Coal Power Generation Report Final

8/3/2019 Coal Power Generation Report Final

1/66

Coal PowerGeneration


2/66

Introduction:

Coal power, an established electricity source that

provides vast quantities of inexpensive, reliable

power has become more important as supplies

of oil and natural gas diminish.


3/66

Coal power is a rather simple process. In most

coal fired power plants, chunks of coal are

crushed into fine powder and are fed into acombustion unit where it is burned.

Heat from the burning coal is used to generate

steam that is used to spin one or more turbines

to generate electricity.


4/66

History:

Coal has played a major role in electrical

production since the first power plants that were

built in the United States in the1880's


5/66

The earliest power plants used hand fed wood or

coal to heat a boiler and produce steam.

This steam was used in reciprocating steam

engines which turned generators to produce

electricity


6/66

In 1884, the more efficient high speed steam

turbine was developed by British engineer

Charles A. Parsons which replaced the use ofsteam engines to generate electricity.


7/66

In the 1920s, the pulverized coal firing was

developed.

This process brought advantages that included a

higher combustion temperature, improved

thermal efficiency and a lower requirement for

excess air for combustion.


8/66

In the 1940s, the cyclone furnace was developed.

This new technology allowed the combustion of

poorer grade of coal with less ash production andgreater overall efficiency.

Presently, coal power is still based on the samemethods started over 100 years ago, butimprovements in all areas have brought coal powerto be the inexpensive power source used so widely

today.


9/66

How Coal Formed?

Coal is a fossil fuel created from the remains ofplants that lived and died about 100 400 million

years ago when parts of the earth were covered

with huge swampy forests.

Coal is classified as a non renewable energy sourcebecause it takes millions of years to form.


10/66

Millions of years ago, dead plant matter fell into swampy

water and over the years, a thick layer of dead plants lay

decaying at the bottom of the swamps.

Over time, the surface and climate of the earth changed,

and more water and dirt washed in, halting the decay

process.


11/66

The weight of the top

layers of water and dirt

packed down the lower

layers of plant matter.

Under heat and pressure,

this plant matterunderwent chemical and

physical changes, pushing

out oxygen and leaving

rich hydrocarbondeposits. What once had

been plants gradually

turned into coal.


12/66

What is Coal?

Coal is combustible material consisting primarily

of the element carbon, but with low percentages

of solid, liquid, and gaseous hydrocarbons and

other materials, such as compoundsofnitrogen and sulfur.

Coal is usually classified into the sub-groups

known as anthracite, bituminous, lignite, and

peat. The physical, chemical, and other

properties of coal vary considerably

from sample to sample


13/66

Types of Coal

Peat

Considered to be a

precursor of coal, has

industrial importance as

a fuel in some regions,

for example, Ireland and

Finland.

In its dehydrated form, peat is a highly effective

absorbent for fuel and oil spills on land and

water.

It is also used as a conditioner for soil to make it

more able to retain and slow release water.


14/66

Lignite

Also known as browncoal, is the lowest rank

of coal and used almost

exclusively as fuel for

electric powergeneration.

Jet is a compact form of

lignite that is

sometimes polishedand has been used as

an ornamental stone

since the Upper

Palaeolithic

It is the lowest rank of coal,

with a heating value of4,000 8,300 Btu per

pound. Lignite is crumbly

and has high moisture

content.


15/66

Whose properties range from

those of lignite to those of

bituminous coal, is usedprimarily as fuel for steam-

electric power generation and

is an important source of

light aromatichydrocarbons for the chemical

synthesis industry.

Sub-Bituminous

Sub-bituminous coal typically

contains less heating valueand more moisture than

bituminous coal (8,300

13,000 Btu per pound). It

contains 35 45% carbon..


16/66

It is dense sedimentary rock,black but sometimes darkbrown often with well-definedbands of bright and dullmaterial, used primarily as fuelin steam-electric powergeneration, with substantialquantities used for heat andpower applications inmanufacturing and tomake coke

Bituminous

Bituminous coal was formed by further addition ofheat and pressure on lignite during coal formation

process. Bituminous coal looks smooth and sometimes

shiny, contain 11,000-15,500 Btu per pound, between

45 86% carbon.


17/66

A grade between bituminous coal and anthracite,

once widely used as a fuel for steam locomotives.In this specialized use it is sometimes known

as sea-coalin the U.S. Small steam coal (dry small

steam nuts or DSSN) was used as a fuel for

domestic water heating.

Steam Coal


18/66

Anthracite

T

he highest rank of coal is aharder, glossy, black coal used

primarily for residential and

commercial space heating.

It may be divided further into

metamorphically altered

bituminous coal and petrified

oil, as from the deposits in

Pennsylvania.

Anthracite was created where additional pressurecombined with very high temperature inside the earth.

It is deep black and looks almost metallic due to its

glossy surface, contain around 15,000 Btu per pound

energy and 86 97% carbon.


19/66

Technically the highest rank is difficult to ignite

and is not commonly used as fuel: it is mostly

used in pencils and, when powdered, as

a lubricant.

Graphite


20/66

The classification of coal is generally based on the content of

volatiles. However, the exact classification varies between

countries. According to the German classification, coal is

classified as follows

German

Classification

English

DesignationVolatiles % C Carbon %

H

Hydrogen %O Oxygen % S Sulfur %

Heat

content

kJ/kg

Braunkohle Lignite 45-65 60-75 6.0-5.8 34-17 0.5-3 9.8 ~1


21/66

How the Coal is mined?

Generally, there are two ways to remove coal from

the ground surface and underground mining.

Surface mining is used when a coal seam is

relatively close to the surface, usually within 200feet.

Kinds of Surfaced Mining:

Area/Strip Mining

Contour Mining

Mountaintop coal mining


22/66

Area/Strip Mining exposes the coal by removing

the overburden (the earth above the coal seam(s))

in long cuts or strips.

The soil from the first strip is

deposited in an area outside

the planned mining area.

Spoil from subsequent cuts is

deposited as fill in the previous

cut after coal has been

removed.

Usually, the process is

to drill the strip of overburden

next to the previously mined

strip.


23/66

Contour Mining method consists of removing

overburden from the seam in a pattern following the

contours along a ridge or around a hillside. This method is most

commonly used in areas

with rolling to steep terrain.

It was once common to

deposit the spoil on the

downslope side of the

bench thus created, but this

method of spoil disposalconsumed much additional

land and created severe

landslide and erosion

problems.


24/66

Mountaintop coal mining

is a surface miningpractice involving removal

of mountaintops to

expose coal seams, and

disposing of associatedmining overburden in

adjacent "valley fills.

Valley fills occur in steep

terrain where there arelimited disposal

alternatives.


25/66

Underground (or deep) mining is used when the coal

seam is buried several hundred feet below the surface.

Room and pillar mining consists of coal

deposits that are mined by cutting a

network of rooms into the coal seam.

Pillars of coal are left behind in order to

keep up the roof.

The pillars can make up to forty percent

of the total coal in the seam, however

where there was space to leave head

and floor coal there is evidence from

recent open cast excavations that 18th

century operators used a variety of

room and pillar techniques to remove

92 percent of the in situ coal. However,

this can be extracted at a later stage.


26/66

There are five principal methods of underground mining:

Longwall mining accounts for about 50 percent of

underground production.T

he longwall shearer has a face of1,000 feet (300 m) or more.

It is a sophisticated machine with a rotating drum that moves

mechanically back and forth across a wide coal seam. The

loosened coal falls on to a pan line that takes the coal to the

conveyor belt for removal from the work area. Longwall systems have their own hydraulic roof supports which

advance with the machine as mining progresses.


27/66

Continuous mining utilizes a Continuous Miner Machine with

a large rotating steel drum equipped with tungsten carbide

teeth that scrape coal from the seam.

Operating in a room and pillar (also known as bord and

pillar) systemwhere the mine is divided into a series of 20-

to-30 foot (510 m) rooms or work areas cut into the

coalbedit can mine as much as five tons of coal a minute,

more than a non-mechanised mine of the 1920s wouldproduce in an entire day.


28/66

Blast mining or conventional mining, is an older

practice that uses explosives such as dynamite to break

up the coal seam, after which the coal is gathered and

loaded on to shuttle cars or conveyors for removal to a

central loading area.

This process consists of a series of operations that begins

with cutting the coalbed so it will break easily when blasted

with explosives. This type of mining accounts for less than 5percent of total underground production in the US today.


29/66

Shortwall mining, a method currently accounting for less

than 1 percent of deep coal production, involves the use

of a continuous mining machine with movable roofsupports, similar to longwall.

The continuous miner shears coal panels 150 to 200 feet

(40 to 60 m) wide and more than a half-mile (1 km) long,

having regard to factors such as geological strata.


30/66

Retreat mining is a method in which the pillars or coal ribs

used to hold up the mine roof are extracted; allowing the

mine roof to collapse as the mining works back towards theentrance.

This is one of the most dangerous forms of mining, owing to

imperfect predictability of when the ceiling will collapse and

possibly crush or trap workers in the mine.


31/66

Dangers to miners Build-ups of a hazardous gas are known as damps, possibly

from the German word "Dampf" which means steam or vapor:

Black damp: a mixture ofcarbon dioxide and nitrogen in a mine can

cause suffocation, and is formed as a result of corrosion in enclosed

spaces so removing oxygen from the atmosphere.

After damp: similar to black damp, after damp consists ofcarbonmonoxide, carbon dioxide and nitrogen and forms after a mine

explosion.

Fire damp: consists of mostly methane, a highly flammable gas that

explodes between 5% and 15% - at 25% it causes asphyxiation.

Stink damp: so named for the rotten egg smell of the hydrogensulphide gas, stink damp can explode and is also very toxic.

White damp: air containing carbon monoxide which is toxic, even at

low concentrations

Chronic lung diseases, such as pneumoconiosis (black lung) were

once common in miners, leading to reduced life expectancy


32/66

Impacts of Coal Mining

Release of methane, a greenhouse gas causing climate

change

Waste products, including uranium, thorium, and

other radioactive and heavy metal contaminants

Acid mine drainage (AMD)

Interference with groundwater and water table levels

Impact of water use on flows of rivers and consequent

impact on other land uses

Dust

Tunnels sometimes damage infrastructure (e.g. roads)

Land rendered unsuitable for other use


33/66

Control of Pollutants from Coal Mining:

Mine Water from Acid Mine Drainage

The first measure is to separate surface waters to

reduce the volume of mine waters to a minimum. Mine waters are first treated in sedimentation

ponds and then in mine water purification plants

which work on the oxidation-neutralisation

principle. Removed are primarily iron, manganeseand non-soluble substances.


34/66

Coal-Fired Power Plant


35/66

Coal-Fired Power Plant

More than half of the electricity generated in the

world is by using coal as the primary fuel.

The function of the coal fired thermal power

plant is to convert the energy available in thecoal to electricity.

Coal power plants work by using several steps to

convert stored energy in coal to usable electricity

that we find in our home that powers our lights,

computers, and sometimes, back into heat for

our homes.


36/66

Coal-Fired Thermal Power Plant


37/66

Major Stages in a Coal-Fired

Power Plant:

Coal Arrival/Coalyard

Storing and Pulverizing

Combustion and Steam

Turbine and Generator

Water Reuse/Condenser Electricitys Path


38/66

Coal Arrival/Coalyard


39/66

Storing and Pulverizing


40/66

Combustion and Steam


41/66

Turbine and Generator


42/66

Water Reuse/Condenser


43/66

Electricitys Path


44/66

Coal Power Stations in the Philippines

Sual Power Station

Mindanao Coal Power Station

Masinloc Power Station

Quezon Power Station


45/66

ASPECTSAND

IMPACTSOF COAL

POW

ER


46/66

Advantages of Coal Power

Electricity Supplying approximately 50% of electricity to the US

Economy Coal-mining stimulates over one million jobs in the U.S.

Coal contributes over $80 billion annually to theeconomy


47/66

Efficiency

Larger power plants are more efficient

38% of the chemical energy is converted to energy

Safe safest fossil fuel to transport, store and use


48/66

Some of the advantages of coal are : Easily combustible, and produces high energy upon

combustion helping in locomotion and in the generation ofelectricity and various other forms of energy;

Widely and easily distributed all over the world;

Comparatively inexpensive due to large reserves and easy

accessibility Good availability

Inexpensive

Very large amounts of electricity can be generated in one

place using coal, fairly cheaply. A fossil-fuelled power station can be built almost anywhere,

so long as you can get large quantities of fuel to it. Most

coal fired power stations have dedicated rail links to supply

the coal.


49/66

Disadvantages of Coal Power

Coal-Fired Power Plants are the largest contributor ofhazardous air pollutants.

Sulfur dioxide (SO2)

Nitrogen Oxide (NOx)

Carbon Dioxide (CO2)

Mercury


50/66

Some disadvantages of coal are that: It is Nonrenewable and fast depleting.

High coal transportation costs, especially for countrieswith no coal resources and hence will require specialharbours for coal import and storage.

Coal storage cost is high especially if required to have

enough stock for few years to assure power productionavailability.

Burning fossil fuels releases carbon dioxide, a powerfulgreenhouse gas, that had been stored in the earth formillions of years, contributing to global warming.

It leaves behind harmful byproducts upon combustion,thereby causing a lot of pollution

Mining of coal leads to irreversible damage to theadjoining environment;


51/66

Some disadvantages of coal are that : Mining and burning of coal pollutes the environment,

causes acid rain and ruins all living creature's lungs.

It will eventually run out.

It cannot be recycled.

Prices for all fossil fuels are rising, especially if the real cost

of their carbon is included.

An average of 170 pounds of mercury is made by one coal

plant every year. When 1/70 of a teaspoon of mercury is

put in to a 50-acre lake it can make the fish unsafe to eat.

Coal power puts the lives of the people who dig the coal in

danger, and it gives them poor lung quality. Also, it ruins the natural habitats of animals.

A coal plant generates about 3,700,000 tons of carbon

dioxide every year; this is one of the main causes of global

warming.


52/66

Some disadvantages of coal are that : A single coal plant creates 10,000 tons of sulfur dioxide,

which causes acid rain that damages forests, lakes, and

buildings.

When people dig for coal, they cut down many trees.

A coal plant also creates 720 tons of carbon monoxide;

which causes headaches and place additional stress onpeople with heart disease.

A 500-megawatt coal- fired plant draws about 2.2 billion

gallons of water from nearby bodies of water. This is

enough water to support approximately 250,000 people. Cultivating coal is a very dangerous job - many men and

women die each year in coal mine related failures and

accidents


53/66


54/66

Toxilogical and Environment Properties of Hazardous Air Pollutants

(HAPs) Emitted from Electric Generating Stations by Coal


55/66


56/66

Characteristics of Major Coal Types Used to Generate Electricity


57/66

Contributions of Coal-Fired Power Plants to Selected

Hazardous Air Pollutant Emissions


58/66


59/66

Residence Time of Hazardous Air Pollutants in Atmosphere


60/66

Control of Collateraland HazardousAir

Pollutants From

Coal-Fired PowerPlants


61/66


62/66


63/66


64/66


65/66


66/66

Integrated Schematic Diagram of Coal-Fired

Power Plant with Pollution Control Equipment

Date post:	06-Apr-2018
Category:	Documents
Upload:	jhonfil-huesca
View:	222 times
Download:	0 times

Coal Power Generation Report Final

Documents