WastetoEnergyPlantTechnology

2.  Waste is a product or substance which is no longer
suited for its intended use. Whereas in natural
ecosystems waste (i.e. oxygen, carbon dioxide and dead
organic matter) is used as food or a reactant, waste
materials resulting from human activities are often
highly resilient and take a long time to decompose.
 For legislators and governments, defining and
classifying waste based on risks related to the
environment and human health are therefore important
in order to provide appropriate and effective waste
management. For the producer or holder, assessing
whether a material is waste or not is important in
identifying whether waste rules should be followed.
Definitions are also relevant in the collection and
analysis of waste data as well as in domestic and
international reporting obligations.
 Waste has been defined in most countries and is
generally tied to the concept of disposal.

3.  Wastes: Wastes are substances or objects which are
disposed of or are intended to be disposed of or are
required to be disposed of by the provisions of
national law.
 Forms of waste: Solid, Liquid, gases
 Solid waste (refuse): The wastes in the solid or
semisolid forms are called solid wastes.
 Refuse comprises all of solid waste resulting from the
normal activities of the community except excreta.
 Solid waste: Solid waste is all-inclusive, encompassing
the heterogeneous mass of throw aways from the
urban community as well as the more homogeneous
accumulation of agricultural, industrial and mineral
wastes.

4. Consequences of solid waste:
1. Littering of food and other solid waste in medieval towns-the practice of
throwing wastes into the unpaved streets, roadways and vacant land led to
the breeding of rats with their attendant fleas carrying bubonic plague.
2. The lack of any plans for the management of solid waste thus key to
epidemic of plague, the Black Death.
3. Ecological phenomena such as water and air pollution have been attributed
to improper management of solid waste.
4. For instance, liquid form dumps and poorly engineered landfills has
contaminated surface waters and ground waters.

5. Methods for the final disposal of solid wastes:
(i) Dumping on land
(ii) Dumping in water
(iii)Plowing into the soil
(iv)Feeding to hogs
(v) Reduction
(vi) Incineration
Objective of solid waste management
The objective of solid waste management is to reduce the quantity of
solid waste disposed off on land by recovery of materials and energy
from solid waste. This in turn results in lesser requirement of raw
material and energy as inputs for technological processes. Such
techniques and management programs have to be applied to each and
every solid waste generating activityin a society to achieve overall
minimization of solid waste.

6. Effective management of solid waste
Effective solid management systems are needed to ensure better human
health and safety. They must be safe for workers and safeguard public health
by preventing the spread of disease. In addition to these prerequisites, an
effective system of solid waste management must be both environmentally
and economically sustainable.
 Environmentally sustainable: It must reduce as much as possible, the
environmental impacts of waste management.
 Economically sustainable: It must operate at a cost acceptable to
community.

7. Waste management systems and their impact on environment

8.  Waste can be classified based on source (who/what
generated the waste? See Figure 1), substance (what is
it made of?), hazard properties (how dangerous is it?),
management (who handles it?) or a mix of these
concepts.

9. Two main waste categories can be established based on the
distinct legislation and policy instruments usually in place: non-
hazardous or solid waste; and hazardous waste. Such a
classification is also used in the Basel Convention. Hazardous
waste is usually regulated at the national level, while non-
hazardous is regulated at the regional or local (municipal) level.
(See Figure 2.)

11.  Non-hazardous/solid waste is all waste which has not been classified
as hazardous: paper, plastics, glass, metal and beverage cans, organic
waste etc. While not hazardous, solid waste can have serious
environmental and health impact if left uncollected and untreated While a
significant proportion of solid waste could theoretically be reused or
recycled, collection by type of waste a prerequisite for reuse and
recycling is one of the biggest waste management challenges.
 Hazardous waste is waste that has been identified as potentially
causing harm to the environment and human health and therefore needs
special, separate treatment and handling Chemical and physical
characteristics determine the exact collection and recycling process.
Flammability, corrosiveness, toxicity, ecotoxicity and explosiveness are
the main characteristics of hazardous waste. Liquid, gaseous and
powder waste need special treatment by default to avoid the dispersal of
the waste. Generally, separate collection and handling are established to
avoid contact with non-hazardous waste. Chemical treatment,
incineration or high-temperature treatment, safe storage, recovery and
recycling are possible modes of treatment for hazardous waste.

12. Most hazardous waste originates from industrial production.
Special kinds of hazardous waste include:
 E-waste is waste from electric and electronic equipment such
as end-of-life computers, phones and home appliances. E-
waste is generally classified as hazardous because it contains
toxic components (e.g. PCB and various metals).
 Medical waste originates from the human and animal
healthcare systems and usually consists of medicines,
chemicals, pharmaceuticals, bandages, used medical
equipment, bodily fluids and body parts. Medical waste can be
infectious, toxic or radioactive or contain bacteria and harmful
microorganisms (including those that are drug-resistant).
 Radioactive waste contains radioactive materials. The
management of radioactive waste differs significantly from that
of other waste.

13.  Why Waste-to-Energy?

14.  Why Waste-to-Energy?

15.  Waste to Energy(WTE) Waste energy works by burning waste at a very
high tempr,heat is then transferred ,transformed into energy. the steam then
drive a turbine-creates electricity and surplus heat which can be used for
district heating and cooling. Also recovered clean water, valuable metals and
construction material from the waste.
 Residual waste to energy is most economical compare to solar, tidal, wind,
Hydro, Thermal and nuclear.
 According to the confederation of European waste to energy plants(CEWEP)
Europe treats 50 million ton of waste at WTE plant, generates an amount of
energy that can supply electricity for 27 million people and heat for 13
million people.
 Worldwide 130 million tonnes of MSW combusted annually in over 600 wte
facilities that produce electricity & steam and recovered metals for recycling.
1ton MSW can generate up to 750 kWh. Ash 10% of original volume.

16.  Apprx.100000MTonnes of waste is generated per day world wide, production
of this waste is expected to be approximate 27 billion tonnes/year by 2050,
1/3 of this waste which will come from Asia( major countries China+ India)
 Waste generation rate in Urban India will become 0.7kg per person per day by
2025, 4-6 times higher than in 2012. Current-0.2-0.45kg/person/day on an avg.
 This waste has a potential of generating 439MW of power,1.3million cubic
meter of biogas per day or 72 MW of electricity from Biogas and 5.4 million
metric tonnes of Compost.
 Morover, 62 million tonnes annual generation of MSW requires 3,40,000
cubic meter of landfill space everyday (1240 hectare per year) if continues to
be dumped.

17. Solid Waste Types
 Municipal solid waste commonly known as trash or garbage, refuse or rubbish
is a waste type consisting of everyday items we consume and discard.
 It predominantly includes food wastes, yard wastes, containers and product
packaging and other inorganic wastes from residential, commercial,
Institutional and industrial sources.
 Organic waste –food scrapes, wood, rubber, canteen or cafeteria wastes, news
papers, tires, furniture etc.
 Municipal solid waste does not include industrial wastes, agriculture waste and
sewage sludge.
 Biodegradable waste-food and kitchen waste, green waste, paper (can be
recycled);
 Recyclable material-Paper, glass bottles, cans, metals, certain plastics, etc.;
 Inert waste- dirt, rocks, debris, C & D waste
 Composite waste-waste plastics, tetra packs, waste closing

18. Waste to energy recovery plant
 waste-to-energy plant converts
solid waste into electricity and/or heat - an
ecological, cost-effective way
of energy recovery. The energy plant
works by burning waste at high
temperatures(850) and using the heat to
make steam. The steam then drives a
turbine that creates electricity.
.

20.  Severe illnesses, including encephalitis and dengue fever, have been attributed
to disease-carrying mosquitoes originating from scrap tire piles.
 Illegal dumping can impact proper drainage of runoff, making areas more
susceptible to flooding when wastes block ravines, creeks, culverts, and
drainage basins.
 In rural areas, open burning at dumpsites containing chemicals may
contaminate wells and surface water used as sources of drinking water.
 Dumpsites that caught fire, either by spontaneous combustion or, more
commonly.
 Rodents, insects, and other vermin attracted to open dumpsites may also pose
health risks. The health risks associated with illegal dumping are significant for
rag pickers and residents living nearby
 Areas used for illegal dumping may be easily accessible to people, especially
children, who are vulnerable to the physical (protruding nails or sharp edges) and
chemical (harmful fluids or dust) hazards posed by wastes.
 (Source: Illegal Dumping Prevention Guidebook. US EPA. EPA905-97-001)

21. 1. Segregation at source-Reduce, Reuse, Recycles,
2. Collection and transportation
3. Treatment and Energy Recovery-Waste which can be heated, converted processed
into gas, fuel and electricity.
4. Scientific land filling for inert, hazardous and Toxic.
Criteria for selection of WTE technology
1. Waste characterization-type ,quantity and waste content.
2. Environment and health-CO2 control, DXNs control, Emission control, landfill
control.( Air, water and land pollution overall)
3. Economy-cost control, profit and growth, relative capital cost, O &M.
4. Energy and efficiency – energy recovery, high efficiency, utilization and safe.
Power generation- Efficiency(50-60% based on VOC)

22. 3 E’s Technology selection Criteria
Environment
Economy
Energy
• Emissions control
• Minimize Landfill
 Cost Vs. Benefit
 Social & Financial
 Energy recovery
 Efficiency
Selection of waste to energy technology is based on scale of waste to be processed,
existing emission norms, energy recovery and economic factors

23. Waste-to-Energy (WtE)
also known as energy-from-waste, is complicated technology in the realm of
renewable energy. The waste that is neither recycled nor used is converted
to energy in the form of heat, steam or electricity. The electricity generated is
fed into the grid and distributed to the households, industries, communities,
etc. Hence, WtE provides a cost effective and hygienic alternative to treat
residual waste, reducing its volume by 90% . WtE is an integral part to reach
100% RE in future along with other renewable sources.

24. Waste to energy recovery
 Stock pallet waste- furnaces-Burn- Heat-steam-Turbine-Electricity, Components:
furnaces, turbines, heat exchanges boilers, generators etc.
 The technology options available for processing the Municipal Solid Waste(MSW)are
based on either Bioconversion or thermal conversion
 The Bioconversion process is applicable to the organic fraction of wastes, to form
compost or to generate biogas such as methane (waste to energy) residual
sludge(manure).
 Various technologies are available for composting such as aerobic, anaerobic & vermi-
composting.
 The thermal conversion technologies are incineration with or without heat recovery,
pyrolysis and gasification, plasma pyrolysis and pelletization or production of Refuse
Derived Fuel(RDF).

25. 1. Thermochemical Conversion of Waste
The three principal methods of thermochemical conversion
of MSW are combustion (in excess air), gasification (in
reduced air), and pyrolysis (in absence of air). The most
common technique for producing both heat and electrical
energy from wastes is direct combustion. Combined heat
and power (CHP) or cogeneration systems, ranging from
small-scale technology to large grid-connected facilities,
provide significantly higher efficiencies than systems that
only generate electricity.
Combustion technology is the controlled combustion of
waste with the recovery of heat to produce steam which in
turn produces power through steam turbines. Pyrolysis and
gasification represent refined thermal treatment methods as
alternatives to incineration and are characterized by the
transformation of the waste into product gas as energy
carrier for later co

26. 2. Biochemical Conversion of Waste
Biochemical processes, like anaerobic digestion, can
also produce clean energy in the form of biogas which
can be converted to power and heat using a gas
engine. Anaerobic digestion is the natural biological
process which stabilizes organic waste in the absence
of air and transforms it into biofertilizer and biogas.
Anaerobic digestion is a reliable technology for the
treatment of wet, organic waste. Organic waste from
various sources is biochemically degraded in highly
controlled, oxygen-free conditions circumstances
resulting in the production of biogas which can be used
to produce both electricity and heat.

27. 3. Physico-chemical Conversion of Waste
The physico-chemical technology involves various
processes to improve physical and chemical properties
of solid waste. The combustible fraction of the waste is
converted into high-energy fuel pellets which may be
used in steam generation. The waste is first dried to
bring down the high moisture levels. Sand, grit, and
other incombustible matter are then mechanically
separated before the waste is compacted and
converted into pellets or RDF.
Fuel pellets have several distinct advantages over coal
and wood because it is cleaner, free from
incombustibles, has lower ash and moisture contents,
is of uniform size, cost-effective, and eco-friendly.

29. Technologies for conversion of WtE
Waste to energy technologies recover energy from organic fraction of waste using either
biochemical or thermo chemical processes
Waste
Thermo chemical
Biochemical
Crushing, compressing,
pelletizing
Incineration
Conventional/
Plasma gasification
Pyrolysis
Biomethanation
Fermentation
Refuse derived fuel
Flue gas/steam
Syngas
Syngas & Bio-oil
Biogas
Ethanol
Mechanical
Electricity
Chemicals
Hydrogen
Transport fuel
Feed stock for
thermal process
Heat
Concept Process Energy carrier Application

31. Incineration
• Incineration involves combustion of
waste at very high temperatures in the
presence of excess oxygen
• Results in the production of ash, flue gas
and heat energy
• Incineration is feasible for unprocessed
or minimum processed refuse besides for
the segregated fraction of the high
calorific waste
Advantages
• Immediate reduction in volume and weight
by about 90% and 75% respectively
• Stabilization of waste
• Energy recovery
Challenges
• Management of dioxins and furans formed
in incineration
Incineration is a maturated technology for processing and energy recovery from waste

32. Organic matter + excess air N2 + CO2 + H2O + O2 + ash + heat

34. Gasification
• Gasification is thermo chemical conversion of
carbonaceous fraction of waste into syngas (CO,
H ,
2 CH4 and CO )
2 in oxygen deficient
environment and at high temperatures (650-
1600°C)
• Inorganic fractions present in the waste
converted to ash and can be safely land filled
• Syngas can be used for variety of applications
such as generation
chemicals, hydrogen
electricity, Bio fuels,
Advantages
• Immediate reduction in volume and weight
• Environment friendly
• Energy efficient
Challenges
• Higher initial cost compared to incineration
• Skilled labour is required
Gasification is more efficient and environmental friendly technology than incineration
for conversion waste into energy

36. Plasma gasification
• Plasma is an ionized gas where the atoms of the
gas have lost one or more electrons and have
become electrically charged
• Waste introduced into the plasma field, where
intense heat breaks down the waste molecules
into simple compounds
• Waste converted into fuel gases with high
calorific value and inert solid slag in the
temperature range 1200 – 2000 C
0
Advantages
• Immediate reduction in volume and weight
• Converts waste to inert vitrified slag
• Suitable for low calorific value waste
Challenges
• Expensive compared to
conventional gasification
• Skilled labor is required
Plasma gasification is an emerging waste to energy technology for processing of variety
of waste such as MSW, medical waste, agro waste etc.

37. Pyrolysis
• Pyrolysis is thermal decomposition of organic
fraction of waste in the absence of oxygen
• Pyrolysis is an endothermic process and usually
required heat is generated by burning of some
of the product gas in separate heater
• Pyrolysis produces three components:
Fuel gas: A mixture of fuel gases
Fuel oil: Consisting of tar, pitch, light oil etc.
Char along with the inert materials in the
waste feed
Advantages
•
Immediate reduction in volume and weight &
less space requirement
• Stabilization of waste
• Easy to operate
Challenges
• Pyrolysis oil is unstable & needs
further processing
• Energy is distributed in 3 fractions
Pyrolysis of waste plastics is an upcoming technology for conversion plastics to either
liquid fuels or chemicals

38. Hydrolysis and fermentation
• First step in conversion of cellulosic
fractions of waste to ethanol is hydrolysis
of cellulose and hemicellulose into simple
sugars using chemicals / enzymes
• Second step is fermentation of sugars into
ethanol followed by distillation
• Lignin is by a product in this process
Advantages
• Generation of drop-in bio-fuels
• Stabilization of waste
• Energy recovery
Challenges
• High capital and O & M Cost
• Convert only cellulosicand hemi cellulosic
fractions
• Conversion of polysaccharides to sugars is
complex
Major challenges in hydrolysis and fermentation are integration of hydrolysis and
fermentation into single step, and availability of low cost enzymes –Biochemical process

39. Besides the individual processes (incineration,
gasification or pyrolysis), combinations of these
processes, possibly combined with other processes (e.g.
melting, distillation) are also applied. A limited selection
of combination processes is presented in the following
subsections.
Combination pyrolysis – gasification
Combination gasification – combustion

40. Refuse Derived Fuel(RDF)
• RDF is produced by removing recyclables and noncombustibles from waste
and producing a combustible material by shredding, compressing and
pelletization of remaining waste
• RDF is easily storable, transportable, and more homogeneous fuel for either
steam/ electricity
furnaces/boilers
generation or as alternate fuel in industrial
• RDF may also be utilized in co-processing in cement kilns, co-combustion in
coal fired power plants
Advantages
• High calorific value of the waste
Challenges
• Suitable for the areas where large
amount of combustible waste is being
generated

41. RDF process flow scheme
RDF is usually prepared in the form of pellet/ briquette/ fluff from dry high calorific
value combustible wastes

42. Typical reaction conditions and products from pyrolysis, gasification and incineration
processes

44.  Handling and storage of waste: Refuse Bunkers, pallets, moving
cranes, storage units, blown air curtains to prevent odor outside.
 Waste incineration: Furnace, fire grates, air blowers, Boilers with
HE and Air condensers, closed loop of water supply feeding station.
 Flue gas treatment unit: Gas cooler, gas scrubber, electrostatic
precipitator, bag filters, addition of lime and activated carbon
process, DeNOx reactor, emission control for residue(APCR)
 Fly ash Chamber and Bottom ash chamber:
 Steam Turbine : low pressure high speed turbines, generators,
electricity tower etc.
 District heating system: part of steam used for community heating.
 Leachte treatment unit: waste water and wet flue gas treatment.
 Magnetic tray: On the bottom of furnace, recycled metals, vitrified
glass and other metals

48.  Renewable resource
 Reduces landfills- volume reduction by 90% only
residue goes to landfill
 Protects clean water supplies
 Reduces air pollution and smog-advanced pollution
control of gas emissions and flue gases.
 Reduces ground and surface water pollution
 Reduces greenhouse gases
◦ Carbon dioxide
◦ Methane

49. THANK YOU FOR YOUR
KIND ATTENTION !!

50. Trend of Resource Circulation Policy

51. Strategy of Waste Resource &
Biomass Energy

52.  Energy Recovery Equation

53. Attributes Incineratio
n
RDF Anaerobic
digestion
Pyrolysis Gasification Landfill gas
Methods Thermoche
m
ical
Thermochemical Biochemical Thermochemi
cal
Thermochemical Biochemical
Suitable waste characteristics Sorted
combustible
waste
Sorted combustible
waste
Sorted organic
waste: suitable for
either wet or dry
waste depending
on type of AD
system
Sorted
heterogeneous
MSW
Sorted organic
(combustible,
putrescible, and
plastic fractions of
the waste)
Unsorted waste
Description Waste is
broken down
to produce
heat.
Waste is broken
down to produce the
high calorific
fraction.
Organic
biodegradable
waste broken
down without
oxygen
(anaerobic) to
produce methane
gas, carbon
dioxide, water, and
digestive (which is
composted). Can
be wet or dry.
Waste is
broken down
by heat in the
absence of
oxygen to
produce fuel
gas.
Waste is broken
down by heat with a
limited quantity of
oxygen to produce
fuel gas.
Waste placed in a landfill
breaks down over time due to
biological, physical, and
chemical processes emerging
technologies, such as
bioreactor landfills, may offer
more sustainable approaches
to landfill disposal of wastes.
Energy form Heat Solid fuel Fuel gas Char,
pyrolysis oil,
and gases
Syngas LFG
General performance Thermal
treatment
can divert 70
per cent of
waste from
landfill
Can divert most
combustible of
waste from landfill
Can divert all or
most organic and
biodegradable
products (food,
yard waste, some
papers)
Can divert
most a mixed
(heterogeneou
s) waste
stream from
landfill
Can divert most
combustible organic
of waste from landfill
A wide range of performance
is available. Individual
facilities are
custom designed and
constructed to meet desired
waste management objectives
COMPARISON OF DIFFERENT TYPES OF WTE
TECHNOLOGY.

54. Community
characteristics
Thermal
treatment is
a high-tech
system that
requires
skilled
technical
operators.
Depending
upon the
specific
technology,
it is suitable
for
communities
ranging from
small
villages
to large
urban
RDF systems
treat waste is a
high-tech system
that requires
skilled technical
operators.
Depending upon
the specific
technology, it is
suitable for
communities
ranging from
large urban
Anaerobic digestion is
a high-tech system
that requires skilled
technical operators. It
is most suited to
reasonably large
urban areas to justify
the construction of the
system
Pyrolysis of waste
is a high-tech
system that
requires skilled
technical operators.
Depending upon
the specific
technology, it is
suitable for
communities
ranging from large
urban
Gasification of
waste is a high-tech
system that
requires skilled
technical operators.
Depending upon
the specific
technology, it is
suitable for
communities
ranging from large
urban
Landfill disposal of
waste is a
necessary element
of an integrated
approach to waste
management in all
Thailand
communities
Factors that influenced
acquisition
The
availability of
local energy
markets is a
critical factor
in the
decision
The availability
of local energy
markets is a
critical factor in
the decision
Availability of local
energy
The availability of
local energy
markets is a critical
factor in the
decision
The availability of
local energy
markets is a critical
factor in the
decision
Low costs relative
to other options.
Limitations on
availability of other
alternatives
Possible environmental
impact
air pollution,
particulate
matter, solid
residue and
wastewater
soot or dust and
air pollution
generated from
fuel burning
odor and disease
generated from solid
wastes fermentation
gas or vapor from
combustion, carbon
black, solid residue
from burning and
wastewater
gas or vapor from
combustion, carbon
black, solid residue
from burning and
wastewater
Methane gas that
is risk to explosion
Energy implication Thermal
energy and
convert to
electrical
energy
Thermal energy
and convert to
electrical energy
Net energy generator Energy for
conventional
engines and boilers
Energy for making
products; Methanol,
Ammonia, Diesel
fuel
Net energy
generator

55. Waste to Energy Fundamentals
There are three principal ways to recover the energy content of
MSW by treating it thermally, as shown
below. These include pyrolysis, gasification and combustion. These
processes are differentiated by the
ratio of oxygen supplied to the thermal process divided by oxygen
required for complete combustion.
This ratio is defined as the “lambda” ratio and in the case of
pyrolysis, it is equal to zero. Gasification is
conducted at substoichiometric conditions and full combustion is
carried out using a lambda greater than
one.
• Pyrolysis λ= 0, no air, all external heat
• Gasification λ = 0.5, partial use of external heat
• Combustion λ = 1.5 +, no external heat
where λ represents: oxygen input/ oxygen

59. The waste is recovered if:
• Its combustion generates more energy than is
consumed by the process itself;
• Most of the waste is consumed during the
operation
• Most of the energy generated is recovered and
used ( either as heat or electricity)
• The waste replaces the use of a source of Primary
Energy

60. A designated calculation procedure takes the amount of useful
electricity and heat DESIGNED to be produced by the facility and
applies appropriate factors to determine the amount of energy
necessary to produce this with modern plant. It then compares this
energy requirement with the energy used by the facility.
This approach uses a complicated set of data including:
• Start-up oil,
• Standby power,
• Imported power,
• Energy required to run the plant and
• Energy required for dust removal and gas clean up.
If the factor produced is < 0.65 the facility is classed DISPOSAL.
If the factor produced is =>0.65 the facility is classed RECOVERY.

61. The definition of energy efficiency used in the revised WFD is:
where:
 Ep means annual energy produced as heat or electricity. It is calculated with
energy in the form of electricity being multiplied by 2.6 and heat produced for
commercial use multiplied by 1.1
 Ef means annual energy input to the system from fuels contributing to the
production of steam
 Ew means annual energy contained in the treated waste calculated using the
lower calorific value of the waste
 Ei means annual energy imported excluding Ew and Ef
 0.97 is a factor accounting for energy losses due to bottom ash and radiation.
Comparison With Other Generating Methods
• Coal Fired Power station: 37% efficient
• Gas Fired CCGT: 41% efficient
• Waste Fired Power Station (EfW) 26% Efficient

62. Calculate the Energy Content of MSW
Total Energy = (Solid waste, lb) * (Energy Content,
Btu/lb)
Specific Energy content =
Total energy Btu
Total waste,lb

64. Electricity output= LHV*Waste flow*Electrical
efficiency
where LHV: MJ/kg, Waste flow: kg/d or yearly
bas