Dr. Virendra K. Vijay

Purification and bottling technology for biogas to make it vehicular Fuel and possible collaboration with NUS By Dr. Virendra K. Vijay Centre for Rural Development & Technology Indian Institute of Technology, Delhi Hauz Khas, New Delhi, India E mail: vkvijay@rdat.iitd.ernet.in IITD

Contents Introduction Biogas potential in India Biogas production from different wastes Studies on Biogas generation from deoiled seed cakes from Jatropha and Pongamia Biogas purification technologies Technology developed at IIT Delhi Studies on membrane gas separation Collaboration between NUS and IITD conclusion

Introduction Go green too much of chemicals and fossil fuels Waste management and recycling green energy a paradigm shift Biogas is an important renewable energy resource It is produced by anaerobic digestion of bio wastes. You have materials around for biogas production It is an environment friendly, clean, cheap and versatile fuel. Biogas generally comprise of 55 65 % methane, 35 45 % carbon dioxide, 0.5 1.0 % hydrogen sulfide and traces of water vapour.

Biogas like Liquefied Petroleum Gas (LPG) cannot be liquefied under normal temperature and pressure. Critical temperature required for liquefaction of methane is 82.1 o C at 4.71MPa pressure, therefore use of biogas is limited nearby the biogas plant. An estimate indicates that India has a potential of generating 6.38 X 10 10 m 3 of biogas from 980 million tones of cattle dung produced annually. The heat value of this gas amounts to 1.3 X 10 12 MJ. In addition, 350 million tones of manure would also produce along with biogas.

Sr. No. Organic Wastes & their Estimated Availability in India Organic Wastes Estimated Quantity 1. Municipal Solid waste 30 million tons/year 2. Municipal liquid waste 12000 million litres/day 3. Distillery (243 units) 8057 kilolitres/day 4. Press mud 9 million tons/year 5. Food & fruit processing wastes 4.5 million tons/year 6. Willow dust 30000 tons/year 7. Dairy industry waste 50 60 million litres/day 8. Paper & pulp industry waste (300 mills) 1600 m 3 /day 9. Tannery (2000 units) 52500 m 3 waste water/day Source: MNES Report, Renewable Energy in India and business opportunities, MNES. Govt. of India, New Delhi, 2001

Biogas Production Process Biogas production process (Anaerobic digestion) is a multiple stage process in which three main stages are: Hydrolysis: hydrolysis is one of the main steps. During hydrolysis, the complex insoluble substrate macromolecules are hydrolysed into simpler and more soluble intermediates by bacteria. Acidogenesis: Volatile acid fermentation, during which the products of hydrolysis are converted into organic acids through the biochemical processes of acidogenesis (where monomers are converted to fatty acids) and acetogenesis (the fatty acids are converted to acetic acid, carbon dioxide, and hydrogen) Methanogenesis: Methane formation, during which the organic acids produced during the fermentation step are converted to methane and carbon dioxide.

Chemical reactions involved in biogas production: C 6 H 12 O 6 3CO 2 + 3CH 4 CO 2 +4H 2 >CH 4 +2H 2 O CH 3 COOH > CH 4 + CO 2

The quantity, rate and composition of biogas generated depends on The nature and concentration of the substrate, Feed rate C N ratio ph value, Bacterial population, Temperature

Biogas Production Potential from different Wastes

Studies on Biomethanation of Jatropha and Pongamia deoiled seed Cakes A research work on biogas production from jatropha and pongamia deoiled cakes has been carried out at IIT Delhi This was started due to availability of large amount of delioed seed cakes as by product of biodiesel programme The experimental study was carried out under batch and continuous feeding of nonedible deoiled seed cakes with the following objectives:

Objectives: 1. To characterize the properties of jatropha and pongamia deoiled seed cakes as feed materials for biomethanation. 2. To study the effect of process parameters on quality and quantity of biogas produced for selection of optimal process parameters. 11

Setup for Batch Biomethanation Study Cork Valve Cork Valve Gas Contituents Analysis (Biogas Analyzer) Cork 5 L Aspirator Bottle [DIGESTER] 5 L Aspirator Bottle Filled With Water Valve Gas Volume Measurement (Measuring Cylinder) 12

Experimental Setup used for Preliminary Batch Study 13

Continuous Feeding Experimental Investigation on Selected Treatments in Digester of 300 Litre Capacity Guide Pipe to Support Gas Holder 66.25 cm Valve Influent Inlet Gas Holder To Gas Flow Meter and Gas Sampler Digester Effluent Oulet 61.5 cm 68.5 cm Slurry Level 72.5 cm 17.5 cm 5 cm 5 cm Annular Ring for Supporting Gas Holder 75 cm Partion Plate Structure of Mini Digester PHASE-II 14

Gas Holder Supporting Structure Ground Level D D 30 30 A C B1 B F 15 Thick Partion Wall 10 Diamter ASB/CEM Pipe Central Guide Frame Flange Plates 7.5 23 All dimensions in centimetres 23 7.5 30 15 Earth Filling 10 Diamter ASB/CEM Pipe CC Foundation (1:3:6) Biogas plant (20 m 3 /d) capacity available at IIT Delhi for study on biomethanation of various substrates 15

1. Characterization of Jatropha and Pongamia deoiled Seed Cakes: Proximate Analysis 1. Moisture content 2. Oil content 3. Total solids 4. Volatile solids, and 5. Non-volatile solids content Ultimate Analysis 6. Carbon 7. Hydrogen, and 8. Nitrogen Manurial Value 9. Phosphorus and Potassium 16

Feed material Moisture content % Oil content % Physiochemical properties Total solids % Volatile solids % Non-volatile solids % Cattle dung 81.6 (442.5 db) Nil 18.4 14.4 (78.8 db) 21.2 Jatropha oil seed cake 07.5 (8.1 db) 8.3 92.5 86.4 (93.0 db) 07.0 Pongamia oil seed cake 10.5 (11.7 db) 7.2 89.5 85.3 (94.8 db) 05.2 Ultimate Analysis and carbon-nitrogen ratio of feed materials Sr. No. Feed material C (%) H (%) N (%) C/N ratio 1 Cattle Dung 35.20 4.60 1.55 22.7 2 Jatropha oil seed cake 48.80 6.20 3.85 12.7 3 Pongamia oil seed cake 47.80 6.50 5.50 8.7 Manurial values of feed materials Sr. No. Feed material Phosphorus (%) Potassium (%) 1 Cattle Dung 0.69 1.66 2 Jatropha oil seed cake 2.09 1.68 3 Pongamia oil seed cake 1.00 1.00 17

To study the effect of process parameters on quality and quantity of biogas produced for selection of optimal process parameters Sl. No. Treatment Substrate concentration of the daily feed material Total solids Volatile solids kg/d kg/d Jatropha deoiled seed cake substrates 1 JC (4.0 DR,0 % CD) 9.25 8.64 Pongamia deoiled seed cake substrates 2 PC (3.5 DR,0 % CD) 8.95 8.53 18

24 h Soaked Pongamia deoiled Cakes 24 h Soaked Jatropha deoiled seed Cakes

Biomethanation in Floating Drum Biogas Plant of 20 m 3 /d Capacity Biogas Plant After Feeding Biogas Plant Before Feeding 20

Orifice Diameter: 6 mm Area: 28.27 mm 2 Gas Pressure: 400 mm of water Gas Flow Rate: 4.75 L/minute CH 4 : 53 %, CO 2 : 43 % A View of Flame on Cattle Dung Derived Biogas Orifice Diameter: 6 mm Area: 28.27 mm 2 Gas Pressure: 100 mm of water Gas Flow Rate: 2.38 L/minute CH 4 : 65 %, CO 2 : 32 % A View of Flame on deoiled seed Cake Derived Biogas

Daily Biogas Production Biogas Production m 3 /d 9.50 9.00 8.50 8.00 7.50 7.00 6.50 6.00 5.50 5.00 4.50 4.00 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 Range of ambient temperature variation 30.7 to 36.6 C Pongamia deoiled seed Cake KC [3.5 DR, 0 % CD] Biogas Production SubstrateTemperature 1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930 40.0 39.0 38.0 37.0 36.0 35.0 34.0 33.0 32.0 31.0 30.0 29.0 28.0 27.0 26.0 25.0 Substrate Temperature, C HRT, Days

Yield at STP, m 3 210.0 200.0 190.0 180.0 170.0 160.0 150.0 140.0 130.0 120.0 110.0 100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 Cumulative Biogas, Methane and Carbon Dioxide Yield Cumulative methane yield Cumulative carbon dioxide yield Cumulative biogas yield 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 HRT, Days Jatropha deoiled seed Cake JC [4.0 DR, 0 % CD] 23

Yield at STP, m 3 240.0 230.0 220.0 210.0 200.0 190.0 180.0 170.0 160.0 150.0 140.0 130.0 120.0 110.0 100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 Cumulative Biogas, Methane and Carbon Dioxide Yield Cumulative Methane Yield Cumulative Carbon Dioxide Yield Cumulative Biogas Yield 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 HRT, Days Pongamia deoiled seed Cake KC [3.5 DR, 0 % CD] 24

1.0 0.9 0.8 Specific Biogas Yield Biogas/kg TS Biogas/kg VS Specific Biogas Yield, m 3 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 HRT, Days Jatropha Oil Cake JC [4.0 DR, 0 % CD] 25

Specific Biogas Yield Specific Biogas Yield, m 3 0.950 0.900 0.850 0.800 0.750 0.700 0.650 0.600 0.550 0.500 0.450 0.400 0.350 0.300 0.250 0.200 0.150 0.100 0.050 0.000 Biogas/kg TS Biogas/kg VS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 HRT, Days Pongamia deoiled seed Cake KC [3.5 DR, 0 % CD] 26

Utilization of Biogas Cooking: Biogas can be used in a specially designed burner for cooking purpose. A biogas plant of 2 cubic metres capacity is sufficient for providing cooking fuel needs of a family of about five persons. Lighting: Biogas is used in silk mantle lamps for lighting purpose. The requirement of gas for powering a 100 candle lamp (60 W) is 0.13 cubic metre per hour. Power Generation: Biogas can be used to operate a dual fuel engine to replace up to 80 % of diesel oil. Diesel engines have been modified to run 100 per cent on biogas. Petrol and CNG engines can also be modified easily to use biogas. Transport Fuel: After removal of CO 2, H 2 S and water vapour, biogas can be converted to natural gas quality for use in vehicles.

4 million family size biogas plants have been installed in India against the potential of 12 million to substitute petroleum, kerosene and direct burning of biomass used for cooking and home lighting. Many projects for energy recovery from municipal solid wastes with an aggregate capacity of 17.6 MW have also been setup at Hyderabad, Vijaywada and other places in India.

Other urban waste projects include a 1 MW project based on cattle dung at Haebowal, Ludhiana; a 0.50 MW project for generation of power from biogas at sewage treatment plant at Surat, Gujarat; and a 150 kw plant for vegetable market and slaughter house waste at Vijaywada. Besides, waste to energy projects with an aggregate capacity of about 30 MW from a variety of industrial wastes also been setup in India.

Some big projects on Biogas in India:

1.89 MW Power Generation Project Based on Biogas Produced from Starch Industry Liquid Waste Through 100% Biogas Engines

12,000 m 3 Biogas per day biomethanation project from Starch Industry Liquid Waste in Salem, Tamilnadu

8.25MW biogas based power project in a distillery at Banur, Dist. Patiala, Punjab

Need for the Biogas Purification and Bottling Potential of biogas is not fully utilized and commercialized so far. For commercialization, its area of application may widen; from cooking fuel to vehicle fuel. For use as a vehicle fuel, it should be bottled like CNG. Before bottling, it should enriched in methane content from 55 % to 95 %; similar to CNG.

CO 2 & H 2 S Removal Processes from Biogas: S. No. Method Advantages Disadvantages 1. Absorption in Water One of the easy and cheap method for CO 2 removal. Recommended for rural application. Water pumping load is high. CO 2 can not be recovered 2. Absorption by Chemicals The chemical absorbents are more efficient in low pressure and can remove CO 2 to low partial pressures in treated gas. Regeneration of the solvent requires a relatively high energy input. Disposal of by-product formed due to chemical reactions is a problem. 3. Pressure Swing Adsorption By proper choice of the adsorbent, this process can remove CO 2, H 2 S, moisture and other impurities. Adsorption is accomplished at high temperature and pressure. Regeneration is carried out by vacuum. It is a costly process. 4. Membrane Separation Modular in nature and separate CO 2 and CH 4 effectively. Suitable to Small capacity, cost is high. Also life of membranes is less. 5. Cryogenic Separation Allows recovery of pure component in the form of liquid, which can be transported conveniently High cost involved makes it impractical for Biogas applications. 6. Chemical Conversion Extremely high purity in the product gas. Process is extremely expensive and is not warranted in most Biogas applications.

Refining and Compression of Biogas Purification is carried out to enrich biogas by scrubbing off the unwanted components i.e. carbon dioxide (CO 2 ) and hydrogen sulfide (H 2 S). It is essential to have more energy per unit volume of compressed biogas and to get rid of the corrosive effect of H 2 S. Various purification processes include absorption into water, absorption by chemical, pressure swing adsorption and membrane separation. One of the simple and cheap method is the use of pressurized water as an absorbent liquid.

Design of Water Scrubbing System Water scrubbing method is found most suitable for biogas enrichment in India due to economy and scale Water is good solvent for CO 2. The solubility of CO 2 in water is governed by variation in pressures and temperatures.

System Operation Raw biogas is compressed up to 1.0 MPa pressure to enhance solubility of CO 2 in water. Pressurized biogas is sent into bottom section of the scrubber. Packing material is used to enhance the contact time (interfacial area) between gas and water. Pressurized water is sprayed from top to absorb the CO 2 from pressurized biogas.

Compression unit : Multi stage compressor : compression of methane enriched biogas at 20 MPa Pressure in cylinder. Filters : for moisture removal. Cylinders: High pressure, seamless, steel cylinders that are already in being used for CNG application. Pipe fittings and accessories : G.I.

Process flow chart of biogas enrichment and compression system Biogas Digester Biogas (CH 4 CO 2 ) Moisture Removal Single Stage Compressor Water Tank Gas Storage Pressure Vessel Water Pump Flow Meter Biogas Scrubber Dissolved CO 2 in Water Enriched Biogas Gas Storage Pressure Vessel Moisture Filters Pressure Reducers Three Stage Gas Compressor High Pressure Cylinders for Storage of Enriched Gas

Biogas Enrichment and Bottling System 1-Biogas plant 11-Safety valve 2-Ball valve 12-Water sprayer 3-Water remover 13-Flange 4-Receiver mounted compressor 14-View glass 5-Pressure gauge 15-Water outlet 6-Gas Storage Vessel 16-Water pump 7-Rotameter 17-Gas filter 8-Supporting stand 18-Pressure reducer 9-Reshching rings 19-Three stage gas compressor 10-Scrubber 20-CNG Cylinder 12 10 11 13 14 NOT TO SCALE 1 2 3 5 6 7 9 8 17 20 19 4 15 16 18 Fig.1: Experimental setup for biogas purification and bottling

Pilot level field Case Study of Biogas as Automotive Fuel Rajasthan Go Sewa Sangh, Durgapura, Rajasthan, India Plant started in 2007 and has been running successfully. A three wheeler runs on biogas daily about 100 km. and approximate 3 kg compressed enriched biogas is required. (First in India)

Biogas Enrichment and Bottling plant at Durgapura Jaipur

Automotive Car and three wheeler Running on Enriched Biogas

Experiment on Membrane for biogas enrichment: Enrichment of CH 4 in raw biogas by using hollow fible membrane module at different operational condition by varying I. Feed gas flow rate II. Gas pressure III. Water flow rate IV. Absorbent medium (water, Aq. KOH solution, Aq, Monoethanolamine solution)

Work in progress Enrichment study is in progress under the flowing conditions : Gas flow rate : 2 LPM Water flow rate : 10 30 LPM Gas pressure : 30 70 psi Water pressure : 40 80 psi

Schematic diagram of Experimental set up P Recycle Line Inlet AMT membrane module N P P N P Outlet R P Valve Raw Biogas R P Pressure Adjuster Pump N R P Valve Needle Valve Rotameter Pressure gauge Water Tank

Experimental set up for membrane module

RESULTS: Raw Biogas composition: 59 64% methane, 35 40 % Carbondioxide, Enriched Biogas from Membrane: 85 88 mole percentage of methane observed at 70 psi gas pressure 80 psi water pressure 2 LPM( at 80 psi) gas flow rate 30 LPM water flow rate

Possible Collaborative work with NUS Development of suitable nano fibrous materials and membranes for Biogas enrichment Joint research on clean energy sources for CDM Joint Review paper/ commentary on renewable energy sources ( Bio energy) in Asian region to be published in the Nature Student& faculty exchange for research work Collaborative work on energy security in Asian region using renewable energy

Conclusions Biogas is a potential renewable energy source for India and other countries for energy security and capturing carbon emission There is need to develop a sustainable renewable energy program on biogas technology for replacing petroleum products by enriched biogas. Biogas system can work as a decentralize source of gas supply for automobiles and power generation for different kinds of bio wastes available in the vicinity. There is great possibility of joint research and collaboration between IIT Delhi and NUS. The two leading universities in Asian region should join hands together on development of green energy sources for energy security in the region