Papers selected for Conference Session titled : Environmental aspects of power generation | Ekološki i klimatski aspekti rada elektrana
Vujo I. Miljevic - Vinca Institute of Nuclear Sciences, Atomic Physics Laboratory P.O. Box 522, 11000 Belgrade, Republic of Serbia
Abstract text
SIMULTANEOS REMOVAL OF SULPHUR DIOKSIDE (SO2) AND NITROGEN OXIDES (NOx) FROM FLUE GASES BY A SPECIAL TYPE OF CORONA BRUSH DISCHARGE WITH THE THREE PHASE TESLA COIL
ABSTRACT
A new method for simultaneous removal of SO2 and NOx from flue gases, a plasma chemistry method called ELFI, has been developed in the Atomic physics laboratory of the Vinca Institute of Nuclear Sciences on the basis of fundamental research of the special type high frequency corona discharge. The by-product of this method is artificial fertilizer, and the problem of the permanent storage of undesired product does not exist. The ELFI module can be added to an existing plant as a by-pass, so it does not obstruct its function.
The results of fundamental research on which ELFI is based are presented on international scientific meetings. Laboratory studies completely fulfilled foreseen expectations for filtering and gave numerous data necessary to project pilot plant. The patents for EFFI technology were granted in: United States of America, European Patent Union -Austria, Belgium, Switzerland and Luxemburg, France, Great Britain, Ireland, Italy, Holland, Germany and Sweden, Japan and Republic of Serbia.
A plasma chemistry method for removal of carbon dioxide – CO2 in the Atomic Physics Laboratory of the Vinca Institute of Nuclear Sciences is in progress.
SIMULTANO ČIŠĆENJE SUMPOR DIOKSIDA (SO2) I AZOTNIH OKSIDA (NOx) IZ DIMNIH GASOVA POMOĆU SPECIJALNOG TIPA KORONA PRAŽNJENJA SA TESLINIM TRANSFORMATOROM SA TROFAZNIM NAPAJANJEM
APSTRAKT
Nova metoda za simultano odstranjivanje SO2 i NOx iz dimnih gasova, plazma hemijska metoda pod nazivom ELFI, razvijena je u Laboratoriji za atomsku fiziku Instituta za nuklearne nauke "VINČA" na osnovu fundamentalnih istraživanja specijalnog tipa visokofrekventnog korona pražnjenja. Sporedni proizvod ove metode je mineralno đubrivo, i problem deponovanja neželjenih produkata ne postoji. ELFI modul može da se doda na postojeće postrojenje, tako da ne ometa njegovu funkciju.
Rezultat fundamentalnih istraživanja ELFI tehnologije predstavljen je na brojnim međunarodnim naučnim Konferencijama. Laboratorijska istraživanja u potpunosti su ispunila predviđena očekivanja i dala veliki broj podataka neophodan za izradu pilot postrojenja. Patenti za ELFI tehnologiju dobijeni su u: Sjedinjenim Američkim Državama, Evropskoj patentnoj uniji – Austriji, Belgiji, Švajcarskoj i Luksemburgu, Francuskoj, Velikoj Britaniji, Irskoj, Italiji, Holandiji, Nemačkoj, Švedskoj, Japanu i Republici Srbiji.
Plazma hemijska metoda za odstranjivanje CO2 u Laboratoriji za atomsku fiziku Instituta za nuklearne nauke "VINČA" je u toku.
Branislav Stanković, Srđan Belošević, Miroslav Sijerčić, Nenad Crnomarković, Dragan Tucaković - Institute of Nuclear Sciences “Vinca“, University of Belgrade, Laboratory for Thermal Engineering and Energy, P.O. Box 522, 11001 Belgrade, Serbia Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade 35, Serbia *(381-11) 3408-204, branstan@vinca.rs
Abstract text
Nitrogen oxides (NOx) released during coal combustion have a significant impact on the environment pollution and for this reason modeling of NOx formation and destruction in a pulverized coal-fired furnace is an important task. NOx formation and destruction mechanisms in coal combustion systems are very complex, hence modeling of these turbulent flows involving chemical reactions is a serious challenge. In accordance with modern modeling techniques, the approach that requires a joint solution of complex transport equations for turbulent flow combined with simplified NOx chemical reaction mechanisms is used in this work. NOx concentration calculation is performed in the velocity, temperature, concentration and other fields which satisfied convergence criteria, according to the system of “postprocessing”. A developed NOx submodel is focused on homogeneous NOx formation and destruction reactions, with an analysis of influence of the reaction rate parameters on NO formation. For the prediction of thermal NO, the Zeldovich mechanism is used. In addition, model contains the formation and destruction reaction processes of fuel NO, mainly by HCN as the predominant volatile intermediate species, taking into account a significant influence of the local oxygen concentration. A correction of the pre-exponential term is applied for reaction rate of the fuel NO formation, with reference to the conditions with relatively low fuel concentration, which are predominant in pulverized coal-fired furnaces. The influence of important reaction rate parameters of NOx reactions is analyzed, and their optimization is carried out as well. NOx submodel is incorporated into the comprehensive model of the reactive two-phase turbulent flow and appropriate numerical code. Verification of numerical code is done simultaneously with examination of the influence of numerical grid on results. Model validation is carried out as well by comparison of the predicted NOx emission with available results of periodical measurements at the Kostolac Power Plant boiler units B-1 and B-2. Numerical results of the gas mixture temperature, and O2, HCN and NO concentration fields is presented in the reference test-case, along with process analysis from the physical point of view. A developed mathematical model of NOx formation and destruction is applied for the numerical simulation and analysis in several test-cases, and in the domain of this part of the problem, the influence of different coal distributions over the burner tiers on NOx emission is investigated. The presented numerical analysis has the potential of model implementation for the prediction of NOx emission from pulverized coal-fired boiler furnaces. Such numerical analysis enables optimization of the operating conditions in a furnace with respect to the reduction of NOx emission and increase in energy efficiency as well.
mr Kemal Bečić dipl.ing., Dino Tica dipl.ing., Enez Đakovac, dipl.ing. - Thermal Power Plant "Kakanj", Kakanj, Bosnia and Herzegovina
Abstract text
Modern electrostatic precipitators and bag filters achieve dedusting efficiency of more than 99,95%. While efficiency of dedusting of electrostatic precipitators considerably decreases for particles of size 0,1-1 m, fabric filters withhold high efficiency of dedusting in wider range of particle sizes. However, fabric filters often experience problems with bag cleanability and high pressure drop, resulting in large and costly casings. Hybrid filters are new concept of dedusting that combines advantages of electrostatic precipitators and bag filters. Because of mentioned characteristics »hybridization« of electrostatic precipitators on existing thermal power units is interesting alternative. Bad experiences in operation of electrostatic precipitator in the Thermal power plant Kakanj, as well as necessity of fulfilling legal limitations of particles emission lead to decision to upgrade existing unit 5 precipitator with bag filter. This paper outlines experiences collected during the operation of hybrid filter of the unit 5 in the Thermal power plant Kakanj, which could be useful since so far there was no experience with such plants in Bosnia and Herzegovina.
Dr. Harald Reissner - AE&E - Air Pollution Control , Dr. Klaus Bärnthaler - AE&E - Air Pollution Control
Abstract text
The program of CEZ plant portfolio renewal in the Czech Republic started in 2005. The program consists also of extensive modernization of two major power plants Tusimice II and Prunerov II (erected in seventies, FGD additionally erected in mid nineties).
Modernization of the existing power plants covers almost all systems including coal handling, boilers, FGD, TG sets, critical and other connecting piping, power feeding, I&C and auxiliary systems.
AE&E has installed several plants in the last 10 years achieving high SO2 removal rates. These plants are using high sulphur coals in the boiler with SO2 concentrations in the flue gas up to 5000 ppm. The experience shows, that especially a proper spray bank design is very important to reach high efficiencies up to 98%. Improved CFD modelling of the FGD absorber is a standard design procedure for such high removal applications.
Flue gas desulphurization system package for all a.m. plants is supplied by AE&E. Tusimice II plant (4x200 MW) is the first one to be completed, the first phase (units 3 and 4) was commissioned in 2009 and guaranty tests were performed in June 2010 sucessfully.
Dr.-Ing. Thomas Riepe - BABCOCK NOELL GMBH, Alfred-Nobel-Str. 20, 97080 Würzburg, GERMANY
Abstract text
How to meet the limits for particle emissions is one of the questions for the existing coal fired power stations in the new EU countries. The existing Electrostatic Precipitators (ESP) are designed for emissions upto 150 mg/m³(nc) or even higher. According to the actual or future limits the real figures sometimes are ten times too high. Economical aspects and space limitations very often are the reason, that a modernization of the ESP is not required. A very economical alternative is the conversion of the ESP to a pulse jet fabric filter (PJFF). New developments of fabric filter technology have solved the problems of the past, like high energy consumptions and short lifetimes of the filter elements. Due to the much smaller space requirements of the fabric filters, in many cases conversions under reuse of the existing ESP-housing and ash handling systems can be done. The presentation will show the way of doing such a conversion and will give a comparison to conventional ESP solutions.
Dr. Morteza Raei Dehaghi - Professor
Abstract text
Energy's future is connected to international relations and environmental issues and there is no way to escape it. As of now, oil is dominant in the world energy and in Iran, 95% of energy consumption came from fossil fuel. Average increase of energy consumption in Iran is three times as that of the world, but these resources are limited and non-renewable and soon will deplete.
Almost 66% of CO2, 80% SO2 and almost all NOx pollution by human being is caused by fossil fuel, which is today's most serious world's dilemma .With the consumption of natural gas, up to some extend, this problem can be solve, but the world's resources are limited.
So, the solution is the use of alternative energy which can be derived from either nuclear energy or new renewable energy such as wind, ocean wave and sunlight, where in large scale are not well-developed yet. Today more than 17% of the world energy consumption is provided by nuclear energy, but still there are worries among public about its operational safety. The main concern is the safety features of the reactors, but recently, new reactor designs drastically features improved safety characteristics. These advanced reactors have new security features which expected to have even better records on reliability and safety than the current dominant reactor types.
The development of 20,000MW nuclear energy generation is Iran's long range program. In the long run, in an environmentally conscious future, nuclear power fares best against fossil fuel and so with the aim of protecting global climate. And in this regard, we should give more concentration on the development of nuclear energy.
Predrag M. Živković, Gradimir S Ilić, Mladen A. Tomić, Mića V. Vukić - Mašinski fakultet u Nišu, Aleksandra Medvedeva 14, 18000 Niš, Srbija , Žarko M. Stevanović, Žana Ž. Stevanović - Institut za nuklearne nauke Vinča, Laboratorija za termotehniku i energetiku, Poštanski fax 522, 11001 Beograd, Srbija , Milan Ogrizović - Gradska toplana Niš, Blagoja Parovića 3, 18000 Niš, Srbija
Abstract text
In this paper overall pollutant emission on the City of Niš territory is estimated. Special attention was made for pollutant emission from traffic, which is being single largest pollutant source in Niš, as well in Serbia and the rest of Europe. For validation of the emission estimation performed by COPERT software, traffic measurement was done for the main crossroads in the City of Niš. CO2 Concentration was measured at 1m distance from the road. Traffic fleet composition was obtained from MUP of R. Serbia, and City of Niš District heating plant presented their data. Estimation of household emission was done on the basis of existiong statistical data, which can be found on the Republic bureau for statistics.
Karl-Heinz SCHMIDT, Wolfgang KARL - BABCOCK NOELL GMBH Alfred-Nobel-Str. 20 97080 Würzburg, GERMANY
Abstract text
Framework conditions for the design of the Pilot Plant for desulphurization
Vattenfall Europe Generation AG has built a 30 MW pilot boiler plant at its Power Plant site Schwarze Pumpe. The purposes of this plant is testing a CO2-free power plant based on the Oxyfuel process.
Babcock Noell GmbH was commissioned with the process design and delivery of the flue gas desulphurization plant (FGD). The plant was handed over in October 2008.
Terms of reference
The FGD is based on the wet scrubbing process, using limestone as absorbent. The task is washing SO2-, SO3-, HCl-, HF-, residual dust emissions and other impurities out of the flue gas. Special attention had to be paid to:
- Operation of a desulphurization plant with a practically nitrogen-free, CO2-enriched flue gas.
- SOx removal of > 99 % at very high inlet concentrations (8.000 – 11.000 mg/Nm3).
- Oxidation of the slurry without dilution of flue gas.
Gypsum is received as product and can be used in the cardboard industry.