Post on 18-Jan-2016
CARBON EMMISION FROM COAL BASED THERMAL POWER
PLANTS
Presented By: Shikhar Singh, Prashant Kashyap and Rishabh P S Gurjar,
2nd Year Students, Department of Mining Engg.
PROCESS OF EMMISION, CAUSES OF HIGH CARBON EMMISION FROM INDIAN POWER PLANTS AND POSSIBILITIES & STEPS TO REDUCE IT
WHAT IS CARBON EMISSION?
Carbon emission is the release of carbon into the atmosphere.
Emitted carbon is mostly of the form CO or CO2.
When coal is burnt, it releases many harmful green house gases of
which CO2 is a major part.
In coal based thermal power plants a huge amount of carbon
emission takes place due to burning of coal.
ANALYSIS OF THE PROBLEM
The problem basically focuses on the emission of green house gases
from coal based thermal power plants of which carbon in the form of
CO2 is a major part. Due to rapid increase in emission of green house
gases and mainly CO2 from these power plants the need for analyzing
and controlling it has become a task of huge importance. In this case
study we have discussed on the following three aspects of the problem:
Process of Carbon emission from Coal based thermal power plants.
Causes of high rate of Carbon emission from Indian power plants.
Various possibilities and steps to reduce the Carbon emission.
PROCESS OF CARBON EMISSION
When pulverized coal burns, it emits enormous quantities of carbon
dioxide along with other pollutants like sulfur dioxide, nitrogen oxide,
mercury, and microscopic particulate matter.
Almost all coal plants operating today use “pulverized coal” (PC)
technology.
Introduction of gasification combined cycle (IGCC) technology.
Process GHG emission from a coal based thermal power plant
Emitted GHGs
SCENARIO IN INDIA
India ranks third in world coal production, producing 293,497.15
metric tons (mt) of coal in 2012.
The majority of this production, approximately 85%, is used for
thermal power generation.
Electricity from coal currently accounts for 71% of India’s total 67
gigawatts of power generated.
India ranks 4th in carbon emission, generating 1.67 metric tonnes (mt)
of CO2 in the year 2010.
Region wise CO2 Emission by thermal Power Plants
2006-07 2007-08 2008-09 2009-100
100000
200000
300000
400000
500000
600000
Region wise CO2 Emission
NorthernWesternSouthernEasternAll India
Year
CO2
Emis
sion
in G
g
Source: Ministry of Power (http://www.powermin.nic.in/)
CAUSES OF HIGH RATE OF CARBON EMISSION
Indian coal is of poor quality and often contain 30-50% ash when
shipped to power stations.
Calorific value and the ash content of thermal coals in India have
deteriorated as the better quality coal reserves are depleted and
surface mining and mechanization expand.
Source: www.frontline.in Volume 25 - Issue 22 :: Oct. 25-Nov. 07, 2008
Deteriorating Quality of Indian Coal
1970s 1980s 1990s
Fixed Carbon 36.5% 32.4% 25%
Volatile matter 25.5% 21.6% 18%
Moisture 10% 16% 12%
Ash 28% 30% 45%
High heating value(kcal/kg)
4,750 4,050 3,000
Majority of the coal production, approximately 70%, is used for thermal power
generation.
India has been slower than other countries in embracing carbon emission reduction as part of normal operating practices in thermal power generation.
REDUCING CARBON EMISSION
Retirement or renovation of old and inefficient plants.
Suggestions made by CEA in one of its reports on thermal power plants
RETIREMENT:
•In one of its reports on energy efficiency in thermal power stations CEA has
suggested that the units which are deviating more from design should retire
first.
•Retirement is linked to commissioning of new units.
•RENOVATION:
•To restore rated capacity and design parameters such as Heat Rate, APC, SOC
etc..
•To make the operating units well equipped with modified/ augmented latest
technology.
•To improve the performance parameters in terms of PLF, Efficiency, Forced
Outages, Availability and Reliability.
Efficiency improvement by accelerating installation of supercritical/ultra supercritical (SC/USC) plants.
A supercritical steam generator is a type of boiler that operates at supercritical pressure, frequently used in the production of electric power.
Source IEA, 2006
Introduction of tighter air pollution norms.
Introduction of the Clean Power Plan in USA.
•The Clean Power Plan establishes state by state targets
for carbon emissions reductions.
• It offers a flexible framework under which states may
meet those targets.
•According to CPP green house gases have been
considered as pollutants that "endanger public health
and welfare."
•The final version of the rule would reduce national
electricity sector emissions by an estimated 32 percent
below 2005 levels by 2030.
COAL BENEFICIATION
It is a process by
which the quality of
raw coal is improved
by either reducing the
extraneous matter
that gets extracted
along with the
mined coal or
reducing the
associated ash or both
Advantages: Increased power generation.
Sustainable, highly efficient power generation.
Increased rail way transport capacity.
Lower pollution emissions .
Economics of Coal Beneficiation
the bid price for coal washing services has been as low as Rs105 per
raw ton.
This is mostly because of intense competition by coal transporters and
agents.
Case Studies and Findings
Increase in overall efficiency; up to 1.2%
Saving in land area for ash dumping; 1 acre per year
Reduction in CO2 emissions (reduced transportations/coal
combustion; > 600,000 ton/yr.
The case study of Dadri Power Plant (4x210 mw), NTPC which uses washed coal
with around 34-35% ash from Central Coalfield Limited’s Piparwar washery
demonstrates the qualitative and quantitative benefits of coal beneficiation :
CARBON CAPTURE AND SEQUESTRATION
PROCESS OF CARBON CAPTURE
It is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere.
According to the 2005 Annual Report of IPCC, the emissions from power plants reduced by upto 87% after the installation of CCS system.
OUTCOMES OF CSS SYSTEM
Initiatives taken by Govt. of India A capacity of 27,485 MW based on supercritical technology has
already been Commissioned and 49,925 MW super critical capacity is
under construction.
All coal fired capacity additions shall be based on supercritical
technology in the 13th Plan.
Renovation, Modernization and Life Extension of old thermal power
generating units and retirement of old and inefficient thermal
generation units, in phased manner, has been undertaken.
Introduction of PAT Scheme.
CONCLUSION National norms for PM are very weak and need to be brought in line
with global standards(like the CPP programme of USA).
Applying more stress on the applications of coal beneficiation methods.
Approvals for new capacities should be only for supercritical/ultra
supercritical plants.
Old, inefficient plants should be closed at an aggressive pace.
Stress on application of Carbon Capture and Sequestration process
should be increased.
REFERENCES
Ministry of Power, Government of India, Annual Report 2001-02 &
2008-09 (www.powermin.nic.in)
Government of India, Central Electricity Authority, 11th Plan Shelf of
Thermal Power Projects,(www.cea.nic.in)
CSE report on “Heat on power-green rating of coal based thermal
power plants”.
International Energy Agency (IEA) www.iea.org/
US Environmental Protection Agency, www.epa.gov
THANK YOU!!!
ANY QUESTIONS?