1. Energy (TKK-2129) Instructor: Rama Oktavian; Dr. Rizka Zulhijah
16/17 Semester genap
Energy (TKK-2129)
Instructor: Rama Oktavian; Dr. Rizka Zulhijah
Office Hr.: M. 10 – 12, T. 10 – 12, W. 09 – 10, F.10 – 15

2. Outlines 1. Coal: Introduction 2. Coal power plant
3. Coal to chemical (CTC)
4. Recent status of coal technology

3. Coal (Intro)
Coal is conventional fossil fuel
Formation of Coal
 Coal deposits are formed from plant material that died and was deposited in a swampy environment - low in O2
 Anaerobic bacteria convert the organic material until environment becomes too acidic and the bacterial die - decomposition stops when the plants have been converted to peat
 Peat becomes buried at bottom of swamp
 Peat is transformed at high pressure and low temperature (< 200 °C) over ~300 million years to coal

4. Coal (Intro)
Coal is conventional fossil fuel
Formation of Coal

5. Coal (Intro) Surface Mining Underground Mining Strip Mining
Coal Mining
Surface Mining
Strip Mining
Underground Mining

6. Coal (Intro)
Types of coal

7. Coal (Intro)
Types of coal

8. Coal (Intro)
Types of coal

9. Coal (Intro) Chemical composition of coal
Source:

10. Coal source
Energy sources in Indonesia
Coal

11. Coal source
Energy sources in Indonesia
Coal

12. Coal source
Energy sources in Indonesia
Coal

13. Coal power plant Process equipment Feedwater
Feedwater used in a steam boiler to transfer heat energy from the fuel burning area to mech. Energy of spinning steam turbine
Boiler
Rectangular furnace, pulverized coal is blown in from fuel nozzles at 4 corners. The coal then burns quickly and forms a fireball at the center.

14. Coal power plant Process equipment Steam Turbine Generator
Is a series of steam turbines interconnected to each other and then a generator
Steam Condenser
Steam enters from the turbine generator and is pumped into the bottom of the condenser, where pumps recycle the condensed steam from the feedwater
Stack
Releases process emissions.

15. Coal power plant
Process diagram

16. Coal power plant Cheap Cheaper per unit energy than oil or natural gas
Pros
Cheap
Cheaper per unit energy than oil or natural gas
Will continue to be an important global resource
Abundance
Coal is the world’s most abundant fossil fuel
Sufficient reserves for the next 250 years

17. Coal power plant Efficiency Larger power plants are more efficient
Pros
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

18. Coal power plant Environmental issues
Cons
Environmental issues
Coal-Fired Power Plants are the largest contributor of hazardous air pollutants.
Sulfur dioxide (SO2)
Nitrogen Oxide (NOx)
Carbon Dioxide (CO2)
Mercury

19. Coal power plant
CO2
Cons
carbon dioxide pollution, making energy use the single largest source of greenhouse gases in the world

20. Coal power plant SO2 Cons
Sulfur dioxide combined with nitrogen oxide react with water and oxygen in the atmosphere to form acidic compounds, which can mix with natural precipitation and fall to the earth as acid rain.
Sulfur dioxide can also combine with nitrogen oxide and other particles to form particulate matter.
trigger heart attacks and strokes
lead to cardiac arrhythmia (irregular heartbeat)
respiratory irritation, and worsen asthma.
premature death (Both short-term and long-term exposure)

21. Coal power plant NOx Cons
When nitrogen oxide (chemically) reacts with volatile organic compounds (VOC’s) and sunlight ground-level ozone or smog is formed.

22. Coal power plant Mercury Cons
One of the most dangerous pollutants released into the air through the exhaust system when coal is burned.

23. Coal power plant SOx NOx Particulate Matter (PM) CO / CO2
Cons
SOx
de-SOx slurry injection
NOx
de-NOx ammonia/urea injection, selective catalytic reduction
Particulate Matter (PM)
bag filters/electrostatic precipitators
CO / CO2
CO usually not an issue with well-controlled power plants
CO2: “carbon capture and sequestration”
Much research into Carbon Capture coal power plants

24. Example for discussion
A coal fired power plant burns 300 tons of sub-bituminous coal per hour to yield 620 MWe.
What is the primary energy content?
How much energy was produced?
What is the efficiency of the process?

25. Example
A) looking at the coal slide that came before we get sub-bituminous coal yields 24 GJ/ton Therefore 300 tons x 24GJ/ton = 7,200 GJ = 7.2 TJ B) Taking the 620 MW over an hour, we get 620 MW x 3600s = 2.23 TJ C) Efficiency is the ratio between the produced power and the primary power 2.23TJ / 7.2TJ = 32.3% efficiency

26. Efficiency of a series of processes
From conversion chain: combustion (& heat exchanger) → steam turbine → electric generator → distribution grid → appliance

27. Thank You !