DEVELOPMENT OF DESULFURIZATION PROCESS IN ROMANIA THERMAL POWER PLANTS

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International Journal of Civil Engineering and Technology (IJCIET)
Volume 7, Issue 2, March-April 2016, pp. 193–202, Article ID: IJCIET_07_02_017
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DEVELOPMENT OF DESULFURIZATION
PROCESS IN ROMANIA THERMAL POWER
PLANTS
Adina TĂTAR
1
Department of Energy, Environment and Sustainable Development, Faculty of
Engineering and Sustainable Development, University “Constantin Brâncuşi” of TG-
JIU, România
Mohammad Ayaz AHMAD
Department of Physics, Faculty of Science, P. O. Box 741,
University of Tabuk, Tabuk, 71491, Saudi Arabia
Georgeta BUICA
Department of Explosion-Proofnes, National Research and Dev. Institute for Labor
Protection “Al. Darabont”, G-ral Vasile Milea str., no. 32-34, Bucharest ROMANIA
Remus DOBRA and Dragos PASCULESCU
Department of Computers and Power Engineering, Faculty of Mechanical and
Electrical Engineering, University of Petroșani, Str. Universității, no. 20, Petroșani,
România
ABSTRACT
The purpose of this paper is an analysis of the SO2 pollution from Rovinari
thermal power plant, before and after the installation of the desulphurisation
facility, taking into account the unwanted effects upon the environment and
human health. Modeling the dispersion of pollutants for the proximity areas of
the Rovinari thermal power plant has been carried out by using the AUSTAL
View specialized software within INSEMEX Petrosani. By putting the
desulphurisation facilities into operation in phases, there is noticed the
compliance with the enforced limit for the SO2 pollutant. By using the
desulphurisation method the obtained coal combustion products are fly ash,
bottom ash, boiler slag, fluidized bed combustion (FBC) ash, semi dry
absorption product, flue gas desulphurisation (FGD) and gypsum. Calculation
of the thermal power plants contribution to the emission ceiling applicable for
sulphur dioxide may be based on the application of the relevant minimum
rates of desulphurisation rather than on the emission limit values for sulphur
dioxide.

Adina TĂTAR, Mohammad Ayaz AHMAD, Georgeta BUICA and Remus DOBRA and
Dragos PASCULESCU
Key words: Atmospheric Emissions, Desulphurisation Facility, Dispersion,
Pollutant, Toxic
Cite this Article: Adina TĂTAR, Mohammad Ayaz AHMAD, Georgeta
BUICA and Remus DOBRA and Dragos PASCULESCU, Development of
Desulfurization Process In Romania Thermal Power Plants, International
Journal of Civil Engineering and Technology, 7(2), 2016, pp. 193–202.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=2
1. INTRODUCTION
Rovinari thermal-power plant is located near Rovinari city, on the eastern bank of Jiu
river, nearby the national road which connects the city of Targu Jiu to Filiasi, in a
hilly area, 150 m above sea level. It was built during 1972-1979, in order to provide
electricity for covering the required consumption at the level of the National Power
System [1, 2].
Nowadays, there are 4 power blocks (blocks 1 and 2 are currently disassembled),
generating a total available power of 1320 MW (4x330MW). The four power blocks
are connected to 2 smoke chimneys (two blocks for each chimney), having 220 m in
height and an exhaust diameter of 8.8 m.
The assessment of the impact of pollutants released into to atmosphere by
Rovinari thermal-power plant is carried out from two points of view:
 As emissions, quantities if polluting substances from burning gases are compared to
the values stipulated by regulations in force (GD, 2010), (Law, 2011), (Order, 2005)
[3, 4].
 And as dispersions (emission) of polluting substances into the area surrounding the
pollution source, the obtained values being reported to the allowable limit values
from regulations in force (GD, 2010), (Law, 2011), (Order, 2005) [1-4].
The most important releases in air resulting from the burning of fossil fuels are the
following: sulphur dioxide, nitrogen oxides, carbon monoxide, powders, but also
greenhouse gases and heavy metals, halogenated compounds and dioxins, released in
small amounts but having significant effects upon the environment due to their
toxicity and persistency.
2. IMPACT OF SULPHUR DIOXIDE RELEASED INTO THE
ATMOSPHERE BY ROVINARI THERMAL POWER PLANT
(a) Sulphur dioxide releases monitoring
The content of sulphur dioxide in burning gases depends on the sulphur content of the
used fossil fuels. In Rovinari thermal-power plant, the main fuel is the lignite having a
calorific power ranging between Pci = 1664÷2456 kcal/kg, a sulphur content ranging
between 0.5÷1.35% and an ash content between 1.8÷25.4%. There is added the
sulphur content from the additional flame support fuel (~8%), which may be naphtha
with a sulphur content between 0.97÷3.3%. The emission limit values for large
burning installations having a nominal thermal power greater than 500 MW and at a
6% O2 content in residual gases shall be reported to the emission limit values
stipulated in Government Decision 541 of 2003. In 2010 [2], Rovinari thermal-power
plant operated with 3 boilers, in all cases being recorded exceeding of SO2
concentrations in burning gases.

Development of Desulfurization Process In Romania Thermal Power Plants
The highest exceeding has been registered for boiler no.5, from 11.50 to 15.92
times the allowable limit Figure 2). For boilers no. 3 and no.4, the recorded values
range between 4146.42 mg/Nm3
and 5450.25 mg/Nm3
(for boiler no.3), respectively
between 3859.17 mg/Nm3
and 5320.44 mg/Nm3
for boiler no.4. There are noticed
10.36 to 13.62 times the allowable limit exceeding for boiler no.3, respectively 9.64 to
13.30 times the allowable limit exceeding for boiler no.4.
Figure 1 Evolution of SO2 concentration in burning gases for year 2010
(b) Research on the dispersion of pollutants released from Rovinari
thermal power plant in November 2010
The modeling of the dispersion of pollutants for areas of Rovinari thermal power
plant has been carried out using Austal View software within INCD INSEMEX
Petrosani (INSEMEX, 2010) [2], this software allowing the modeling of the
dispersion of pollutants released from one or more sources and at the same time
provides a diagram of the existing situation and a forecast of scenarios proposed by
the operator.
The meteorological data required for the graphic representation of pollutants
emissions through Austal View were obtained from the industrial weather station – GJ
2 – located in Rovinari, and are related to the following: temperature, precipitations,
wind speed and direction, relative humidity, pressure, solar radiation. According to
APM Gorj (Environmental Protection Agency Gorj), the average wind speed in
November 2010 is 0.675 m/s (the maximum wind speed being 2 m/s), and the
predominant wind directions is from N to NE. The wind rose related to this area is
presented in Figure 3.
During November 2010, when the impact upon the air study was carried out, there
were operating 3 Power Blocks (3, 4, 5), Block no. 6 being in repair. The graphic
representation of the results of the mathematical modeling of the dispersion of SO2,
NO2, CO and TSP pollutants was done using georeferenced topographic maps, at a
scale of 1:90,000 [1-4].
The calculations were done within a 20 km x 20 km grid, with a 400 m step for
main characteristic pollutants released by the stationary directed burning sources from
Rovinari thermal- power plant. The software provides the dispersion modeling over
these mediation intervals. There have been achieved dispersion maps and there have
been determined the daily and hourly average and maximum values of the
concentration of pollutants in the ambient air.

Dragos PASCULESCU
Figure 2 Wind speed related to Rovinari area
In November 2010 [1], values of the SO2 concentrations at the emission, for the
three Power Blocks of Rovinari thermal-power plant, exceed the allowable limit
stipulated through Government Decision 541 of 2003. The highest SO2 concentration
value was recorded in Power Block no. 5, being 15.92 times higher than the limit
value at the emission.
The SO2 analyzer of GJ-2 Station from Rovinari which continuously monitors the
quality of air from the area and achieves the combined contribution of several sources
did not operate within November 2010. The average wind speed recorded by GJ-2
Station is 0.675 m/s (2 m/s maximum speed), and the average air temperature is
10.17o
C (15o
C being the maximum of the month).
(c) SO2 dispersion-average hourly concentration
From the analysis of the dispersion map, there is noticed that the average hourly
concentration obtained by modeling, represents 218% the limit value for human
health protection. This value is registered at a 2000 m distance in the southern
direction and covers a 1600 m2
surface (Piscul Teiului). In the SW, at a 3200 m
distance from Rovinari thermal-power plant, the concentration of the pollutant ranges
between 200 – 500 μg/m3
(D. Maiag, V. Lupilor, V. Scoarţei, Rogojel village, Pd.
Dragoteşti, Bohorel village, D. Găvan). The highest values of the concentration are on
the southern side of the contaminant plume, having a value which is 2.18 – 1.53 times
higher than the maximum admitted concentration (C. Roşii, Timişeni, Jidovia, D.
Bogdan, Pd. Timişeni, s Bohorel village). The largest surface, in the Southern
direction, is covered by a pollutant cloud having a concentration which is 1.53 – 1.2
times higher than the maximum admitted concentration. In the other areas, the
concentration of the pollutant has values which do not exceed the limit valued for the
protection of human health: Rovinari, Negomir, D. Racilor, V. Rogojel (100 – 200)
μg/m3
; Mătăsari, D. Curăturile, Ştiucani, Brădet village, V. Borelului (20 – 100)
μg/m3
(Figure 4).

Figure 3 SO2 dispersion – average hourly concentration
(d) SO2 dispersion – maximum hourly concentration
By reporting the values obtained through modeling, for the maximum hourly
concentration, to the limit value for human health protection stipulated in Order n0.
592/2002, it is noticed that the highest value of the maximum hourly concentration
(2.81 times higher than the maximum admitted concentration) is located at a 2km
distance from the objective, in the southern direction (P. Teiului). High concentrations
are diffused in the area of the source.
The contaminant plume covers the S-SW direction, and the highest values are
recorded at 1200 m from the source, to the south, over a 11600 m2
surface,
representing 218 – 154% of the maximum admitted concentration (D. Bogdan, D
Curături, Timişeni, Pd. Timişeni, Mătăsari, Jidovia, Bohorel village). In the SW
direction, the concentration of the pollutant does not exceed the maximum admitted
concentration: Rovinari, Dl. Crucea Înaltă, Mătăsari, Pd. Dragoteşti, Jilţ (100 – 200)
μg/m3
; Rogojel, Brădet village, D. Malului, V. Boncea, D. Găvan (20 – 100) μg/m3
[5-8]. In the areas of C. Roşii, Jilţ, D. Racilor, V. Timişeni, V. Lupilor, V. Scoarţei,
the maximum hourly concentration ranges between 200 – 500 μg/m3
(Fig. 5).

Dragos PASCULESCU
Figure 4 SO2 dispersion – maximum hourly concentration
3. EMISSION LIMIT VALUES OF ROVINARI THERMAL
PLANT
In order to comply with the emission limit values, the operators of large combustion
plants have developed programs for the progressive reduction of annual emissions of
sulfur dioxide, nitrogen oxides and dust [5-8].
These programs were then negotiated and approved by local environmental
authorities, becoming an integral part of the compliance programs.
The programs for the progressive emissions reduction of pollutants must contain
information relating to:
 operating data of large combustion plants;
 establish the emission limit values and justify of any applied derogation;
 technological measures proposed for the progressive reduction of sulfur dioxide
emissions, nitrogen oxides and dust to achieve emission limits;
 deadlines for implementation of technological measures;
 measures for emission monitoring;
 cost estimates for implementation of technological measures to reduce emissions;
 Emissions target of each large combustion plants.
All final proposals were included in the national program to reduce emissions
sulfur dioxide content, nitrogen oxides and dust from large combustion plants,
approved by the Ministry of Environment.

Through the National Program shall ensure a reduction in annual emissions sulfur
dioxide content, nitrogen oxides and dust, according to table 1
Table 1 Total annual emission levels
Year SO2 (tons) NOx (tons) Dust (tons)
2007 540000 128000 38600
2008 530000 125000 33800
2010 336000 114000 23200
2013 148000 112000 15500
2016 - 80000 -
2017 - 74000 -
To fulfill the objectives of the National Program and compliance to achieve its
goal of reducing emissions by adopting measures for complying with the emission
limit values were established three stages:
Step I: until 31.12.2006;
Step II: 01.01.2007 – 31.12.2013;
Step III: 01.01.2016 – 31.12.2017.
The measures proposed and assumed by progressively reducing the emissions
program are in accordance with the provisions of European Commission document
„Integrated pollution prevention control (IPPC) directive” – a reference document
concerning the best available techniques for the Large Combustion Plants – BREF [1-
8].
To accomplish the objectives of the National Program and to ensure compliance
with emission limit values Rovinari thermal power station was included in the second
stage (01.01.2007 – 31.12.2013) for sulfur dioxide and dust and the third stage
(01.01.2016 – 31.12.2017) for nitrogen oxides [5-8].
Figure 5 Desulfurization of combustion gases using wet process
Analyzing the methods [5-8] of sulfur dioxide detainment from flue gases used
worldwide and considering the environmental legislation, it opted for flue gas wet
desulphurisation, using absorbents limestone and resulting product of the process of
retaining dioxide sulfur, gypsum, like in figure 5.
Reducing and controlling emissions of sulfur dioxide from combustion processes
can be achieved by using two kinds of measures:
 primary measures such as using of fuel with low sulfur content and injecting the
adsorbent (CaO or CaCO3) in thermal power plant furnace;
 Secondary measures such as washing combustion gases in the absorbent solution (Ca
(OH) 2 or NaOH) in special installations (scrubbers).

Dragos PASCULESCU
The main feature of the wet desulfurization is a simultaneous reduction of sulfur
dioxide and producing gypsum and also supplies control of limestone essential to
overcome the fuel sulfur fluctuations [5-8].
By washing and humidifying the gas to obtain a 50 ÷ 60°C cooling at the wet
process. In these circumstances raise the smoke plume dispersion is limited and
disadvantaged. The effect of reducing the amount of dioxide remains in the
atmosphere, in this case, only to be felt throughout the territory, over long distances.
In order to achieve close control of the gas / fluid required to achieve a high
efficiency of sulfur dioxide removal, using a spray absorber tower. Flue gas enters
absorber, which goes through many levels of counterflow spraying.
The sulfur dioxide and other acidic gases (e.g. HCl and HF) are absorbed in the
washing slurry which falls to the bottom of the tank known as the reaction tank. Here,
the finely divided lime is added to neutralize the slurry and washing the regenerate.
Oxygen in the form of compressed air is injected to wash the reaction finished, and
the formation of gypsum. Gypsum resulting from the reaction of crushed limestone
and sulfur dioxide is discharged along with slag and ash through the dense fluid
method at the Gârla deposit.
Figure 6 Desulfurization SO2 concentration evolution in 2011
Reducing concentrations of sulfur dioxide to be placed in the emission limit value
of 400mg/m3
by making installations of wet flue gas desulfurization at IMA 2 (boiler
5 + boiler 6) had deadline for completion, December 31, 2011. For IMA1 (boiler 3 +
boiler 4) the deadline for reducing the concentration of sulfur dioxide in the flue gas
wet desulfurization was 31 December 2013. National Program to reduce emissions of
SO2, NOx and dust requires progressive measures, which for SO2 and dust were due
for completion end of 2013, and for NOx is set at the end of 2017.
Both Rovinari and Turceni thermal power plant in order to reduce the content of
sulfur dioxide in the flue gas and compliance with the emission limit value, it has
opted for wet process gas desulphurisation. Reducing particulate emissions in order to
comply with the emission limit value was made by the execution of modernization
work.
4. CONCLUSIONS
The quality of the air is majorly influenced by the presence of pollutant sources into
the atmosphere: smoke chimneys from Rovinari thermal-power plant, Cicani-Beteregi
ash and clay storage, the lignite exploitation quarries, waste dumps and road traffic.

Through the step by step start of desulphurisation facilities it is noticed the imposed
limit for the SO2 pollutant will be respected. Following the modernization workings
and carried out repairs, the emissions of powders into the atmosphere have decreased,
the concentration in burning gases (according to self- monitoring results) being for all
boilers under the design values (Tătar, 2011) [9].
The Rovinari Energy Complex – Thermal-Power Plant obtained transition in
2013, respectively in 2017, in order to frame into the emission limit values according
to Government Decision 541of 2003, with further modifications and completions, for
the SO2, NOx and powders pollutants
In May 2011, the operation of boiler no. 3 has been stopped, and starting with
June the desulphurisation facility has been operating, the concentrations of sulphur
dioxide in burning gases being situated below the limits stipulated by regulations in
force. The lowest value of sulphur dioxide in burning gases was recorded in June
(169.00 mg/Nm3
), being 2.4 times lower than the limit value, and the highest
concentration was measured during October (398.3 mg/Nm3
) which was located near
the limit value.
For boiler no.4, all measured concentrations of sulphur dioxide were higher than
the limit value. The lowest concentration was recorded in September (4020.54
mg/Nm3
), representing 10 times the limit value, and the highest concentration was
measured in November (5201.15 mg/Nm2
), being 13 times higher than the limit value.
Sulphur dioxide concentrations measured for boiler no. 5 reached the highest values
in 2011. In this case, the lowest sulphur dioxide concentration was recorder in January
(4595.92 mg/Nm3
), being 11.5 times over the admitted limit. The highest sulphur
dioxide content was measured in September (6569.15 mg/Nm3
), being 16 times
higher than the limit value.
Above all the results were found in satisfactory and also in good agreement with
the other workers [10 and references therein] working in the same field.
ACKNOWLEDGEMENT
The authors acknowledge the support of the Department of Control Engineering,
Computers, Electrical Engineering and Power Engineering, The Faculty of
Mechanical and Electrical Engineering, University of Petroșani, Str. Universității, no.
20, Petroșani, România. And also, the author, Mohammad Ayaz Ahmad would like to
acknowledge financial support for this work from the Deanship of Scientific Research
(DSR), University of Tabuk, Tabuk, Saudi Arabia, under grant no. S-00236-1436 [11-
15].
REFERENCES
[1] GD 440, (2010), Romanian Government Decision no. 440 of 2010 on the
establishing of measures for limiting emissions of certain pollutants coming from
the large combustion plants.
[2] INSEMEX, (2010), Computer modelling of the dispersion of dust from dust and
gas stations for fans of the Jiu Valley mining operations, Research Study,
National Institute for Research and Development in Mine Safety and Protection
to Explosion Petrosani, Romania.
[3] Law 104, (2011), Romanian Law on the quality of environmental air.
[4] Order 833/545/859, (2005), Order of the Ministry of Environment and Water
Management, Ministry of Economy and Trade and Ministry of Administration

Dragos PASCULESCU
and Interns, on the approval of the National program for the reduction of sulphur
dioxide, nitrogen oxides and powder emissions coming from large combustion
plants.
[5] Caluianu, S., Cociorova, S., Măsurarea şi controlul poluării atmosferei. Editura
Matrix Rom, 1999.
[6] [6] Negoiu, D., Kriza Angela, Poluanţi organici în aer. Editura Academiei
R.S.R., Bucureşti, 1977.
[7] [7] Pârvu, C., Ecologie generală. Editura Tehnică, Bucureşti, 1999.
[8] Norma Europeană EN 12341/1998. Calitatea aerului. Determinarea fracţiei PM10
din materii sub formă de pulberi în suspensie.
[9] Tǎtar A., (2011), Study of methods and techniques for depolluting the air from
Rovinari area, PhD. Thesis, University of Petrosani, Petrosani, Romania.
[10] A. Hajdarevic, L. Banjanovic-Mehmedovic, I. Dzananovic, F. Mehmedovic, M.
Ayaz Ahmad, (2015), “Recurent Neural Network as a Tool for Parameter
Anomaly Detection in Thermal Power Plant”, International Journal of Scientific
and Engineering Research (IJSER), Vol. 6(8), pp. 448-455.
[11] Dragos Pasculescu, Remus Dobra, Mohammad Ayaz Ahmad, (2016),
“Dosimetric Quantity System for Electromagnetic Fields Bio-effects”,
International Journal of Scientific Research (IJSR), Vol. 5(2), pp. 26-32.
[12] Remus Dobra, Dragos Pasculescu, Mohammad Ayaz Ahmad, (2016),
“Simulation of Electromagnetic Field Distribution Generated by Wave
Transmitters”, Asian Academic Research Journal of Multidisciplinary, Vol. 3(1),
pp. 160-173.
[13] Anghel Drugarin Cornelia Victoria, M. Ayaz Ahmad, N. Ameer Ahmad, Draghic
Silviu,(2015), “The Mathematical Study of Data Transmission in Digital
Electronics”, International Journal of Advanced Research (IJAR), Vol. 3(3), pp.
697- 702.
[14] Anghel Drugarin Cornelia Victoria, M. Ayaz Ahmad, N. Ameer Ahmad,
Vyacheslav V. Lyashenko, (2015), “Algorithmic Research and Application Using
the Rayleigh Method”, International. Journal of Science & Research (IJSR), Vol.
4(4), pp. 1669-1671.
[15] Manjinder Bajwa and Piyush Gulati, Comparing The Thermal Power Plant
Performance at Various Output Loads by Energy Auditing (A Statistical
Analyzing Tool), International Journal of Mechanical Engineering and
Technology, 2(2), 2012, pp. 111–126
[16] Raj Kumar Yadav, Pankaj Singh, Anurag Singh and Sandhya Yadav,
Comparing Industrial Waste Heat Used In Typical Thermal Power Plant,
International Journal of Mechanical Engineering and Technology, 6(11),
2015, pp. 57–63
[17] Mohammad Ayaz Ahmad, Mahmoud Yassen El-Bakry, Taymour A. Hamdalla,
Mir HASHIM Rasool, Shafiq Ahmad, (2016), “A Systematic Study of High
Energy Nuclear Collisions (light and heavy nuclei) by Simulations / Event
Generators”, International Journal of Advanced Research (IJAR), Vol. 4(1), pp.
28-43.

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