• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.3
• /
• pp.249-254
• /
• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.2
• /
• pp.264-270
• /
• 2016

This Study is to into fuel using a torrefation reaction to food waste. When the fuel of only food waste alone, fuel value is was performed at a ratio of sewage sludge constant attempts to prevent low. Mixing ratios of food waste and sewage sludge, 10:0, 8:2, 6:4, 5:5. Regardless mixing ratio, it was possible to confirm that decreases the moisture content of 10% or less at a reaction temperature of $240^{\circ}C$ or higher. As the ratio of the reaction temperature and the sewage sludge is high, the fixed carbon content is increased. It was measured at up to 36%(mixing ratios6:4, reaction temperature $270^{\circ}C$) from the initial 1.1%. From the reaction temperature $240^{\circ}C$ satisfied with 3000Kcal/Kg or more is a SRF criteria shows the calorific value. It was possible to obtain a heating value that is increased from the raw sample approximately sextuple. As reaction temperature is heightened, Van krevelen Diagram moved to the range of Lignite range. It was possible to obtain high fuel ratio and 5,500Kcal/kg or less of a combustility index as the sewage sludge mixing ratio becomes high. Increase the fixed carbon content, than those food waste alone solid fuel into and improved fuel costs, it is necessary to ensure that the quality of the fuel is improved.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.9
• /
• pp.793-802
• /
• 2009

Adsorption properties were estimated for the organic silicon compounds (siloxanes) in an actual landfill gas (LFG) using adsorbents such as coconut activated carbon, coal activated carbon, silica gel, sulfur adsorbent, carbonized sludge, and molecular sieve 13X. Coconut activated carbon showed the highest removal efficiency of more than 95%. The desorption of hexamethyldisiloxane (L2) from the adsorbent, however, resulted in the remarkable concentration variation of the compound in the treated gas. Silica gel, which had high adsorption capacity for L2 in single substance adsorption experiment in the other study, could not remove the component in the actual landfill gas while it adsorbed well octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in the LFG. Therefore the elimination of hexamethyldisiloxane is an important factor to determine the level of total organosilicon compound in pretreated landfill gas. Moreover, the L2 from the actual landfill gas was effectively adsorbed by the serial adsorption test using two columns packed with coconut activated carbon which has the great capacity of siloxanes removal among others. In order to utilize efficiently LFG as a renewable energy, the emission and adsorptive characteristics of the substance to be treated should be considered for the organization, operation, and management of pretreatment process.

• Journal of the Korean Institute of Gas
• /
• v.14 no.3
• /
• pp.41-45
• /
• 2010

The physical properties of DME(Dimethyl Ether) are very similar to LPG and well-mixed. As cetane number of DME is similar to diesel fuel that can replace diesel fuel and alternative energy. DME is a clean energy source that can be manufactured from various raw materials such as natural gas, CBM(Coal Bed Methane) and biomass. DME has no carbon-carbon bond in its molecular structure and its combustion essentially generates no soot as well as no SOx. The development of DME process in KOGAS have 4 section. First, syngas section can be manufactured various syngas ratio. This completes the tri-reforming process for the synthesis gas ratio of approximately 4.0 to 1.0 range can be adjusted. Second, $CO_2$ is removed from the $CO_2$ removal section of about 92~99%, so the maximum concentration of $CO_2$ entering the DME synthesis reactor should not exceed 8%. Third, in the DME synthesis section, if the temperature of DME reactor increases, the activity of DME catalyst increased. but for the long-term activity is desirable to maintain the proper temperature. Finally, the purity of DME in the DME purification section is over 99.6%.

• Asian Journal of Turfgrass Science
• /
• v.24 no.2
• /
• pp.199-204
• /
• 2010

Much of the coal ash by thermal power plant has gradually been increased, however researches on the recycling of bottom ash has not been investigated enough so far. In this research, the lysimeter test was conducted to find out the possibilities of bottom ash as soil amendment to improve the physiochemical properties of sandy topsoil of turfgrass in golf course. The turfgrass growth test and leaching test were conducted on the lysimeter. The lysimeter columns were manufactured with various topsoil mixing ratios of 0, 10, 20, 30, and 50% of bottom ash with sand. As a result of leachate analysis through the lysimeter column, the higher ratios of bottom ash mixed affect significantly on water holding capacity of topsoil sand media with decreasing of the percolation rate. The results of leachate analysis in every three days interval, the pH of leachate increased with the bottom ash ratios, but the volume of $NO_3$-N, $NH_4$-N and K decreased significantly. However, the level of EC of leachate had constantly maintained. These results indicate that the application of bottom ash may improve turfgrass growth with water holding capability and fertility of sandy topsoil. However, the negative effects of the bottom ash also evaluated by reducing water permeability and solubility of $PO_4$-P by adsorption into soil particles. The results indicates that the reasonable mixing ratio of the bottom ash as soil amendment should be less than 20% (v/v) with sand which has a low water-holding and fertility in golf course topsoil layers.

• Korean Chemical Engineering Research
• /
• v.44 no.3
• /
• pp.307-313
• /
• 2006

In order to improve the efficiency of methane steam reforming process, a part of the system which produces hydrogen from heavy hydrocarbon resources such as coal, we combined metal catalyst with CaO sorbent and fabricated catalyst/sorbent. To increase the porosity and the compressive strength of sorbent, carbon black and ${\alpha}-alumina$ were mixed with CaO powder during preparation. The effects of sorbent composition on the physical properties were investigated by SEM, TGA, BET, XRD, abrasion strength measuring device and adsorption-desorption instrument. Sorbent with 5 wt％ $Al_2O_3$ and 10 wt％ carbon black showed the best physical features with $7.61kg_f$ strength and 47％ $CO_2$ adsorption capability. Various metal catalysts such as Ni, Co and Fe were supported on the sorbent developed and 10 wt％ Ni/sorbent was selected for methane steam reforming process based on the result of reaction experiment. The reaction system using the catalyst/sorbent showed better $H_2$ productivity compared to the detached system with catalyst and sorbent, indicating the effectiveness of the system developed in this study.

• Clean Technology
• /
• v.13 no.4
• /
• pp.266-273
• /
• 2007

The adsorption properties of the activated carbon-based adsorbents were studied to remove COS emitted from $SO_2$ catalytic reduction process on the integrated gasification combined cycle (IGCC) system in this work. Transition metal supported catalysts and mixed metal oxide catalysts were used for the $SO_2$ catalytic reduction. The mechanism of COS produced from the $SO_2$ reduction and the COS concentration s according to the reaction temperature were investigated. In this study, an activated carbon and a modified activated carbon doped with KOH were used to remove the very low concentration of COS effectively. The adsorption rate and the breakthrough time of COS were measured by a thermo gravity analyzer (TGA, Cahn Balance) and a fixed bed flow reactor equipped with GC-pulsed flammable photometric detector (PFPD), respectively. It was confirmed that the COS breakthrough time of the activated carbon doped with KOH was longer than that of an activated carbon. In conclusion, the modified-activated carbon having a high surface area showed a high adsorption rate of COS produced from the $SO_2$ reduction.

• Korean Chemical Engineering Research
• /
• v.51 no.6
• /
• pp.692-699
• /
• 2013

In this study, isothermal (350, 375, 400, 425, 450, 500, $850^{\circ}C$) experiments were carried out using a custom-made thermobalance to analyze the thermal decomposition properties of refuse plastic fuel (RPF), which is to be used as a cofiring fuel with a sub-bituminous coal at commercial circulating fluidized bed (CFB) boiler in Korea. In isothermal pyrolysis results, no change in the reaction model was observed in the temperature range of $375{\sim}450^{\circ}C$ and it was revealed that the first order chemical reaction (F1) is the most suitable among 12 reaction models. The activation energy shows similar results irrespective of application of reaction model in that the activation energy was 39.44 kcal/mol and 36.96 kcal/mol when using Arrhenius equation and iso-conversional method ($0.5{\leq}X{\leq}0.9$) respectively. Mean-while, the devolatilization time ($t_{dev}$) according to particle size (d) of RPF could be expressed as $t_{dev}=10.38d^{2.88}$ at $850^{\circ}C$, operation temperature of CFB and for even distribution and oxidation of RPF in CFB boiler, we found that the relationship of average dispersion distance (x) and particle size was $x{\leq}1.58d^{1.44}$.

• Journal of the Korean Institute of Navigation
• /
• v.10 no.2
• /
• pp.31-55
• /
• 1986

Generally, the development of shipping is characterized by the amount of traffic flow (traffic volume) and seaborne cargo in the sea. Movement of ships is an essential element of constructing the traffic flow which is represented the dynamic movement of ships in the sea, but on the other band the numbers of arriving and departing the port is the basic factor consisting of the static movement of ships. The amount of cargoes by coastal vessels and ocean trade vessels have increased tremendously with the great growth of the Korean economy these days. This increase of the seaborne cargoes has made the Korean coastal traffic flow so congested that this can be a cause of large pollution as well as great marine casualities such as a loss of human lives and properties . And also the future coastal traffic is expected to increase considerably according to our economic development and high dependence upon foreign trade. Under the circumstance, to devise the safety of coastal traffic flow and to take a proper step of a efficient navigation, there is a necessity for analyzing and surveying the coastal traffic trend and the characteristics of cargo movement. In order to grasp the dynamic movement of ships in the Korean coast, O/D analysis is executed. This paper aims to secure the basic data necessary for a comprehensive plan and estimation of vessel traffic management system for the enhancement of safety, order and efficiency of vessel traffic in the Korean coast. The analyzed results of the traffic flow and seaborne cargoes of the Korean coast are summarized as follows : 1) The congestion by the vessels occurred around the ports such as-in proportion of ship's number (proportion of tonnage) -Incheon 18.5%(14.8%), Pohang 5.9% (9.9%), Samil 5.2%(8.3%), Mokpo 8.6%(0.8%), Pusan 13.5%(36.4%), Ulsan 9.1%(16.2%). 2) It is found that the area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed thatthe area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed that the coastal vessels are main elements constituting the coastal traffic and that there are much traffic flow among five ports as following through the precise O/D analysis of ship's coastal movement. Incheon-Samil, Ulsan, Pusan, Jeju Pusan -Samil, Ulsan, Incheon, Jeju Pohang -Samil, Inchoen, Jeju Pohang -Samil, Incheon, Jeju Ulsan -Samil, Incheon, Jeju Samil -Ulsan, Pusan, Incheon 4) The amount of cargoes to abroad are in proportion about 81% of total and the amount of coastal cargoes are about 19%. Of those, cargoes in and out to Japan are about 26% and to South-east Asia are about 27%. 5) The chief items of foreign cargoes are oil(38.33%), iron ore(13.98%), bituminoous coal(12.74%), grain(8.02%), lumber(6.45%) in the import cargoes and steel material(21.96%), cement(17.16%), oil(6.81%), fertilizer(3.80%) in the export cargoes. 6) The 80.5% of total export cargoes and 92.4% of total import cargoes are flowed in five main ports. 7) The chief items of coastal cargoes are oil (42.45%), cement(16.86%), steel material (6.49%), anthracite(6.31%), mineral product(4.3%), grain, and fertilizer. Almost 92.24% of total import and export oil cargoes in Korea is loaded and unloaded at the port of Samil & Ulsan.

• Resources Recycling
• /
• v.8 no.4
• /
• pp.11-19
• /
• 1999

Fly ash generated from (he pulverized coal power plant have caused the serious ocean pollution due to the disposal in the ash pond, the life reduction of a power plant and the waste of re-utilizable resource The research to reuse the unburned carbon and mineral composing of the ash has been progressed. In this study. the physical and chemical characteristics of high grade ash and unburned carbon particles obtained from countercurrent column flotation are investigated. The cleaned ash of the less 0,5% loss on Ignition(LOI) in carbon content is a spherical sphere and 39.8${\mu}m$ in size of MMD(Mass Median Diameter). 2.22 $m^2/g$ of specific area. The morphology of high LOI carbon particles is a amorphousness, 76.6 ${\mu}m$ of particle size and 15.2 $m^2/g$ of specific The high grade cleaned ash and the high LOI ash have some difference in the light of physical. chemical and morphological characteristics