NON CONVENTIONAL ENERGY SOURCES

WASTE TO ELECTRICAL ENERGY (WTEE)

TECHNOLOGY

GENERATING WEALTH FROM GARBAGE

CONTENTS

1. ABSTRACT

2. RESOURCE RECOVERY

3. PROCESSED SOLID WASTE COMBUSTION

a. REFUSED DERIVED FUEL - PROCESSES

b. REFUSED DERIVED FUEL - PREPARATION

c. REFUSED DERIVED FUEL - CLASSIFICATION

d. REFUSED DERIVED FUEL - CHARACTERSTICS

e. REFUSED DERIVED FUEL - HIGHLIGHTS

4. WTEE – SOCIO ECONOMIC PROJECT

5. DEVELOPMENT & FUTURE OF WTEE

6. CONCLUSION

7.BIBLIOGRAPHY

ABSTRACT

What happened on May, 2004 in Mumbai?

Due to failure of local grid. The business capital of India jammed for hours. Being largest

railway network city, even the locals also stick to tracks. This incident shows the human

connection with electricity. Electrical energy is an essential ingredient for all activities, as

well as the lifeblood of economies throughout the world. It plays a vital role for economic

growth and quality life improvements: with the increase in population of the world. The

demand for power has gradually increased. Hence the burden on the countries, especially

developing countries like India have increased to meet the demands in the present day. Most

of the demands are met by conventional sources such as fossil fuels, hydal, nuclear power etc.

The use of these sources have not only resulted in their depletion. But also increased the

population. Hence there is a great need for improving technology in the use of non-

conventional sources of energy which could greatly decrease the environmental needs and

which would assure the future needs particles to rural people at affordable rates.

This paper presents an overview of waste to electrical energy technology The basic concept

and different features of WTEE is described. It includes the various processes to produce

Refused Desire Fuel (RDF), its characteristics and classifications. This shows the solution to

disposal of municipal and agricultural solid waste which is an increasing problem today and

the developments and goals are described.

RESOURCE RECOVERY….For the foreseeable future,

the disposal of municipal and agriculture

solid waste will continue to be an

increasing problem. This waste is either

composed, land filled, recycled or

converted to some form of energy but we

have another option called as Resource

Recovery. Recovering the energy from

municipal and agricultural solid waste.

And using this energy for power

production by Incineration and

Biomethanisation. Under this resource

recovery we have three options for power

production.

1. Unprocessed Solid Waste

Combustion.

2. Processed Solid Waste

Combustion.

3. Solid waste to liquid\gas convert

ion

1. UNPROCESSED SOLID

WASTE COMBUTION…………The mass burn technologies

use municipal solid waste (MSW).

The MSW under goes only limited

processing to remove non combustible

and over sized items. Mass burn

technologies include water wall

furnace, rotary kiln furnace, refractory

furnace water cooled rotary

combustion furnace and controlled air

furnace.

2. PROCESSED SOLID WASTE

COMBUSTIONUnder this process Refused

Derived Fuel (RDF) is used. The solid

waste are subjects to various process to

improve their physical & chemical

properties. These processes include

drying, comminution, densification,

physical separation and chemical

modification.

3. SOLID WASTE LIQUID /

GAS CONVERTION

TECHNOLOGYThese technologies convert

solid waste into either liquid or gas

fuels. This fuel can then be burned in a

conventional manner.

PROCESSED SOLID WASTE

COMBUSTION :The WTEE technology

identified in this subsection are refused

derived fuel which has been processed

from MSW. Due to having improved

combustion characteristics and emition

characteristics and easy preparation. We

prefer this processed solid waste

combustion.

Refused Derived Fuel-Processes

Five major processes are available to

improve the physical and chemical

properties of agricultural and other

solid waste.

DRYING…..

Removal of physically based water either

thermally& mechanically in Centrifuges

and process.

COMMINUTION……….

Reducing of particle size by

shredding, cutting, grinding

&pulverization.

DENSIFICATION……..

Increasing of bulk density of waste

through palletizing, cutting Briquette,

extrusion ,as rolling compressing.

PHYSICAL SEPARATION

Removal of unwanted components

from solid waste.

CHEMICAL MODIFICATION

Changing of waste’s chemical

structure.

RDF-PRODUCTION PROCESS

The Process :

The conversion process of garbage into

fuel fluff / pellets involves the following

processes:

Pre-sizing

Drying

Screening / Sieving

Separation of Combustibles

Size Reduction and production of Fuel

Fluff

Densification (with Binder and

Additives)

LAY OUT

REFUSED DERIVED FUEL-

PREPARATIONFollowing are the unit operations of the

process of refinement of MSW. These are

Material handling, size reduction, Drying,

Cyclone separation.

STEP I

The picked MSW is then allowed into the

premises of the plant over a sorting

conveyor to allow manual separation of

unwanted material like stones, rubber glass

etc and also a magnetic separator for

elimination of Iron objects.

STEP II

The manually sorted out MSW is then

passed to a homonegeniser for segregating

the MSW over a screen, which will pass

material to the Primary crusher.

STEP III

The screened MSW is fed to an impact or

for disintegration of the MSW in to small

pieces .There is no limit on the input size.

The moisture will be high. It may contain

some sand and silt, which may have some

abrasion affect and corrosion affect.

STEP IV

A conveyor to the rotary then transports

the discharge of Impact or to dryer for

moisture removal.

STEP V

The rotary dryer comprises of rotary dryer,

feeding, hot air circulation in co current

fashion with a cyclone separator and

blower and chimney for removal of fines.

STEP VI

The discharge of Rotary dryer will be

dried MSW. This is fed to a screen to

remove fines of less than 5-mm size,

which is primarily sand. This can be used

as manure. Over 5 mm will be fed to the

air classification system..

STEP VII

The discharge from the secondary screen

will be fed to AIR DENSITY

SEPERATOR (ADS) system in which the

material is fed through a rotary air lock.

The discharge from the rotary lock is

subjected to airflow in a zig -Zag

construction, which is controllable, by

dampeners. Hot air from Hot air generator

is also introduced here in addition to the

rotary drier for achieving higher dryness.

In this system the light combustible system

(organic and combustibles) is segregated

and the heavier material (inert) falls by

gravity.

The key factor for the separation is dryness

of the feed. Highly wet input material will

not separate and loss of combustible

fraction may occur. The rejects at the ADS

will be non-combustible fraction. This

fraction is conveyed and manual sorting is

resorted to pick up heavier fraction of

combustibles like woody biomass, coconut

shell, etc to return the same to feed.

STEP VIII

The discharge from ADS (Combustible

fraction) is further subjected to a

secondary shredding for finer

disintegration of the refined, combustible

fraction of the Processed MSW. The unit

also comprises a cyclone separator and a

bag filter unit and a suction blower in

closed circuit.

STEP IX

The discharge of the Secondary Crusher

cyclone is palletized through a pellet mill

POWER PRODUCTION :The specific processed fuel (RDF) which

produced from above process is used to

fire in specially design furnaces like

Traveling grate furnace, Spreader stoker

fired boiler, and Suspension fired boiler

and Fluidized bed combustor for

production of steam. This steam can be

used to run Turbine which is mechanically

coupled with Generator which produces

Electrical power.

LAY OUT OF WATER PLANT

RDF - CHARACTERSTICS:

Refused derived fuel has better emission and burning characteristics and it is a low cost

substitute for other fossil fuels like coal, gas. High sulphur content of oil and coal when burnt

pollute the environment. There is no sulphur in RDF. RDF have a consistent quality have

high burning efficiency. Are ideally sized for complete combustion. Combustion is more

uniforms compared to coal and boiler response to changer in stream requirements is faster to

higher quality of volatile material.

RDF Characteristics

Ash Content - 2-10%

Moisture Content - 8%

Volatile Material - 75-80%

Sulphur Content - Nil

Calorific Value - 3,500 - 4,000 K.cal/Kg

Efficiency of Boiler :

Using Coal - 48%

Using RDF -

53%

Fuel pellets from garbage: a better option

RDF - HIGHLIGHTS :

Comparing to coal and other fossil fuels. RDF has several activities and consistent

characteristics over other fuels.

RDF - CHEAP FUEL :

RDF is a low cost substitute for coal and other fossil fuels. It is cheaper than coal, lignite,

peat. It won’t cost that much as coal. It takes only transportation and processing cost, which

is, has less comparing to other fuels.

RDF ECOFRIENDLY FUEL :

RDF has better emission characteristics than coal. In the process due to reduction of sand

and reduced moisture content it has improved calorific value. It won’t emit any harmful

gases, which cure global warming like CO2, CO and methane (C2H4).

Due to less carbon content this avoids methane gas, which is produced due to decomposition

of waste.

RDF – ALLROUNDER :

RDF is not only used for power generators. It can be also used for burning in process plants

like Paper Mills, Alluminium Industries and other steam production purpose. This is most

economical to use instead of other furnace feedings.

WTEE –SOCIO ECONOMIC

PROJECT :

Waste to electrical energy is the best

alternative comparing to other

conventional and non-conventional

sources. This is mass reliable and cheap

source. WTEE won’t give any harmful

pollutents and it decreases the problem of

waste disposal and decomposition of

waste. This WTEE system can aid in

saving a lot of urban land, which is

wasted. And this is the system among the

other non–conventional sources, which is

more reliable.

This WTEE is the only solution to meet

our future needs. According to Central

Pollutions Control Board (CPCB) the per

capita generation of MSW per head is 350

gms. From this statistics being second

largest population country our India won’t

get any power scarcity if we use this

WTEE technology.

DEVELOPMENTS & FUTURE OF

WTEE :

This WTEE technology is in practice since

1942 in US and Germany. In India it

comes in to the picture in 2003. The first

power plant using waste to electrical

energy technology (WTEE) is

commissioned on Dec, 20th 2003 of

capacity 6MW named as SELCO at

Elicatta village in Shadnagar of

Mahaboobnagar District. This plant using

700 tons of MSW of 2200 tons generated

every day in twin cities of Hyderabad.

Another plant named as Shriram Energy

Systems Ltd., also producing 6 MW of

power at Vijayawada using RDF as fuel

processed from MSW generated in

Vijayawada & Guntur cities.

The technology development board and

technology information forecasting and

assessment council (TIFAC) are trying to

assist industries on this technology. The

above cited SELCO is going to establish

another 20 MW power plant in Hyderabad

city. And Shriram Energy got permission

to install Another plant in vizag. This

processed to our state that the WTEE

plants are only in AP and our president

also appreciated.

CONCLUSION :With the above discussion we conclude that this WTEE technology is the better solution.

Being second largest population country the demand has drastically increased. And most of

our Indian villages still unelectrified. According to CPCB studies in India 70% of cities

won’t have sufficient facilities for transportation of MSW. By using this WTEE we can

avoid the MSW disposal problem and we can save a lot of money which is going to be

wasted for transporting to outer yards of cities and a lot of urban land which is wasted under

dump yards.

Not only in cities, this WTEE technology is also suitable for rural villages where Agricultural

and solid waste is abundant.

By preserving the Agricultural waste according to seasonal crops, we can light so many

villages which are not aware of electricity. If we implement this technology in rural areas we

wont need to wait upto 2012 for “MISSION-2012 POWER FOR ALL”.

COURTACY

Power Plant Engineering - BLACK & VEATCH

SRIRAM ENERGY SYSTEMS, VIJAYAWADA.