Your SlideShare is downloading. ×
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) ...
Upcoming SlideShare
Loading in...5
×

Investigation and analysis of air pollution emitted from thermal power plants

276

Published on

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
276
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
34
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Investigation and analysis of air pollution emitted from thermal power plants"

  1. 1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 32 INVESTIGATION AND ANALYSIS OF AIR POLLUTION EMITTED FROM THERMAL POWER PLANTS: A CRITICAL REVIEW S. Paliwala , H.Chandrab and A. Tripathic a Department Of Mechanical Engineering, Sunderdeep College of Engineering & Technology, Ghaziabad (Research Scholar, Singhania University) b Department Of Mechanical Engineering , Bhilai Institute of Technology, Durg-491001 (CG) India c Jaypee University of Engineering and Technology, Guna- 473226 (M.P.) India ABSTRACT A critical review of air pollution emitted from thermal power plants has been carried out by considering several literatures. It is concluded that the disposal of fly ash generated in thermal power plants poses a problem, as it required a large amount of land for dumping, however if utilized properly, this may turn into a resource material for number of sectors for Indian economy. Also it is found that biomass fired power plant using rice husk and cotton stalk as fuel has much lower efficiency than coal based power plant. Therefore, there is need to improvement in overall efficiency of biomass fired thermal power plant by proper improvement in the design DF boiler, heat transfer surfaces, fuel field systems, combustion equipment and by improving the fuel qualities, in order to give sufficient rise in overall efficiency of plant. 1. INTRODUCTION In India approximately 70% of power generation is obtained via thermal power plants. In India oil/gas reserves are not much, though India has abundant coal reserves, (with high ash content) which are expected to last nearly 200 years at the present consumption rate (1). So almost all the thermal power plants were using lump of coal in their boilers and were disposing of coal residue as bottom ash commonly known as furnace clinker (or cinder), coal breeze or ash, depending upon the extent of combustion it had undergone and its granulometry. The quality of fuel used for combustion in furnace of boiler is responsible for the energy efficiency and environmental pollution of thermal power plant. However the coal found in different coalfields of India is characterized by low calorific value and high ash content [31]. So, for getting a unit amount of electricity, large amount of pollutants are generated. It is desirable to have a good quality of coal for power generation, as it reduces the pollutants generated/unit of electricity. Out of different air pollutants, ash is mineral matter present in the fuel. For a pulverized coal unit 60-80 % of ash leaves as fly ash with the flue gases. Though there are several devices for collection of fly ash, the two efficient (≥ 99 % collection INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) ISSN 0976 – 6340 (Print) ISSN 0976 – 6359 (Online) Volume 4, Issue 4, July - August (2013), pp. 32-37 © IAEME: www.iaeme.com/ijmet.asp Journal Impact Factor (2013): 5.7731 (Calculated by GISI) www.jifactor.com IJMET © I A E M E
  2. 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 33 efficiency) emission control devices are fabric filters and Electrostatic Precipitator (ESPs) [42]. Fabric filters have low installation cost but high maintenance cost; and large pressure drop, which reduce the plant efficiency. The ESP is one of the most widely used devices for controlling particulate matter especially fly ash. Although they often demand higher capital investment in comparison with gas cleaning methods, the low operating cost and maintenance costs, the high collection efficiency (> 99%) & the ability to face severe operating conditions make ESPs suitable in the pollution problems characterizing many processes installations such as coal-based thermal power plants, cement plants, iron industries and glass manufacture [39, 26, 28, 37, 6, 22,8]. In this paper a detailed literature survey is performed to get the types of pollutants emitted from conventional as well as cogeneration power plants and methodology to reduce the harmful pollutants. 2. POLLUTIONS EMITTED FROM CONVENTIONAL POWER PLANTS Due to abundant coal reserves in India, coal based thermal power plants exist in large numbers and new plants are being proposed to meet future energy demands. Burning of fossil fuels, especially coal causes considerable air pollution. Since the amounts of air pollutants emitted are usually above the given national and international recommendations and standard, thermal power plants should be equipped with suitable pollution control devices. Since the power demand is growing and also power plants are shifted towards their centers of demand in urban areas, the evaluation of environmental impact from such plants is becoming more and more important. Environmental Impact Assessment (EIA) is the official appraisal of the likely effects of a proposed policy, program, or project on the environment; alternatives to the proposal; and measures to be adopted to protect the environment. The primary purpose of the EIA process is to encourage the consideration of the environment in planning and decision making and ultimately to arrive at actions, which are more environmentally compatible [33, 5, 34, 32, 22, 10]. Electric power plays a crucial role in the economic development of a country. So it is worth to investigate the economics of thermal power plant. For the study of economies the estimates relating to investment cost, energy cost or real costs per MWh capacity for the sets functioning in the Indian thermal power stations are required. Such estimates are not available, so we have to compute them from cost function for these sets, with cost being dependent on capacity of power plant [31, 35 and 36]. In thermal power plants the cost associated due to environment is also significant factor in the analysis of economics, which is due to the pollution control equipments used in the thermal power plants [29]. [21] Performed analysis for effects of thermal power plants on atmospheric electrical parameters and Observations of the surface atmospheric electric field, point discharge current and wind in the vicinity of a thermal power plant were made during three field observational programmes. Results of these observations are presented and they are used for determining the minimum distance from the source point for expecting normal fair weather surface atmospheric electric field. Measurements of surface atmospheric electric field may be considered as one of the aids for the detection of pollution caused by industrial processes. SO2 is a major constituent in air pollution and affects the environment by no. of ways like acid rain, corrosions and severe damage to the health. SO2 causes a wide variety of health and environmental impacts because of the way it reacts with other substances in the air. Particularly sensitive groups include people with asthma who are active outdoors and children, the elderly, and people with heart or lung disease. Intensity of SO2 emission can be observed by following example. A typical 6 MW power generation unit using furnace oil containing 2 % Sulphur will emit 388 tons of SO2 per year, based upon 320 working days or A 22.5 MW power generation unit will emit 1690 tons of SO2 per year by using Pet Coke [4, 15]. [41] Presents a technique to study air pollution by combining high spatial resolution data obtained by a mobile platform and those measured by conventional stationary stations. Conventional stations provide time-series point data but cannot yield information that is distant from the sites. This
  3. 3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 34 can be complemented or supplemented by mobile measurements in the vicinity of the conventional sites. Together, the combined dataset yields a clearer and more precise picture of the dispersion and the transformation of pollutants in the atmosphere in a fixed time frame. Several experiments were conducted in the years 2002-2003 to track the impact of power plant plumes on ground receptors in the immediate vicinity (within a radius of 30 km) of the plants, using a combined mobile and stationary dataset. [12], studied the evolution of aerosol emissions from coal-fired power plants due to coagulation, condensation, and gravitational settling and health impact and found that the scavenging efficiencies of aerosol emissions from coal-fired power plants under different removal mechanisms (coagulation, heterogeneous nucleation and gravitational settling) as a function of time. It also analyses the 'health impact' of the aerosol before and after the above dynamic mechanisms by comparing the respirable dust fractions. [1] Concluded in their research that solid waste (flyash) [11] has attained an apparent scenario for scientific & strategic concern in India due to large-scale dependence on coal-based thermal power plants. Waste utilization as the best option of pollution- prevention and disaster risk strategy has been worked out during previous decades to open doors for flyash utilization on various sectors of developmental and manufacturing sectors. [38] explored the environmental challenges faced by Indian thermal power industries and found that top management commitment and support; training and awareness of internal people, unacquainted society, and poor legislation are the few important challenges for effective implementation of environmental management practices in Indian power industries. 3. POLLUTIONS EMITTED FROM COGENERATION POWER PLANTS [27] Performed thermodynamic and economic analysis of 1.4 MWe Rice Husk fired cogeneration in Thailand and found that the rice husk-match cogeneration is more economically feasible than the thermal-match cogeneration. The capacity of back pressure steam-fired boiler is 18 tons/hour of steam at 25 bar (absolute) and 400oC. The rice husk-match cogeneration can generate power of 1,432 kW while the thermal-match cogeneration can produce power only 923 kW. The economic analyses in terms of the net present value (NPV), simple pay-back period (PBP), and internal rate of return (IRR) are also evaluated. Results show that the rice husk-match cogeneration has NPV of 0.30 million US$/year, PBP of 3.7 years and IRR of 27%, while the thermal-match cogeneration has NPV of 0.18 million US$/year, PBP of 5.5 years and IRR of 17%. Rice husk is one of the most widely available agricultural wastes in many rice producing countries around the world. Globally, approximately 600 million tons of rice paddy is produced each year. On average 20% of the rice paddy is husk, giving an annual total production of 120 million tones. In majority of rice producing countries much of the husk produced from processing of rice is either burnt or dumped as waste. Burning of RH in ambient atmosphere leaves a residue, called rice husk ash. For every 1000 kgs of paddy milled , about 220 kgs ( 22 % ) of husk is produced, and when this husk is burnt in the boilers , about 55 kgs ( 25 % ) of RHA is generated [14, 18, 30, 2, 24, 3]. [9] performed a case study and found that Rice husk is a potential source of energy for an agricultural country like Thailand with high rice production. Rice mills can use the rice husk generated by them as a fuel to produce energy. However, the environmental profile of the energy production must be assessed to ensure reduced environmental damage. This study has been carried out at the Roi Et Green Project which is a pilot project of capacity 9.8 MW using rice husk as the feedstock. The power plant uses 290 tons of rice husk and 1,400 tons of water in one day, and has a power requirement of 1 MW. Net power output is 8.8 MW, which will be sold to Electricity Generation Authority of Thailand (EGAT) for 21 years under the small power producer (SPP) scheme. The raw materials consumed and environmental emissions of energy production from rice husk are determined. The study shows that the emissions of SO2 and NOX are lesser in case of coal
  4. 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 35 and oil-fired power generation, but higher than for natural gas. The emission of CO2 from combustion of rice husk are considered zero since they do not contribute to global warming. [25] checked the feasibility of feasibility of installing rice husk power plant in Chhattisgarh to meet sustainable energy demands and found that, the use of rice husk for electricity generation in efficient manner in Chhattisgarh is likely to transform this agricultural by product or waste into a valuable fuel for industries and thus might help in boosting the farm economy and rural development of this newly developed state. In fact a systematic approach to this material can give birth to a new industrial sector of rice husk power production in India. Coal is used widely as a thermal energy source in thermal power plant for production of electricity but available coal in India is of poor quality, with very high ash content and low calorific value. Utilization of huge amount of coal in thermal power plant has created several adverse effects on environment leading to global climate change and fly ash management problem. Coal based thermal power plants all over the world is cited to be one of the major sources of pollution affecting the general aesthetics of environment in terms of land use, health hazards and air, soil and water in particular and thus leads to environmental dangers. So, the disposable management of fly ash from thermal power plant is necessary to protect our environment. It is advisable to explore all possible application for fly ash utilization. Several efforts are needed to utilize fly ash for making bricks, in manufacture of cement, ceramics etc. Various governmental and nongovernment bodies working in the field of utilization of fly ash for construction of road/road embankment. The utilization of fly ash gives good result in almost every aspects including good strength, economically feasible and environmental friendly [17, 16, 11, 19, 20]. [13] and [23] found in their research that measurements of CO2 (direct GHG) and CO, SO2, NO (indirect GHGs) were conducted on-line at some of the coal-based thermal power plant in India. The objective of the study having three major objectives: to quantify the measured emissions in terms of emission coefficient per kg of coal and per kWh of electricity, to calculate the total possible emission from Indian thermal power plant, and subsequently to compare them with some previous studies. Instrument IMR 2800A Flue Gas Analyzer was used on-line to measure the emission rates of CO2, CO, SO2, and NO at 08 numbers of generating units of different ratings. Certain quality assurance (QA) and quality control (QC) techniques were also adopted to gather the data so as to avoid any ambiguity in subsequent data interpretation. For the betterment of data interpretation, the requisite statistical parameters (standard deviation and arithmetic mean) for the measured emissions have been also calculated. 4. CONCLUSIONS 1. The disposal of fly ash generated in thermal power plants poses a problem, as it required a large amount of land for dumping, however if utilized properly, this may turn into a resource material for number of sectors for Indian economy. 2. To meet the better emission standards the size of ESPs should be increased which is costly affair. A cheaper option is to adapt micro processor controller charging system which will enhance the migration velocity and hence met the emission standards. The cost of such device will be much cheaper as compared to increase the size of ESP. 3. Proper action should be taken for improvement in clear power generation technology, for this purpose there should look on renewable energy source. In power generation biomass is one of best renewable energy source. 4. Biomass fired power plant using rice husk and cotton stalk as fuel has been also considered, these plants are having much lower efficiency than coal based power plant. Therefore, there is need to improvement in overall efficiency of biomass fired thermal power plant by proper improvement in the design DF boiler, heat transfer surfaces, fuel field systems, combustion equipment and by improving the fuel qualities, in order to give sufficient rise in overall efficiency of plant.
  5. 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 36 REFERENCES [1]. Ansari F.A., Gupta A. K., and Yunus M., 2011, Fly ash from coal fed Thermal Power Plants: Bulk Utilization in Horticulture-A long Term Risk Management Option, International Journal of Environmental Research, Vol. 5, No. 1, pp. 101-108. [2]. Beagle, E.C. 1978. Rice husk conversion to energy. FAO consultant. Rome, Italy. [3]. Bhattacharyya Subhes C., 1995, Thermal Power Generation and Environment: A Review of the Indian Case, International Journal of Energy Research, Vol. 19, pp. 185-198. [4]. Buecker B., 2006, Wet lime stone Scrubbing fundamentals, Power Engineering, Vol. 110, pp. 32-37. [5]. Canter, L. W., 1996, Environmental Impact Assessment, Mc Graw-Hill Co., New Delhi. [6]. Chandra A., Sabberwal S. P., and Mukerjee, A.K., 18th – 21st June, 1996, Performance Evaluation of an ESP Using Low Grade coal, Sixth International Conference on Electrostatic Precipitator, Budapest, Hungary, pp. 209-214. [7]. Chandra A, Sabberwal S P, Mukerjee A K., July 1996, Particulate control in Badarpur Thermal Power Plant; Evaluation and Performance Upgradation of Electrostatic Precipitator Unit, Research report submitted to BTPS, Centre for Energy Studies, I.I.T. Delhi, New Delhi. [8]. Chandra A., and Vanchipurackal Ison V., 14 – 17th May, 2001, Performance Upgradation of ESP using Difficult Coal, Eighth International Conference on Electrostatic Precipitator, Series B-3, Brimingham, Alabana, USA. [9]. Chungsangunsit T., Gheewala S. H., and Patumsawad S, Environmental Assessment of Electricity Production from Rice Husk: A Case Study in Thailand, Electricity Supply Industry in Transition: Issues and Prospect for Asia, 14-16 January 200, pp. 20-51. [10]. Csanady, G. T., 1973, Effect of Plume Rise on Ground Level Pollution, Atmospheric Environment. Vol.7, pp. 1-16. [11]. Fly Ash Mission’, (TIFAC), Department of Science and Technology, Ministry of Science and Technology, Government of India, Technology, (1994) [12]. Garcia-Nieto, P. J., 2006. Study of the evolution of aerosol emissions from coal-fired power plants due to coagulation, condensation, and gravitational settling and health impact,Journal of Environmental Management, Vol. 79,pp.372-382. [13]. Ghodke S., Kumar R., Singh N., and khandelwal H., 2012, Estimation of Green House Gas Emission from Indian Coal Based Thermal Power Plant, IOSR Journal of Engineering, Vol. 2, No. 4, pp: 591- 597. [14]. Giddel M.R and. Jivan A.P, Waste to Wealth, Potential of Rice Husk in India a Literature Review. International Conference on Cleaner Technologies and Environmental Management PEC, Pondicherry, India. January 4-6, 2007. [15]. Goswami Ram S., 2005, Flue gas desulphurization – An Overview of system and technologies, Environmental Pollution Control Journal, Vol. 8, pp. 5-8. [16]. Jha C. N. & Prasad J. K. 2000, Fly ash: a resource materifsinceal for innovative building material - indian perspective substitute and paint from coal ash” 2nd international conference on “fly ash disposal & utilization”, New Delhi, India. [17]. Kumar Vimal and MathurMukesh, 2003, Clean environment through fly ash utilization. Cleaner Technology, Impacts/12/2003-2004, MOEF-CPCB, Govt. of India, pp. 235-255. [18]. Madhumita Sarangi S. Bhattacharyya and R. C. BeheraRice Effect of temperature on morphology and phase transformations of nanocrystalline silica obtained from rice husk, 82: 5, 377 — 386. [19]. Maitra Saikat, Cremic product from fly ash global prospective. In preceding of the national seminar on fly ash utilization, February 26-27 NLM Jamshedpur India,(1999). [20]. Mandal, P. K., 2008, High unburnt carbon problem in fly ash & bottom ash in some Indian stations. 2008, Water & Energy International. Vol. 65, pp. 34-44. [21]. Manohar G.K., Kandalgaokar S.S., and Sholapurkar S.M., 1989, Effects of thermal power plant emissions on atmospheric electrical parameters, Vol. 23, Issue 4, pp. 843-850. [22]. Masters Gilbert M., 2000, Introduction to Environmental Engineering and Science, Prentice Hall of India, New Delhi. [23]. Mitta M.L., Sharma, C., 2003. Anthropogenic emissions from energy activities in India: generation and source characterization. Part I: emissions from thermal power generation in India. URL: http://www.osc.edu/research/pcrm/emissions/India.pdf.
  6. 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 4, July - August (2013) © IAEME 37 [24]. Natarajan, E., Nordin, A. and Rao, A.N. 1998. Overview of combustion and gasification of rice husk in fluidized bed reactors. Biomass and Bioenergy. 14: 533-546. [25]. Pandey R., Sar Santosh K. Bhui Ashish Kumar, 2012, Feasibility of feasibility of installing rice husk power plant in Chhattisgarh to meet sustainable energy demands, International Journal of Advanced Engineering Research and Studies, Vol. I, Issue IV pp. 57-60 [26]. Peavy Howard S., Rowe Donald R. and Tchobanoglous George, 1985 Environmental Engineering, New Delhi, Mc Graw-Hill Book Company, pp. 536-539. [27]. Peerapong, P. and Limmeechokchai, B., 2009, Thermodynamic and Economic Analysis of 1.4 MWe Rice Husk Fired Cogeneration in Thailand , International Journal of Renewable Energy, Vol. 4, No. 2, pp. 35-46. [28]. Ray, T. K., 1990, Parameters Affecting Fly Ash Precipitator Performance, Journal of Institute of Engineers, Vol. 71, pp. 22-30. [29]. Robert, John J., 1984, Air Quality Management, Handbook of Air Pollution, John Wiley Publication, New York, pp. 969-1003. [30]. Rozainee M., Ngo S.P., Salema A.A., 2008, Effect of fluidising velocity on the combustion of rice husk in a bench-scale fluidised bed combustor for the production of amorphous rice husk ash, Bioresource Technology Vol. 99, pp. 703–713 [31]. Sarkar, Samir, 1998, Fuels and Combustion, Orient Longman, Mumbai, pp. 217-256. [32]. Singh, Shekhar, 1998, Environmental Issues in the Energy Sectors, Proc. Energy Growth Sustain, Indian National Academy of Engineering, pp. 285-305. [33]. Singh, R. K., Katare, V. and Rajak, S. N., 1991, Environmental Impact Assessment and Management of Coal Mines and Thermal Power Plants in Singrauli Region, Indian J. of Environmental Protection, Vol. 11, No. 1, pp. 45-53. [34]. Sinha, S., 2001, Environmental Guidelines for Power Plants in India and other Nations, Environment Quality Management, pp. 57-69. [35]. Sodha, M. S. and Chandra R., 1992, Optimum Size of Thermal Power Stations, International journal of energy research, vol. 16, pp. 623-635. [36]. Sodha, M.S., Chandra R., and Rana Ashutosh, 1994, Optimum Size of Base Load Generators for Growing Demand, International journal of energy research, vol. 18, pp. 345-357. [37]. Srinivas, D.S.R.K., 1996, Status of Electrostatic Precipitator Technology Usage in India, TERI Information Monitor on Environmental Science, Vol. 1, No. 1, pp. 1-12. [38]. Tiwari J.K. and Rawani A. M., 2012, Environmental Challenges to Thermal Power Industries: An Exploratory Study in Indian Context, International Journal of Science and Nature, Vol. 3, No. 4, pp. 842-846. [39]. Turner D B., 1970, Workbook of Atmospheric Dispersion Estimates, U.S. Environmental Protection Agency, Washington D.C., USA. [40]. White, J.H., 1963, Industrial Electrostatic Precipitation. International Society of Electrostatic Precipitation. [41]. Yao X. H., Lau N. T., Fang M., and Chan C. K., 2006, Use of stationary and mobile measurements to study power plant emissions. Journal of the Air & Waste Management Association Vol. 5, pp. 6144- 151. [42]. Sanjay Paliwal & H. Chandra, “Investigation of Particulate Control in Thermal Power Plant using Electrostatic Precipitator”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 3, 2013, pp. 149-154, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. [43]. Wani Ahmad, MSK Prasad, Bhat Javed and V Thangapandian, “Coal Accident Analysis, Risk Quantification and Suggestive Scheme Improvements in Coal Bunkers of Abstract Thermal Power Plants”, International Journal of Industrial Engineering Research and Development (IJIERD), Volume 3, Issue 2, 2012, pp. 18 - 25, ISSN Online: 0976 - 6979, ISSN Print: 0976 – 6987. [44]. Vivek singh and Dr. A.C. Tiwari, “Performance Analysis of Electrostatic Precipitator in Thermal Power Plant”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 431 - 436, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359

×