The present research examined the technological trends in optimizing the gasification of waste. Generally, when thepercentage of impurities in waste is high, the energy density is low. High-temperature and high-pressure steam is difficult to obtain during energy recovery in incineration. Therefore, the energy recovery rate is low. However, if reaction conditions were optimized in gasification technology, it would be possible to produce synthetic gas with a high percentage of CO and H2. With regard to synthetic gas, there are many different types of energy recovery (steam turbines, gas turbines, gas engines) other than incineration, and it is possible to improve the recovery ratio through gas cleaning. Technologies that have the potential to optimize gasification in each phase were studied. With regard to domestic industry, optimization technology should be applied when planning and operating waste gasification.
In this research, the upgrading technology and policy trends for biogas were examined with a focus on the European Union (EU). Depending on the capacity of the biogas upgrading facility investment costs are different. In addition, biogas upgrading technology-specific energy demand is lowest in the amine scrubber process. Organic waste met the sustainability criteria. Also, the energy content was four times larger, and the results showed that the utilization value was significant. Through cogeneration, and it can secure various markets. Because of these advantages, various policies are being promoted in the EU. In the future, South Korea needs to model its biogas policy after the upgrading technology and policy trends in the EU, and it should strive to create a market for biomethane.
Global increase in the demand for the new Electrical and Electronic Equipment (EEE) results in the rapid increase of waste electrical and electronic equipment (WEEE) (or electronic waste). Significant efforts on developing diverse WEEErecycling policy and programs such as extended producer responsibility (EPR), WEEE directive, and the restriction of the use of hazardous substances (RoHS) directive are being made by many developed nations. This study focuses on determining priority among proposed WEEE recycling policy research projects by a number of experts from academia, institutions and recycling industry using quality function deployment (QFD) method to better manage and recycle WEEE in Korea. In order to develop effective WEEE recycling policy, a total of 12 different WEEE recycling policy research projects were proposed by a total of 11 experts related WEEE recycling. Reliability and validity evaluation of the proposed projects were conducted, along with SPSS statistical software. By using the QFD method, a survey regarding potential problems, suggestions, and difficulties at several WEEE recycling facilities were conducted and evaluated. Evaluation of the proposed projects was made by house of quality (HOQ). In this study, proposed research projects with higher importance index include WEEE collection system, development of WEEE recycling guideline, and establishment of WEEE generation/collection/recycling national database. The QFD method employed in this study can be effectively used as a decision-making process tool in WEEE recycling policy and road map.
In this study proximate analysis method was applied to food waste, mold, sewage sludge, PKS, PET in considering the characteristics of individual waste. It has been observed that this proximate analysis method based on the characteristics of individual waste required to dry the waste for more than 180 min, until the moisture contents reached the range of 105℃~ 110℃ and they reached the constant weight. Also it has been suggested that 7 min of ignition at 950℃ for volatile matters and 120~180 min of ignition at max. 815℃ for ash were recommended.
The management of household hazardous waste (HHW), a component of municipal solid waste (MSW) has become a major of concern partly due to their potential toxicity upon disposal. Improper management of such waste can deteriorate the environment and cause serious damage to the human health. This paper discusses the current fundamental management practices, which include the generation rate, collection systems and treatment using the survey reviews of households and interviews held with experts in the Daejeon metropolitan city. Surveys of more than 378 people in Daejeon Metropolitan City were conducted to investigate the characteristics, generation rate, social behavior and awareness regarding disposal of HHW. The target items used in this study includes used lamps, used batteries, pharmaceuticals, and household pesticide chemicals. According to the survey conducted, the generation rates of HHW varied depending upon the dwelling type, collection system, and waste type. Apartment complex residents participated actively in source separation, using the established collection system with limited items (e.g., fluorescent lamps and batteries), while single family housing residents tend to store HHW at households. There is still a need for public awareness, detailed policies and legislation requiring source segregation at households, and better collection systems for HHW. The results of this study can be used for developing better management of HHW in municipal solid waste streams to prevent potential environmental impacts and human health risks
As global warming is higher by CO2, most of countries have an effort to develop CO2 reducing technology like a CO2 sequestration and a CO2 curing method using cement based materials. In this study, CO2 uptake rate and compressive strength were investigated when CO2 curing method was applied in cement mortar. The CO2 uptake rate was ranged from 10.1% to 11.6% by mass measurement method and from 6.2% to 16.3% by TGA method. This means that mass measurement method by electronic scale is more accurate than TGA method to estimate CO2 uptake rate. The early compressive strength of 1 hour CO2 curing specimens was higher than that of 1 hour atmospheric curing specimens, but lower than that of 5 hours steam curing specimens. 3 days and 7 days compressive strength of specimens by atmospheric curing and steam curing were increased both. But compressive strength of 1 hour CO2 curing specimens was lower than that of other two curing methods.
The organic solvent is used in many industries. Generation of waste organic solvent is continuously increasing. The 2009 years total domestic production organic solvent is in use 21% total designation waste production with 682 thousand tons. processes of a waste organic solvent and management issue is increasing in advanced countries. To resolve this problem, evaluate the characteristics of a batch distillation column purification to propose alternative. Therefore, this study compares a refinement recovery characteristic of simple distillation and 10-stage distillation tower. It grasps a characteristic regarding refinement recovery of the waste organic solvent (Propylene Glycol Mnomethyl Ether Acetate)PGMEA which occurred at LCD processes through study of a hundred steps of distillation tower. In this study, the evaluate scale-up separation characteristics difference using 10-stage and 100-stage batch distillation column. The actual process of making a demonstration plant appointed by using waste organic solvents of high purity propose a method for recycling.
In this study proximate analysis method was applied to food waste, mold, sewage sludge, PKS, PET in considering the characteristics of individual waste. It has been observed that this proximate analysis method based on the characteristics of individual waste required to dry the waste for more than 6 hr, until the moisture contents reached the range of 105oC ~ 110oC and they reached the constant weight. Also it has been suggested that 7 min of ignition at 950oC for volatile matters and 2 ~ 3 hr of ignition at max. 815oC for ash were recommended.
This paper addresses the fugitive emission factors of showcase at use-phase and disposal-phase. The residual quantities of Korean-made fifty- two waste showcase were weighed, using a commercial recover of refrigerants to determine the emission factors at the disposal-phase. On the other hand, the emission factors at use-phase were estimated from the residual quantities and operating times. The average residual rate of fifty two scarp showcase is determined to be 75.6 ± 5.3%. The emission factor at the use-phase is estimated to be 2.8 ± 0.7%/yr in the case of using average age of 11.1 years and the average residual rate determined here. The emission factor at the disposal-phase, refrigerant is accomplished has not recycled, the residual rate was assumed that the emission factor. We estimate 7.8 g/yr for the average emission quantity of refrigerant per operating showcase, while 234.4 g for that per waste showcase. Since the chemical compositions of refrigerant of waste showcase were the same as those of new refrigerant, it is expected that the refrigerant recovered from waste showcase can be reused for refrigerant.
The waste-to-energy (WTE) industry draws global attention by using wastes as energy resources. Korean government is very inclined to invest in the WTE industry. Therefore, it is believed that there will be an industrial scale-up. Also it is needed to make proper strategies for promoting the industry by creating the added value of related companies. This study analyzes whether the value-added structure of Korean WTE industry exhibits a virtuous cycle through the value chain (VC) within related companies by using a regression analysis based on a survey to Korean WTE companies. As a result, the government’s R&D support is analysed not to contribute to an increase in the R&D investments of the WTE companies. Also an increase in corporates’ R&D investments does not lead to an increase in corporates’ R&D outputs. An increase in corporates’ R&D outputs, however, has the positive influence on an increase in production. In contrast, an increase in production does not have an effect on a decrease in production costs. And a decrease in production costs does not lead to an increase in profit rates per sales. In addition, it is shown that an increase in profit rates per sales does not contribute to an increase in production and R&D investments. Therefore, it is estimated that the Korean WTE companies do not organize the virtuous cycle of the VC yet. This study has a policy implication to need further efforts to create the virtuous cycle in the VC of Korean WTE industry.
In this study, five sediments samples were collected at near Hansan island. These samples were characterized whether they were contaminated or not. For this purpose, physico-chemical properties and metal contents were analyzed. From the elemental analyses, XRD, and XRF analyses, all samples showed similar elements, oxides, and minerals. In general, Cd, Cr, Ni, Pb, and Zn concentrations were below the contamination standards. Concentrations of Cu, however, exceeded the contamination standards of USEPA and Ontario sediment quality guidelines for some sampling sites. Ignition losses of the all samples were greater than 8%, which is a value indicating whether the sample is heavily polluted or moderately polluted. All the samples were classified as heavily polluted due to the high value of ignition loss. Therefore, sediments of the near Hansan island are required for periodic and strict management to prevent any harmful effects to the surrounding environments.
Methanol is one of the clean burning fuel with versatile applications. As a combustion fuel, it provides extremely low emissions. Methanol can also be used as a primary transporation fuel or a fuel additive and expecially as a raw metalial for methyl t-butyl ether. Methanol synthesis from synthetic gas was carried out in the Ru-CuO/ZnO/Al2O3 catalytic system. The influence of various factors, such as the reaction temperature, the concentration of ruthenium (Ru) and the reaction pressure was discussed, respectively, and the most preferred condition were obtained. The results showed that metanolsynthesis could be prepared from carbon monoxide and hydrogen under reaction conditions. The reaction of Ru-CuO/ ZnO/Al2O3 catalyst (E-catalyst) was operated most preferably at 160oC and 40 bar.
According to the change of waste management policy, the focus of product-oriented environmental management has been moved from follow-up management to advanced prevention since early 2000s. For achieving advanced prevention, assessment models to evaluate environmental performance of goods need to be established which can be used at design and manufacture stage for analyzing expected environmental loads and promoting recycling of resources. In this study resource recyclability assessment model for non-energy goods was developed. The model mainly consists of assessment items and instructions of each item. Assessment items are composed of 6 common items and 1 individual item for each group of target goods.
Electrochemical reductive extraction of tin from semiconductor plating process wastewater was experimented using synthetic wastewater. Copper and graphite plate were used as a cathode and an anode, respectively. The tin extractioncould be optimized in pH 0.5 and polar space of 60 mm. The extraction rate of tin per minute was increased as current and initial tin concentration increased, and more than 87% and 97% of tin could be extracted within 80 minutes at 500 mg/L and 1,000 mg/L of initial tin concentration, respectively. The electrochemical reaction orders and kinetic coefficients were 1.24 ~ 1.26 and 0.004 ~ 0.006 (L/mg)(n-1)min-1. The residual concentration of tin could be expressed as Ct= (Co (-0.246)+ 0.0012t) (-4.065).