• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.11
• /
• pp.1178-1182
• /
• 2012

The organic linings at flue gas desulfurization systems (FGD system) in power plant have the excellent chemical properties but, lose the anticorrosive properties according to the aging with environment conditions. The properties of the organic linings depend on the manufacturing company. Therefore, the basic properties of organic linings for the preestimate of life time should be examined by conducting the aging and the bond strength test according to temperature. The pre-aging samples were compared with the post-aging samples. The temperature conditions of the aging process were 70, 150 and $200^{\circ}C$. The bond strength was calculated and the cross sections of fracture surface were examined by optical microscope and SEM. The $T_g$ was examined by DSC, DTA and TGA.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.4
• /
• pp.589-598
• /
• 2000

A pilot-scale Spray Drying Sorber (SDS) system was set up to evaluate the effect of spray characteristics on the desulfurization yield. The size distribution and the Sauter Mean Diameters of slurry droplets were measured in advance using the optical size measurement system, Malvern 2600. The desulfurization yield of the drying chamber by size was measured for the conditions of inlet gas and spray injection. As a reagent, 10% limestone slurry of $Ca(OH)_2$ was treated with flue gas containing $SO_2$, and the combustion gas analyzer and gas detectors were attached to measure the $SO_2$ concentration. With a flow rate of 144 Nm3/h and a temperature range of $200{\sim}300^{\circ}C$, the experiments were performed for the Stoichiometric Ratio (SR) of 1.0 to 3.0 and droplet mean diameter of 6.5 to $34.3{\mu}m$. In case of smaller spray droplets, the desulfurization efficiency improved due to the increase of total droplet surface area, while the reduction in evaporation time reduced the contact time between the droplets and $SO_2$ gas. In some typical region of droplet diameter, this negative effect, reduction of contact time, became dominant and the desulfurization yield decreases the desulfurization yield in spite of the expansion in absorption area. These results revealed that there exists the optimal size of spray droplets for a given state, which is determined by the compromise between the total surface area of slurry droplets and the evaporation time of droplets. The measurements also indicated that the inlet temperature of flue gas changes the optimal injection condition by varying the driving force for evaporation. The results confirm that the effect of the evaporation time of slurry droplets should be considered in analyzing the desulfurization yield as well as the total surface area, for it is a significant aspect of the correlation with the capabilities of $SO_2$ absorption in wet droplets. In conclusion, the optimal condition of spray can be determined based on these results, which might be applied to design or scale-up of SDS system.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.10
• /
• pp.1373-1383
• /
• 2001

The desulfurization characteristics of anthracite in a bench scale pressurized fluidized bed combustor are investigated. The coal used in the experiment is domestic anthracite from Kangwon Taeback area. The desulphurization experiment is performed with limestone from Chungbuk Danyang. The pressure of the combustor is maintained at 6 atm, and the combustion temperatures are 850, 900, and 950$\^{C}$. The superficial gas velocities are 0.9, 1.1, and 1.3 m/s. The excess air ratio is varied from 5 to 35%. The Ca/S mole ratios are 0.5, 1.5, 2.5 and 4.5 mole. All experiments are executed at 2m bed height. Consequently, SO$_2$ concentration in the flue gas is increased with incresing bed temperature and superficial gas velocity. However SO$_2$ concentration is decreased with incresing excess air ratio and Ca/S mole ratio.

• Particle and aerosol research
• /
• v.9 no.4
• /
• pp.239-246
• /
• 2013

The purpose of this study is to determine the feasibility of dry-type desulfurization process for actual application to coal-fired power plant. We used actual exhaust gas from Facility Y, Plant #2 to fabricate a demo-scale testing device to attempt to improve the efficiency of desulfurization. A spout-bed circulating dry scrubber convergence system connecting turbo reactor with bag filter was devised, then analyzed for performance characteristics of $SO_2$ removal for Ca/S mole ratio, superficial gas velocity, and ammonia injection, and for secondary reaction characteristics of the non-reactive sorbent at the bag filter. As a result, the installation of spout-bed circulating dry scrubber convergence system showed better economy and efficiency for removing sulfur than the existing wet/semidry-type desulfurization process. In addition, the best efficiency for desulfurization occurred when connected to the bag filter, with differential pressure maintained at 150 $mmH_2O$.

• Korean Chemical Engineering Research
• /
• v.57 no.5
• /
• pp.743-748
• /
• 2019

This study focuses on the simulation of wet flue gas desulfurization process for improving the production of gypsum by the utilization of low-grade limestone. At present, high-grade limestone with a $CaCO_3$ content of 94% is used for producing merchantable gypsum. In modeling process, a lot of reactions are considered to develop model. First, the limestone dissolution is simulated by RSTOIC model. Second, SOx absorption and crystallization is used by RCSTR model. Finally the gypsum is separated by using SEPERATORS model. Modeling steps make it easy to reflect further side reactions and physical disturbances. In optimization condition, constraints are set to 93% purity of gypsum, 94% desulfurization efficiency, and total use of limestone at 3710 kg/hr. Under these constraints, the mass flow of low-grade limestone was maximized. As a result, the maximum blending quantity of low-grade limestone for 2,100 kg of high-grade limestone that satisfies constraints is about 1,610 kg.

• Korean Chemical Engineering Research
• /
• v.47 no.4
• /
• pp.512-517
• /
• 2009

$SO_2$ concentrations in oxy-fuel combustion flue gases increases about three times as high as that of conventional air combustion system owing to the flue gas recirculation for the control of combustion temperature. So the desulfurization reaction is different from that of the conventional air combustion system due to exceptionally high $CO_2$ and $SO_2$ concentration. In this study, drop tube furnace(DTF) system was used to investigate the desulfurization characteristics of limestone in oxy-fuel combustion furnace. The experiments were performed under $O_2/CO_2$ atmosphere to examine the effect of operating variables such as reaction temperatures, Ca/S ratios and inlet $SO_2$ concentrations on the $SO_2$ removal efficiencies. $SO_2$ removal efficiency increased with reaction temperature, Ca/S ratio and inlet $SO_2$ concentration. And the addition of water vapor resulted in about 4~6% of increase in $SO_2$ removal efficiency.

• Journal of ILASS-Korea
• /
• v.15 no.4
• /
• pp.177-181
• /
• 2010

This paper has designed a mixing enhancement apparatus called Lobed-plate and Step-plate and comparatively calculated desulfurization efficiency of when its shape was changed. The parameters used at this time were the shape, SR ratio and the number of nozzles of the mixing enhancement apparatus and comparatively analyzed desulfurization efficiency according to these parameters. As a result, the Step-plate appeared as more highly by around 4% than Lobed-plate in desulfurization efficiency according to the shape of the mixing promotion apparatus, and when the desulfurization efficiency as a SR ratio is considered, it appeared highly by an average of 5% when the SR ratio is 3 rather than 2. As a result of comparing desulfurization efficiency by fixing the SR ratio and setting the number of nozzles as 4 pieces and 6 pieces, there was no big change in desulfurization efficiency when the SR ratio is 2, but it could be confirmed to improve by around 5% when the SR ratio is 3 when time passed 8 seconds.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.2
• /
• pp.189-195
• /
• 2020

In this study, the inlet duct and guide vane of the gas floating absorption tower were redesigned to improve the desulfurization efficiency so that the exhaust gas can be uniformly introduced into the absorption tower. In order to reduce the sulfur oxide pollutants among the main sources of air pollutants in industrial boilers, the existing equipment is redesigned and solved. For this purpose, change the exhaust gas, the slurry and recycling the adsorbent to improve the removal efficiency of SOx component in the exhaust gas inside the gas floating absorption tower so as to uniformly contact. And the initial design value and CFD value for the pressure loss from the boiler outlet to the gas floating absorption tower outlet are verified. Also, the velocity distribution of the exhaust gas, the concentration distribution of the recycled adsorbent, the liquid slurry behavior, and the pressure loss were compared. The results confirmed that the desulfurization efficiency was improved because the pressure loss from the boiler outlet to the absorption tower outlet was reduced and the deflection of the exhaust gas was minimized.

• Journal of the Korean Ceramic Society
• /
• v.53 no.1
• /
• pp.34-42
• /
• 2016

Characteristics of wet flue gas desulfurization and in-furnace desulfurization of domestic and overseas limestone with different crystallinity and crystalline size are studied in this article. Properties of desulfurization were evaluated in relation to physicochemical/ mineralogical characteristics, degree of pore formation for different calcination temperatures and TNC(total neutralizing capability). TNC of domestic high crystalline limestone was lower than that of overseas one. On the other hand, the porosity after calcination was shown to be relatively high for domestic limestone, which had high initial rates of desulfurization reactions in-furnace. Based on low pore formation and porosity with high TNC of crystalline high-Ca limestones compared to macrocrystalline ones, the former are preferred for wet desulfurization processes.

• Journal of the Mineralogical Society of Korea
• /
• v.21 no.2
• /
• pp.193-200
• /
• 2008

We tried to evaporate and dry the moisture contained Flue gas desulfurization gypsum and phosphogypsum by using the microwave directly. In the result of the heating to the Flue gas desulfurization gypsum and phosphogypsum using 2.45 GHz microwave which was created by magnetron 700 W, 1,000 W and 1,700 W, respectively. According to the increasing the microwave output intensity from 700 W to 1,700 W, the evaporate time of moisture was shortened from 10 to 3 minutes. Gypsum were changed to calcium sulfate hemihydrate. However, ${\beta}$-calcium sulfate hemi-hydrate were not changed to anhydrite.