Energy has a major economical and political role to play in the modern day society. Energy consumption in the developed countries has more or less stabilized whereas in developing countries like India and China it is increasing at a phenomenal rate. The Government is looking forward to Biomethanation as a secondary source of energy by utilizing industrial, agricultural and municipal solid wastes. A large amount of money is being invested in this direction with various projects under different stages of implementation and many to follow them. Hence the long-term sustainability of the technology needs to be judged. Various potential merits of Biomethanation like reduction in land requirement for disposal, preservation of environmental quality, etc. are the spin off of the process. A study of biomethanation plant in different developed countries and India has been carried out. To understand the technical feasibility in the Indian context, a comparison is made between the characteristics of Indian waste and the ideal wastes characteristics. Further problems of the operational stability, commercial viability of biomethanation in India, developmental plans covering issues in the formulation of national policy, improvements in collection and transportation systems, marketing strategy, and funds allocation has been highlighted .With the growing energy crisis supplemented by environmental concerns, Biomethanation can serve as a potential waste-to-energy generation alternative. With the ever increasing awareness of green house gases and its adverse impact on the environment, pursue of Biomethanation of Municipal Solid Waste will drastically reduce the emission of CH4 and CO¬2, earning the country precious carbon credits. It will also forge India among developing countries, leading in adoption of technology which suffices the broad guidelines as laid under KAYOTO PROTOCOL.

1. BIOMETHANATION
OF
MUNICIPAL SOLID WASTE
Presented by,
Salin Kumar Sasi

2. URBAN WASTE SCENARIO
• Urban India generates about 1.4 lakh MT/day of MSW
• Requires 1750 acres of land for land filling/year
Courtesy-MNRE

3. PHASES
• PHASE I – MSW SCENARIO IN INDIA
• PHASE II – BIOMETHANATION
• PHASE III – FACTORS AFFECTING
BIOMETHANATION
• PHASE IV – BIOMETHANATION PROCESS
• PHASE V – BIOMETHANATION OF MSW IN INDIA
• PHASE VI – BIOMETHANATION PLANT IN
ABROAD AND INDIA
• PHASE VII – RESULTS AND DISCUSSIONS

4. PHASE I
MSW SCENARIO IN INDIA

5. Courtesy-MNRE

6. TECHNOLOGICAL OPTIONS FOR
ENERGY RECOVERY FROM URBAN WASTES

7. Courtesy-MNRE

8. Courtesy-MNRE

9. POTENTIAL OF ENERGY FROM
URBAN WASTES
2007 2012 2017
MSW
1.48 2.15 3.03
(lakh tpd)
MW 2550 3670 5200
MLW
17.75 20.70 24.75
(mcd)
MW 330 390 460
Courtesy-MNRE

10. INDIAN SCENARIO
• As per MSW Rule 2000, biodegradable material
should not be deposited in the sanitary landfill
• Therefore there is almost no scope of generation of
biogas in the form of landfill gas from new sanitary
landfills
• However, there is a huge potential of trapping the
landfill gas generated in the old dump-sites across
the country, particularly the large ones with more
than 5 meter thickness (height plus depth)
Courtesy-MNES

11. Courtesy-NEERI

12. WTE TECHNOLOGIES
• Bio-methanation
• Incineration
• RDF
• Gasification
• Integrated systems

13. MERITS OF BIOMETHANATION
• Reduction in land requirement for MSW disposal.
• Preservation of environmental quality.
• Production of stabilized sludge can be used as
soil conditioner in the agricultural field.
• Energy generation which will reduce operational
cost.
• Supplement national actions to achieve real, long
term, measurable and cost effective GHG’s
reductions in accordance with Kyoto Protocol.

14. PHASE II
BIOMETHANATION

15. Courtesy-MNRE

16. PRINCIPLES
• Complex process leading to generation of methane
and carbon dioxide.
• Process involves three steps (Barlaz et al 1990)
 Hydrolysis
 Acidification
 Methanogenesis
• Process can be carried out in
 Single step
 Two step

17. HYDROLYSIS
• Anaerobic bacteria breakdown complex organic
molecules (proteins, cellulose, lignin and lipids)
into soluble monomer molecules such as amino
acids, glucose, fatty acids and glycerol.
• Monomers are available to the next group of
bacteria.
• Hydrolysis of complex molecules is catalyzed by
extra cellular enzymes (cellulose, proteases and
lipases).
• Hydrolytic phase is relatively slow ,can be
limiting in anaerobic digestion.

18. ACIDOGENESIS
• Acidogenic bacteria converts sugar, aminoacids and
fatty acids to organic acids (acetic, propionic, formic,
lactic, butyric acids), alcohols and ketones (ethanol,
methanol, glycerol and acetone), acetate, CO2and H2.
• Acetate is the main product of carbohydrate
fermentation.
• The products formed vary with type of bacteria as
well as with the culture conditions (temperature, pH
etc).

19. ACETOGENESIS
• Acetogenic bacteria converts fatty acids and
alcohols into acetate, hydrogen and carbon dioxide .
• Acetogenic bacteria requires low hydrogen for fatty
acids conversion .
• Under relatively high hydrogen partial pressure,
acetate formation is reduced and the substrate is
converted to propionic acid, butyric acid and ethanol
rather than methane.

20. METHANOGENESIS
• Methanogenesis in microbes is a form of anaerobic
respiration.
• Methanogens do not use oxygen to breathe, oxygen
inhibits the growth of methanogens.
• Terminal electron acceptor in methanogenesis is
carbon.
• Two best described pathways involve the use of
carbon dioxide and acetic acid as terminal electron
acceptors:
CO2+ 4 H2 → CH4 + 2H2O
CH3COOH → CH4 + CO2

21. Organic matter
(Carbohydrates, lipids, proteins etc)
Lipase, protease, pectinase
Stage 1 Hydrolysis
cellulase, amylase produced
by hydrolytic microorganisms
Carboxylic volatile acids, keto acids,
hyroxy acids, ketones, alcohols,
simple sugars, amino aicds,H2 and CO2
ß-oxidation, glycolysis
Stage 2 Acidogenesis
deamination, ring reduction
and ring cleavage
Short chain fatty acids
(mainly acetic and formic acid)
Stage 3 Acetogenesis
Acetate CO2 and H2
Stage 4 Methanogenesis
Methane +CO2 Courtesy-Kashyap .D.R et al ,2003

22. PHASE - III
FACTORS AFFECTING
BIOMETHANATION

23. Courtesy-MNRE

24. NUTRIENTS
• Lower nutrient requirement compared to aerobic
bacteria.
• COD:N range is 700:5.
• N used in synthesis of Enzymes, RNA, DNA.
• Concentration of various nutrients (Speece et. al
,1996)
N : 50 mg/l
P : 10 mg/l
S : 5 mg/l

25. pH
• Most important process control parameter.
• Optimum pH between 6.7 & 7.4 range for
methanogenic bacteria (Zehnder et. al. 1982).
• Excess alkalinity or ability to control pH must be
present to guard against the accumulation of excess
volatile acids.
• The three major sources of the alkalinity are lime,
Sodium bicarbonate and sodium hydroxide.

26. TEMPERATURE
• Constant and Uniform temperature maintenance.
• Three temperature range
Psychrophilic range ; < 200 C.
Mesopholic range ; 200 C to 400C.
Thermophilic range ; >400 C.
• Rates of methane production double for each 100C
temperature change in the mesophilic range .
• Loading rates must decrease as temperature decreases
to maintain the same extent of treatment.
• Operation in the thermophilic range is not practical
because of the high heating energy requirement
(Ronald L. Drostle – 1997)

27. • Study of temperature variation (Alvarez Rene et al 2007).
 Forced square-wave temperature variations
(i) 11 0 C and 25 0 C,
(ii) 15 0 C and 29 0 C,
(iii) 19 0 C and 32 0C.
 Large cyclic variations in the rate of gas production
and the methane content.
 The values for volumetric biogas production rate and
methane yield increased at higher temperatures.
 The average volumetric biogas production rate for
cyclic operation between 11 and 25 0C was 0.22 L d -1 L -
1 with a yield of 0.07 m 3CH kg -1 VS added (VSadd)
4

28.  Between 15 and 29 0C the volumetric biogas
production rate increased by 25% (to 0.27 L d -1L-1with
a yield of 0.08 m 3CH 4 kg -1 VSadd).
 Between 19 and 32 0C, 7% in biogas production was
found and the methane yield was 0.089 m3 CH4 kg-1
VSadd.
 Digester showed an immediate response when the
temperature was elevated, which indicates a well-
maintained metabolic capacity of the methanogenic
bacteria during the period of low temperature.
 Periodic temperature variations appear to give less
decrease in process performance than as prior
anticipated.

30. Courtesy- Alvarez Rene et al 2007

31. SOLID RETENTION TIME (SRT) AND
HYDRAULIC RETENTION TIME(HRT)
• SRT is defined as the average time the solid particles
remains in the reactor.
• The anaerobic digestion is typically performed in
Continuously Stirred Tank Reactor (CSTR).
• The performance of CSTR is dependent on hydraulic
retention time (HRT) of the substrate and the degree of
contact between the incoming substrate and a viable
bacterial population (Karim et al.,2005).
• An increase or decrease in SRT results in an increase or
decrease of the reaction extent.

32. MIXING
• Mixing creates a homogeneous substrate preventing
stratification and formation of a surface crust, and
ensures solids remain in suspension.
• Mixing enables heat transfer and particle size reduction
as digestion progresses .
• Mixing can be performed in two different ways(Kaparaju
P et al,2007):
 Continuous mixing – SRT is equal to HRT
 Non-continuous mixing – SRT is more than HRT

33. • The effect of continuous , minimal (mixing for 10 min
prior to extraction / feeding) and intermittent mixing
(withholding mixing for 2 hr prior to extraction/feeding)
on methane production was investigated in lab-scale
CSTR (kaparaju P. et. al ,2007) .
• On comparison to continuous mixing, intermittent and
minimal mixing strategies improved methane
productions by 1.3% and 12.5%, respectively.

34. ALKALINITY
• Calcium, magnesium, and ammonium
bicarbonate are examples of buffering substances
found in a digester .
• A well established digester has a total alkalinity
of 2000 to 5000 mg/L.
• The principal consumer of alkalinity in a reactor
is carbon dioxide .

35. TOXICITY
• Toxicity depends upon the nature of the substance
, concentration and acclimatization .
• NH 4-N concentration of 1500-3000 mg/L at 200C
and pH 7.4 and above is considered stimulatory .
• Anaerobic process is highly sensitive to toxicants
due to slow growth rate.

36. PHASE-IV
BIOMETHANATION PROCESS

37. Courtesy-MNRE

38. BIOMETHANATION INCLUDES FOUR
MAJOR ELEMENTS
1. Pretreatment.
2. Digestion.
3. Gas purification
4. Residue treatment.

39. PRETREATMENT
• Separate out inorganic matter and materials which
disrupt mechanical operation of the digester
• Increase the biodegradability of the substrate.
• Classification of the refuse by either wet or dry
separation processes
• Provides the feedstock with a high concentration of
digestible matter, relatively free of metals, glass and grit
• Dry separation processes offer the advantage of
flexibility in selecting the desired water content
• Wet separation processes operate at low solids
concentrations, and have the disadvantage of requiring a
dewatering step

40. DIGESTION
• Organic feedstock is mixed with nutrients and control
chemicals.
• Lime and ferrous salts are added for pH and hydrogen
sulfide control.
• Digester operates at mesophilic conditions ( 370C ).
• The conversion occurs in two steps firstly solids are
solubilized or digested by enzymic action, secondly the
soluble products are fermented in a series of reactions
resulting in the production of methane and carbon
dioxide.

41. PRODUCTS OF DIGESTION
• Consist of two streams
 The gas stream is composed of approximately equal
volumes of methane and carbon dioxide.
 The slurry stream is composed of an aqueous
suspension of undigested organic matter.

42. SINGLE-STAGE HIGH RATE
DIGESTION
• Process done in single digester
• Uniform feed is very important
• Digester fed on daily cycle of 8 or 24 hours.
• Digester tank may have fixed roof or floating
roof.

43. TWO-STAGE DIGESTION
• Seldom used in modern digester design.
• High rate digester coupled with second tank in
series.
• Second tank not provided with mixing
contraption.
• Less than 10% of the gas generated comes from
second tank

44. GAS TREATMENT AND HANDLING
• Gas from digester contains methane, carbon dioxide and
trace quantities of hydrogen sulfide.
• CO2 and H2S must be removed if the methane gas is to
be pumped for combustion purpose.
• Standard method of removing acid gases from natural
gas is by absorption with monoethanolamine (MEA), the
MEA is then regenerated and recirculated.
• Methane must also be dried, accomplished by a glycol
dehydration process in which the moisture is absorbed in
dry glycol, which is also regenerated and recirculated.

45. PHASE V
BIOMETHANATION OF MSW IN
INDIA

46. Courtesy-MNRE
Project for generation of 5 MW power from Municipal Solid
Waste at Lucknow (Courtesy MNRE)

47. ENERGY RECOVERY POTENTIAL
Courtesy-Ambulkar.A.R et al 2003

48. ENERGY GENERATION/CONSUMPTION IN
SYSTEM
Energy Resources Material Resources Manure
Commercial Non-conventional Biogas Biomethanation
sources sources Technology
Processing
of waste
Industrial Agricultural
Degradable
Utilization Consumption Inerts organic matter
Human
Consumption
Municipal
Solid waste
Waste Generation
Role of Biomethanation Technology
Energy Generation-Consumption in System in the system
Courtesy-Ambulkar.A.R et al 2003

49. PARAMETERS RESPONSIBLE FOR TECHNICAL
FEASIBILITY OF BIOMETHANATION PLANT
Parameters related with Technical
Feasibility
Need for obtaining waste Ensuring process kinetics Ensuring the
with desired composition to be fast enough for conditioning of waste
addressing the following implementation at plant at processing site with
issues: scale addressing the respect to the
• Annual seasonal following parameters with following points:
variation in waste optimum conditions: • Removal of non-
composition. • pH biodegradables
• Identification of • Digester Temperature • Removal of
points for collection (Thermophilic, binders like soil
of waste. mesophilic conditions) particles, stones,
• Source specific • Carbon to Nitrogen ratio etc.
collection of waste. • Maintenance of • Adjustment of
COD/BOD values of the water content in
reactor feed. the feed to the
reactor.
Courtesy-Ambulkar.A.R et al 2003

50. PARAMETERS AFFECTING THE COMMERCIAL
VIABILITY OF BIOMETHANATION PLANT
Factors affecting the
economy of plant
Compromise with the Costs associated with Problems associated with
Energy inefficiency associated marketing of products
quality of raw material as Pre- and Post- treatment
with the plant • Uncertainty in markets
energy generation of the feed
• Biological processing is a time
source • Raw material being a for the digestate
consuming process and hence represents a
•MSW being a heterogeneous
energy generation rates are commercial risk, which
heterogeneous mixture with
low. impacts on the
mixture has a considerable amount
• Net energy generation rate is technology’s costs.
remarkable seasonal of inerts and needs
low as it involves the • Other energy
variation which pre-treatment.
efficiencies associated with
hampers the quality • Large amount of generation sources
both biogas generation and will have to competitive
of product wastewater is
biogas combustion. edge over the biogas.
generated with
• The calorific value of biogas is • Compost is not yet
needs an efficient
comparatively less as it established as a
method for treatment.
contains about 50% CO2 along product marketable.
with methane.
Courtesy-Ambulkar.A.R et al 2003

51. PARAMETERS FAVORING THE COMMERCIAL
VIABILITY OF BIOMETHANATION PLANT
Factors enhancing the
economy of plant
Reduction in costs Financial Incentives from
• Reduction in raw government
material transportation • Financial and fiscal
cost. incentives offered by the
• The feed MSW is very Ministry of Non
cheap and so less raw Conventional Energy
material cost. Sources.
• Constitutional Amendment
Act and emphasis on
privatization has led to the
creation of this market in
India.
Courtesy-Ambulkar.A.R et al 2003

52. PHASE VI
BIOMETHANATION PLANT IN
ABROAD AND INDIA

53. VALORGATM PLANT AT FRANCE
• Principle
The Valorga process is an anaerobic biological treatment
process for waste organic fraction .
• Advantages
 Adapted to the treatment of organic municipal solid
waste
 The process operates under anaerobic conditions with a
high dry solid content of 25 - 35 %, owing to a specific
process design.
 Anaerobic digestion leads to the production of a high
methane content gas: the biogas.
 Does not require a large land area.

54. VALORGATM PROCESS

55. SPRERI PLANT AT ANAND
Courtesy- SPRERI

56. SPRERI PLANT AT ANAND
SARDAR PATEL RENEWABLE ENERGY RESEARCH INSTITUTE

57. APPROPRIATE RURAL TECHNOLOGY
INSTITUTE (ARTI), PUNE
Schematic description of the small ARTI compact
biogas plant. Courtesy-ARTI

58. APPROPRIATE RURAL TECHNOLOGY INSTITUTE
(ARTI), PUNE
Construction of an ARTI compact ARTI biogas plant for treatment of
biogas plant. kitchen waste at household level.
The design, has won the Ashden Award for Sustainable Energy 2006

59. Bhabha Atomic Research Centre (BARC), Mumbai
Courtesy-MNES

60. Biogas Plant at Trombay
Courtesy-MNES

61. Parameters of BARC technology
Courtesy-MNES

62. The Energy and Resources Institute (TERI), New Delhi
Courtesy-TERI

63. The Energy and Resources Institute (TERI), New Delhi
Waste is fed into the acidification module. UASB unit
Courtesy-TERI

64. PROJECTS INSTALLED FOR
ENERGY FROM URBAN WASTES
• 6.6 MW project based on MSW at Hyderabad
• 6 MW project based on MSW at Vijayawada
• 5 MW project based on MSW at Lucknow
• 1 MW power from Cattle Dung at Ludhiana
• 150 kW plant for Veg. Market, sewage and
slaughterhouse waste at Vijayawada
• 250 kW power from Veg. Market wastes at
Chennai.

65. PHASE VII
RESULTS ANS DISCUSSIONS

66. SALIENT POINTS
ULTIMATE GOAL OF BIOMETHANATION
DEVELOPMENT OF NATIONAL POLICY
DEVELOPMENT OF APPROPRIATE TECHNOLOGY
IMPROVEMENTS IN COLLECTION AND
TRANSPORTATION SYSTEMS
MARKETING STRATEGY
ALLOCATION OF FUNDING
PUBLIC AWARENESS

67. CONCLUSION
Considerable potential for enhancing the biogas
production from the present stock of MSW
generated in the country.
Drastic reduction in the emission of CH4 and
CO2, earning the country precious carbon credits.
Assist in implementation of KYOTO protocol.

68. REFERENCES
 Alvarez Rene and Liden Gunnar (2007), ‘The effect of temperature variation on biomethanation’, Bioresource
Technology 99 (2008) pp 7278- 7284.
 Ambulkar A.R and Shekdar A.V (2003), ‘Prospects of biomethanation technology in the Indian context: a
pragmatic approach’, Resources Conservation and Recycling 40 (2004) pp 111-128.
 Bhattacharyya J.K., Kumar S., Devotta S., (2008), ‘Studies on acidification in two-phase biomethanation
process of municipal solid waste’, Waste Management 28 (1), 164-169. Bioresource Technology 77 (2000) pp
612-623.
 Dhussa A. K and Tiwari R.C (2000), Article on Waste-to-energy in
India.http://www.undp.org.in/programme/GEF/march00/page 12-14.
 Kaparaju P, Buendia I, Ellegaard L and Angelidakia I (2007), ‘Effect of mixing on methane production during
Thermophilic anaerobic digestion of manure: Lab-scale and pilot-scale studies’, Bioresource Technology 99
(2008) pp 4919-4928.
 Karim K., Hoffmann R., Klasson K.T., Al-Dahhan M.H.,(2005), ‘Anaerobic digestion of animal waste : effect
of mixing’, Science Technology 45, pp 3397-3606.
 Kashyap. D.R, Dadhich. K. S, Sharma. S. K (2003), ‘Biomethanation under psychrophilic conditions’,
Bioresource Technology 87 (2003) pp 147 - 153.
 Kim I.S., Kim D.H., Hyun S.H.,(2002), ‘Effect of particle size and sodium concentration on anaerobic
thermophilic food waste digestion’, Science Technology 41,pp 61-73.
 Kumar D., Khare M., Alappat B.J.(2001), ‘Leachate generation from municipal landfills in New Delhi,
India’.27th WEDC Conference on People and Systems for Water, Sanitation and Health, Lusaka, Zambia.
 Mahindrakar AB, Shekdar AV.(2000), ‘ Health risks from open dumps: a perspective’, Bioresource Technology
63 (2000) pp 281 - 293.
 Muller Christian., (2007), ‘Anaerobic digestion of biodegradable solid waste in Low and Middle income
countries’, Eawag Aquatic Research.
 Municipal Solid Waste (Management and Handling) Rules,(2000), MNES, Govt of India, New Delhi.

69.  NEERI Report (2005), ‘Assessment of Status of Municipal Solid Waste Management in
Metro Cities, State Capitals, Class I Cities and Class II Towns’.
 Parkin G. F,Owen, William F, (1986)*, ‘ Fundamentals of anaerobic digestion of
waste water sludges’, J. Env. Engg. Div. ASCE, Vol. 112, No. 5, pp 867-920.
 Ronald, L. Drostle, (1997)*, ‘Theory and practice of water and waste water treatment’,
John Wiley and sons, Inc USA ( NewYork).
 Sawyer, Clair N, Mc Carty, Perry L. and Gene F. Parkin (2003), ‘Chemistry for
Environmental Engineering and Sciences (Fifth Edition), Tata McGraw Hill Book
Company, pp 689-697.
 Solid waste manual (2004), MNES, Govt of India.
 Speece R.E. (1983)*, ‘Anaerobic biotechnology for Industrial waste water treatment’.
Env. Sci.and Tech Vol.17, No.19, pp 416A.
 Vavilin V.A., Angelidaki I., (2005), ‘Anaerobic degradation of solid material:
Importance of initiation centers for methanogenesis, mixing intensity and 2D distributed
model’, Biotechnology, Bioengineering 89(1), 13-122.
 Zehnder, A.J, K. Ingvorsen and T. Marti (1982)*, ‘ Microbiology of methanogen
bacteria in anaerobic digestion’, pp 45-68.
* - Papers not referred in original

70. WISHING A VERY HAPPY
TEACHER’S DAY