Tucked away in southern Poland is the world’s first and largest Coal Fired Boiler.
In June 2009 the Lagisza Power Plant started operation. At the heart of this plant is the powerhouse fossil fuel run boiler which produces 460,000 Kilowatts. Your average domestic boiler produces from 12 Kw to 70 Kw. This means the Lagisza boiler is about six and a half thousand times as powerful as your home boiler, and at a production cost of around £340,000,000 you’d sure hope so!
What is CFB technology?
A piece of coal is around 440 million years old. All that time ago, it was part of a fern or primitive tree growing in a bog. When it died and was buried, it was eventually compacted into layers of rock. Natural gas formed from gases released from decaying matter into pockets between the rocks.
Fossil fuels were formed from the decayed remains of organisms that were once alive, so they are rich in carbon. When they are burned, that carbon is released as carbon dioxide, a natural greenhouse gas. Human activity that has burned up fossil fuels in the last 100 years has increased the atmospheric level of carbon dioxide, leading to global warming and climate change.
Of all the Fossil Fuels, Coal, Oil and Natural Gas – Coal has the most reserves. In total 97% of all the reserves of fossil fuels we have on Earth are coal deposits. If we continue to use coal at the rate we do today, it could last as long as 1500 years. However, if usage rises by 5 per cent each year, which it could as our reliance on coal could increase as oil and gas run out, we could only have 87 years worth of coal still to burn.
In recent years the pressure to reduce greenhouse gas emissions sky rocketed with the adoption of the Kyoto Protocol, and the urgency to reduce CO2 emissions in fossil fuel plants has become imperative. While this plant is still powered by fossil fuels, the focus was set on improving the efficiency and environmental performance of new and old coal fired plants like Lagisza.
Enter Foster Wheeler – who for the last three decades have been developing CFB or Coal Fired Boiler technology.
Unlike conventional steam generators that burn the fuel in a massive high-temperature flame, CFB technology does not have burners or a flame within its furnace. CFB uses fluidisation technology to mix and circulate fuel particles with limestone as they burn in a low temperature combustion process. The limestone captures the sulphur oxides as they are formed, while the low burning temperature minimises the formation of nitrogen oxides.
So CFB technology allows Lagisza to operate a clean coal platform with a low temperature combustion process that cleanly and efficiently burns both traditional fuels and carbon-neutral fuels.
Furthermore, the fuel and limestone particles are recycled over and over back to the process, which results in high efficiency for burning the fuel, capturing pollutants, and for transferring the fuel’s heat energy into high-quality steam to produce power.
Other CFB plants
In 2007 Russian wholesale power supplier, OGK-6, wishing to upgrade its fleet, decided to opt for the same CFB technology as Lagisza, although at smaller scale, just 330,000 Kw .
The new supercritical CFB is being constructed at the utility’s Novocherkasskaya site, with a commercial operation date of 2013.
I Foster Wheeler technology was selected for three main reasons: proven supercritical CFB concept, as demonstrated by the Lagisza project; high fuel flexibility; good combustion efficiency with low emissions. The main fuels used are local anthracite and coal.
CFB technology offers a number of advantages for recycling of older power plants like Lagisza.
Recycling these plants will improve efficiency, make it possible to use multiple fuels and control harmful emissions.
The CFB Boiler recycled existing land when it replaced old power blocks of the existing 1960s-era Lagisza Power Plant. The CFB boiler was built right next-door to the old boilers. The plant uses coal as a primary fuel source, provided from ten local coal mines.
In addition to this, plant efficiency has increased from about 35 per cent to nearly 44 per cent. Compared to the original plant, nitrogen oxide (NOx) at the new CFB plant is reduced by 71 per cent and CO2 by 28 per cent.
In the Future
The design of the Foster Wheeler’s CFB boiler is affordable, efficient, and enhances environmental performance. High efficiency leads to lower fuel requirements, and lower levels of ash and emissions, including carbon dioxide (CO2). In addition, CFB technology has excellent fuel flexibility and offers the option of co-firing of bio-fuels with different grades of coals, which can further reduce CO2 emissions.
Overall, the world’s first CFB has proven to be an excellent breakthrough, and the boiler operation has been stable and easy. This provides a good knowledge base on which to start planning CFB plants almost double the size at 800,000 Kw to be installed in the near future, hopefully keeping our precious Coal supplies intact for many years to come.
Here at Commercial Heat and Air Ltd we can offer high quality boiler service in London