김다미 Dami Kim , 김명진 Myoung-jin Kim

DOI:10.9786/kswm.2015.32.4.317

Abstract

Mineral carbonation using alkali industrial waste is an eco-friendly, economic technology used not only to reuse waste but also to store carbon dioxide. Alkali waste such as slag, cement waste, and coal ash has been mainly used as a raw material required for the technology. Many studies have been conducted to find optimal conditions for Ca/Mg extraction and carbonation with various extraction solvents under different temperatures, pressures of carbon dioxide, ratios of liquid to solid, and reaction times. Furthermore, in order to secure economic feasibility, there have been recent attempts to proceed the mineral carbonation at the room temperature and atmospheric pressure, to recover highly pure carbonate salts, and to reuse the extraction solvent. We expect that future researches will be in quest of economically storing as much carbon dioxide as possible by developing raw materials and carbonation technologies which provide high carbonation efficiency. In this article, we have reviewed recently published domestic and international research papers and then classified them according to the kind of industrial waste and the carbonation technology (direct and indirect carbonations).

Key Words

Mineral carbonation, Alkali industrial waste, Carbon dioxide, CCS, Review

정구황 Goo-hwang Jung , 현재혁 Jae-hyuk Hyun , 최경훈 Kyung-hoon Choi , 윤주영 Joo-young Yoon , 서승덕 Seung-deok Seo , 채상협 Sang-hyup Chae

DOI:10.9786/kswm.2015.32.4.329

Abstract

Recently, many countries have been interested in waste-to-energy policy and technology due to the economic crisis from high oil price and the demands on securing the sustainable energy sources. As one of the efforts to achieve the sustainable society and maintain low impact of global warming in Korea, the act on the promotion of saving and recycling resources was enacted to implemetnt the effective reduction of waste at source level, reduce, recycling and recovery of waste to energy. Attaining an efficient recovery of waste heat in a cogeneration plant from incineration facilities is important as a resource recovery of waste to energy. In this study, the waste heat recoveries changed by reducing feed pressure in incineration conditions were analyzed. As results, changing the operating condition in steam header resulted in stable heat supply and increase of waste heat recovery.

Key Words

Waste-to-energy, Waste heat recovery, Sustainable energy source, Incineration operating condition

반종기 Jong-ki Ban , 박진규 Jin-kyu Park , 안영미 Young-mi Ahn , 윤석표 Seok-pyo Yoon , 이남훈 Nam-hoon Lee

DOI:10.9786/kswm.2015.32.4.335

Abstract

Heat is generated from decomposition of wastes as a result of chemical and biological processes in aerated landfills. The purpose of this study was to assess temperature and predict its variations in an aerated landfill. In the phase of aeration, temperature was increased slightly from 30 to 34oC until 65 days and then increased significantly from 34 to 74℃ by termination of aeration. It indicates that the amount of oxygen supplied in the starting phase of aeration was insufficient to decompose organic carbon because oxygen supplied in the landfill was only consumed for methane oxidation. Additionally, to minimize the risk of self-ignition, drying and process inhibition, aerated landfills should be operated in a temperature range of 54 ~ 66℃ through cooling by water addition and terminating or excessive oxygen supply. In this study, a stoichiometric modeling approach considering methane oxidation and decomposition of organic carbon has been suggested for predicting temperature variations in aerated landfills. As a result, the predicted temperature variations obtained the stoichiometric modeling led to similar results compared with measured temperature in aerated landfill. Therefore, it showed that the stoichiometric approach was appropriate for predicting temperature variation in aerated landfills. In addition, heat generation rates for methane oxidation and decomposition of organic carbon were 89.5 and 387.8 MJ/m³·yr, respectively.

Key Words

Landfill, Aeration, Temperature, Stoichiometric modeling, Heat generation

문희성 Hee-sung Moon , 이재영 Jai-young Lee

DOI:10.9786/kswm.2015.32.4.342

Abstract

In this study, the authors applied a modified SRF product quality based on a mix of disposable plastic bags and bulky waste to estimate the mixing ratio which can be the energy efficiency of coal for fuel. This study was performed to find physical properties of bulky wasteand element analysis for the mixd disposable plastic bag. Also, SRF (solid recovery fuel) was tested to figure out, physicochemical properties by standard method. As the results, the physical properties of bulky waste shows 89.6% of wood. Then the author measured disposal plastic bag as follows : [3 : 7], [5 : 5], [7 : 3] quality criteria by the mixing ratio of bulky waste. The low calorific value was proportionally increased whenever the mixing ratio of disposable plastic bag was increased. Therefore, the author can surmise that the mixing ratio between bulky waste and disposable plastic bag was [6 : 4]. It shows 5,950 kcal / kg value as much as coal fuel.

Key Words

Inclusion of bulky waste, Disposable plastic bag, SRF(solid recovery fuel), Energy to waste

신명환 Myeong-hwan Shin , 송건호 Geon-ho Song , 백승민 Seung-min Baek , 김우석 Woo-suk Kim , 곽윤근 Yoon-keun Kwak

DOI:10.9786/kswm.2015.32.4.348

Abstract

Recently, demand for construction aggregates is increasing due to the growth of construction site scale. As natural aggregate sources are becoming depleted due to high demand in construction field, the utilization of recycled aggregate (RA) as coarse aggregate in concrete is becoming more important. In this study, the authors analyze the mechanical properties of normal- and high-strength concrete beams using RA and investigate the usefulness of the minimum steal ratio for RA reinforced concrete beams. The experimental results show that application of the minimum steel ratio to RA reinforced concrete beams is possible.

Key Words

Recycled coarse aggregate, Recycled concrete aggregate (RCA) Minimum reinforcement ratio, Shear span to depth ratio, Tension reinforcement ratio

윤영삼 Young-sam Yoon , 강준구 Jun-gu Kang , 손준익 Jun-ik Son , 김기헌 Ki-heon Kim , 이수영 Suyoung Lee

DOI:10.9786/kswm.2015.32.4.357

Abstract

According to the elementary analysis on organic wastes, the C/N ratio, a major condition for anaerobic digestion, is 5.40 to 9.23, except for food waste leachate (FWL). Defined by Tchobanoglous’ mathematical biogas prediction model, methane gas and biogas productions increased, depending on the mixing rate of FWL. Furthermore, anaerobic digestion both wastewater sludge and food waste leachate based on the right mixing ratio, increases methane gas productions compared to digesting wastewater sludge alone. In other words, co-anaerobic digestion is more likely to realize biogasification than single anaerobic digestion. We mix food waste leachate and wastewater sludge from the dairy and beer manufacturing industry by the proportion of 1 : 9, 3 : 7 and 5 : 5. It turns out that they produced 118, 175 and 223 CH₄ mL/g VS in the dairy manufacturing and 176, 233 and 263 CH₄ mL/g VS in beer manufacturing of methane gas. The result suggests that as the mixing rate of food waste leachate rises, the methane gas productions increases as well. And more methane gas is made when co-digesting wastewater sludge and food waste leachate based on the mixing ratio, rather than digesting only wastewater sludge alone. Modified Gompertz and Exponential Model describe the BMP test results that show how methane gas are produced from organic waste. According to the test, higher the mixing rate of food waste leachate is, higher the methane gas productions is. The mixing ratio of food waste leachate that produces the largest volume of methane gas is 1 : 9 for the dairy industries and 3 : 7 for brewery. Modified Gompertz model and Exponential model describe the test results very well. The correlation values (R²) that show how the results of model prediction and experiment are close is 0.920 to 0.996.

Key Words

Beverage manufacturing, Food waste leachate, Methane and biogas production, Model prediction

명소영 So-young Myung , 장완복 Wan-bok Jang , 유시리 Shi-ri Yu , 엄태인 Tae-in Ohm

DOI:10.9786/kswm.2015.32.4.368

Abstract

Hydrofluorocarbons (HFCs) emerged as alternative refrigerants after chloro fluorocarbons (CFCs) and hydro-chloro fluorocarbons (HCFCs) were identified as substances requiring control by the Montreal Protocol on Substances that Deplete the Ozone Layer. However, because the Kyoto Protocol considered HFCs as greenhouse gases, and their impact on climate change has been increasing, major developed countries have been strengthening the existing level of regulations related to the use of HFCs as refrigerants. In addition, South Korea has also passed various legislations relating to refrigerant management, in the form of policies such as the Wastes Control Act, the Act on Control etc. of the Manufacture of Specific Substances for the Protection of the Ozone Layer, the Clean Air Conservation Act, and the Act on Resource Circulation of Electrical and Electronic Equipment and Vehicles. However, reports indicate that these regulations have not been followed effectively due to the lack of a specific system relating to the phased management of production, use, and disposal of refrigerant materials. In order to identify and solve the problems relating to refrigerant management in South Korea, this study investigates the current state of refrigerant management in three separate phases: production, use, and disposal of refrigerants. Outstanding refrigerant management policies are also analyzed, using those enacted in the EU, United States, and Japan as examples, and these are then compared to regulations in Korea.

Key Words

Regulations in refrigerant management, Greenhouse gas, HCFC, HFC

손해준 Hae-jun Son , 고아람 Ah-ram Ko , 이우근 Woo-keun Lee

DOI:10.9786/kswm.2015.32.4.378

Abstract

Converter slag is discharged as by-product from steel making process. Its chemical composition is similar to that of blast furnace slag. Therefore its recyclability is high. But actually it was not widely recycled relatively. We studied to prepare insulating brick with it for enhancing the recyclability. We discussed mixing ratio of melting slag and converter slag and also additional amounts of Al-dross and NaOH as affecting factors. According to our results, 0.195 W/mK of thermal conductivity and 3.02 MPa of compressive strength were obtained at the following condition mixing ratio 60 : 40, aluminum dross 1.5wt%, NaOH 5.6wt%. It seemed that the thermal conductivity of prepared brick was decreased with increasing amount of Al-dross and NaOH. It is satisfied with the standard of insulating fire bricks (KS L3301).

Key Words

Insulating brick, Convert slag, Melting slag, Thermal conductivity

권영현 Young-hyun Kwon , 유흥민 Heung-min Yoo , 손준익 Jun-ik Son , 강준구 Jun-gu Kang , 이동진 Dong-jin Lee , 신선경 Sun-kyung Sin , 김기헌 Ki-heon Kim

DOI:10.9786/kswm.2015.32.4.383

Abstract

This study tried to seek the plan to recycle chicken residues (bones of seasoned spicy chicken and fried chicken) which are sent out thermally after chickens are delivered to homes and people eat them by grasping their basic characteristics. The analytical results of the weight reduction rate through the change before and after the weight is reduced have found that the average weight reduction rate of 38.0% is shown in the seasoned spicy chickens and fried chickens. The analytical results of low-heating value of chicken residues to grasp the thermochemical characteristics have found that the seasons spice chickens and fried chickens satisfy the SRF quality basis, 3,500 kcal/kg as 5,020.9 kcal/ kg and 5,295.2 kcal/kg respectively. On the other hand, the analytical result of TG has found that the thermal weight reduction rate is relatively clear in the fried chickens. It is inferred that creation of the fried chickens is more uniform than that of the seasoned spicy chickens and the effect of bound water is lower than other biodegradable substances. And it is judged that the potential that they can be utilized as sold fuel without any separate preprocessing through the drying process only is shown.

Key Words

Chicken residues, Loss rate, Basic Characteristics Analysis, Heating value

최덕진 Duck-jin Choi , 김한봄 Han-bom Kim , 유상열 Sang-yeol Yoo

DOI:10.9786/kswm.2015.32.4.391

Abstract

Nowadays, we are witnessing all the industrial structures being reorganized on the axis of the carbon dioxide technology to solve the problem of global warming. Therefore, there is need for various approaches even in the construction material industry to realization of the reduction of greenhouse gases and the recycling. Thus, this study sought to apply low energy binder material manufactured with industrial by-products to the extruded panels and develop a composite panel through the modularization of the insulator and the extruded panel. Results are as follows. Regarding the physical properties, the LEC panel had a lower flexural strength with 1.0 N/mm² than the plain panel, while showing no less absorption rate, percentage of water content, density and compression strength than the plain panel. Panels and insulation attachment was found suitable for B Bond's XPS. It is found that B's glue for XPS is appropriate for putting together the panel and the insulator. As for the thermal transmission coefficient, the LEC panel was lower with 0.384 W/mK than the plain panel but the difference with the composite panel was a mere 0.047 W/mK indicating a similar thermal property to that of the plain composite panel.

Key Words

Extruding panel, Insulation, Composite panel, Thermal transmittance

김덕영 Duk Young Kim

DOI:10.9786/kswm.2015.32.4.400

Abstract

The process that a new energy policy introduces and merges into the formal social system is an important but difficult journey for the transition to the low carbon society. Meanwhile, the government was obliged to allocate carbon emission reduction, the companies are called obligatory participants through emissions trading scheme were building an internal greenhouse gas reduction system to reduce Risk and to respond this new system. However, the internal response and reduction system of the Waste Field are easy to exposure to the ETS Risk because the local government employee is unaware of the ETS. Thus, it is necessary to establish a framework for rational decision making institutions through analyzing the existing system of greenhouse gas energy target management system. This study was predicted for the first phase emissions trading allowances based on excess or deficiency received through the 2015 quota allocation applications and explained the process proceeded in greenhouse gas energy target management system by the Jeju Special Self-case analysis of the waste sector, predicted potentially losses cost during the first phase in the emissions trading credits that are traded on the KRX market price. Furthermore, throughout the sensitivity analysis of major waste process parameter suggested the internal system to reduce greenhouse gas emissions directly as well as external policies by the direct participation of citizens through the local recycling center expansion. After all, this study suggested the need for the construction of internal and external system corresponding to these systemic risk.

Key Words

Carbon emission trading system, Climate change, Greenhouse Gas Energy Target Management Scheme

이경호 Kyeong Ho Lee , 원종철 Jong Chul Won

DOI:10.9786/kswm.2015.32.4.408

Abstract

LFG, generated by the decomposition of wastes, is very humid and has high temperature. When it cools during its transfer in the piping system, condensate forms, blocking the flow of LFG. Typical condensate removal devices, which works on the principle of trap usually used in the sewer pipe and utilizes water to prevent the intrusion of outer gas and to drain condensate, have limitation for their uses in landfill by the evaporation of water when it comes to dry condition in the landfill. In this study we investigated the temperature distribution in the waste layer and the possibility of the evaporation of water in the trap. LFG could be cooled down or heated by the temperature of waste layers where the transfer pipe locates. Evaporation rates, estimated by the use of temperature distribution in the landfill, were high enough to cause malfunctions when the difference of temperature between LFG and waste layer is high.

Key Words

Evaporation, Condensate removal device, Trap, LFG