Byung-Hyun Shon

Numerical Study for Flow Uniformity in Selective Catalytic Reduction(SCR) Process

Abstract Performance of NOx removal in SCR(Selective Catalytic Reduction) process depends on such various factors as catalyst factors (catalyst composition, catalyst form, space velocity, etc.), temperature of exhaust gas, and velocity distribution of exhaust gas. Especially the flow uniformity of gas stream flowing into the catalyst layer is believed to be the most important factor to influence the performance. In this research, the flow characteristics of a SCR process at design stage was simulated, using 3-dimensional numerical analysis method, to confirm the uniformity of the gas stream. In addition, the effects of guide vanes, baffles, and perforated plates on the flow uniformity for the inside and catalyst layer of the reactor were studied in order to optimize the flow uniformity inside the SCR reactor. It was found that the installation of a guide vane at the inlet duct L-tube part and the installation of a baffle at the upper part is very effective in avoiding chaneling inside the reactor. It was also found that additional installation of a perforated plate at the lower part of the potential catalyst layer buffers once more the flow for very uniform distribution of the gas stream

Changes in the Physical Properties of Granite by Weathering

Abstract Because the stone cultural properties located outdoors, they have been altered and deteriorated in external appearance due to environmental factors. Damage to stone cultural properties is accelerated particularly due to recent industrial development and environmental pollution. When fresh granite was dipped into the seawater, the mineral compositions(Ca, K) of the granite surface were lower then those of the fresh granite and density of the weathered granite was steadily decreased from 2.600 g/cm 3 to 2.580-2.582 g/cm 3 . Also, absorption capacity of the weathered granite was steadily increased from 0.392% to 0.526~0.616%. In the case of TiO 2 was coated to the granite, the change of density and absorption ratio of TiO 2 coated granite were decreased. Therefore, the TiO 2 coating considered to be a viable method to assist in the conservation of stone cultural properties from environmental contaminants. Key Words : Absorption ratio, Stone cultural properties, Density, Physical property, Granite

The physicochemical characteristics of manufactured RPF by industrial combustibility waste

Industrial combustible waste is very valuable source for refuse derived solid fuel since its heating value is usually over 3,000kcal/kg. Especially, synthetic high molecular compound which is high of productivity and heating value is used as raw material in many cases. Film type plastic has been widely used for producing RPF because their shaping is easy and they has high heating value. On the other hand, the possibility of various type of waste as a source for RPF in this study. It has been found that resin compound drived and tire derived solid fuel showed more than 6,000kcal/kg of heating value. But the heating value decreased by adding paper and wood waste.

Simulation of the flue gas treatment processes of an industrial-waste incinerator using Aspen plus

The interest on the recovery of thermal energy using the waste has been rising to solve the problems of continuous increase of waste generation and the depletion of the fossil fuel recently. The incineration has been used most popularly as a treatment process of the waste for the energy recovery. However, it is expected that incineration and design cost will increase in the treatment of air contaminant emitted from incinerator. This research has simulated the actual incinerator and the flue gas treatment system using the Aspen plus which is the software to simulate the chemical process. The incineration process is composed of the 1st and 2nd combustor to burn the waste, SNCR process to reduce the using the urea, and the steam generation process to save the energy during incineration. The slurry was used as an acid gas (HCl, ) treatment materials and the removal efficiency for the products from the neutralization of acid gas in SDA and combustion ash was simulated at the bag filter. The simulation result has been corresponded with the treatment efficiency of emitted gas from the actual industrial waste incinerator and it is presumed to be used to forecast the efficiencies of flue gas treatment system in the future.

Properties of inorganic components in the specified waste

The interest on the recovery of thermal energy using the industrial waste has been rising to solve the problems of continuous increase of waste generation and the depletion of the fossil fuel recently. To recovery from the waste among the new recyclable energies has been proved as the most favorable when the potential value of energy source is compared. The RDF made from the industrial waste has been approved as the most economical method. This research has analyzed the heavy metal components containing in the industrial waste. The concentration of Cl and S in the industrial waste generated in C-industrial complex are slightly high than that of the B- and A-industrial complex. The main components generated from A-industrial complex, B-industrial complex, and C-industrial complex are alumina-silicates, calcium alumina silicates, and the mixture of lime and calcium alumina silicate. These results could be used to reveal the origin of inorganic components in industrial waste and utilized as a basic data to improve the performance of the RDF as fuel.

A Numerical Calculation for the Optimum Operation of Cyclone-based Combustion System

Abstract This research carried out a 3-dimensional simulation using computerized fluid dynamics (CFD) for the flow characteristics, temperature distribution, velocity distribution and residence time, etc. in a reactor in order to derive the optimal combustion conditions of an innovative combustion system. The area-weighted average temperature of the outlet of a furnace during combustion at a condition of fuel input rate 1.5 ton/hr, residence time 1.25 sec and air/fuel ratio 2.1 was 1,077℃, which is a suitable temperature for energy recovery and treatment of air pollutants. Exhaust gas is discharged through a duct at a 40∼50 m/s maximum speed along strong vortexes at the center of a combustion chamber, so strong turbulence is created at the center of a combustion chamber to enhance the combustion speed and combustion efficiency. In this system, the optimum operation conditions to prevent incomplete combustion and suppress the formation of thermal NOx were air/fuel ratio 1.9∼2.1 and fuel input rate 1.25∼1.5 ton/hr.Key Words : CFD, Cyclone, Combustion, Temperature distribution, Velocity distribution

A study on determinants having influence on heating value of waste-derived solid fuels

The manufacturing of the solid fuel using wastes has been studied on the purpose of the reduction of green house gases and the profit-making as alternative fuel, and thus, it has become as technically improved as to be used as business. However, the production of solid fuel with multi-wastes combination needs a caution while the solid fuel with one-waste has not a significant component change. This study analyzes the solid fuel components through the practical plant experiment to the various wastes. The resulted data shows a different pattern than the theoretical one in the component analysis, and it can be concluded that the adequate uniform mixing has a great influence on the manufacturing of the solid soil.

A Study on Numerical Calculations of Hybrid Air Pollution Control System Coupled with SDR and Bag Filter

In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.

Decomposition of Liquid Wastes(Waste Oil & Solvents) under High Temperature Conditions

This study was investigated to determine the combustion characteristics, decomposition efficiency, and the flue gas concentrations after combustion in the high temperature reactor(, 1 atm) for the liquid wastes(waste oil and waste solvent) generated from the industrial complex. The concentration of nitrogen oxide(NOx) is decreased and the synthetic gas is increased when the mass ratio of /waste is about 1.53 because the reaction condition was changed to reduction state. And BTEXs(benzene, toluene, ethylbenzene, xylene) are decomposed more than 99.99%. If the highly concentrated liquid waste (waste oil and waste solvent) is treated under the operating conditions suggested by this study, our treatment method for the liquid waste was found to be proper because of the contaminants emission concentration is very low. In addition, the synthetic gas after combustion can be used as an alternative fuel.

A Study on the Thermal Characteristics of Waste Organic Sludges Generated from the Industrial Complex -Paper and Beverage Manufacturing Industries-

We analyzed the physical and chemical properties such as proximate analysis, ultimate analysis, heating values, thermogravimetric analysis, and combustion test for the organic sludges generated from paper and beverage manufacturing industries in the industrial complex. The average water and combustible content of the organic sludges from paper and beverage manufacturing industries were 66.07% and 14.67%, 54.98% and 26.77%, respectively. From the ultimate analysis of the organic sludges, C, H, O, N, and S compositions were 21.75%, 3.42%, 32.70%, 0.63%, and 0.30%, respectively. For beverage manufacturing industries, C, H, O, N, and S compositions were 39.88%, 4.28%, 23.20%. 2.65%, and 0.35%, respectively. According to the results of investigating the lower heating values by Dulong`s equation, 1 sludge(T company) was on the range of over 2,000 kcal/kg. This sludge could be directly applied to industries which try to use the energy by direct incineration. From the TGA test, the minimum combustion temperature of A company`s sludge was about for direct use for energy and that of 3 sludges(C, I, and T company) were at least over .