This study reviewed the previous odor monitoring statuses of industrial complexes in the domestic metropolitan cities (Ulsan and Daegu) of Gyeongsang Province and their relevant counter-measures. In addition, it identified future technical and management issues and made suggestions on how to overcome them. The statuses and counter-measures were mainly obtained through domestic research studies from the 2020s. The target industrial complexes included manufacturing plants inside metropolitan city areas where severe civil complaints could occur. The counter-measures were generally classified into further in-depth odor analysis through the placement of monitoring equipment at multiple locations, scientific odor prediction and source tracking by integrating regional database systems or applying mathematical models, reasonable diagnosis and follow-up action after the identification of odor issues, and effective mutual communication with on-going or potential civil complaints from nearby residents through the Internet or smartphone apps. Additionally, this study suggested the automation of odor monitoring by using improved technologies with enhanced reliability through machine learning. These technologies would make it possible to organize a feasible monitoring network by deploying multiple low-cost odor sensors with automatic calibration and validation capabilities. Furthermore, this odor monitoring data could be made more effective when implemented together with health impact analyses based on secondary data from employees at workplaces or nearby residents.

This paper introduces a new technique for the analysis of the electro-chemical lighting of conducting polypyrrole (Ppy) films using a self-devised quartz crystal and Si-Photodiode combination method. The quartz crystal used in this study had mirror finished Au electrodes. The electrodes did not have light transmission properties so the light intensity could be measured only using reflection mode. The reflection mode light measurement was advantageous for obtaining total light amount measurements because these measurements cannot be obtained from transmission mode light measurements using a normal semi-conductor ITO electrode. After polymerizing the Ppy thin film on the quartz crystal, the changes in electrical properties, the mass changes of the thin film due to the movement of anions, and the changes in viscoelasticity and light intensity accompanying the electrochemical reaction were detected simultaneously through cyclic voltammetry. Furthermore, all the measured variables related to the electrochemical oxidation-reduction reaction were analyzed. Based on the results, it was suggested that this technique is useful for electrochromic analysis with normal metal electrodes using reflection mode. In particular, these results imply possible future developments for chemical, biochemical, and electrochemical sensors.

Concern about global warming and the energy crisis have led to a growing interest in developing potential alternative energy sources. The methane contained in a biogas stream is higher than 50%. Thus, the proper separation and utilization of the bio-methane contained in biogas can convert this stream into a valuable renewable energy source. In this work, the adsorption capacities of pure carbon dioxide and methane and the selectivities of their mixtures on LTA, FAU and MFI zeolites with different numbers of sodium ions were calculated by a Monte Carlo simulation. Based on the MC data, ideal adsorbed solution theory (IAST) and real adsorbed solution theory (RAST) were discussed. At a low pressure, the number of sodium ions played an important role in the adsorption capacity of carbon dioxide, while the accessible volume of zeolites determined the maximum adsorption capacity of carbon dioxide and methane. In the context of binary CO2/CH4 adsorption, the selectivity of the MFI zeolite was well described by IAST over the investigated pressures and compositions. In the FAU framework, the selectivity was predicted fairly well by RAST with Si/Al ratios of 2.5 or higher. However, below 2.5, the selectivity was not well predicted due to strong non-ideal behavior in the adsorbed phase.

In this study, a comparative environmental evaluation was conducted by employing LCA technology to compare a new process that decomposes VOCs using a plasma reaction by corona discharge and a conventional activated carbon adsorption process to remove VOCs emitted during the adhesive film manufacturing process. The environmental impact was estimated by collecting field data from a new process demonstration facility of 50 Nm3/min and the current adsorption one of 400 Nm3/min and utilizing the Ministry of Environment’s LCI DB. The scope of the analysis was from the latter stage of VOCs emission to atmospheric discharge. The comparative assessment was based on six categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone layer destruction, and photochemical oxides creation. Comparing the total emission quantity of the new process with that of adsorption showed that global warming decreased to 79.9%, photochemical oxide creation to 42.6%, acidity to 80.8%, and abiotic resource depletion to 72.2%. In particular, the eutrophication of the new process was reduced by more than 90% compared to adsorption due to adsorption’s additional environmental impacts from the use of regenerative activated carbon. The new process showed a positive effect in terms of the environment because the total emissions in all environmental categories were reduced compared to the current activated carbon adsorption process. Reducing the atmospheric emissions by increasing the VOCs removal rate is important because the photochemical oxide formation is above 50% for both processes. Weighted analysis showed that replacing the current adsorption process with the new plasma decomposition process decreased the overall environmental impact to 65.5%.

There is increasing interest in using hydrogen as a carbon-free fuel. In particular, hydrogen production through the decomposition of ammonia has been actively studied because ammonia is considered a realistic hydrogen carrier for importing hydrogen from abroad. In this article, the activity of cobalt catalysts supported on various carbon supports was evaluated in terms of ammonia decomposition. Carbon nanotubes (CNT), graphitic nanofibers (GNF), graphite, activated carbon (AC), and carbon black (CB) were used as carbon supports. The ammonia conversion decreased in the order of Co/CNT ~ Co/GNF > Co/Graphite >> Co/AC > Co/CB under reaction conditions with 25% ammonia. When comparing the turnover frequency (TOF) considering the number of active sites on the cobalt catalysts, it decreased in the order of Co/CNT > Co/GNF ~ Co/Graphite >> Co/AC ~ Co/CB. In addition, to check the catalytic performance of non-precious bimetals, CoNi alloy catalysts supported on GNF were compared. The ammonia conversion decreased in the order of 10 wt% Co/GNF ~ 2.5 wt% Ni-7.5 wt% Co/GNF > 5 wt% Ni-5 wt% Co/GNF > 7.5 wt% Ni-2.5 wt% Co/GNF > 10 wt% Ni/GNF. Based on the above results, it can be concluded that the dispersion of the cobalt catalyst is the main variable for the ammonia decomposition reaction, but in the case of CoNi alloy catalysts, the interaction between the metals is also important.

Fossil fuels used in the transportation sector are a major cause of severe air and environmental pollution. Furthermore, policies regulating diesel use are being implemented worldwide in order to achieve carbon neutrality. As a result, biofuels are gaining attention as an alternative to diesel. However, research enabling large-scale production is essential for industrial application, and securing efficiency comparable to that of conventional fossil fuels is crucial. In this study, a deoxygenation reaction using oleic acid was conducted to produce hydrocarbon-based biofuels, and changes in the reaction efficiency during the scale-up process were analyzed. Differences in the reaction efficiency were observed when the capacity was increased. In addition, the reaction temperature and reaction time were set as parameters for optimization. Analysis showed that a reaction at 350 oC for 7 hours resulted in the highest conversion (78%), while the selectivity for hydrocarbons (C9 ~ C17) was 30%. Thus, biofuels produced as a result of fuel characteristics analysis have the potential to replace fossil fuels.