Biogas Generation and its Utililities GUIDE :- Prof.A.M.Andhare Suyash Shukla Roll no:- 77 R.C.E.M

Contents What is biogas? Biogas generation Applications of biogas Biogas as fuel Biogas to power Disadvantages Conclusion

What is biogas? Typically 55% methane (CH 4 ) 45% carbon dioxide (CO 2 ) H 2 S and H 2 O and trace gases Energy comes from methane only Energy value of methane 37.78MJ/Nm3 Energy value of biogas 21MJ/Nm3

Anaerobic digestion technology In the absence of dissolved oxygen, anaerobic microorganisms will tend to ferment biodegradable matter to carbon dioxide and methane which can be collected and use as a fuel. This process is called “anaerobic digestion”

What is Biodigester? Biodigester is a system that promotes decomposition of organic matter. It produces biogas, generated through the process of anaerobic digestion. Biogas generated can be used for cooking, heating, electricity generation, and running a vehicle.

Generation of biogas

Biogas utilisatio n Electrical energy Therma l energy Feeding in gas grid Biogas cleanin g Biogas upgrading Cogeneration Cooking Lighting Cooling Heating Direct burnin g Vehicle fuel Spreading Gardening Agriculture Transport Energy crops, grass from Landscape maintenance (grass, maize, beets) Agricultural residues (manure, slurry) fermentationfermentation Bioenergy System with Liquid and Solid Feeding Storage Separation solid components become compost solid components become compost liquid components back to the fermentation or spreading

Biochemical Process of Biogas Production Carbohydrate f.e : Glucose :-C 6 H 12 O 6 → 3 CO CH 4 50 % : 50 % Fat: Palmitic acid :- 2 C 6 H 32 O H 2 O → 9 CO CH 4 28 % : 72 % Protein:_ 2 C 13 H 25 O7N3S + 12 H 2 O → 13 CO CH NH H 2 S 38 % : 38 % : 18 % : 6 %

The Process of Biodigestion Hydrolysis Acidification Methanogenation

Factors effecting the biogas production pH value Carbon-Nitrogen ratio Temperature Retention time Loading rate Dilution and consistency of inputs Heavy metals Volatile solids Stirring

CH4-enriched biogas: a transport fuel Biogas scrubbed to 97% CH4 has as energy value of 36.6MJ/nm3 1nm3of biogas produces 0.57 nm3 CH4- enriched biogas 10km to 1nm3of CH4-enriched biogas, Volvo V70

Asset value of biogas used as transport fuel 1nm3of CH4-enriched biogas replaces 1L of petrol 1nm3of biogas produces 0.57 Nm3 CH4-enriched biogas 1nm3of biogas replaces 0.57L of petrol Unleaded petrol costs €1/L (April 2005) Assume excise duty relief (Bio fuels Directive) Economic value of 1Nm3of biogas €0.47 (VAT at 21%)

BIOGAS TO POWER Power is in short supply. 78,000MW planned in 11 th Plan lac villages and 56 % of household are non electrified- Power is in big deficit. Rural, decentralized and renewable power -A Priority. Process industries need high quality and uninterrupted power. Any expansion /New downstream projects will require additional, quality power. Power generation/Cogeneration is becoming an important revenue stream.

Power production adds significant costs to the overall digester project, but without the power production capability these anaerobic digester systems would not be cost effective at the current $1M plus price tag.

BIOGAS TO POWER  Successful reference plants available –reduced risk.  Elemental Sulphur as a high value bi-product from Bioskrubber process, an added advantage.  benefits – Generate more power, get more benefit  Therefore generating additional power from biogas now makes good business sense.

Biogas application from “ Heat to Power ” A High Value Shift Biogas already available with many distilleries. Current utilization of biogas - mostly as heat value. Biogas fired Gas Engines - for high value shift. 1 m3 of gas fired in engine can give 2 units of power. H 2 S in the biogas must be removed for gas engine application. Typical H 2 S in biogas from distilleries is 3% to 5%.Should be brought down to 250 ppm.

Applications It may be used as main fuel for cooking, direct lighting. Generation of electricity using internal combustion engines/ steam turbines or gas turbines The residue of input coming out from digester is used as fertilizer to enhance the crop production

Disadvantages Biogas has corrosive nature and storage of biogas is not practical. Regular cleaning with periodic removal of solid residues from the system must be maintained Gas production is lower than the capacity of plant Gas leakage from dome and gas valve is likely to occur Blockage in inlet connection

Future of BIO-ENERGY Biomass-fired electric power plants Liquid fuels e.g. bio-ethanol, bio-diesel Improved cook stove tech Cottage industrial applications e.g. brick- making, ceramics, tobacco curing,etc. Large industrial applications/ electricity generation

REFERENCES Dr Jerry D Murphy :- Anaerobic digestion and biogas,may Chris Henry." What is an Anaerobic biodigester?”.July 10, 2006 Non conventional energy sources by s.k dubey, s.k. bhargava