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Technological Intervention in Waste Management
Dr. Anurag Garg Centre for Environmental Science & Engineering Indian Institute of Technology Bombay, Mumbai
inThe Waste Management Conclave, Vikroli
Organized by Godrej & Boyce Mfg. Co. Ltd.
May 9, 2016
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Municipal Solid Waste Generation (MT/day) in the State of Maharashtra ( 2012-2013)
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Classification of MSW
MSWcomponents
Inorganic(e.g.metals,inerts)
Non-biodegradable(e.g.plas;cs)
Readilydegradable(e.g.foodwaste)
Slowlyorpar;allydegradable(e.g.paper,tex;le)
Organic
Biodegradable
General MSW Composition In Mumbai (in percent wet basis)
MSW components Value
Biodegradable fraction 62
Paper 7.5
Plastic 10
Glass 0.7
Metals 0.2
Inert (stones, bricks etc) 15 Miscellaneous (leather, cotton rubber, bones etc) 4.6
Moisture 54 C/N 39.04 High calorific value (HCV) (MJ/kg 7.47
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MSW Generation and Disposal in Mumbai (HT, 15th Dec 2014)
• Total MSW: 10,060 MT/day
• Per capita generation: 450 g/day
• Composition: ü Biodegradable wet waste = 54% ü Biodegradable dry waste = 15% ü Sand, stone and fine earth = 12% ü Paper, metal and other usable metals = 10% ü Plastic = 9%
• Disposal: ü Deonar dumping ground ü Mulund dumping ground ü Kanjurmarg dumping ground
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Waste Hierarchy – A Shift in Thinking
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Energy Savings Of Recycling
Material Relative energy needed to manufacture vs energy generated from incineration
Newspaper 2.6 times Office paper 4.3 times Glass containers 30 times Tin cans 30 times Aluminum cans 350 times Plastics 3 – 5 times Textiles 5 – 8 times
Functional Elements of a Waste Management System
• Waste generation • Waste handling and separation, storage and
processing at the source • Collection
• Separation, processing and transformation of solid waste
• Transfer and transport
• Disposal
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Waste processing methods
Biological processes
Composting
Anaerobic digestion
Compost
Biogas, digestate
Gasification/ Pyrolysis
Thermal processes
Incineration Heat, gases, ash
Producer gas, solid fuel, tar
Majoroutputs Major Treatment Processes for MSW
Prediction of MSW derived Refuse Derived Fuel Composition and its Performance Evaluation in
Energy Recovery Processes - A Preliminary Study
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Components RDF Composition (%) Remarks
Compostable (Yard waste, Food scraps)
21.6 Components contributing to biogenic fraction = compostable + paper + wood + textile & leather RDF Quantity = 2237000 kg/d = ~ 23% of MSW
Paper 7.5 Plastics 35.5 Rubber, leather and textiles 3.3 Metals 0.7 Wood 3.8 Glass 0.4 Other 27.2 Moisture content (%) 25.5
Calorific value 11.09 MJ/kg
Co-Combustion Scenarios
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RDF outlets Cement plant (1 Mt/y) Power plants (2780 MW)
Scenario No. 1 2 3 4 5 6 7
RDF share (%) 0 25 30 40 0 4 4.5
Coal feed rate (kg/h)
25047 18786 17533 15028 1901216 1825167 1815661
RDF feed rate (kg/h)
0 6262 7514 10019 0 76049 85555
Mass and Energy Flow Modelling for Cement Kilns
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Scenario 1 2 3 4 5 6 7
Net CO2 (RDF biogenic fraction
+ transport) 37535 34378 33752 32511 2847665 2809514 2804692
SO2 1.00 0.87 0.84 0.79 75.7 74.2 74.0 SO3 0.013 0.011 0.011 0.010 0.96 0.94 0.93
Net SOx 1.01 0.88 0.85 0.80 76.7 75.1 74.9 NO 19.6 16.3 15.6 14.3 1491.1 1450.5 1445.4 N2O 14.4 12.0 11.5 10.5 1093.5 1063.7 1060.0
Total NOx (including transport)
54.4 45.9 44.3 41.2 4110.9 4010.5 3997.3
HCl 0.2 1.4 1.7 2.2 16.6 31.3 33.1 CO 13.1 11.4 11.1 10.6 984.8 965.3 962.5 HC 0.81 0.70 0.68 0.65 60.73 59.53 59.35
Ash content 0.87 0.77 0.75 0.72 6.61 6.49 6.48 PM (transport) 2.7 2.4 2.3 2.2 203.5 199.5 198.9
* All values presented here in kg/h
Comparison of Emissions in Different Combustion Scenarios
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Environmental Impacts of using RDF as Co-fuel in Cement Kiln
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GW A WS
% R
educ
tion
Coal + 25% RDF Coal + 30% RDF Coal + 40% RDF
GW – Global warming; A – Acidification and WS – winter smog 16
Change in Electricity/ Heat Production
Reduction in production/ emissions
Cement kiln Power plant
Electricity/ heat production (%)
7 – 16 1.4 & 1.6
Global warming (%) 8 – 13 1.5 & 1.7
Acidification (%) 12 – 15 2.0 & 2.3
Winter smog (%) 13 – 20 2.0 & 2.3
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Change in Electricity/ Heat Production
Reduction in production/ emissions
Cement kiln Power plant
Electricity/ heat production (%)
7 – 16 1.4 & 1.6
Global warming (%) 8 – 13 1.5 & 1.7
Acidification (%) 12 – 15 2.0 & 2.3
Winter smog (%) 13 – 20 2.0 & 2.3
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Development of Community Level Composting Bins – Decentralized Biodegradable Waste
Management
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Purpose: • Reduce the time for biodegradation • Increased yield and better quality • Reduce need for waste transfer
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Schematic Representation of Study
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Moistureconten
t(%)
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rature(°C)
Time(days)
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Moistureconten
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Moistureconten
t(%)
Tempe
rature(°C)
Time(days)
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AmbienttemperatureMiddletemperatureBotoomtemperature
Temperature and Moisture Content Profiles in (a) Drum 1 (b) Drum 2 (c) Drum 3
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Mass Reduction and Yield
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Feedstock Drum1 Drum2 Drum3Yield(%
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Mass(kg)
Mass Yield
Parameters Compost
Withoutinoculum
Withinoculum
TOM(%) 42.36 37.53
pH 7.1 7.3
EC(dS/m) 2.41 2.2
C/Nra;o 12.11 9.67
Timetakentoachievethermophilicphase
22days 8days
Timetakenforac;vephaseofcompos;ng
55days 39days
GI(%) 80% 90%
Comparison of Compost with and without Inoculum
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Parameter Drum 1 Drum 2 Drum 3 P A S , U K (2011)
F A I , I n d i a (2007)
Trace elements (mg/kg)
B 7 0 . 0 5 (11.27)
6 8 . 0 5 (33.65)
4 9 . 9 3 (32.4)
Ba 6.65 (0.28) 3.2 (0.1) 2 0 . 7 7 (2.08)
Co 0.55 (0.1) 0.1 (0) 1.05 (0.1) Cr 8.8 (0.07) 5 . 3 7
(0.88) 16 (0.14) 100 50
Cu 7.15 (0.21) 4 . 6 2 (0.32)
1 3 . 1 7 (1.38)
200 300
Ni 4.55 (0.1) 2 . 7 5 (0.28)
7 . 0 2 (0.67)
50 50
Pb 10.2 (0.14) 1 1 . 1 2 (1.09)
1 3 . 5 7 (0.81)
200 100
Sr 13.7 (1.27) 1 4 . 3 (0.42)
2 8 . 4 7 (1.23)
Zn 3 0 . 2 5 (0.21)
2 3 . 3 7 (1.52)
1 3 . 1 7 (1.38)
400 1000
Drum 1
Drum 2
Drum 3
FAI, India
(2007) pH 5.12
(0.2) 7.1
(0.2) 7.3
(0.1) 6.5-7.5
EC (dS/m)
2.11 (0.8)
2.41 (0.3)
2.2 (0.1)
≤ 4
TOM (%)
61.23 (3.5)
42.36 (2.18)
37.53 (1.85)
35-40%
C/N ratio
14.68 (1.03)
12.11 (1.24)
9.67 (2.11)
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Compost Characteristics
MSWM Issues/ Challenges
• Availability of MSW characterisation data covering seasonal variations
• Improper segregation of waste
• Need for proper waste management facility (with proper measures for monsoon season) and skilled manpower
• Market uncertainty for the products generated from MSW processing
• Redevelopment and scientific closure of existing landfills
• Identification of hazardous and toxic consumer products requiring special waste management units
• Public awareness
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Opportunities
• Volume reduction at the source of generation by producing compost or biogas
• Possibility for generating energy from waste
• Employment generation
• Saving significant land space by processing the waste
• Environmental protection by suppressing the generation of Greenhouse gas emissions
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References • Srivastava et al., 2014. Urban solid waste management in developing world
with emphasis on India: Challenges and Opportunities. Reviews in Environmental Science and Biotechnology, pages 17. (Available online)
• URL 1. http://mpcb.gov.in/muncipal/pdf/Regionwise_MSW_Generation2014.pdf
• URL 2. http://www.seas.columbia.edu/earth/wtert/sofos/DBSSRS_Article_-_WTE_INDIA_BRIEF_Revised.pdf
• URL 3. CPCB (Central Pollution Control Board). Waste generation and composition. Accessed on 23rd March, 2011 from: http://cpcb.nic.in/wast/municipalwast/Waste_generation_Composition.pdf
• Sharholy, M., Ahmad, K., Mahmood, G., Trivedi, R.C., 2008. Municipal solid waste management in Indian cities – A review. Waste Manage. 28, 459-467.
• Hindustan Times, 15th December 2014.
• Planning Commission Report, Volume I (2014)
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Decentralized Systems
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