter 1: introduction a. Need to train masons b. Why we need to train masons c. Objectives of the Biogas Mason Training (BMT) .d. Expected Outputs e. History of biogas in the country .f. Biogas Technology History and its development in Kenya .g. Biogas Programme objectives and targets .ii) Chapter 2: size selection a. Guideline for the selection of the proper size of the biogas plant. .b. Looking for client personal information. c. Selection of appropriate size of Biogas Plant based upon dung availability .d. Chapter 3: site selection e. Sites selection for BGP .f. Cowshed or Pigsties .iii) Chapter 4: construction .a. Types and quality standards of construction materials .b. Cement c. Sand .d. Gravel/ballast e. Bricks f. Process .g. Methods of laying out of Biogas Plant .h. The Reference Line .i. Steps for setting up the reference line j. The Radius Stick and its importance in the dome construction k. Methods of digging the pit .l. Fixation of the centre point m. casting concrete of Foundation base n. Wall Construction o. Fixing of inlet pipe p. Building the dome .q. Plastering digester .r. Back filling. s. Curing of wall .t. Fixation of dome gas pipe .u. Plastering of the upper part of the digester (gas storage) v. Expansion/compensating chamber .w. Construction of Mixing Chamber iv) Chapter 5: piping .a. Fixation of pipeline alignment and digging of trench b. Water traps v) Chapter 6: finishing works .2
a. Indoor piping .b. Checking for leakages .c. Function of test unit chamber d. Some new technologies and modification of gas appliances e. Gas utilization f. Example of some biogas consumption rates in various applications vi) Chapter 7: operation of the biogas plant .a. Filling up of the digester with feedstock vii) Chapter 8: slurry utilization .a. Composition of biogas slurry b. Uses of biogas slurry .c. Slurry distribution and application methods .viii) Chapter 9: trouble shooting .ix) Chapter 10: role of KENDBIP .x) Appendixa. Formsb. Roles of mason:c. Roles of supervisor:d. Promotion and marketing:e. User manualNOMENCLATUREKENDBIP Kenya National Domestic Biogas ProgrammeBMT Biogas Mason TrainingCHAPTER 1: INTRODUCTIONNeed to train masonsBuilding of a quality bio digester requires good knowledge and skills on the part of the constructor, the mason.Good functioning or performance of a bio digester is associated with the selection of the right size, choosing the right site forconstruction, selecting the construction materials and appliances to comply with the quality standards, constructing thecomponents with strict adherence to the norms and ensuring effective operation and maintenance activities – most of whichare the responsibilities of the mason.Why we need to train masons?This handbook is designed for the mason, who wants to make a living out of building biogas digesters. For biogastechnology to perform well, a guided approach is needed to achieve this; disseminate, build, and sell the technology.We are training masons so that they know how to build a bio-digester and to standardize the bio-digester, so peoplecan use the same sizes criteria.The objectives of the Training are streamlined in this manual as follows:a) To build technical capacity to groups of artisans/technicians so that they get involved in the construction of biogasplants for their own income generation and faster biogas promotion and dissemination in the country.b) To strength KENDBIP’s capacity for promoting domestic biogas plants in many regions of Kenya.c) We expect the masons to train the end user how to operate and maintain the Biogas plant.Expected Outputs3
At the end of the training, all participants: To be familiar with the domestic biogas program in the country To acquire detailed knowledge on biogas technology, its importance and use of biogas plant-products (biogas andbio-slurry). To have the required skills to be able to construct domestic biogas plants, ability to plan, set out and constructthrough:- Reading biogas plant drawing.- Selection of appropriate plant size, construction sites and materials.- Advice and make contract with clients.- Plan lay out and digging of pits.- Construction of biogas plant and chambers- Laying of pipelines and installation of appliances- Advice on the use of bio-slurry as fertilizer- Carry out/guide households on how to operate and maintain the plants- Provide after-sales-services Masons should be familiar with their roles and responsibilities related to Promotion, Quality Management andextension of biogas slurry uses.Biogas Technology History and its development in KenyaThe first biogas digester was built in Kenya in 1957 to provide gas and fertilizer. The effluent was foundas an excellent fertilizer.The German development cooperation (GTZ) started promoting biogas in the middle to late 1980s in Kenya, incollaboration with the Ministry of Energy under the Special Energy Programme. It opted for the floating drum type, possiblydue to local steel manufacturing capacity and built approximately 400 biogas units, a high proportion of digesters appear tooperate below capacity, are dormant or in disuse after construction because of management, technical, socio-cultural andeconomic problems.Consequently, biogas technology acquired a less favourable reputation and the penetration rate in the countryremains very low. It is impossible to estimate what percent remain in working condition due to the dispersed and sometimesuncontrolled and informal nature of installations.Biogas Programme objectivesThe proposed goal of the programme is to improve the livelihoods and quality of life of rural farmers in Kenyathrough exploiting the market and non-market benefits of domestic biogas.Biogas in general (The gas and its composition)Biogas is a combustible gas produced by anaerobic digestion of organic materials like animal dung, agriculturalwastes and human excreta. During the anaerobic digestion process, methane (CH4), 65% carbon dioxide (CO2), 35% andtraces of hydrogen sulphide (H2S) are produced as by-products.The gas is only combustible if the quantity of methane in the mixture is above 50%. After these organic materials have beendigested, they go out as slurry, which is a rich fertilizer for agricultural production.Some properties of BiogasColorlessIt has a rotten egg smell due to a presence of hydrogen sulphide.Flammable4
Ideal Conditions for gas productionBiogas is produced by anaerobic (absence of air) digestion of organic materials.Three different groups of micro-organism act on the substrate under airless condition, at different stages of digestionprocess, and their collective name is “putrefactive” or methane bacteria. Other conditions are:- Temperature: 20-35 0C- pH (Neutral)- Retention time 40-60 days- Dilution 1:1 (dung: water)Benefits of Biogas:1. Biogas provides energy, to cook ; reduce workload for women for collecting firewood and time saved can be usedfor other activities.2. Improving health;by not using firewood and reducing indoor air pollution.3. Agricultural productivity by encouraging zero grazing4. Environment protection and sanitation: reducing water pollutionUses of Domestic Biogas Cooking using special biogas stoves or modified conventional stoves Lighting using special biogas lamps or modified kerosene pressure lamps. Refrigeration, Baking ovens, Chicken incubators and brooders replacing charcoal, kerosene or electricity Used for house warming and heating equipment.Different models of biogas plants Fixed dome- Continuous- Semi-batch- Batch Floating drum BalloonFig 1:Fixed dome Biogas Plants(1)Biogas plant from Chengdu/China(2)Janata plant from India5
(3)Dheenbandhu plant of AFPRO from India(4)Modified BORDA from BurundiDifferent Components of a biogas PlantThe cylindrical and hemispherical masonry structure, that is constructed underground following specific vertical andhorizontal dimensions as per respective technical drawing details.It consists of: Dung and urine mixing chamber (connecting a shed and digester) The digester for anaerobic digestion The slurry outlet and man holeExpansion or compensation chamber with over flowThe slurry canalSlurry storage pitHow the biogas plant operatesThe plant feeding is done through inlet pipe into the digester, where an anaerobic digestion occurs, this internally builtgas pressure pushes digested slurry out through an outlet opening to the expansion chamber and finally out through an overflow point and slurry canal.CHAPTER 2: SIZE SELECTIONGuideline for the selection of the proper size of the biogas plant:Sizing follows three parameters: daily feed, retention time and digester volumeConsumption based on 60 days hydraulic retention time & ambient temperatures 20 – 250cGiven: 1 cow produce an average of 15 kg. of dung per dayMixing ratio of dung to water/urine 1:11 kg. of cow dung produce 40 litres of gas per day2 cowsx15kg/day 30kg/dayDilute at ratio 1:1 30kg/dayx2 60litresRetention time of 60 days; 60litresx60 days 3600 litresVolume 3600/1000 3.6m3 4m3No. of normalDigester adult animalssizeCows(m3)Daily dung Water /FeedingUrine To(Kg)mix withDung (Lts)41-2303063-4444495-670706Number ofH/H Stoves &running timeat a rate:200 350lts/hr.1(For 3hours)1(For 4hours)1(For 6hours)Number ofLamps &running time ata rate:120 - 180lts/hr.1 (For 2hours)1 (For 4.5hours)2 (For 3.5hours)
137-81041041(For 6hours)3 (For 6hours)Observations: If cows are out-door grazed, multiply with 3 the number of cows. Pigs manure can equally be used and provides even more gas than cow dung. Kenyan household uses around 6 hours for cooking.Looking for client personal information: Clients energy requirement Clients priority plans and future prospects Number of people who are to be served Number of people or animals-determines the amount of organic material available for feeding the plant daily Animal rearing system Slurry use discharge The size of the farm for slurry use Hygienic and sanitation conditions to be achieved Biogas plant costs-affordability by the clientSelection of appropriate size of Biogas Plant based upon dung availabilityConsidering many factors already discussed at this point, it is easy to decide the size of the biogas plant to beinstalled, domestic biogas plants standards (4m3, 6m3, 8m3 10 m3 or 12m3), the quantity of daily feeding materials and thepre-determined hydraulic retention time (HRT) of 60 days will eventually guide the digester volume.CHAPTER 3: SITE SELECTIONSites selection for BGP Site should be convenient as possible to feed the digester. Consider existing structures at the Site and how they can be incorporated in the biogas system e.g. cowshed,kitchen stove etc. Consider the terrain-ground level, the existing natural slope if it allows slurry to flow by gravity.A level ground will have a different approach from a ground with a defined slope.Where there is no slope, the slurry will be considered for drying or composting. Consider infrastructures around the site like roads, pipeline, rivers, rocks, obstacles like big trees etc. Consider the gas utilization points in terms of distance and slope, so that costs are reduced in piping material andwater trap provisions. Consider clients future plans, like house expansion, new house construction increasing number of animals etc.Where these structures don’t exist, and a biogas plant is required, it is necessary to consider them in the initial planning,such structures ease the work for dung collection, mixing with water and feedingCowshed or PigstiesDepending on the cowshed or pigsty which should be connected to the plant, the direction for slurry flow should beestablished, in case of agricultural plant connected to toilets, it doesn’t only solve the problem of emptying the filled up pits,but also brings about a better and safe use of human wastes for agricultural production. It is important that the slurry out letis always at a lower point than the plant. After these considerations, laying out of the biogas plant can be done.7
CHAPTER 4: CONSTRUCTIONA. Types and quality standards of construction materialsCEMENTCement should be good and high quality Portland cement from a brand with a good reputation should be stored 20 cm awayfrom any walls.SANDSand should be clean and not contain soil or other material; dirty sand will have a very early negative effect to the structure.Coffee wire should be used to remove any unwanted materials. Coarse and granular sand are suitable for concreting work,however fine sand should be used for plastering works. River/lake sand is well graded hence preferred. Avoid dusty sand.GRAVEL/BALLASTThe size of gravel should neither be very big nor very small and should be clean, hard and angular in shape. If dirty shouldbe cleaned first before use and the maximum size of gravel should be ¾” or ¼ the slab thicknessBRICKSBricks should be of high quality, made in the size of 23cm by 11cm by 7cm and the brick should be well burnt, straight, andregular in shape and size. In some area that you cannot burn, you may use bricks made of cement of the same size at theratio of 1:8.Quantity requirements of construction materials (BOQs) refer to the appendixB. ProcessMethods of laying out of Biogas Plant1. Locating of suitable position for the biogas chamber2. Fixing the relative positions of mixing chamber / inlet, digester, manhole, expansion chamber and slurry pits.3. Using the respective drawing and their horizontal dimensions and add 45cm to the digester and expansion chamberradii to allow working area for the wall and plaster.4. Using Colour powder to indicate demarcationThe Reference LineA reference line is a thin string connecting two leveled points passing across the centre of a biogas plant from which allvertical measurements are taken.Main vertical measurements of the working drawings are given in relation to the reference line.The reference line is 100 cm above the overflow point (10cm above ground) of the expansion chamber.Steps for setting up the reference line.Step 1: After setting the demarcation of the plant fix a post 1 at the lowest point of the stable.Step 2: Position peg number two at point of slurry overflow at a height of 10cm above ground and fix a post 2, 1m away inline with peg 1 and 2.Step 3: Measure 100cm above the top level of peg number 2 and transfer the measurement to post 2 tie a string at thatpoint.Step 4: Use water/spirit level to get a point at post number 1.Step 5: Fix a string between post number 1 and 2 in horizontal position passing over the center of the digester.Step 6: Verify if lowest point at inlet with reference line is 15cm or less.8
Step 7: If more than 15cm reposition peg number 2.Step 8: Indicate both center point for digester and expansion chamber on the reference line by fixing small nail on thosepoints.In order not to lose the level of the reference line it is advisable to also mark it on a tree or building near to the plant.In case of slope setting of reference line should be along a contour or across the slope. The same 10cm is applied in slopesituation.Displacing the reference line will influence negatively the amount of gas to be stored, the pressure and the slurry movement.Tools: pegs, string, nail, spirit level/water levelThe Radius Stick and its importance in the dome constructionThis is a guide stick, measured specifically for controlling the radius of the digester and controls the bricks inspherical shape while constructing. This gives the measurement from the radius point to the inner wall of thehemispherical digester.The radius stick end can spin around the nail or round iron bar and can be fixed with binding wire or manila rope. How to make a radius stick:Several ways can be applied, whereby the radius of the digester is marked by a nail at the length of this piece oftimber, alternatively steel or bamboo can be used.The importance of the radius stick is to ensure that all blocks and bricks go round on a given radius and it makes around and a dome shape.Methods of digging the pitPit digging depends on the digester size. The radius of any digester is increased by 40 - 45cm to allow working area aroundthe digester. Where ground water table is high, a small pit is dug aside the digester pit to allow water to collect so that it canbe removed manually or pumped out when digging continues.Soil scooped from the pit should be placed at least one meter away from the edge of the pit.It is advisable that digging should not be done during rainy seasons and dig a cone incase of loose soil.Tools: Radius stick, peg, plumb bob, spade, malletFixation of the centre pointFor the construction of the wall and dome, a GI pipe is fixed at the radius point and defined in the middle of the excavatedpit below the reference line. The distance to the reference line is given in the drawing. From the center point use radius stickto get the diameter. Tools: Radius stick, peg, plumb bob, stringCasting concrete of Foundation baseStep1: Using a radius stick establish the slab ring.Step 2: level the base and incase of a cone, dig the depth according to drawing.Step 3: establish the slab height by use of pegs leveled by a spirit level.Step 4: Pouring concrete on the slab to a depth of 75mm together with the floor of the digester.Step 5: Using the radius stick immediately lay one or more courses of bricks/blocksStep 6: The first course of bricks is laid at half brick while the rest are laid quarter brick.9
The mortar ratio of 1 cement to ¼ lime to 4 sand (1:1/4:4). Or lay blocks in the normal wayIt is important to use the technical drawing from the beginning in order to have all the dimensions in place.Tools: Radius stick, brick trowel, spade, ho
- Reading biogas plant drawing. - Selection of appropriate plant size, construction sites and materials. - Advice and make contract with clients. - Plan lay out and digging of pits. - Construction of biogas plant and chambers - Laying of pipelines and installation of appliances - Advice on the use of bio-slurry as fertilizer
Nepal Biogas Plant -- Construction Manual Construction Manual for GGC 2047 Model Biogas Plant Biogas Support Programme (BSP) P.O. Box No.: 1966, Kathmandu, Nepal September, 1994 Sundar Bajgain Programme Manager Biogas Support Programme Tel. 5521742, 5534035 Email snvbsp@wlink.com.np Introduction The success or failure of any biogas plant mainly .
biogas produced is used as energy in cooking food and heating water. The entire biogas system works normally and operates properly. But, after one year, the only problem we met is that the biogas production is low. The purpose of our study is to check if the weakness of the biogas volume is due to the dimensions of the biogas system.
the biogas plant begin to produce biogas normally you should add raw fermentation materials into the biogas plant regularly. 2) For the 1.2m3 biogas plant to keep a 0.6m3/d biogas production, 20kg cow dung or 15kg pig dung is needed daily. 3) In the period of normal operation you can increase the concentration of the
biogas technology and the construction of biogas plants was launched in Cameroon. . hands-on manual. The tables and engineering drawings contained herein provide standard values . 10 m³ biogas plant produces 1.5-2 m³ and 1001 digested-slurry fertilizer per day on dung from 3-5 head of cattle or 8 - 12 pigs. With that much biogas, a 6 - 8 .
In some countries, biogas contributes significantly to the national energy balance. It may be used both as a fuel and to generate electricity. To produce these statistics, biogas data collection should focus on plant capacity and production of biogas and electricity. Project and policy monitoring More detailed biogas statistics may be required to
Biomass Biogas Biomass Biogas Biomass Technology Upgrades Maximum Potential Current. Emissions, metric tonnes (10. 3 . Mg for CO2eq) Feedstocks Collection and Transport Conversion Savings-80 -40 0 40 80 120 160. NOX PM CO2eq NOX PM CO2eq NOX PM CO2eq NOX PM CO2eq NOX PM CO2eq NOX PM CO2eq. Biogas Biomass Biogas Biomass Biogas Biomass Technology .
biogas technology specifically, the government has organized the National Project on Biogas Development nation-wide, and several NGO's have been active in implementing the program on the ground. Currently, there are thought to be about 2.5 million (Dutta et al., 2007) household and community biogas plants installed around India. 1.2 Why biogas?
Siklus Akuntansi Jasa BAGIAN PROYEK PENGEMBANGAN KURIKULUM DIREKTORAT PENDIDIKAN MENENGAH KEJURUAN DIREKTORAT JENDERAL PENDIDIKAN DASAR DAN MENENGAH DEPARTEMEN PENDIDIKAN NASIONAL 2003 Kode Modul: AK.26.D.2,3. BAGIAN PROYEK PENGEMBANGAN KURIKULUM DIREKTORAT PENDIDIKAN MENENGAH KEJURUAN DIREKTORAT JENDERAL PENDIDIKAN DASAR DAN MENENGAH DEPARTEMEN PENDIDIKAN NASIONAL 2003 Kode Modul: AK.26.D.2,3 .
