Dear Energy Professional, Dear Colleagues
On 31st October, 1-2 November, we were in Afsin Elbistan coal mine and thermal power plant premises to participate "Clean Coal Technologies" workshop, which was organized by Chambers of Mining, Mechanical, Chemical and Electrical Engineers of Turkey.
Our workshop agenda covered the following key subjects
- Coal, its importance in Turkish Energy politics
- Turkish Local energy resources, renewable potentials
- Coal mine regional site planning
- Economics of Elbistan Coal Reserves,
- Coal preparation, Enhancing, Selective Mining,
- Recultivation of coal fields, Plant Recovery
- Coal gasification at site, underground in the mine field
- Coal gasification and liquefaction, above ground
- Applicable Coal firing technologies,
- Assessment of existing indirect pulverized coal firing
- New Coal firing technologies, Circulating Fluidized Bed,
- Integrated gasification combined cycle, applications
- Flue gas desulphurization, e/p dust collectors,
- New High Voltage Power transmission applications/ new solutions
We all know that the most important electric power generation projects are in "Afsin Elbistan" region where the largest lignite mines are located in Turkey; including almost half of the entire local proven reserves.
The existing power plants (Groups A and B) are based on pulverized coal firing technology which need relatively higher calorific value plus less moisture. Indirect type Pulverized coal firing technique can be successful only if you lower the moisture content and hence with higher the calorific value.
Available coal has a challenging content with very poor Low calorific value at about average 1150 kcal per kg, and 55% moisture, 20% ash, 1.5-4% sulphur.
We had the opportunity to listen/ visualize important presentations of Turkish academicians as well as market experts from public and private enterprises.
On Friday morning, we had the site visit to Elbistan lignite mine field in Kislakoy. We were very proud to observe that Kislakoy Lignite mine fields were extraordinary. It was a huge man-made valley, with huge bucket wheelers, reclaimers, and stackers - coal band conveyors in operation. It is my feeling that there are so few similar examples on the world.
We then passed near recultivated coal fields with new trees planted on. It was an extraordinary application of recultivation on already depleted coal fields.
Finally we arrived to the thermal power plants, named A and B each with 1400 MWe installed electric generating capacity at full load.
Thermal Power plant (A) has no fluegas desulphurization. It was built in early 1980s, and its firing technique was based on indirect firing of pulverized coal. Power plant (A) electrostatic precipitators were designed at low capacity dust collecting. One other set of E/Ps were loaded with 30% of incoming pulverized coal for drying prior to final firing in the boiler combustion chamber. Hence they cannot carry the extended load and they are out of service most of the time.
In the indirect coal firing technique, you dry the incoming coal/ lignite first in the coal mills with hot flue gas and then you send 30% of that pulverized wet coal into a second set of electrostatic precipitators (vapor/brueden filters at +62m boiler elevation ) for further drying with outgoing hot flue gas.
This “indirect firing” was borrowed from cement process; it might be called technology plagiarism, and that can not be proven after 20 years of interrupted operation. Operation was almost in mess, non-stop operation was not possible for 4 units altogether. When they call that “indirect coal firing” as the great western technology, I cannot conceal my smile.
E/Ps are out of service most of the time, and the 2 of total 4 stacks in operation pour huge flyash into atmosphere. If E/Ps are not working properly in a thermal power plant, and furthermore if they have no flue gas desulphurization on the stacks, then it is our sincere feeling that those power plants have to be stopped for operation since their harm to nearby environment is greater that the expected gain in electricity generation to the national grid.
We then visited the thermal power plant named B. That was brand new thermal power plant in final acceptance until year 2008.
We have been informed that the major foreign contractor company in charge of boilers had bankruptcy in year 2002 and the plant was completed by jointly and severally liable partner companies. Practically there is limited or even almost no engineering capability nor responsibility in case of any boiler malfunction. Local contractor companies have limited major boiler engineering capability and/or contractual responsibility; hence they just wait in their prefabricated site facilities to pass the final acceptance period.
Another point is that B Thermal power plant has no individual coal feeding system in operation. That is tendered but the new facility is expected to be in operation in the next 3-5 year time. There is one temporary coal feeding system 5-km long from nearby Thermal Power plant A, but that extension line seems not sufficient to operate the B unit in full capacity. So you have a thermal power plant with no major incoming fuel facility to fire.
Thermal Power plant Unit-B is brand new, clean, and better, fully equipped with sufficient capacity flue gas desulphurization systems, with high capacity flue gas dust collecting electrostatic precipitators. We visualized almost no apparent dust on the existing stacks. It has 4 units of water based cooling towers and 2 common stack for all 4 units. We could see only harmless vapor outgoing from cooling towers.
You can collect the outgoing dust- fly ash, but thermal power plant has no ash dam/ no ash collecting area. Ash is collected in nearby open area and left there at the mercy of nature’s hard wind. When the hard wind blows, everywhere comes under ash rain.
Another important point to note is that the thermal power plant- Unit-B is constructed at the center of new coal field, so you have no ability to get coal underneath of the power plant. That is another poor planning.
B plant was in operation with 2 units when we were in the plant. One boiler had boiler tube failure. The other was out of operation due to water shortage.
Both thermal power plants were equipped with water cooling. That water cooling process needs huge amount of water. Available water is not sufficient for both plants to be in full operation. If they do, then the nearby municipalities can not supply water to their citizens for their household consumption. We were told that new water dams were in tendering and they would be in operation within 3-5 year time. If you need that much water, why don't you make the power plant design for air cooled operation? It would certainly cost some more money but you could have all boiler units in operation when needed.
This site report is a sort of black humor. Clean Coal Technologies Workshop in Elbistan will create a great opportunity for all interested local parties to enable them to learn from past mistakes, to investigate the possible/ applicable technologies, to investigate and assess the available intellectual capability of the local human resources.
We were very pleased to join/ support/ contribute to the event, hope to organize similar events in international platforms.
Your comments are always welcome.