18-02-2010, 12:36 PM
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IGCC POWER PLANTS A new technology to answer global warming
INTRODUCTION
Developing cost-effective carbon capture technology is one of the most important environmental challenges facing the utility industry in the 21st century
.The process offers options to eliminate greenhouse gases, produce hydrogen and liquid fuels.
. The potential for carbon dioxide sequestration makes IGCC technology even more appealing and environmentally responsible. . A more complex, but even more economical option.
. In this technology we build a sort of refinery to generate "Synthetic gas" from poor lignite then we fire this synthetic gas in the combined cycle power plants similar to natural gas firing.
IGCC technology is first innovated by Germans during 2nd world war to produce gas and liquid fuel for the fighting war vehicles .
Crude oil now costs more than 75 US Dollars per barrel, therefore IGCC technology is now an attractive fuel option.
The basic IGCC concept was first successfully demonstrated at commercial scale at Pioneer Cool Water Project at Southern California in 1989.
CONSTRUCTION
Main parts
Slurry Preparation Unit
Entrained bed Gasifiers
Gas Turbine Generator
Heat Recovery Unit
Steam Turbine Generator
GENERATOR &HEAT RECOVERY UNIT
Clean syngas from gasifier after removal of impurities is feed to gas turbine.
If any shortage of syngas we can use natural gas to drive the turbine.
Waste gas from the GT pass through the HEAT RECOVERY UNIT and produce very high pr steam.
The steam from gasifier cooling process and steam from heat recovery unit feed into steam generator.
This process is 50% more efficient than direct coal firing plant.
BENEFITS OF IGCC POWER PLANTS
The primary environmental benefit is nearly zero air pollution.Coal-fired power plants are responsible for 60% of sulfur dioxide emissions, 33% of mercury emissions, 25% of nitrogen oxide emissions, and more than 33% of the nation's carbon dioxide air emissions..
Less water consumption (about 20-30%) than a conventional coal power plant.
Less fuel consumption.
IGCC is more efficient, creating more electricity per unit of coal and less CO2. "Efficiency will be increased from about 33% from a traditional coal-fired plant to 38% .
Cheaper power cost than natural gas fired power plants.
We can reduce the uncertain availability of imported crude oil, which raises concerns for national security and economic development...
DRAWBACKS OF IGCC POWER PLANT
High cost of power production compared to Direct coal firing power plants.
Gasification plants come at a high price tag . They have typically cost Rs 60 m to Rs 80 m per megawatt of capacity compared to Rs 50 m per megawatt for a conventional coal plant and Rs27.5 m per megawatt for natural gas plants.
Refractory wear and life are extremely sensitive to gasifier operating conditions.
FUTURE SCOPE.
87 new IGCC Projects are under construction.
10 power plants with installed capacities ranging from 60 to 500mw are expected to be operational between 2004 and 2010.
IGCC Power projects reduce GLOBAL WARMING
Efficiency can shoot up 50 to 60% with Future generation technology and reductions in the release of carbon dioxide.
Turbines with higher efficiencies and operating temperatures are being developed.
Early 1990s, the best turbines available had efficiencies of only 50 percent. But today it is operating in the 57 to 58 %efficiency range .
Scientist developing potentially low-cost configuration for a future gasifier. Called the "transport reactor," the gasifier is an advanced circulating fluidized-bed reactor.
CONCLUSION
Improvements in IGCC technology between now & 2020 are expected to reduce cost of electricity generation with co2 capture by 20-30%.
The time has changed and petroleum now costs more than 75 US Dollars per barrel, therefore IGCC technology is now an attractive fuel option.
The syngas and the hydrogen produced from this process will take care of the future fuel requirement of the Universe.We got enough coal reserve for another 250 years whereas crude oil reserve is only for few more decades.
