Study of Different Parameters for Removal of Sulphur Dioxide Contained in Flue Gases to Control Air Pollution at Rajasthan , India (original) (raw)
Related papers
Removal of Sulphur Dioxide from Flue Gases in Thermal Plants
2010
The demand of electricity is continuous increasing and it is expected to double in 7 -10 years and the pollution in the environment likely to increase in the coming years. The main pollutants from the thermal power plants are dust and objectible gases like CO, CO2, SO2, NO2 etc. SO2 is a major constituent in air pollution. Sulphur dioxide (SO2) which produces during combustion of Coal in power plants and reacts with atmospheric water and oxygen to produce sulphuric acid (H2SO4). This sulphuric acid is a component of acid rain, which lowers the pH of soil and freshwater bodies, resulting in substantial damage to the natural environment and chemical weathering of statues and structures. Hence our aim of the project is removal of SO2 in flue gases and production of commercial applicable product with these gases. Laboratory studies were conducted to compare the efficiency of different concentration of NaOH, pH of solution, and temperature of NaOH solution for absorption of SO2 contained...
Use of natural soda ash production process waste for SO2 removal
Environment Protection Engineering
Results of ChemCad © 6.0 simulation have been presented on usability of natural soda ash production process waste in order to remove SO2 from flue gas. Properties and concentrations of the solutions used in this study belong to the waste stream of Eti Soda Inc., and the flue gas compositions were acquired from an existing thermal power plant. SO2 and H2O feed rates and flue gas entrance temperature to the absorption tower were optimized through the response surface methodology (RSM) in order to attain highest SO2 removal yields. It has been found that SO2 removal remained at 33.83% when the waste composition was lower than 2 wt. % while 100% SO2 removal was reached as the waste composition was increased to 8 wt. %. This result clearly demonstrates that treatment of natural soda ash production process waste can be done safely and economically while serving as an SO2 removal agent at the same time.
SOR process: A tool for reduction of SO2 emission
Sulphur dioxide (SO 2 ) emissions are prominently due to burning of fossil fuels at power plants and other industrial facilities, as well as fuel combustion in mobile sources such as locomotives, ships, and other equipment. Rapid SO 2 emission has in recent times become a major source of concern because it can cause breathing problems, respiratory illness, changes in the lung's defenses, cardiovascular diseases and damage to vegetation and building due to acid rain. There are multiple approaches for SO 2 removal from flue gases. The regenerative process for SO 2 emission reduction is one of recently developed techniques, which employs the use of aqueous solutions of organic and inorganic buffering agents. An indigenous amine solvent and regenerative process called sulphur oxide regeneration (SOR) is being collaboratively used for removal of SO 2 from flue gases. The solvent was developed after extensive screening work among different organic compounds in the laboratory. The developed solvent has high selectivity towards absorption of SO 2 which reduces SO 2 level in treated gas. The solvent is nonvolatile and chemically and thermally stable which reduces solvent make up. Pretreated flue gas is scrubbed in the absorber by the solvent and treated gas is routed to the atmosphere. SO 2 evolved in regenerator is routed to Sulphur Recovery Unit (SRU). The process is hybridized with SRU to treat incinerator flue gas to improve sulphur recovery from 97% to 99.9%. Recycle of SO 2 to upstream of SRU enhances its capacity. Besides the above advantages, heat recovery from flue gas is an additional benefit of the process.
SO2 Emission Control and Finding a Way Out to Produce Sulphuric Acid from Industrial SO2 Emission
Journal of Chemical Engineering & Process Technology, 2015
Sulphur dioxide (SO 2) is one of a group of highly reactive gases known as "oxides of sulphur". SO 2 is linked with a number of adverse effects on the respiratory system and other environmental issues. It is an important industrial emission gas which causes several difficulties in the environment like acid rain. Sulphur dioxide is a ubiquitous component of fuel combustion exhausts and one of the first air pollutants to be regulated all over world. Several approaches have been adopted to reduce SO 2 content in the environment. One of the most difficult environmental problems facing industry is how to economically control SO 2 emissions. Conversion of H 2 SO 4 from SO 2, which could be a great impact on reducing pollution. Production of sulphuric acid is one of the best choice considering its economical values and utilities. This paper addresses the different processes to control SO 2 and to use SO 2 in most economic and productive way to reduce SO 2 effect in environment. A review of various treatment methods has been provided and a brief description of each process has been included and their technical applicability is also compared.
Industrial & Engineering Chemistry Research, 1996
Removal of SO 2 from flue gas by the absorbent prepared from coal fly ash, calcium oxide, and calcium sulfate was studied under different reaction conditions to elucidate the effects of the reaction temperature, water vapor pressure, and coexistence of NO in a flue gas. The SO 2 removal activity increased with an increase in NO concentration up to 500 ppm at 130°C. The SO 2 removal activity increased as the water vapor pressure increased until a monolayer coverage with water molecule is achieved. As the adsorbed water exceeded the monolayer coverage, the SO 2 removal activity suddenly decreased and calcium sulfite became the main product instead of calcium sulfate. The NO removal activity increased with an increase in SO 2 concentration up to 2000 ppm at 130°C. The NO removal also increased with an increase in water vapor pressure. The NO removal markedly decreased as the adsorbed water exceeded the monolayer coverage.
Journal of material cycles and waste …, 2005
Sorbents synthesized from various types of ash (coal fly ash, coal bottom ash, oil palm ash, and incinerator ash) for flue gas desulfurization were investigated. The sorbents were prepared by mixing the ashes with calcium oxide and calcium sulfate using the water hydration method. The effects of various sorbent preparation variables, such as the hydration period, the ratio of calcium oxide to ash, and the amount of calcium sulfate, on the Brunauer-Emmett-Teller (BET)-specific surface area of the resulting sorbent were studied using a two-level full factorial design. The surface area of the sorbents obtained range from 15.4 to 122.1 m 2 /g. Regression models were developed to correlate the significant variables to the surface area of the sorbents. An analysis of variance (ANOVA) showed that the model was significant at a confidence level of 95%. It was found that apart from all the individual variables studied, interactions between variables also exerted a significant influence on the surface area of the sorbent. From the activity test results, it was found that sorbents prepared from coal fly ash and oil palm ash have the highest SO 2 absorption capacity. Scanning electron microscope (SEM) analysis showed that the sorbent was composed of a compound with a high structural porosity, while an X-ray diffraction spectrum showed that calcium aluminum silicate hydrate compounds are the main products of the hydration reaction.
Chemical …, 2007
The removal of sulfur dioxide (SO 2 ) from simulated flue gas was investigated in a laboratory-scale stainless steel fixed-bed reactor using sorbents prepared from various siliceous materials, i.e., coal fly ash (CFA), oil palm ash (OPA) and rice husk ash (RHA) mixed with lime (CaO) by means of the water hydration method. Experiments were carried out with a flue gas flow rate of 150 mL/min, reaction temperature of 100°C, and SO 2 concentration of 1000 ppm. It was found that sorbents prepared from RHA have high BET surface areas and high SO 2 sorption capacities, based on breakthrough curve analysis. In addition, the SO 2 breakthrough curves were also described in terms of a simple first-order deactivation model containing only two rate constants, one of which, k s , describes the surface reaction rate constant while the other, k d , describes the deactivation rate constant. The values of k s and k d obtained from the deactivation kinetics model were in good agreement with the experimental breakthrough curves and were also compared with those available in the literature.
REMOVAL OF SULFUR DIOXIDE FROM FLUE GAS USING ABSORBENT PREPARED BY WATER AND STEAM HYDRATION
ASEAN JOURNAL ON …, 2003
Active absorbent for flue gas desulfurization was prepared from coal fly ash, calcium oxide (CaO) and calcium sulfate (CaSO 4 ) by hydro-thermal process; steam and water hydration. The absorbents were examined and compared for its micro-structural properties. The experiments were conducted based on Design of Experiments (DOE) according to 2 4 factorial design. The effect of various absorbent preparation variables such as hydration period (Factor A), ratio of CaO to fly ash (Factor B), amount of calcium sulfate used (Factor C) and drying temperature (Factor D) towards the BET surface area of the absorbent were studied. The BET surface area of the absorbent was in the range of 12.9-169.3 m 2 /g. Fisher's test showed that there is a strong influence of factor A, B and D towards the absorbent surface area, while its dependence on factor C is negligible. Comparison between absorbents prepared from water and steam hydration showed that the BET surface area of absorbents prepared from water hydration gives a higher surface area, but at a lower rate. The optimum BET surface area for the prepared absorbent 169.3 m 2 /g, was obtained at the following absorbent preparation variables using water hydration; hydration period of 24 hours, ratio of CaO to fly ash of 1:2, CaSO 4 amount of 3g and drying temperature of 200˚C.
Treatment of reduced sulphur compounds and SO2 by Gas Phase Advanced Oxidation
Chemical Engineering Journal, 2017
Reduced sulphur compounds (RSCs) emitted from pig farms are a major problem for agriculture, due to their health and environmental impacts and foul odour. This study investigates the removal of RSCs, including H 2 S, and their oxidation product SO 2 using Gas Phase Advanced Oxidation (GPAO). GPAO is a novel air cleaning technique which utilises accelerated atmospheric chemistry to oxidise pollutants before removing their oxidation products as particles. Removal efficiencies of 24.5 and 3.9 % were found for 461 ppb of H 2 S and 714 ppb of SO 2 in a laboratory system (volumetric flow Q = 75 m 3 /h).
REMOVAL OF SULFUR DIOXIDE FROM SULFURIC ACID PLANT EMISSIONS
A bench scare systenr v,as buirt to study the absorption of surfur dioxide by sodium rrydroxide. The sysrem includecl nteans for the generation of sulfur dioxide, i'corpo'ation,of it i1 o t"::y3,air to simulate polluted air at yarious cancentarions and absorption packed beis ny, absorption u'as car-r.ied out using a counter-currenl stream of NaOH solution oTrorior, foncentralions' The ntethod of Box-wilson experimental desi'gn v,as employed for *, artrrrrination o7 tt',r"opiiirtunt conditions which givi the highe.st absorption effciencv' At high concentration of SOt in oir,-fri{n itsorption q::g"y "was attained for a constant Na()H concentration. 1'he best absorbent was foutid to b, 0"'33 g mol'L't ' LehltTl reported poilution problems of laree quantiry of acidic waste water withdrawn' In the absorption with ammonia[8]' IY*r'o separate scrubbers built one have the other were used and ammoniacal solution added from the top of the column. The process requires careful control of pH levels to be installed in both scrubbing units to prevent heavy foggirtg conditions. The produced ammonium sulfate represented both economic and pollution problems to get rid of, even into ferlilizer industrv, because it was the least acceptable and low srade fertilizert3l. In addition, the cost rlf "nrmJniu used in scrubbing is high in comparison with other materials{2'3]' The disadvantage of the orocess were confirmed by Sander et al of Lurgi r r rl9l umon". In the process of adsorption with lime' SO2 arrd 02 in the flue gas react with caustic lime to form .alcium suifite or sulfate as solid products that a::e separated from tl,e absorption liquor' The clear iiquia is returned to ittt scrubbing unittr"l' Johanston and Singhltrl recognized scaiing as a serious problem in this system of SOz scrubbin;3' The flue gas desulfurization system of Kawasalti Heaw Industriesll2] is a very recent simplified lime/iimestone gypsum process' While the systern was highly efficient (more than 90% absorption) and reiable, it is large in size and the equipment cost is slightlY higStrzl'