Designing and fabrication of organic waste based biogas power plant

Project Title

Designing and fabrication of organic waste based biogas power plant

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Kitchen waste (KW) can be utilized to produce biogas due to its high biodegradability, calorific value and nutritive value to microbes, which will reduce our dependency on fossil fuels. The research work was conducted to investigate the production ability of biogas as an alternative energy from KW with co-digestion of cow manure (CM) through anaerobic digestion (AD). Firstly, three digesters were prepared to observe the individual degradation rate of KW, CM and co-digested KW with CM at room temperature (25°C~30° C) and at temperature of 37°C (mesophilic digestion) respectively and observed the degradation rate for co-digested KW with CM was higher than KW and CM alone. Secondly, three digesters were constructed to observe the effect of alkalinity at temperature 37° C and loading rate 200 gm/L. Three alkali (NaOH) doses 1.0%, 1.5% and 2.0% on wet matter basis of kitchen waste were applied to improve biodegradability and biogas production. The highest degradation rate was 6.8 ml/gm which was obtained from 1.5% NaOH and also observed that biogas production was almost doubled from treated KW than untreated KW. Finally, a portable biogas reactor was fabricated for pilot-scale biogas production which included an agitator and heating system. This reactor was operated at both 37° C and room temperature at a loading rate of 200 gm/L and observed that the digestion rate was faster at 37° C than room temperature. The prime object of this work was to investigate the prospect of kitchen waste for biogas production and ultimate protection of environment from the bad effect of methane gas that would be produced by uncontrolled anaerobic digestion.

Project Objectives

Biogas generated from Biogas  plant will be used for cooking purposes.

Generation of electricity from Biogas plant for home by using biogas in gas turbine

The heat generated can be utilized to heat building or to dry wood or harvest products.

Pollution will be controlled by using organic waste of home at bio gas plant.

To increase the renewable energy production from biogas with small-scale concepts for energy self-sufficiency.

To reduce greenhouse gas emissions due to the consumption of renewable energy sources and to the adequate waste management.

To increase governmental support to biogas technology by new regulations on energy self-sufficiency with net balance.

• purify the methane gas by removel of co2 ,h2s and water

• Purification of methane gas by using   chemical combustion with CaCo3 and KOH.

•Pollution will be controlled by using organic waste at bio gas plant.

Project Implementation Method

Organic input materials such as foodstuff remnants, fats or sludge can be fed into the biogas plant as substrate. Renewable resources such as corn, beets or grass serve as feed both for animals such as cows and pigs as well as for the microorganisms in the biogas plant. Manure and dung are also fed into the biogas plant. In the fermenter, heated to approx. 38-40 °C, the substrate is decomposed by the microorganisms under exclusion of light and oxygen. The final product of this fermentation process is biogas with methane as the main ingredient. But aggressive hydrogen sulphide is also contained in the biogas. A fermenter made of stainless steel has the clear advantage that it withstands the attacks of the hydrogen sulphide and is usable for decades. Furthermore, a stainless steel fermenter provides the opportunity to operation the biogas plant also in the thermophile temperature range (up to 56 °C).Once the substrate has been fermented, it is transported to the fermentation residues end storage tank and can be retrieved from there for further utilization. The residues can be utilized as high quality fertilizer. The advantage: Biogas manure has a lower viscosity and therefore penetrates into the ground more quickly. Furthermore, the fermentation residue quite often has a higher fertilizer value and is less intense to the olfactory senses. But drying it and subsequently using it as dry fertilizer is also an option. The biogas generated is stored in the roof of the tank and from there itis burned in the combined heat and power plant (CHP) to generate electricity and heat. The electric power is fed directly into the house. The heat generated can be utilized to heat building or to dry wood or harvest products. Processing of biogas Gas supply to the kitchen for cooking purposes.

Benefits of the Project

Organic waste bio gas power plant reduces the amount of waste and generates products of value, such as biogas and nutrient-rich digestate. Contrary to the wide dissemination of digesters in rural areas where animal manure is used as feedstock and despite its apparent potential, organic waste bio gas power plant still plays a negligible role as a treatment option for organic kitchen and market waste in cities of low-and middle-income countries

Biogas manure has a lower viscosity and therefore penetrates into the ground more quickly. Furthermore, the fermentation residue quite often has a higher fertilizer value and is less intense to the olfactory senses. But drying it and subsequently using it as dry fertilizer is also an option. The biogas generated is stored in the roof of the tank and from there itis burned in the combined heat and power plant (CHP) to generate electricity and heat. The electric power is fed directly into the house. The heat generated can be utilized to heat building or to dry wood or harvest products. Processing of biogas Gas supply to the kitchen for cooking purposes.

The use of biogas is suitable for cases where both strictly regulated cooking for large groups (with up to 15 persons) and unregulated individual use by numerous detainees is practiced. It is recommended that all the gas produced per day is consumed in order to reduce purchasing of conventional cooking fuel and to avoid losses given the limited gas storage capacity of the digester dome.

Technical Details of Final Deliverable

• Check the gas-tightness of the pipes (pressure-test) Close the main valve (on top of the dome) and connect a gas pressure meter (0 – 160 mbar) in the kitchen ahead of the (closed) kitchen valve. Open the main valve 46 Anaerobic Digestion of Biowaste in Developing Countries and wait until the pressure rises up to at least 100 mbar, then close the main valve. Wait 10 minutes. If the pressure decreases by more than 5 mbar, use a soap and water solution to detect the leaks. Necessary repair work can then be undertaken to fix the leaks. Repeat the test until the pressure remains constant. • Check the gas tightness of the dome (pressure-test) Connect the pressure gauge right after the main valve on top of the dome. If the pressure, even after several days of no gas being consumed never rises up to the maximum design pressure (i.e. the pressure at which the slurry level in the compensation chamber reaches overflow point), then the dome is probably not gas tight and needs to be checked. Leaks can be detected by applying soap water on the dome, if accessible, and then repaired. • Check blockage of inlet pipe Another reason for low gas production is clogging of the inlet pipe. This will eventually prevent feeding substrate into the digester. Depending on the design, the inlet pipes can be unblocked either with a long plastic tube or wooden stick at the feeding point or at the inspection chambers (if available). • Check blockage of gas pipe by condensed water Check and empty the condensate water trap. • Observe the slurry level in the compensation chamber The level should be high in the morning as gas is produced overnight, and lower during the course of the day when gas is consumed. • Check gas-producing activity of digestate If the pH in the digestate is neutral but it is not clear if the slurry inside the digester is still active (i.e. producing gas), the balloon test can be applied. Fill approximately 1 L of slurry in a 1.5 L PET-bottle, put a balloon onto the top of the bottle and seal it with tape to prevent gas escaping. Leave the bottle with the attached balloon for one week in the sun, shaking it carefully on a daily basis to avoid the formation of a hard scum layer in the bottle. If the slurry still contains anaerobic bacteria, the balloon will slowly inflate. However, this method cannot determine the gas content (methane or carbon dioxide). 

Regular monitoring of the biogas production is useful as the operator then learns to detect disturbances in the biology inside the digester. However, as no simple, reliable and inexpensive biogas flow meters are available and experience shows that this extra-effort by operators cannot be expected and ensured, regular measurement of the daily gas production is not considered essential. This implies that the operator must react quickly when observing problems. 

Final Deliverable of the Project Hardware SystemCore Industry Energy Other Industries Others Core Technology Wearables and ImplantablesOther Technologies Clean TechSustainable Development Goals Responsible Consumption and ProductionRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	78200
digester tank 1000L	Equipment	1	13000	13000
collector tank	Equipment	1	6800	6800
overflow tank	Equipment	1	6800	6800
Gas purified tanks	Equipment	3	2000	6000
pipe length 2*700	Equipment	1	1400	1400
fitting components &material	Equipment	1	5000	5000
construction material charges	Equipment	1	2000	2000
compressor	Equipment	1	2000	2000
Gas turbine	Equipment	1	10000	10000
chemicals	Equipment	1	2000	2000
inlet mouth	Equipment	1	1000	1000
Air exaust	Equipment	1	1000	1000
transport charges	Equipment	1	1500	1500
2 pressure gauge	Equipment	1	1000	1000
others	Equipment	1	9700	9700
copies	Miscellaneous	2	3000	6000
others	Miscellaneous	1	3000	3000