USER MANUAL
Contents
1. 30 Step 6 Step 7 Step 8 Step 9 Step 10 Step 11 Step 12 User Manual Unloading Step 5 is repeated 1 2 times Pump is turned off and disconnected allthe electrical parts from the fermenter are removed and turned off Flush the container with air or another gas preferably CO or N While opening the container an explosive mixture of gases can occur To prevent from creating a dangerous environment the container should be hooked up to a device producing exhaust like a car or a generator To control the content of the plant the Dr ger can be installed as usual to the gas measurement compartment The exhaust pipe should be connected to an inlet of the fermenter and let run until the gas analyser shows that only the wanted gas is exiting through the gas outlet During the whole process of flushing and opening it is very important to remove all kind of electri cal devices and to turn off the power supply to avoid electrical sparks as well as to refrain from making fires on the site Open the container Before opening the container the Drager should be disconnected from the measurement compart ment and placed in front of the fermenter on top of the door This helps to ensure a safe gas com position Then the lock can be removed and the door can be opened carefully It is recommended to open it only a crack wide and wait for a few minutes During this time the out coming gas can be controlled via Drager If no dang2. The digestate samples should then be labelled and stored separately and labelled with their origin point El User Manual Unloading Step 13 Step 14 32 Unload the container To be able to enter the container easily the wooden logs next to the door should be removed Then the percolation collection pipe shall be unlinked Following that the unloading of the digestate can be started see Figure 27 Placing a wooden board at the entrance enables the works men to push the wheelbarrows straight inside the fermenter The discharged material should be placed near the container in the shape of a compact pile It is important to make sure that only as little material as possible does come in contact with oxygen to pre vent harm for the bacteria on the inside of the pile If available the heap should be covered with a plastic to protect the mate rial from environmental influences Clean the container As preparation for eventual maintenance the container shall be cleaned properly The inside should therefore be hosed down with water and remaining solids shall be swept out of the fermenter see Figure 28 If the dirt on the walls is significant these parts should not only be sprinkled but also swept with a broom Following the clean ing part the fermenter should be dried us ing a cloth After that the plant should be left to dry overnight Figure 26 Sampling the digestate reacted feed stock Figure 28 Cl
3. Faucets are not in the right position Adjust the faucets to initial state Filter is clocked Exchange the filter Filter is not placed accurate Adjust the placement Pump sucks air Check the connections Not enough Percolat Add percolat water Percolation is not starting This failure is present if the pump has started but no percolation sound occurs inside and no percolate passes the filter Table 16 Trouble shooting for percolation error Possible reason Solution Faucets are not in the right position Adjust the faucets to initial state Pump has run dry Float the pump No Percolate in the fermenter Add Percolate The pump is clogged Follow the instruction in IV_C Pump is not starting This failure is noticeable if the pump mode is switched from automatically to manual and the pump is not yet running Table 17 Trouble shooting for pump error Possible reason Solution Power cut Check the functioning of the Lamp at the pole where the pump is connected to Some switch is not in the right position Check all the switches Some wire has a failure Check the wires and connections The time switch or the pump is faulty Replace or repair the faulty device 27 User Manual Reaction Observation Treatment and Troubleshooting PH Value too low lt 6 During the reaction of the biogas production the substances of the feedstock are decayed in several steps to methane Some of the intermediate products are represented as acids The chall
4. inside amp outside of the container with an anti corrosion paint Renew sealing of the floor with silicone Install an supplementary door frame made out of wood Seal the left door wing with silicone Use rubber band for example from an old bicycle tire to improve air tightness of the door The Figure above shows the construction of the percolation system as well as of the gas tapping device The materials used for both systems mainly consist of common plumbing equipment that can be found in any plumbing store Percolation system Gas tapping Figure 2 Model of the container with its two main work systems User Manual Preparation and Assembly II B Setting up the Percolation System Table 2 List of the material used to assemble the percolation system Describtion Time Workers Pipe Faucet Percolate collection pipe T element Elbow Cap Filter module Filter Pipe connection with thread Transition part 2 5 inch to 1 inch Transition part 1 inch to 0 5 inch Pump Plastc box Inlet connection Rubber hose PVC glue Measuring tape Drilling device Amount 1 2 days 12 3 6m PRPRPrPNrPrPRPrPORrPRrPNUWRE A The following illustration shows the setting of the percolation system A connection is installed be tween the green faucet outlet seen on Fig 2 and the percolate collection pipe on the inside of the con tainer see Fig 5 The following part is a T element which leads to the red faucet inlet for the f
5. Gas meter Figure 19 Model of the gas tapping system Initial State Gas Tapping During the reaction the gas tapping system has to be in the following state to perform properly The flashback arrestor is filled with enough water to be sure the open end of the hose is submerged in water The pink faucet 5 is closed The blue faucet 6 is closed The brown faucet 7 is closed The grey faucet 8 is closed The black faucet 9 is open 23 User Manual Reaction Observation Treatment and Troubleshooting Fill Flash Back Arrestor Table 11 Short description of filling the flash back arrestor Description Amount Time 5 min Workers 1 To successfully avoid the ignition of possibly flammable gas exiting the fermenter the flash back arrestor needs to be filled with water Starting from the initial state the following steps have to be performed to ad just the water level in the flash back arrestor Step 1 To avoid any gas to exit the fermenter whilst the flash back arrestor is unscrewed the yellow green faucet 10 is closed Step 2 The bottom part of the bottle trap is screwed off Step 3 Water is filled into the cup like part Step 4 The part gets screwed on again Step 5 Yellow green faucet 10 is opened again Empty Condensate Trap every day if gas is produced Table 12 Short description to empty the condensate trap Description Amount Time 5 min Workers 1 The vapour condensed from the gas is col
6. are dissolved Though for liquids an add ing is possible over the percolation system By the time the liquid is prepared in a bucket starting from the initial state the following steps have to be performed to add the substances to the fermenter Depending on the liquid the operator should wear rubber gloves and safety goggles during the adding Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 The garden hose is connected to the opening at the red faucet 2 Fill the hose with water until there is no air in it anymore using a small plastic bottle of water H Holding the open end closed with a finger the hose gets submerged in the liquid to be added make sure the hose remains in place The pump mode is switched from automatical to manual The percolation starts running The red faucet 2 is opened The green faucet 1 is closed The pump will now suck in the liquid over the percolation system As soon as the adding has been accomplished the system should be rinsed with approximately 20 of water except if water has been added The green faucet 2 is opened The red faucet 1 is closed The pump mode is switched from manualto automatical The initital state is recreated Figure 18 Filling the garden hose connected to the percolation system with water 21 User Manual Reaction Observation Treatment and Troubleshooting Exchange the Filter app every seven days
7. of the measurements division is a faucet to control the gas flow Following this device a T element leading to a piece of pipe that is connected to a further faucet is foreseen This part is used to con nect a gas analyser to the system Further down the pipe should be connected to the flash back arrestor see Figure 8 This element prevents any sparks from entering the fermenter This is achieved by letting the gas pass through water which is filled into an ordinary bottle trap The gas enters the trap through a pipe part which is connected to the lid of the bottle trap and reaches to the bottom of the device where it exits the pipe part It then flows up to the top of the compartment where an outlet pipe is placed This gets connected to the condensation trap 11 User Manual Preparation and Assembly The gas coming from the fermenter can still contain some water steam which could harm the gas meter Therefore a condensation trap is installed in advance using a T element see Figure 8 This component consists of a simple piece of hose vertical which is followed by a piece of pipe and a valve that is used to empty the condensation trap from time to time Both ends of the hose are connected to transition parts and should be tightened with a hose clip The horizontal opening of the T element is con nected to an additional T element where an other faucet is positioned to link a device for gas analyses Subsequently an elbow part is conn
8. prepared to be closed Time switch connected to the pump Model of the percolation system with legend Percolate analyses in progress Filling the garden hose connected to the percolation system with water Model of the gas tapping system Gas measurement using Dr ger X am 7000 Gas meter and the reading Weight the sodium hydroxide Dissolving sodium hydroxide in water Percolation pump disassembled for cleaning Releasing the percolate from the container Sampling the digestate reacted feedstock Unloading of the digestate Cleaning of the container for eventual maintenance List of Tables Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Table 15 Table 16 Table 17 Table 18 Table 19 Short description of the assembling of the container List of the material used to assemble the percolation system List of the material used to assemble the gas tapping system Short process description with necessary materials Possible contents and some estimation of their amount Short description to float the pump with water Short description to run the percolate system the first time Short description to take a sample from percolate Short description of liquid addition during the reaction Short description of exchanging the filter Short description of filling the flash back arrestor Short description to empty the condensate trap Short description f
9. sparks make no fire Keep the door closed during the raction Let no air enter the pump Use both hands if opening or closing a faucet to avoid punctual load Control performance of the filter reguliarly Keep measurement devices well calibrated Kepp the NaOH supply dry Keep the electronical connections and equipment dry Empty the condensation trap reguliarly Control level in the flash back arrestor reguliarly Ensure a horizontal state of the gas meter Keep the work site clean User Manual Preparation and Assembly II_ Preparation and Assembly This chapter is subdivided into three parts A describes the very beginning of setting up a container B at tends to the assembling of the percolation system and C treats the assembling of the gas tapping system IA Setting up the Container Table 1 Short description of the assembling of the container Describtion Amount Time 1 2 weeks Workers 28 Site il Shovel 1 2 Stone plates concrete Ca 15m Container il Transportation truck 1 Welding device il Iron rings iy Anti corrosion paint 3 4 gallons Brush 23 Wood 3 2 25m 5cm 1 5cm 2 2 34m 1 5cm 1 5cm Knive 1 Old bycicle tire 1 2 Epoxy glue 1 2 First of all the site for the plant must be found It is important to have enough space to bring materials to the fermenter using large transporting vehicles When a location is available a fundament is to be prepared The future container should be in a p
10. CO and lowest 0 Step 9 The black faucet 9 is opened X am 7000 Step 10 The Drager is disconnected to the inlet at the pink faucet 5 Though the pump device remains attached for another 10 min to flush the sensors Step 11 The Drager is turned off hold two blue but tons for 3sec 25 User Manual Reaction Observation Treatment and Troubleshooting Gas Meter twice a day Table 14 Short description to read the gas watch Description Amount Time 1 min Workers 1 The gas watch performs a continous measurement of the quantity of the gas running through it The watch can not be set to zero therfore the values have to be read and the initital value has to be subtracted QUE ood Figure 21 Gas meter and the reading Starting from the initial state the following steps have to be performed Step 1 The blend of the container where the gas watch is set in is lifted up Step 2 The whole number is read from the watch and recorded 26 User Manual Reaction Observation Treatment and Troubleshooting IV_C Errors amp Troubleshooting Inconsistent Percolation The failure is noticeable if during the percolation the sound inside the fermenter is on and off Visually it is also possible to see the percolate running intermittently through the filter Start with the procedure from top to bottom in the trouble shooting table Table 15 Trouble shooting for inconsistent percolation Possible reason Solution
11. Table 10 Short description of exchanging the filter Description Amount Time 5 min Workers il Fresh filter il Due to the suspends in the percolate the pump is protected by a filter This filter needs to be exchanged ap proximately every ten days or if pollution is visible To exchange the filter starting from the initial state the following steps have to be performed Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 22 The pump is switched from automatic to manual mode and starts running As soon as the spinkling is audible the pump is switched off again At once the orange faucet 4 is closed The green faucet 1 is closed The filter unit can be opened the percolate inside is lost The new filter is placed ensure accurate fitting The filter unit is closed thightly The green faucet 1 is opened The orange faucet 4 is opened the percolate captured in the pipes float the pump and the filter Test the filter by switching the pump to manual mode and let it run Switch it back on automati cal to retrieve the initital state By doing this the proper function of the filter can be tested no leaking If this is not the case repeat the whole procedure starting at Step 2 User Manual Reaction Observation Treatment and Troubleshooting Iv B Gas Tapping Yellow green faucet 10 Manometer Black faucet 9 Grey faucet 8 Brown faucet 7 Blue faucet 6 Pink faucet 5
12. V_A Adding Figure 23 Dissolving sodium hy liquids during the reaction droxide in water 28 The Pump is clogged Table 19 Short description of unclogging the pump Description Amount Time 15 min Workers 2 Wrench 2 User Manual Reaction Observation Treatment and Troubleshooting Solids that have passed the filter might block the pump and stop its functioning In this case the solids need to be removed Starting from the initial state of the percolation system see IV A in the manual the following steps have to be performed Figure 24 Percolation pump disassembled for cleaning Step 1 The power is turned off Step 2 The green faucet 1 is closed Step 3 The orange faucet 4 is closed Step 4 The red faucet 2 is opened to release the liquid inside the pump Step 5 The connections of the pump to the pipe system are unscrewed Step 6 Before removing the pump make sure one person stabilises the percolation pipes otherwise sealing can get damaged Step 7 Open the pump using a wrench Step 8 Reassemble the pump again make shure to stabilise the pipes Step 9 The red faucet 2 is cosed Step 10 The green faucet 1 is opened Step 11 The orange faucet 4 is opened Step 12 The power is turned on again 29 User Manual Unloading V_ Unloading Table 20 Process short description with necessary material Describtion Amount Time 1 day Workers 25 Wheel barrel 23 Fully assembled fermenter 1 Pe
13. Z rcher Hocnscnuia aquatic research 8 zh Life Sciences und Facility Management Sandec Water and Sanitation in Developing Countries USER MANUAL GUIDANCE FOR OPERATOR OF DRY FERMENTATION PLANTS FOR SOLID WASTE Appendix E by Lucien Biolley Renate Diggelmann Bachelor of Sciences 2008 Institute of Environment and Natural Resources at Zurich University of Applied Science 05 12 2011 Supervision Switzerland Prof Dr Urs Baier Zurich University of Applied Sciences ZHAW Yvonne V geli Swiss Federal Institute of Aquatic Sciences and Technology Eawag Department of Water and Sanitation in Developing Countries Sandec Supervision Ghana Prof Dr Ebenezer Mensah Kwame Nkrumah University of Science and Technology K N U S T Kumasi Content IH ILA NB ILC HI IV IVA IV_B IV_C V Introduction Preparation and Assembly Setting up the Container Setting up the Percolation System Setting up the Gas Tapping System Loading Reaction Observation Treatment and Troubleshooting Percolation System Initial State Percolation System Float the Pump with Water Running the Percolation System the first Time Percolat Sample twice a day Adding Liquids during the Reaction Exchange the Filter app every seven days Gas Tapping Initial State Gas Tapping Fill Flash Back Arrestor Empty Condensate Trap every day if gas is produced Gas Measure twice a day Gas M
14. d turned on the automatical mode describtion of the time switch can be found in III_ Loading Step 11 Float the Pump with Water Table 6 Short description to float the pump with water Description Amount Time 10 min Workers 1 Bucket il Garden hose 1x 5m 1x 20m To run the percolation system the first time before starting the pump needs to be flooded The easiest way to do this is by using water Starting from the initial state the following steps have to be performed Step 1 A bucket of water gets filled with water from the tap near the container app 5m depending on hose length Step 2 To the opening at the red faucet 2 a hose is connected Step 3 This hose is connected loosly to an other hose witch is hocked on to a water tap The two hoses are hocked together where the bucket of water from step 1 is placed Step 4 The red faucet 2 is opened Step 5 The water tap is opened water runs through the hose Step 6 By the time the water is visible inside the filter the green faucet 1 is closed This decreases the probability of captured air Step 7 The water is now pressed through the pump and fills the hole system until it exits trough the sprinkels inside the container The pump is now floated with water and ready to be switched on 18 Runnin User Manual Reaction Observation Treatment and Troubleshooting g the Percolation System the first Time Table 7 Short description to run the percolate system the f
15. eaning of the container for eventual maintenance User Manual References VI References Fei Baffoe Bernard Double stage dry wet fermentation of unsorted municipal solid waste Buch Cottbus Brandenburg University of Technology Cottbus 2006 Ferreira das Neves L cia Maria Gon alves Anaerobic Co Digestion Of Organic Wastes Buch Minho Uni versidade do Minho 2009 33 List O f Figures If no other source is declared the figures were generated by the authors themselves in the time period of the bache Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 34 lor thesis The present pilot plant with its assembly Model of the container with its two main work systems The percolation system with flow direction Percolation system inside the container The percolate outlet port collection pipe Gas outlet port from the container roof Model of the gas tapping system with the gas flow in black arrows Gas tapping system Loading of the container using a wheel barrel Loading and preparing of layers inside the container Modell of the loaded container Loaded container after assembling the percolate outlet port Silicon sealing using a silicon gun Door
16. ected to the T element which is linked to a piece of pipe This pipe finally leads to the inlet of the gas meter see Figure 8 The gas meter is used to count the liters of gas produced To make sure it registers the gas flow the gadget must be installed levelled The inlet and outlet of the gas meter are linked to transition parts using a pipe connection with a thread on one side The device is sheltered in a plastic box to prevent water damage The transition part on the gas meter outlet leads to an elbow element that is connected to a short piece of pipe directing to a T element Figure 8 Gas tapping system The last two parts of the measurements section consist of a faucet and a connection for a pressure gauge on the one opening of the T element see Figure 8 The final element on the second opening of the T element is a faucet to control the outlet of the gas It has to be closed for example while analysing the gas Finally a gas storage device could be installed as ultimate module 12 HI Loading User Manual Loading Table 4 Short process description with necessary materials Describtion Time Workers Wheel barrel Peek Showel Silicon Percolat outlet port Lock Amount 1 day 25 23 1 2 1 2 2 3 tubes 1 1 The loading of the container is the last possibility to easily take influence on the later reaction Therefore the preparations in advance are important As soon as all the materials are calcu
17. ek 1 2 Showel 1 2 Garden hose 1 Water supply 1 Polytank 3001 258 Sample buckets App 6 Drager 1 Exhaust source il Plastic cover 1 Broom 1 Cloth 1 2 Before unloading a batch the further procedure should be clear It is important to know whether the mate rial is reused or not Feedstock is called digestate after the reaction and is commonly used to inoculate the following reaction Also the percolate from the dismissed process should be stored to inoculate the next batch if there are no other specific plans for inoculation this procedure is described within Step 1 to 7 Pre liminary to the described procedure app 12 hours before starting the automatic percolation performed by the time switch needs to be turned off This helps to release the percolate from the fermenter in little time Starting from the initial state of the percolation system the following steps have to be performed Step 1 A hose is tapped to the percolate sample outlet port at the yellow faucet 3 Step 2 The orange faucet 4 is closed Step 3 The pump is switched from automatic to manual mode and the pump starts running Step 4 Right away the yellow faucet 3 is opened to release the percolate into buckets see Figure 25 Step 5 Ifthe pump starts to suck air through the percolation outlet port the pump is turned off for 30 min and re started after the percolate has covered the outlet port again Figure 25 Releasing the percolate from the container
18. enge about this is that the microorganisms to decompose those acids into methane are sensitive to low values of pH If the bacteria get affected the reaction acidifies itself as the produced acids are not decayed anymore Therefore the pH value is to be kept artificially on a high level above 6 during the reaction The most efficient treatment is to add a solution of sodium hydroxide As a matter of precaution the project members should wear safety goggles as well as rubber gloves whilst working with sodium hydroxide to prevent damages Table 18 Short description to correct pH value Description Amount Time 15 min Workers 1 Bucket 1 x NaOH 1 x water 2 Garden hose 1 Plastic bottle il Scale 1 Sodium hydroxide 05 ike Water Ca 50 droxide If the treatment is performed for the first time in a current re action the starting quantity should be low It is recommended to start with 0 5 kg dissolved in 301 of water The highest con centration should not extend 1 5 kg per 30l according to safety issues Starting from the initial state of the percolation system see IV_A in the manual the following steps have to be per formed Step 1 The amount of sodium hydroxide is measured using the scale Step 2 50lof water are kept ready in a 100l bucket Step 3 The sodium hydroxide is slowly stirred in Attention Heat is produced Step 4 After preparing the sodium hydroxide sollution the adding is performed as described in I
19. er occurs the door can be opened completely Following that the fermenter should be ventilated for about one day to make sure no harming gases to the works men are remaining inside Untilthe door will be closed again it should be supported to lessen the weight and prevent it from hanging Test the percolation To control the state of the sprinkler system the red faucet can be connected to a hose which is linked to the water supply Then the pump needs to be started Through the open door the per formance of the sprinkler system can be controlled If the liquid exits the pipes with too much pressure more openings have to be drilled If the water does not reach to the very back of the container some of the holes can be closed with insulating tape If many openings are clogged the drillings need to be enlarged Check the digestate decayed feedstock To control the execution of the digestion the digestate needs to be controlled This can be done by inspecting the material visually and examine the degree of degradation A further parameter to be checked is the wetness of the material If the digestate is evenly moist the percolation system fulfilled its purpose Where dry spots can be discovered the sprinkler system was inadequate Take samples of the digestate for COD To get an impression of the evenness of the performed fermentation samples should be taken from different sections of the container back centre front top middle and bottom
20. eter twice a day Errors amp Troubleshooting Inconsistent Percolation Percolation is not starting Pump is not starting PH Value too low lt 6 The Pump is clogged Unloading VI_ References 10 13 17 18 18 19 20 21 22 23 23 24 24 24 26 27 27 27 27 28 29 30 33 User Manual Introduction I_ Introduction The following manual should provide future managers of the considered biogas plants with all the infor mation needed to start maintain and end the reaction as well as give them some background information about the whole proceedure The guidebook of this plant aims to help nonprofessionals to generate biogas as a renewable resource to cover their energy need without polluting the environment with additional greenhouse gases The inten tion of this method also is to reduce the threat on Ghana s forests because of the use of wood fuels and to generate a use of wastes The following user manual is a part of the outcome of a bachelor thesis by Swiss students working at K N U S T in 2011 To understand the whole context of the plant all results of the thesis Biogas from solid waste development and further engineering of dry fermentation technology in Kumasi Ghana should be taken into account The documentation treats the so called single stage batch process where the plant consists of one or more fermenter assembled with a percolate system and a gas tapping part In the beginning the feedstock is l
21. he side can turn the automatical mode on and off 16 Figure 15 Time switch connected to the pump User Manual Reaction Observation Treatment and Troubleshooting IV Reaction Observation Treatment and Troubleshooting This chapter is subdivided in three parts A is the percolate system and B is the gas tapping see Figure 2 Both will be described with their standard position initial state in which they should be kept during ordinary process Then the different situation like sampling for analysis purposes and other things follow Procedures that repeatedly need to be done are marked with a red star In the end there is part C about typical errors that may occur and situation requiring a certain treatment with guideline for troubleshooting IV_A Percolation System Orange faucet 4 Yellow faucet 3 Green faucet 1 Red faucet 2 Filter Pump Figure 16 Model of the percolation system with legend 17 User Manual Reaction Observation Treatment and Troubleshooting Initial State Percolation System During the reaction the percolation system has to be in the following state to perform properly The green faucet 1 is open The red faucet 2 is closed The yellow faucet 3 is closed The orange faucet 4 is open The filter is assembled with a functional and therefore unsoiled filter that is assembled correctly The pump is connected to the electricity using the time switch The time switch is set an
22. illing with liquid This faucet is then connected to a transition part that is hooked up to a rubber hose The part to the right leads to the filter compartment It con sists of a hard plastic shell with an inlet and an out let The percolate flows through the inlet where it passes the filter itself and exits to the right It then enters the pump and flows up to the actual inlet of the percolation system The pipe leading to the top of the container encloses a T element which directs to the yellow faucet This part is set up to take per colate samples for measurements and monitoring of the process There is a further faucet installed above the mentioned T element to prevent the pump from sucking air while starting it manually On top of the pipe there is an elbow part needed and a further piece of pipe to lead to the inlet connection To link the inlet with the pipe an additional elbow part is put in place Generally all parts of the percolation system and of the gas tapping parts which are stuck together and not screwed should be glued together with PVC glue to make sure no leaking occurs flow direction Figure 3 The percolation system with User Manual Preparation and Assembly After the percolate enters the container it must be distributed over the feedstock as regularly as possible on the inside This can be achieved by installing two pipes on the ceiling The pipes must reach to the very back of the fermenter They ca
23. irst time Description Amount Time 30 min Workers 2 Bucket 2 Garden hose 1x 5m 1x 20m At this moment the fermenter inside is still dry and no percolate has entered To run the fermentation water and percolat from previous reaction will be added Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 At the moment the pump gets switched on manually a second person has to tear the loosely connected hoses appart This must take place inside the bucket under the water surface To make sure the pump sucks no air The previously calculated amount of water is added portionaly By filling up one bucket up to a level that is kept note of while the content of the other one is beeing pumped in Alternately the buckets get filled and emptied so one worker can take note of the amount that gets pumped in By the time the necessary quantity is reached the green faucet 1 is opened Right after the red faucet 2 is closed The percolation is running now To reach the initial state only the set up pump has to be switched to the automatical mode for advise see III_ Loading Step 11 19 User Manual Reaction Observation Treatment and Troubleshooting Percolat Sample twice a day Table 8 Short description to take a sample from percolate Description Amount Time 5 min Workers il Sample flask il Hach HQ40d Multimeter il During the reaction some in process control IPC has to be performed to gain information about the reac
24. lated and present the loading can be startet At this moment a representative sample including all the materials is taken It will be used for COD TS and VS analysis Table 5 Possible contents and some estimation of their amount Material describtion Organic waste Coarse woody material Cow dung can be used as inoculent Inoculent usually from previous reactions Calciumcarbonate Percolate usually from previous reactions Water Estimated amount 6 8t 10 50kg 0 8t 6 8t 3 6kg 750 1000L 750 1000L 13 User Manual Loading Step 1 The coarse and woody material if present is placed on the floor Step 2 Organic waste and inoculent from previous reac tions are filled into the container if no inoculent use cow dung The easiest way to do this is using a weel barrel therefore build a ramp with a wooden board to en ter the container with the help of some additional worksmen alternately one load of each ingredient is added 14 Figure 9 Loading of the container using a wheel barrel se s l a pF a BF s A 4 Figure 10 Loading and preparing of layers inside the container User Manual Loading This leads to diagonal layers of the materials shown in Figure 11 Step 3 Calciumcarbonate is added to help keeping the reaction within a comfortable pH range pH buff a Feedstock layer ering The whole amount is spread between the Inoculent layer layers during the loadi
25. lected in the condensate trap From time to time at least once a week the trap needs to be emptied To empty it starting from the initial state the following steps have to be performed Step 1 The blue faucet 6 is opened The condensate exits the system Step 2 The blue faucet 6 is closed again Gas Measure twice a day Table 13 Short description for the gas measurement Description Amount Time 20 min Workers il Drager X am 7000 1 Pump attachment for Drager 1 24 User Manual Reaction Observation Treatment and Troubleshooting To keep track on the reaction inside the fermenter the gas quality is measured twice a day This is also pos sible if the reaction does not yet produce gas thanks to the Drager X am 7000 being equipped with a pump Starting from the initial state the following steps have to be performed Step 1 The Drager device is turned on push green button for 3sec Let it equilibrate the sensors Step 2 Run fresh air calibration of the Drager Menu Fresh air calibration Step 3 The black faucet 9 is closed Step 4 The hock up for the Drager device is connect ed to the inlet at the pink faucet 5 Step 5 The pink faucet 5 is opened Step 6 The pump device is attached to the Dr ger and the pump starts The Drager records time of the pump running Step 7 The values are observed during ten minutes During this time they stabilise however the best values observed are noted highest CH lowest
26. n be fixed to the roof by metal rings which are welded to the ceiling as mentioned above see Figure 4 The pipes leading to the back of the fermenter contain holes on the side with a width of two mm The punctures are positioned on the sides of the pipes and have different distances start ing with 20 cm in the beginning and decreasing towards the back to 7cm The very end of the pipes must be connected with an appropriate piece The inlet connection is hooked up to a pipe con nection with a thread which is glued to a short piece of pipe that is connected to an elbow After that part a further piece of pipe follows which is connected to a T element The one exit leads to the first percolate pipe and the second to a further piece of regular pipe On the end of this part an elbow is attached that is connected to the second percolate pipe Figure 4 Percolation system inside the container Now only one part is missing to ensure the per colate floats back to the outlet without carry ing solids of relevant size to the pump To make sure this does not happen a percolate connec tion pipe should be installed on the bottom in the fore of the fermenter This part has to be connected to a transition part that leads to the outlet of the percolate system The pipe should also be modified by drilling holes into it 2mm The openings will serve as the inlet of the per colate The pipe is comparable to a drainage where the percolate is drai
27. ned out of the feedstock and then led to the outlet With this last part the percolation system is completed User Manual Preparation and Assembly Figure 5 The percolate outlet port collection pipe User Manual Preparation and Assembly IH C Setting up the Gas Tapping System Table 3 List of the material used to assemble the gas tapping system Describtion Amount Time 1 2 days Workers 1 2 Pipe Valve T element Elbow Pipe connection with thread Gas inlet connection Transition part linch to 0 5 inch Gas meter Pressure gauge Drager Rubber hose PAO sin Water bottle Hose clip PVC glue Epoxy glue Old bicycle tire Knive ES E D E PRPrPWRrRrREPOAL A PRPrPrPNP After assembling the percolation system the gas measurements should be installed The outlet of the gas is located on top of the container Next to the connection a short piece of a one inch pipe should be installed see Figure 6 which is attached to an edge connection Figure 6 Gas outlet port from the container roof 10 User Manual Preparation and Assembly Following this part a further piece of pipe is needed which is also joined to an edge part This piece of pipe must reach to the edge of the container so that the pipe leading the gas to the measurements can be linked to it Pressure gauge Gas analyser Condensation trap Figure 7 Model of the gas tapping system with the gas flow in black arrows The first part
28. ng Step 4 After loading the mentioned materials into the container the sealing is checked Step 5 The percolat outlet port is assembled a E mc Step 6 Figure 12 Loaded container after assembling the Optional To lessen pressure on to the door right percolate outlet port in front of it some wooden loggs can be placed see Figure 12 Step 7 Then silicon is poured on the sealing where later the door will tighten with it Figure 13 Silicon sealing using a silicon gun 15 User Manual Loading Step 8 The door gets closed and locked Figure 14 Door prepared to be closed Step 9 Optional Additionaly the door can be pressed closer with a wooden block that is arrested Step 10 Percolat and water are added using the percola tion system The detailed describtion of this step can be found in Reaction observation treatment and troubleshooting Fillthe Pump with water and Adding liquids during the reaction Step 11 The last thing to do is to programm the time switch that automatically controls the percolation Then the initial state of the plant described in Reaction observation treatment and troubleshooting is set see Figure 15 The time switch consists of 48 tiny red switches of which each one controls the electricity during 30 min If this red switch is positioned in the outer circle the electricity will pass this very moment and therefore the pump will run An additionaly switch on t
29. oad ed into the fermenter and the door is closed For the remaining time of the reaction the door stays closed PN Sax 5 TE 1 The present pilot E with its assembly User Manual Introduction By that time the process called anaerobic digestion which is carried out by different types of bacteria de gredading organic material starts generatinf biogas This reaction also appears naturally in some environ ments like moors manure pits or land fills Ferreira das Neves 2009 To create the needed surroundings several conditions must be guaranteed The first and most important is the absence of oxygen The working bacteria can only exist in a anaerobic milieu A further condition is a damp ambience because the used bacteria live in liquids Therefore a percolation system must be installed inside the plant see chapter TI Preparation and assembly The temperature of the organic material influences the time needed for the reaction The process in this plant prevers a temperature between 30 35 Celsius Fei Baffoe 2006 The last main condition to be assured is a optimal pH which describes the acidic or basic character of the percolate This factor should be kept at a value between 6 and 7 5 to assure the right condition for the bac teria Ways to adjust the pH can be found in the chapter IV Reaction observation treatment and trouble shooting During the work on the container the following points should always be kept in mind Avoid
30. or the gas measurement Short description to read the gas watch Trouble shooting for inconsistent percolation Trouble shooting for percolation error Trouble shooting for pump error Short description to correct pH value Short description of unclogging the pump Table 20 Process short description with necessary material 10 13 13 18 19 20 21 22 24 24 24 26 27 27 27 28 29 30 35
31. osition to allow the percolate to exit at the container outlet There should also be some kind of preservation to the subsidence of the container like a concrete surface or ground covered with stone plates The next step is to purchase a second hand shipping container The biggest abundance can be found at bigger ports like the one in Tema Ghana Before buying the container several points should be checked No rust or other signs of corrosion A good quality door sealing No hanging door A floor without gaps cracks No bumps in the walls User Manual Preparation and Assembly After guaranteeing these conditions the transportation of the container can be started Nevertheless it is crucial not to damage the device in any way while transporting it to the site If there are any ventilation holes in the container these need to be welded up so that no air can enter the plant anymore Subsequently the inlet for the percolation system and its outlet as well as the gas outlet needs to be prepared The openings must be the right size to fit a connection to a regular one inch plumbing pipe A further welding task is the installation of the bracket for the percolation system During the next phase measures to preserve the condition of the container shall be undertaken The following list contains possible measures to ensure a sustainable state of the container but is not man datory depending on the present state Paint the surface
32. tion and its progress The sample will be measured twice daily in pH temperature and redox potential App every 7 days a COD Chemical oxygen demand measurement is carried out Outgoing from the initial state the following steps have to be performed Figure 17 Percolate analyses in progress Step 1 The pump is switched from automatical to manual mode and then turned on Step 2 The percolation starts when the sprinkling inside the container is audible then the yellow faucet 3 is opened carefully Step 3 By holding the sample flask under the pipe outlet at the yellow faucet 3 app 200 300ml of percolate is sampled Step 4 The yellow faucet 3 is closed Step 5 The pump is switched from manual to automatic mode Step 6 The electrode of the Hach HQ40d Multimeter is placed inside the sample switched on and measured ON button green Read button Step 7 every 7 days For the COD the sample is filled into a plastic bottle which is labelled with the name of the sample and the date The analysis is carried out by the civil engineering laboratory 20 User Manual Reaction Observation Treatment and Troubleshooting Adding Liquids during the Reaction Table 9 Short description of liquid addition during the reaction Description Time Workers Bucket 1 x adding 1 x water Garden hose Plastic bottle Amount 15 min depending on the substance During the reaction it is impossible to add any solids unless they
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