Week 08 Lecture Material.pdf

Urban Services planning
Dr. DEBAPRATIM PANDIT
ARCHITECTURE AND REGIONAL PLANNING, IIT KHARAGPUR
Module 08: Adoption of advanced waste treatment technologies
Lecture 36 : Waste to Energy Part 1: Biomethanation
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 Waste to Energy
 Biomethanation
 Biomethanation: Benefits and considerations
 Biomethanation Process
 Nisargruna Biogas Technology
 Typical design of Biogas Plant
 Biogas Application
 Biomethanation plant at Koyambedu wholesale market by Chennai Metropolitan
Development Authority
CONCEPTS COVERED
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Waste to Energy
Waste to Energy(WTE): Generating energy (heat or electricity) from MSW.
Biological processes: Biomethanation (Electricity, Automotive fuel, Cooking/Heating fuel, Biogas pump)
Thermal processes: Combustion of refuse derived fuel (RDF), Incineration of waste,
Co-processing of combustible dry waste fraction
At Source Reduction & Reuse
Recycling
Composting
Waste to Energy
Landfills
Least Preferred
Most Preferred
(Source: CPHEEO(2016))
Energy recovery is considered when all reduce, recycle, and recovery processes have been adopted and there is a
considerable pressure on landfill site area.
 WTE facility are considered on a case-by-case basis
Financial support for setting up WTE plant:
 PPP approach (build, operate and maintain) for 20 years
 Private entity (developer or technology provider)
 Full time staff on long term contract
 Past O&M experience of at least one similar facility
Guidelines by the Task Force Constituted By Planning
Commission on Waste to Energy
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Anaerobic decomposition of biodegradable matter in closed chamber under controlled conditions (temperature, moisture, pH)
Results in:
Biogas (Methane and carbon dioxide) + Partially digested sludge(pathogen may be present) + hydrogen sulfide (H2 S)
Biogas calorific value: 5,000–6,000 kilocalories per cubic meter (kcal/m3 )
Solid Waste Management rules, 2016
Similar to composting
India MSW: High organic and moisture content
Earlier experience with cattle manure(Gobar Gas Plant) and toilet linked biogas plants (4.3 million)
Scale of biomethanation:
Small scale (restaurant/canteen waste)
Medium scale
(market waste: flower, fruit, vegetable, slaughterhouse)
Large scale
Biomethanation
e.g., 16 TPD MSW + 4 TPD slaughterhouse waste plant in Vijayawada
30 TPD market waste based plant in Koyambedu, Chennai
500 TPD MSW based plant in Lucknow
Decentralized systems(<5 TPD)
Centralized systems(upto 50 TPD digesters
and multiple modules)
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 Biogas: Electricity and heat production
 Cleaned Biogas (95% CH4) can be used as vehicle fuel (CO2<5% and H2S is removed)
 Reduces landfill area and other associated benefits
 Stabilized sludge: Soil conditioner/fertilizer
(Aerobic composting of the sludge for effective pathogen kill temperature of 60°C–70°C for 2 days)
 Time required for biomethanation is less than composting (Area is also less)
Biomethanation: Benefits and considerations
 Biomethanation costs more(similar to in-vessel composting) but results in less odor and
pest/bird problems and can be set up in residential areas
 Design and engineering of plant:
As per feed
Digester should be leak-proof
Proper O&M
 Biomethanation plants require consistent supply of clean organic matter(Food waste, slaughterhouse waste is suitable)
 Issues with MSW quality and quantity
 Economic viability of facility (market for biogas and sludge manure in proximity)
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 Scrubbing of gas for automobile use
Biomethanation Process
Pre-treatment:
Anaerobic Digestion:
 Source segregation or sorting at facility
 Shredding ensures better digestion
 Microbial activity in stages within 1 digester or 2 digesters in tandem
Hydrolysis (hydrolytic bacteria)
Acidogenesis (acidogenic bacteria)
Biomethanation (methanogenic bacteria)
 Biphasic fermenters improves efficiency further and reduces time
(Methanogenesis happens separately at near neutral pH range in 2nd phase)
e.g., TERI Enhanced Acidification and Methanation (TEAM) Bioreactor
 Feed as per desired solid content (6-10% sometimes even 20% (dry fermentation))
 Retention time 14-30 days
 Water source: Clean water/sewage/Re-circulated effluent
Gas Recovery:
Residue Treatment:  Dewatering of sludge(50-55% solid) and effluent can be recycled
 Aerobically curing
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Biomethanation Process
 As per technology, process temperature, waste composition
 Mesophilic digester: 20 to 30 days; Thermophilic digester: 14 days
 Affects microbial growth and thus biogas quantity produced
Mesophilic range: 25°C–40°C
Thermophilic range: >45°C (ideally 55°C–60°C)
Temperature:
 pH range (6.0 to 8.5 pH)
 Methanogenic bacteria are sensitive (close to neutral pH)
pH:
Carbon-to-
nitrogen ratio:
 Optimum: 20:30
High C/N ratio results in lower gas production
Low C/N ratio: Ammonia accumulation & High pH (>8.5) toxic to methanogenic bacteria
 Balancing: Organic waste (high carbon) and sewage/animal manure (high nitrogen)
Optimal organic loading rate:  As per plant size
 Agitation/stirring of digester determines biogas quantity
Retention time:
Moisture and solid content, Toxicity
• Digestion is faster (shorter retention time/small reactor)
• Effective pathogen kill
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Nisargruna Biogas Technology
Developed by Bhabha Atomic Research Centre (BARC)
Processes kitchen waste, paper, grass, gobar and dry leaves
High quality(nitrogen content high) manure and methane gas
Technology: Biphasic biomethanation
Floating dome design
(underground reactor and contents flow under gravity)
Area: 50 m2 (less space) Waste:100 kg per day
End product: Cooking gas fuel for domestic/industrial purpose
(Source: https://www.barc.gov.in/technologies/kitchen/index.html)
Receiving &
Processing
platform
Mixer platform
Primary Digester
Biogas Storage
Dome
Secondary Digester
Biogas for cooking or
electricity generation
Water Seal
Sand Filter
Compost Manure
Recycled Water
Air Compressor
Solar Water Heater
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Typical design of Biogas Plant
50 TPD feed (biodegradable MSW and cattle manure)
A = Slurry preparation tank for cattle manure
B = Screened cattle manure slurry in which
segregated, shredded MSW is fed
C = Primary digester
D = Secondary digester
E = Gas Holder
F = Solid residue from filter press taken to F
G = Dirty water to be periodically drained,
bottom sludge to be pumped out and land filled
H =Shed for aerobic windrow composting/
vermicomposting
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Biogas Application
Biogas is best used locally (limited pipe network) after moisture removal(using condenser)
Use: Cooking and lamps (limited application in urban area)
Piped natural gas (PNG) line insertion:
Requires CO2 removal and compression to required pressure(Possible in large plants : 12,000 m3 per day)
Electrical power generation (Large scale)
(Internal combustion engines/gas turbines)
e.g., Solapur Bio-Energy Systems Pvt. Ltd (SBESPL):2013
400 TPD MSW: Biomethanation (thermophilic digestor)
Power generation: 4MW (to Grid by MSEDCL)
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(Source:
NIUA,2015)
Biomethanation plant at Koyambedu wholesale market by Chennai
Metropolitan Development Authority
 Market receives 700 trucks and generates 150 MT of waste every day
 2005: CMDA approached Ministry of Non-convetional Energy Sources (Now MNRE)
 75% financing via MNRE from UNDP, Global Environmental Fund(GEF) (5.5 crore INR)
 Central leather research institute: Technology provider
 Biogas Induced Mixing Arrangement(BIMA) digester (patented technology)
 Plant established in 2006, 30 MT per day capacity
 Waste characteristics: Vegetable waste 21%, Fruit waste 15%, Flower waste (10%),
Banana stem etc. (38%), Packing material (hay, straw, paper) 16% Moisture:75%
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Biomethanation plant at Koyambedu wholesale market by Chennai
Metropolitan Development Authority
 Private contractor transfers waste from market to receiving platform at plant
 From receiving platform to conveyor hopper using grabs
 Waste is then shredded to 15-20 mm size
 Mized with water and pumped to digestor using screw pump
 Gas is stored in dry type gas holder (530 m3)
 H2S concentration is reduced below 500 ppm
 Electricity is produced
 Power generated to Tamil Nadu Electricity Board grid
 Excess gas is burn in flare
 Dewatered sludge (screw press) to manure via composting
Average Biogas production: 2500 m3 per day (Methane 65%)
Power Generation: 2600 KwH/day (500 Units)
INR 5per unit (adequate for O&M cost)
Green house gas reduction: 8208 Tons of CO2 equivalent/annum
(Carbon credit: USD 5-15 per Ton)
(Source: NIUA,2015)
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REFERENCES
1. CPHEEO(2016), Municipal Solid Waste Management Manual, Ministry of Urban Development,
Government of India (Part 1, 2 and 3)
2. NIUA (2015), Compendium of good practices: Urban solid waste management in Indian cities
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CONCLUSIONS
 Biomethanation is an alternative to composting when the market for compost is limited.
 Large scale Biomethanation in urban areas is feasible with proper operation and logistics
planning.
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KEY POINTS
 Waste to Energy
 Biomethanation
 Biomethanation: Benefits and considerations
 Biomethanation Process
 Nisargruna Biogas Technology
 Typical design of Biogas Plant
 Biogas Application
 Biomethanation plant at Koyambedu wholesale market by Chennai Metropolitan
Development Authority
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Lecture 37 : Waste to Energy Part 2: Refuse Derived Fuel
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 Refuse Derived Fuel
 SWM Rules, 2016
 RDF production process
 RDF utilization process
 Case studies: Reuse Derived Fuel
CONCEPTS COVERED
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Refuse Derived Fuel
Refuse derived fuel (RDF):
Fuel derived from combustible waste fraction such as plastic, wood, pulp or organic waste(except chlorinated
materials) in pellets or fluff form through drying, shredding, dehydrating and compacting of solid waste.
Calorific value:
Segregated MSW (typical combustible fraction) : 2000-2500 Kcal/kg
Mixed plastic : 6000 Kcal/kg; Coal(Indian): 2500-5000 Kcal/kg
Other Parameters: Water content, Ash content, Sulphur content and Chlorine content
Used for: Steam or electricity generation
Alternative fuel for industrial furnaces or boilers
(e.g., co-processing/co-incineration of waste in cement, lime, and steel
industry and for power generation)
RDF Composition:
 Composition and energy content varies as per waste material feed & sorting, separation, and
processing efficiency and technology
 RDF quality is as per end use
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SWM Rules, 2016
 ULBs should facilitate construction, operation and maintenance of waste to energy processes including refused
derived fuel following guidelines and standards of Ministry of Urban Development and Central Pollution
Control Board respectively
Private sector participation
Decentralized processing
 All non recyclable waste of calorific value >1500 Kcal/kg to be used for energy generation as RDF directly or
indirectly or in co-processing in cement or thermal power plants
 5 % of fuel requirement for all industries within 100 km of a RDF plant to be met by RDF
 Pollution Control Board or Pollution Control Committee clearance required for Waste to Energy
plants >5T per day
 Pre-process and post-process rejects from these facilities to be cleared regularly
 Lack of separate standard for RDF composition, conditions of use, or environmental monitoring (RDF
incineration) unlike other countries
 RDF based power projects come under the purview of the Electricity Act, 2003
 RDF facilities and cement kilns using RDF are also governed by the Environment Protection Act,
National Ambient Air Quality Standards, 2009, laws regarding stack emission monitoring and
other air, water and environmental protection acts by State pollution control board
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RDF production process
 Sorting or mechanical separation
 Size reduction (shredding, chipping,
milling)
Post shredding:
 Drying
 Separation
 Screening
 Air density separation
 Blending
 Packaging
 Storage
Pelletization process
 Final characteristics of RDF (size, moisture, ash content, calorific value, chloride, heavy metals,
etc.) depends on end use
 Configuration of unit operations and utilized technologies depend on the recovered materials
and the RDF quality required
Raw Garbage
Pre-segregation
unit
Primary
shredding
Hot air drying
Secondary
shredding
Air classification
Refused derived
fuel
Storage
Hot air
generator
Blender or
additives
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 Pellets: 10–15 mm particle size (Binder or additives mixed with shredded garbage in a
mixer before pelletizing)
Pelletization to RDF fluff (shredded un-consolidated RDF)
RDF production process
Pellet conveyor
RDF Pilot Plant Bengaluru 1998 (Source: CPHEEO(2016))
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RDF utilization process
 RDF is incinerated in a moving grate furnace or boiler
 RDF as feedstock for pyrolysis and fluidized bed systems
 Partial substitute for fossil fuel in cement and coal based power plants considering emission standards
 RDF is found to be suitable for co-processing in cement plants(fed into kiln or in the pre-calciner)
Retro fitting of feeding mechanisms in cement plants
(RDF should be of consistent quality, heat value, low chorine and composition specific to cement
plant requirements)
Incineration
Co-processing
Moisture < 20%
2D < 120 mm, 3D < 70 mm
Chlorine< 0.7%, Calorific value preferably > 3,000 kcal/kg
Sulfur < 2%
Free from PVC, explosives, batteries, aerosol containers, biomedical waste
 Distance is key (less than 200 km)
 Crude RDF from many locations to ensure consistent supply (refinement facility at plant)
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Co-processing of Segregated Plastic Waste: An Initiative of Jabalpur Municipal Corporation and ACC–Holcim
Case studies: Refuse Derived Fuel
High Court of Delhi: Environmental and health hazards of plastic waste
Recommendation: Use of plastic waste as fuel in the cement kilns
Non-recyclable plastic waste to be co-processed in rotary cement kilns
Jabalpur municipal corporations + Kymore Cement Works of ACC Limited
Collection and delivery managed by waste pickers, sub-vendors, kabadi system
Storage and handling facility at ACC–Kymore
340 tonnes of MSW (5% plastic and combustible fractions:15–20 tonnes per day)
Non-recyclable fractions of waste were segregated and transported to cement plant
(e.g., double coated plastic, torn paper, jute, tetrapaks, thermocol, waste tyres, etc.)
High temperature and long residence time in kiln ensures complete destruction(safe and green)
Pilot: Replicated in other parts of the country
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Ramky Enviro Engineers Ltd. Hyderabad
4500 TPD of MSW from Greater Hyderabad Municipal Corporation
45 % waste (+70mm fraction): RDF
Used in cement plants in Andhra Pradesh and Karnataka
Trommel screen
Process flow chart
(Source: https://optoce.no/wp-content/uploads/2019/03/RDF-India_ICR_Dec-2017.pdf)
Waste
screening by
70mm trommel
+70mm
fraction for
RDF
-70mm fraction
for Compost
Processed RDF for
cement plant
Unprocessed RDF
stored in yard
Window aerobic
composter
Moisture and gas
loss
Compost
screening by
20mm and 4mm
trommel
+20mm and
+4mm fraction
sent to landfill as
rejects
-4mm fraction as
compost
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UltraTech Jaipur RDF facility
150 TPD of RDF from 500 TPD MSW
Jaipur Municipal Corporation
Process flow chart Ballistic separator
RDF specification:
Size <50mm
Calorific value: 3000-3500kcal/kg
Moisture content: 10-20 per cent
Bulk density: 0.2t/m3 .
(Source: https://optoce.no/wp-content/uploads/2019/03/RDF-India_ICR_Dec-2017.pdf)
MSW unloading
and storage
Manual Inspection
Magnetic
separation
Trommel Screening
Secondary size
reduction 0-50mm
RDF Fluff
Ballistic separation
Primary size
reduction 0-
1000mm to 0-
200mm
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REFERENCES
2. RDF production and utilisation in India by Palash Kumar Saha, Kåre Helge Karstensen, Kannan
Vairavan and Vinoth Balakumar (Link: https://optoce.no/wp-content/uploads/2019/03/RDF-
India_ICR_Dec-2017.pdf)
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CONCLUSIONS
 Refuse derived fuel produced by ULBs should be of consistent quality and quantity.
 While actual RDF is being produced by private companies under PPP mode the raw
material supply should be the responsibility of the ULB.
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KEY POINTS
 Refuse Derived Fuel
 SWM Rules, 2016
 RDF production process
 RDF utilization process
 Case studies: Reuse Derived Fuel
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Lecture 38 : Waste to Energy Part 3: Incineration
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 Incineration
 Incineration in India
 Incineration Plant design and operation
 Stack emission standards
CONCEPTS COVERED
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Incineration
 Incineration is combustion of waste at very high temperatures in the presence of oxygen
 Incineration results in production of ash, flue gas, and heat
 Energy generated: Heat or electricity(steam turbine generators)
Preferred waste fraction:
Segregated non-recyclable waste of high calorific value (dry waste)
Lower calorific value (LCV) > 1,450 Kcal/kg (all seasons)
Average annual LCV > 1,700 Kcal/kg
Incineration can deal with unprocessed, hazardous and clinical waste
Pretreatment of mixed waste is necessary
Potential for energy generation:
 Composition of waste, Density, Moisture content, and inert material content
 Consistency in waste supply > 500 TPD segregated waste
 Market demand and agreements for selling electricity or steam
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 The ULB waste management operations should be mature and advanced before setting up a incineration plant
 Management charges and tipping fees
 Institutional Capacity and skill manpower requirement
 High capital investment and longer planning period(25 years)
 Stakeholder participation and opinion
 Proper operation maintenance and monitoring
 Incineration results in energy recovery but the primary goal is to reduce landfill area requirement
 Incineration results in emission of green house gases which requires elaborate emission control equipment
Incineration
Siting criteria
 Proximity and arrangement with landfill for residue disposal(bed and fly ash)
 Landuse: Medium or heavy industry
 300–500 meters from residential zones
 Steam producing plants: Vicinity of consumers
 Economic and Environmental cost
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Incineration in India
MSW in India: High organic, moisture and inert content
Low calorific value (800-1100 kcal/kg) (Joshi and Ahmed, 2016)
 Small incinerators for hospital waste
 Waste quality and quantity issues in most plants
WTE Plants (as of January 2015)
Delhi:
Timarpur-Okhla Waste Management Company (2012)
1,600 TPD of waste(Pre-processing), 16 megawatts (MW) of electricity
Delhi, Ghazipur:
433 TPD of RDF, 12 MW power, (PPP) Operator: IL&FS
Bengaluru:
8-MW plant, (PPP) M/s Srinivasa Gayithri Resources Recovery and BBMP
Pune:
Rochem Separation Systems (pilot project), Gasification technology
700 TPD of waste, 10 MW of electricity
Hyderabad: 1,100 TPD of MSW for 11-MW power RDF Power Projects
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Incineration plant design and operation
Waste Reception and Handling
 Concrete bed with shed
 Weighing and inspection
 Mixing of waste using cranes with grapples
(to balance calorific value, size, structure, composition)
 Storage capacity (3–5 days)
 Odour, noise, and emission control
Waste reception and handling area (storage, on-site pre-treatment facilities)
Combustion and steam generation system
Flue gas cleaning system
Energy generation system (steam turbine and generator)
Hauling and disposal system for residual waste
Monitoring and control systems
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Steam to turbine
Combustion of volatiles
boilers
chimneys
Flue gas
drying and
cleaning
Feed hopper
MSW
delivery
Storage
bunker
Combustion
of solids
Slag removal Control room
Electrostatic precipitator
Combustion boiler chamber
Waste bunker
Wet scrubber
DeNOx Plant
Stack
Primary air system
Grate incinerator
Slag discharger
Turbine/Generator
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Incineration process
 Continuous feeding of waste to grate via a crane and a feeding chute or conveyor
 Uniform layer of waste on grate results in uniform energy generation
 Grate moves the waste in a tumbling motion through various zones
 Multiple incineration lines for continuous operation and mandatory maintenance periods
 Grate at bottom and boiler at top
 Ash & non-combustible waste leaves grate as slag or bottom ash (20%–25% by weight)
(Source: Gupta et al. , 2018)
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 Furnace technology and Grate design
(stable, continuous operation with full burning of waste and flue gases)
 Gas phase combustion temperature: Minimum 850°C
 Residence time of flue gases
 Optimum oxygen content (< 6%)
 Effective removal of Fly ash to reduce formation of dioxins and furans
 Flue gas treatment system
Grate Incinerator
Used for untreated, non-homogenous, and low calorific municipal waste
Reciprocating grates
Reverse reciprocating grate
Push forward grate
e.g., Timarpur Okhla MSWM Project WTE facility Delhi: Reciprocating forward
moving grate incinerator
Rocking grates, Travelling grates, Roller grates, and Cooled grates
Fluidised bed incinerator
Rotary kiln incinerator (hazardous waste and biomedical waste)
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Flue Gas Recirculation
 Passed through dust filter and partly recirculated into the furnace
 Reduction of secondary air(10%–20%)
 NOX reduction
 Air is added to the combustion chamber
Primary, Secondary and Tertiary air(re-circulated flue gases)
Primary air from waste bunker & Secondary air is blown in the incineration chamber
Haulage and Disposal System
MSW converted to carbon dioxide (CO2), water vapor, and toxic gases
Flue gas treatment system
Residues(fly ash) and spent scrubbing liquids
Fly ash from filter systems (contaminated and handled separately)
Bottom ash is treated and used as construction material
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Inputs to Waste incineration plants
Electricity, heat, fuel, water(flue gas treatment, cooling, and boiler operation), flue gas
treatment reagents, water treatment reagents, high pressure air
Outputs (Environmental Considerations)
Volatile and gaseous emissions
Fly ash and dust carrying toxic contaminants
Ash leachate can contaminate soil and water
Emission depends waste stream and engineering design and emission abatement technologies
Emissions: Hydrogen chloride, hydrogen fluoride, sulphur dioxide, NOx, carbon monoxide, volatile
organic compound, heavy metals, etc.
Dioxins and furans
 NOX and dioxin reduction (through proper combustion, temperature, oxygen content etc.)
 Flue gas treatment and reduction (recirculation, precipitation of ashes in the boiler etc.)
 Installation of air pollution control equipment
(bag house filters, dry, acid gas removal systems, catalytic reduction systems etc.)
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Stack Emission Standards
SWM Rules, 2016: Emission standards for incineration
SWM 2016:
Central Pollution Control Board (CPCB)
standards for ambient air quality and
levels of dioxins and furans around
waste to energy facilities
Parameters Emission Standards
Particulates 50 mg/Nm3
Half hourly average value
HCl 50 mg/Nm3
SO2 200 mg/Nm3
CO
100 mg/Nm3
50 mg/Nm3 Daily average value
Total Organic Carbon (TOC) 20 mg/Nm3
Half hourly average value
HF 4 mg/Nm3
NOx (NO and NO2) 400 mg/Nm3
Total dioxins and furans 0.1 ng TEQ/Nm3 6 – 8 hours sampling
Cd + Th + their compounds 0.05 mg/Nm3
Anywhere between 30
minutes – 8 hours of
sampling time
Hg and its compounds 0.05 mg/Nm3
Sb + As + Pb + Cr + Co + Cu + Mn
+ Ni + V + their compounds
0.5 mg/Nm3
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REFERENCES
2. Gupta et al. (2018), Waste to energy technologies in India: A review , Journal of Energy and
Environmental Sustainability, 6 (29-35)
3. Joshi R, Ahmed S, 2016, Status and challenges of municipal solid waste management in India: A
review, Environmental Chemistry, Pollution & Waste Management, 2, 1- 18
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CONCLUSIONS
 While challenges remain in setting up and operating an incineration plant, this can be
considered for urban areas as the only option if landfill space is limited or not available.
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KEY POINTS
 Incineration
 Incineration in India
 Incineration Plant design and operation
 Stack emission standards
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Lecture 39 : Waste to Energy Part 4
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⮚ Experimental technologies: Pyrolysis
⮚ Experimental technologies: Gasification
⮚ Quick comparison of different WTE technologies
⮚ Currently operating WTE plants
⮚ Selection of a suitable technology
⮚ Case study: Assessment of energy recovery potential and analysis of environmental impacts of
waste to energy options using life cycle assessment
CONCEPTS COVERED
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Experimental technologies: Pyrolysis
⮚ Thermal method (500°C–1,000°C ) to break down organic constituents in an anaerobic environment
(thermal decomposition, destructive distillation, carbonization)
Pyrolysis produces:
⮚ Syngas (methane, carbon dioxide, hydrocarbons, hydrogen and carbon mono-oxide)
⮚ Liquids (tar, pitch, light oil, and low boiling organic chemicals like acetic acid, acetone, methanol, etc.)
⮚ Solids residues/Char (elemental carbon along with the inert material)
❑ Syngas is utilized in energy applications
Net calorific value (Syngas): 2,800–4,800 kilocalorie per normal cubic meter (kcal/Nm3)
Burned in a boiler to generate steam (electricity generation and industrial heating)
Fuel in gas engine
After reforming in gas turbine
Chemical feedstock
❑ Small temperature pyrolysis (synthetic diesel fuel from plastic waste)
❑ Gas and char combustion used for the pyrolysis process itself
❑ Tar generated creates problems
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Feedstock for pyrolysis:
⮚ High calorific value, less moisture content and
homogenous
⮚ Plastics can be used
⮚ Carbon rich organic material
Reactor:
Rotary kilns, rotary hearth furnaces, and fluidised
bed furnaces 500°C–800°C (MSW)
Plasma Pyrolysis Vitrification
Uses a plasma reactor which generates extremely high temperature (5,000°C–14,000°C) using high
voltage between two electrodes
Hazardous waste: Plasma pyrolysis facility at Taloja, near Mumbai
Experimental technologies: Pyrolysis
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Involves partial combustion of waste to generate
energy at high temperature (>650oC) with a
limited amount of air (i.e. partial combustion).
Gasification produces:
Char, Tar and Syngas
70% mass and 90% volume reduction of waste
Feedstock: Carbonaceous material of MSW
Gasification of MSW happens in two chambers
Fixed bed gasifiers
Fluidised Beds
Plasma gasification
NERIFIER gasifier: Nohar, Hanugarh, Rajasthan by
Navreet Energy Research and Information (NERI)
(agro-biomass, sawmill dust and forest dust)
TERI gasifier: Gaul Pahari Campus, New Delhi
Experimental technologies: Gasification
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Quick comparison
of different WTE
technologies
Criteria Incineration Pyrolysis Gasification
Refuse Derived
Fuel
Composting Anaerobic digestion
Status of
technology used
Widely used in
developed
countries
Mostly used in developed countries Widely used
Types of solid
waste
Unsorted waste
Specific type of
recyclable plastic
waste
Unsorted
waste
Unsorted waste
without hazardous
and infectious
waste
Sorted organic
waste, high lignin
material is
acceptable
Sorted organic waste,
animal or human
excreta, less suitable
for high lignin waste
Final products Heat Heat, Pyrolysis Oil Heat, Char RDF
Compost/ humus
product
Compost/ humus
product, low calorific
RDF heat
Adverse impacts
Air pollution from
toxic gas emissions
High energy consumption during
operation, noise and air pollution
Uncertain heating
value
Odour and insect
problem
Problem of leaking
methane gas
Air pollution High Medium High Low
Solid waste
generation due
to rejects
Low High Low
Volume
reduction of
waste
75 – 90% 15 – 30% 45 – 50%
Contribution to
energy
Power generation
from heat
Power generation,
pyrolysis oil as raw
material
Power
generation
Energy from RDF None
Power generation from
biogas
Contribution to
food
None
High contamination,
None
None Used as compost for cultivation
(Source: Gupta
et al. , 2018)
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Currently operating WTE plants
State Project/ Under Trial
Installed
Capacity
(MW)
Delhi M/s Ramky Group, Narela-Bawana 24.00
Delhi
M/s Jindal Urban Infrastructure Pvt Ltd.,
Okhla
16.00
Delhi
M/s IL&FS Environnent Infrastructure
and Services Ltd., Ghazipur
12.00
Madhya Pradesh M/s Essel Infra at Jabalpur 9.00
Maharashtra
M/s Solapur Bio-energy Systems Pvt. Lt.,
Solapur
3.00
Himachal Pradesh M/s Elephant Energy Private Ltd., Shimla 1.75
S.No. States Composting
Vermi-
Composting
Bio-
methanation
Refuse
Derived Fuel
Incineration/
Gasification
1 Andhra Pradesh - 18 8 - -
2 Assam 1 - - - -
3 Delhi 1 - - - 3
4 Goa 7 - - - -
5 Gujrat - 93 1 3 -
6 Haryana 4 - - 4 -
7 Jammu and Kashmir - 2 - - -
8 Karnataka 104 57 27 4 -
9 Madhya Pradesh 11 - - 1 1
10 Maharashtra 43 31 42 5 1
11 Meghalaya 1 1 - - -
12 Odisha 1 - - - -
13 Punjab - 1 - 2 -
14 Tamil Nadu 12 - 3 19 -
15 Telangana 10 3 1 3 -
16 Uttar Pradesh 13 - - 4 -
Total 208 206 82 45 5
Note: The following states have no facilities: Andaman Nicobar, Arunachal Pradesh, Bihar, Chandigarh, Chhattisgarh, Daman Diu, Himachal
Pradesh, Jharkhand, Kerala, Lakshadweep, Manipur, Mizoram, Nagaland, Pondicherry, Rajasthan, Sikkim, Uttarakhand, West Bengal
(Source: Gupta et al. , 2018)
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⮚ Depends on many factors including waste characteristics and waste collection, segregation and sorting system
⮚ Major factors for comparison: Environmental benefits and energy recovery potential
Life cycle assessment(LCA)
Selection of a suitable technology
Nagpur: LCA of anaerobic digestion, composting, material recovery facility and landfilling
Least environmental impact: Scenario with material recovery facility, composting and landfilling
Mumbai: LCA of open dumping and six alternative scenarios (recycling, composting, anaerobic
digestion, incineration and landfill with and without landfill gas recovery)
Best scenario: Combination of recycling, anaerobic digestion, composting & land-filling inert waste
Delhi: LCA of 5 options (anaerobic digestion, composting, RDF, incineration and landfilling)
Least environmental impact: Composting, anaerobic digestion, RDF and landfilling
(Source: Khandelwal
et al., 2019)
(Source: Sharma
and Chandel,
2017)
(Source: Bohra
et al., 2012)
Khandelwal, H., Thalla, A.K., Kumar, S., Kumar, R., 2019. Life cycle assessment of municipal solid waste management options for India. Bioresour. Technol. 288, 121515
Sharma, B.K., Chandel, M.K., 2017. Life cycle assessment of potential municipal solid waste management strategies for Mumbai, India. Waste Manag. Res. 35, 79–91.
Bohra, A., Nema, A.K., Ahluwalia, P., 2012. Global warming potential of waste management options: case study of Delhi. Int. J. Environ. Technol. Manag. 15, 346–362
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Case study: Assessment of energy recovery potential and analysis of
environmental impacts of waste to energy options using life cycle assessment
WTE potential (energy recovery and environmental impacts)
Technologies considered: Landfill gas to energy, Anaerobic digestion, Mass incineration and RDF incineration
Six scenarios:
Dhanbad Municipal Corporation (DMC),Jharkhand, India
 MSW generation rate: 0.41 kg/c/d
 No waste treatment plant or sanitary landfill
 Compacted at transfer station and disposed in open dump site
Scenario 1 (Baseline): Landfill without energy recovery
Scenario 2: Landfill with gas recovery and electricity generation
Scenario 3: Anaerobic digestion and landfilling
Scenario 4: Mass incineration (combustible components: wet & dry waste) and landfilling
Scenario 5: RDF incineration and landfilling
Scenario 6: Anaerobic digestion, mass incineration and landfilling
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LCA as per ISO 14040/14044 standards
Goal & scope
Life cycle inventory
Life cycle impact assessment
Interpretation
Goal and scope:
⮚ Electrical energy recovery potential and nutrient recovery(compost) potential of each option
⮚ Recovered material can help in avoiding raw/virgin material extraction and processing and their
environmental impacts
Functional units:
LCA inputs and outputs based on similar functional unit.
Software used: SimaPro 8.0.5 (India data) for environmental impacts analysis
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System boundary:
⮚ Primary waste collection: Low capacity
vehicles with 3 chambers (wet, dry and
hazardous waste)
⮚ Secondary collection: Large trucks (transfer
station to disposal facility)
⮚ Transportation out of system
boundary(distance same for most
scenarios)
⮚ Segregation & sorting within
system boundary (separation
within incineration plants)
MSW collection and
transportation
Landfilling
Landfilling with
energy recovery
Landfill gas
Anaerobic
digestion
Biogas
Mass
incineration
RDF preparation
RDF
incineration
Segregation
and sorting
Electricity
& digestate
Emission
into air,
water &
soil
Raw
material,
energy &
water
Electricity
Input Output
64%
36%
28%
28%
28%
100 %
100 % 36% 36% 36% 72%
36%
Scenario 1 – Landfilling
Scenario 2 – Landfill gas to energy
Scenario 3 – Anaerobic digestion & landfilling
Scenario 4 – Mass incineration & landfilling
Scenario 5 – RDF incineration & landfilling
Scenario 6 – Anaerobic digestion, mass incineration & landfilling
(Source: Atul Kumar et. Al., 2022)
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Emissions:
⮚ Direct emissions (As per raw
material input in system)
⮚ Indirect emissions are caused
due to avoided electricity and
fertilizer production
Input
Unit/ tonne waste
input
Value
Energy/ fuel
Diesel L 1.96
Electricity kWh 70
Raw material
Water Cu.m 1.11
Lime Kg 10.2
Sodium hydroxide Kg 1.96
Urea Kg 4.64
Activated carbon Kg 0.12
Output
Unit/ tonne
waste input
Value
Avoided burden
Electricity production kWh 837
Emissions into air
Carbon dioxide Kg 357.73
Carbon monoxide Kg 0.4
Nitrogen oxides Kg 1.6
Fly / bottom ash Kg 250
Sulphur dioxide g 42
Hydrogen chloride g 58
Hydrogen fluoride g 1.0
Particulates g 38
Mercury mg 50
Lead mg 81
Cadmium mg 6.0
Arsenic mg 5.0
Dioxins/ furans ng 0.629
Output Value (g)
Emissions into soil
Cadmium 0.015
Chromium 0.03
Copper 1.3 x 10-6
Lead 0.069
Zinc 2.19
Nickel 0.161
Output Value (mg)
Emissions into water
Chemical Oxygen Demand 3.0
Biochemical Oxygen Demand 0.90
Total nitrogen 0.327
Total phosphorus 0.016
Lead 0.126
Copper 0.017
Nickel 24
Mercury 0.117 (Source: Atul Kumar et. Al., 2022)
Mass Incineration
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Maximum Electricity Recovery: Combination of mass incineration of combustible fractions and landfilling (602 kWh/Tonne)
Next: RDF incineration and landfilling (472 kWh/Tonne)
Minimum Electricity recovery: Landfill gas to energy (54 kWh/Tonne)
Maximum Environmental impact: Landfilling without energy recovery followed by landfill gas to energy
Environmental benefits in other scenarios are due to avoided impacts from electricity generation
Global Warming Human Toxicity
(Source: Atul
Kumar et. Al.,
2022)
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Maximum net savings(All environmental impact
categories): Combination of mass incineration and
landfilling
Energy recovery from waste is beneficial overall.
Case study: Assessment
of energy recovery
potential and analysis of
environmental impacts of
waste to energy options
using life cycle
assessment
Photochemical ozone creation Eutrophication
Acidification (Source: Atul Kumar et. Al., 2022)
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REFERENCES
2. Gupta et al. (2018), Waste to energy technologies in India: A review , Journal of Energy and
Environmental Sustainability, 6 (29-35).
3. Atul Kumar, Sukha Ranjan Samadder(2022), Assessment of energy recovery potential and analysis of
environmental impacts of waste to energy options using life cycle assessment, Journal of Cleaner
Production, Volume 365, 132854
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CONCLUSIONS
⮚ Environmental benefits and energy recovery potential are key to determine appropriate
WTE technology options.
⮚ LCA approach helps us to do a comprehensive evaluation of environmental impact
assessment of any viable WTE option.
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KEY POINTS
⮚ Experimental technologies: Pyrolysis
⮚ Experimental technologies: Gasification
⮚ Quick comparison of different WTE technologies
⮚ Currently operating WTE plants
⮚ Selection of a suitable technology
⮚ Case study: Assessment of energy recovery potential and analysis of environmental impacts of
waste to energy options using life cycle assessment
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Lecture 40 : Life Cycle Assessment
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 ISO 14040:2006 LCA framework
 Goal and Scope Definition
 Goal and Scope definition in the context of Solid Waste Management
 Life Cycle Inventory analysis
 Landfills as carbon sink
 Life cycle Impact Assessment
 Life Cycle Interpretation
 Examples
CONCEPTS COVERED
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Environmental impacts of a product, process or service
are investigated throughout its life cycle
This is possible through first compiling an inventory of
inputs and outputs to this product, process or service
and otherwise known as inventory analysis.
In the impact assessment phase potential
impacts of the above inputs and outputs are
evaluated
Finally, the results are interpreted as
per the objectives of the study
ISO 14040:2006 LCA framework
International Standards Organisation (ISO) provides a
standardized framework for conducting LCA
Goal and scope
definition
Life cycle inventory
analysis
Life cycle impact
assessment
Interpretation
The framework for life cycle assessment
Direct
applications:
• Product
development
and
improvement
• Strategic
planning
• Public policy
making
• Marketing
• Other
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Goal and scope definition
Goal and scope is defined as per the intended application and may be revised midway
Goal: Reason for conducting the study and its audience
Comparative assertions for public
Scope:
 The product, process or service and its functions
Functions are performance characteristics for reference or comparison
Functional units are thus defined and measurable
 System boundary
Defines the unit processes and the level of detail of the study
Some life cycle stages, processes, inputs or outputs is deleted if it does not alter the results and
conclusions significantly
Beginning(raw material and intermediate products) and ending of the process(intermediate and final
products) and the transformation during the process
 Cut off criteria for input output allocation
 LCIA methodology and types of impacts
 Interpretation
 Data and data quality requirements, assumptions, limitations,
 Type of critical review and format of report
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(Source: Finnveden G. et.al. (2000))
Elementary composition of
constituents of waste.
This is used as input in the
comparison of incineration and
landfill options.
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Food Waste,
Newspaper,
Corrugated Board,
Mixed Cardboard,
Polyethylene (PE),
Polypropylene (PP),
Polystyrene (PS),
Polyethylene
Terephthalate (PET)
Polyvinyl Chloride
(PVC))
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System boundaries can be also time related, geographical boundaries
Goal and scope definition in the context of solid waste management
Upstream and downstream system boundaries
In MSWM input is solid waste which originates from households and other generators
Upstream system boundary
Parts of the system/process, which are identical in all compared systems can be ignored
Downstream system boundary
Materials or energy can be recycled into new products.
Recycled products and products replaced by these are not followed to their disposal normally
Time aspects
Land fill and Incineration: Effect of time is significant. Thus a boundary may be defined.
In landfill the impacts are spread over a long time.
Similarly materials are persistent (e.g. plastics) and leaching out of metals is also slow
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Goal and scope definition in the context of solid waste management
Multi-input allocation
 It case several products are inputs to a processes allocation of environmental interventions for each
product becomes difficult.
 Multi-input allocation is done considering physical, chemical or biological relationships
Open-loop recycling (Refers to the situation when a product is recycled)
 Environmental interventions can be allocated between the two products and only one is considered
 Considering both products within the system boundary
The recycling system
Primary material used in both products
Materials disposed from both products
Recycled material replaces virgin material with similar functions
Thus downstream processes are considered identical and disregarded
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Life cycle inventory analysis
Data collection and calculation phase
Relevant inputs are linked to the outputs
 Product system and process identification
 Raw materials and energy extracted from environment(Input)
 All inputs return to the environment as emissions to air, water and land
 Process flow chart and data on each process (collected from scientific literature, government and industry sources)
Boundaries are set for the product system under consideration
 from the environment
 from other product systems
 from processes not taken into account
Aggregated data results in an inventory table.
Economic inputs and outputs converted to environmental inputs(resources) and outputs(emissions)
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Life cycle inventory analysis
Impact categories
Input related categories
1. Abiotic resources (deposits, funds, flows)*
2. Biotic resources (funds)
3. Land
Output related categories
4. Global warming
5. Depletion of stratospheric ozone
6. Human toxicological impacts
7. Ecotoxicological impacts
8. Photo-oxidant formation
9. Acidification
10. Eutrophication (incl. BOD and heat)
11. Odour
12. Noise
13. Radiation
14. Casualties
Deposits: Resources which cannot be renewed within a limited time (mineral
ores and fossil fuels)
Funds: Resources which are renewable but can be depleted (wood and fish).
Flows: Resources which cannot be depleted (wind and solar radiation). These
can be deflected though.
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 Carbon flows into landfill is modeled
 Biotic (from renewable sources) carbon is generally disregarded
 Non-biotic carbon (from fossil sources) is considered
Assumption:
On harvest of biotic resources, new resources are planted (uptake an equivalent amount of CO2)
Landfills as carbon sinks
Incineration: 100 % of the carbon emitted as CO2(Since biotic emission may be disregarded)
Landfill: 70 % is emitted quickly(system boundary) as CO2 and CH4 after decomposition
CO2 is disregarded, but CH4 emissions are considered.
Rest 30 % carbon is trapped in the landfill.
Cellulose:
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Life cycle impact assessment (LCIA)
Normalisation relates the magnitude of the impacts in
the different categories to reference values
Grouping includes sorting and possibly ranking of the
indicators
Weighting: Aggregating results across impact
categories resulting in a single result
LCIA is exploration and evaluation of the magnitude and significance
of the potential environmental impacts of a product system.
LCIA includes:
 Selection of impact categories, category indicators and
characterization models
 Assignment of LCI results to the selected impact
categories (classification)
 Quantification of the contributions to the
chosen impacts from the product system
(characterization)
Different from EIA and is a relative approach based on a functional unit.
Inventory
Table
CO2
CH4
CFC
SO2
NOx
NH4
NOx
NH4
P
CO
D
…………………………
GLOBAL
WARMING
ACIDIFICATION
EUTROPHICATION
…………………………
ENVIRONMENTAL
INDEX
CLASSIFICATION AND
CHARACTERISATION WEIGHTING
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Life Cycle assessment framework
Life cycle interpretation
 Results of LCIA phases are interpreted as per the goal and
scope of the study
 Includes assessment and sensitivity check for inputs,
outputs and methodological choices
 Uncertainty of the results (ranges and/or probability
distributions)
Completeness: Ensure availability of relevant and
complete information and data required
Sensitivity check: Ensure reliability
of the final results and conclusions
Effect of uncertainties in the data,
allocation methods or calculation of
contributions
Consistency check:
Assumptions, methods and
data are consistent with the
goal and scope
Inventory
Analysis
Impact
Assessment
Identification
of
Significant
Issues
Evaluation by:
-completeness
check
-sensitivity check
-consistency check
-Other checks
Conclusion, Limitations and
recommendations
Direct
Applications
-Product
development and
improvement
-Strategic
Planning
-Public Policy
making
-Marketing
-Other
Interpretation
Goal &
Scope
Definition
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Example: Newspaper recycling system
WASTE PAPER
TRANSPORT INCL
RELOADING
RECYCLED PULP
PRODUCTION
ADDITIVES
EL
HEAT
NT
WASTE
THERMO
MECHANICAL
PULP, TMP
PAPER PRODUCTION
EL
HEAT
AVOIDED WOOD EXTRACTION
AVOIDED
WOOD
AVOIDED
DIESEL
AVOIDED TRANSPORT
AVOIDED CLEANING
AVOIDED
ENERGY
AVOIDED THERMO
MECHANICAL PULP (TMP)
PRODUCTS
AVOIDED VIRGIN PAPER
PRODUCTION
AVOIDED
HEAT
AVOIDED HEAT PRODUCTION FROM
FOREST RESIDUES AND OIL
AVOIDED
EL
AVOIDED HEAT
AVOIDED
EL
AVOIDED
HEAT
• Boxes indicate processes
• Circles indicate flows
• Thicker lines indicate more processes
and data connected to box/ circle
• NT waste – Non-treated waste
• Grey areas – avoided processes & flows
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Example: PET recycling system
WASTE PET BAILING TRANSPORT
PET RECYCLING
EL STRAPPINGS
EL
NATURAL GAS
NITROGEN
POLYMER
FILTER
SCREENS
AVOIDED EL
AVOIDED
RESOURCES
AVOIDED
NT WASTE
AVOIDED VIRGIN PET
PRODUCTION
PET: Polyethylene terephthalate
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Example: Composting system
FOOD WASTE
ENERGY
INCL EL
NT
WASTE
COMPOSTING
RESIDUE AVOIDED
ARTIFICIAL
FERTILISER
TRANSPORT
LANDFILLING OF
SLUDGE
AVOIDED
SPREADING OF
ARTIFICIAL
FERTILISER
AVOIDED
PRODUCTION
OF ARTIFICIAL
FERTILISER
TRANSPORT
COMPOSTING
FACILITY
SPREADING OF
COMPOSTING
RESIDUE
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REFERENCES
1. Life Cycle Assessments of Energy from Solid Waste, By: Göran Finnveden, Jessica Johansson, Per Lind
and Åsa Moberg, Published By: Stockholms Universitet/Systemekologi OCH FOA, 2000
2. Life Cycle Assessment: Principles And Practice By: Scientific Applications International Corporation
(Saic)National Risk Management Research Laboratory, Office Of Research And Development, U.S.
Environmental Protection Agency, EPA/600/R-06/060, May 2006
3. ISO 14044(2006), Environmental management — Life cycle assessment — Requirements and
guidelines
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CONCLUSIONS
 LCA offers a more comprehensive way to evaluate the environmental impacts of a
product, process or a service.
 Standardized frameworks also ensure consistency of the analysis and interpretations.
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KEY POINTS
 Life Cycle Assessment Framework
 ISO 14040:2006 LCA framework
 Goal and Scope Definition
 Landfills as carbon sink
 Life Cycle Inventory analysis
 Life cycle Impact Assessment
 Life Cycle Interpretation
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