Amine-stabilization of KOH on activated carbon surface in the preparation of a selective CO2 adsorbent

( Adelodun Adedeji Adebukola ),조영민 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

A review on the effect of amination pretreatment for the selective separation of CO₂

Adelodun, A.A.,Kim, K.H.,Ngila, J.C.,Szulejko, J. Applied Science Publishers 2015 APPLIED ENERGY Vol.158 No.-

For the cost-effective control of unregulated CO<SUB>2</SUB> emissions, its capture through modifications to adsorbents has recently gained much attention. In this respect, amination through basification of activated carbon (AC) surface is one of the practical approaches to separate CO<SUB>2</SUB>. To learn more about such mechanism, a number of key variables (e.g., the nature of the AC surface groups, their CO<SUB>2</SUB> absorption enthalpy, and the effect of amination on adsorption) are reviewed. The potent role of amination is hence described with respect to the significance of pretreatment prior to amination technique by comparing the performance of diverse media (e.g., advanced oxidation processes (AOP), Ca(NO<SUB>3</SUB>)<SUB>2</SUB>, and KOH) for such application. The analysis of collected adsorption data suggests that the efficiency of amination and eventual selective adsorption of CO<SUB>2</SUB> can be improved by such pretreatment as KOH sintering in terms of inducing stronger surface CO<SUB>2</SUB> binding energy.

Surface oxidation of activated carbon pellets by hydrogen peroxide for preparation of CO₂ adsorbent

Adelodun, A.A.,Lim, Y.H.,Jo, Y.M. Korean Society of Industrial and Engineering Chemi 2014 Journal of industrial and engineering chemistry Vol.20 No.4

This work attempted to use H<SUB>2</SUB>O<SUB>2</SUB> as an oxidant for the incorporation of surface oxygen functionalities (SOFs) on activated carbon in the preparation of a CO<SUB>2</SUB> adsorbent. Experimental results showed that oxidation at lowered temperature improved both structural and chemical properties more than those at ambient temperature, although oxidation at this temperature with 30% H<SUB>2</SUB>O<SUB>2</SUB> incorporated the highest amount of useful SOFs for amination purpose. pH<SUB>pzc</SUB> value was most significantly reduced by altering the temperature either way while dilution seemed to have positive impact regarding this property. Pre-treatment ultimately enhanced the selectivity for CO<SUB>2</SUB> adsorption as well as its capacity.

Analysis of Spatial-temporal Variability and Trends of Extreme Precipitation Indices over Chungcheong Province, South Korea

Bashir, Adelodun,Golden, Odey,Seulgi, Lee,Kyung Sook, Choi The Korean Society of Agricultural Engineers 2022 한국농공학회논문집 Vol.64 No.6

Extreme precipitation events have recently become a leading cause of disasters. Thus, investigating the variability and trends of extreme precipitation is crucial to mitigate the increasing impact of such events. Spatial distribution and temporal trends in annual precipitation and four extreme precipitation indices of duration (CWD), frequency (R10 mm), intensity (Rx1day), and percentile-based threshold (R95pTOT) were analyzed using the daily precipitation data of 10 observation stations in Chungcheong province during 1974-2020. The precipitation at all observation stations, except the Boryeong station, showed nonsignificant increasing trends at 95% confidence level (CL) and increasing magnitudes from the west to east regions. The high variability in mean annual precipitation was more pronounced around the northeast and northwest regions. Similarly, there were moderate to high patterns in extreme precipitation indices around the northeast region. However, the precipitation indices of duration and frequency consistently increased from the west to east regions, while those of intensity and percentile-based threshold increased from the south to east regions. Nonsignificant increasing trends dominated in CWD, R10 mm, and Rx1day at all stations, except for R10 mm at Boeun station and Rx1day at Cheongju and Jecheon stations, which showed a significantly increasing trend. The spatial distribution of trend magnitude shows that R10 mm increased from the west to east regions. Furthermore, variations in precipitation were very strongly correlated (99% CL) with R10 mm, Rx1day, and R95pTOT at all stations, except with wR10 mm at Cheongju station, which was strongly correlated with a 95% CL.

Environmental and Economic Costs of Household Food Waste in Daegu

( Bashir Adelodun ),김상현,( Golden Odey ),최경숙 한국농공학회 2020 한국농공학회 학술대회초록집 Vol.2020 No.-

Food waste has become a global issue with increasing attention among the researchers and policymakers due to its significant environmental and economic impacts and the associated unsustainable use of resources. While food wastage occurs at each stage of the supply chain with food loss at the upstream, the impacts of food waste occurring at the downstream are enormous due to the accumulated added values, especially at the consumption stage of the supply chain. In this study, the environmental and economic implications of household food waste were investigated. The primary data of household food waste was collected through direct sampling from households in Daegu, South Korea. The GHG emission potential factor for each of the food wasted items was adopted from the literature, and the water footprint was based on the water footprint concept, i.e., indirect water use, while the sale prices were used to assess the economic cost of wasted food items. The GHG emission and water footprint assessments associated with environmental impacts and the economic cost of wasted food items were conducted. The findings showed that a daily average of 12.36 kg food waste was generated between July and December 2019 among the sampled households, with watermelon, rice, and leafy vegetable responsible for 9, 8, and 8%, respectively, of the total weight of the 42 food wasted items. The environmental impacts indicated that 17.16 ± 16.14 kg CO_2-eq and 11.07 ± 10.22 m³ of green house gas emissions and water footprint, respectively, were associated with the household food waste. Beef, rice and cheese had the highest amount of GHG emissions of 21, 16, and 14% of the total emissions, respectively, while beef, soybean and rice accounted for 30, 10, 9% of the total water footprint, respectively, that were lost due to food waste. Further, the average estimated economic cost associated with wasted food items was 100, 220.96 ± 102,409.22 Korean won, with fish, beef, and leafy vegetable accounting for 14, 10, and 9%, respectively, of the total economic cost. This study, therefore, provides insight into the enormity of environmental and economic implications of household food waste among Korean households.

직접무게측량을 통한 한국 가정의 음식쓰레기 특성 분석

바실아델러둔 ( Bashir Adelodun ),조건호 ( Gun Ho Cho ),김상현 ( Sang Hyun Kim ),이슬기 ( Seul Gi Lee ),최경숙 ( Kyung Sook Choi ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

Studies on food waste have gained increased attention in recent time due to its adverse effects on the environment and associated waste of resources. It is established that food waste at the consumption stage of the supply chain is more pronounced in the developed countries, among which Korea belongs. Addressing the food waste generation is a promising way to achieving sustainable development goal of the United Nations on sustainable consumption and production patterns which Korea is desirous of pursuing. However, inadequate information on the actual amount of household food waste generation has repressed the appropriate policy interventions designed to reduce and set a performance target for food waste generation. This study investigated the quantity of food waste in Korean households using a novel direct weighing sampling method of characterization. The households were selected from three different housing systems, including apartment (33), villa (31), and house (20). The results showed that the average food waste generated among the sampled Korean households was 0.29 ± 0.20 kg per capita per day, with fruits, vegetable, and rice and rice products contributed highest proportions of 30.04, 26.76, and 14.46%, respectively. The inedible portion accounted for 1.17% of the total food waste. The statistical analyses revealed the non-significant difference (p = 0.3524) in food waste generation among the different housing systems. However, there were variations in the quantity of food waste type among the investigated housing systems. The outcomes of this study can further be explored for the estimation of embedded resources and environmental impacts of household food waste.

Surface oxidation of activated carbon pellets by hydrogen peroxide for preparation of CO2 adsorbent

Adedeji A. Adelodun,임윤희,조영민 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

This work attempted to use H2O2 as an oxidant for the incorporation of surface oxygen functionalities (SOFs) on activated carbon in the preparation of a CO2 adsorbent. Experimental results showed that oxidation at lowered temperature improved both structural and chemical properties more than those at ambient temperature, although oxidation at this temperature with 30% H2O2 incorporated the highest amount of useful SOFs for amination purpose. pHpzc value was most significantly reduced by altering the temperature either way while dilution seemed to have positive impact regarding this property. Pretreatment ultimately enhanced the selectivity for CO2 adsorption as well as its capacity.

Influence of Operation Conditions on the Performance of Non-thermal Plasma Technology for VOC Pollution Control

Adedeji A. Adelodun 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.92 No.-

The viability of non-thermal plasma (NTP) systems for the treatment of various VOC types was assessed. Also evaluated were the individual and collective influences of selected process parameters on the NTP-VOC systems’ performances. To this end, the process and performance evaluations of the reported NTP-VOC pairs, based on the established (VOC molecular weight, input voltage, specific input energy (SIE),flow rate, and degradation efficiency) and calculated (processing rate, system efficiency, cumulativeenergy density (e), and space-time yield) parameters were reported. With a catalyst, an increase in thegasflow rate enhanced the processing rate of the system by approximately 50%. At the same time, theinfluence of a on the byproducts remains unpredictable. Also, the correlation values of the processing rateagainst the system efficiency were significantly high and positive (0.9423). About 87% of the calculatedattributes correlated with the double-barrier discharge reactor. Theflow rate and input voltage evincedas the most influential parameters for all NTP-VOC systems. Moreover, the estimated e (J/L) is morereliable than the SIE for performance comparison. Conclusively, the processing rate, space-time yield, andenergy density are the derived attributes that should be considered before any NTP-VOC process design.

CMIP5 및 CMIP6모델의 연별 및 계절별 기후인자 모의 비교분석

바실아델러둔 ( Bashir Adelodun ),이슬기 ( Seulgi Lee ),미르자주네이드아흐메 ( Mirza Junaid Ahmad ),최경숙 ( Kyung Sook Choi ) 한국농공학회 2023 한국농공학회 학술대회초록집 Vol.2023 No.0

Increasing climate extremes have continued to impact on the socioeconomic well-being and ecosystems due to climate change. However, reliable projection of important climate variables such as precipitation and temperature are critical to develop adaptation, mitigation, and resilience strategies against various future climate change impacts. Thus, it is important to comprehensively evaluate the applicability of GCM models for effective representation and reliable projections of local climatic characteristics. This study evaluates the performance of 24 GCMs from the Coupled Model Intercomparison Project Phases 5 and 6 (11 from CMIP5 and 13 from CMIP6) and their multi-model ensembles to simulate precipitation, maximum (T_max), and minimum temperature (T_min) at annual and seasonal scales over Chungcheong region from 1975 to 2015. The inverse distance weighting and quantile delta mapping were applied to bias correct the GCM data. Six major evaluating indices comprising of Normalized root mean square error (NRMSE), Nash-Sutcliffe efficiency (NSE), and Modified Index of agreement (Mod_IoA) for temporal performance and Kling-Gupta Efficiency (KGE), Spatial efficiency metrics (SPAEF), Fraction skill score (FSS) for spatial performance assessment were used after which a comprehensive GCM ranking was applied. The overall results of the performance evaluation of bias-corrected GCMs showed that CMIP6 models performed better in simulating precipitation, T_max, and T_min at both temporal and spatial scales. For CMIP5, the top 3 performing GCMs are GISS, ACCESS1-3, and MRI-CGCM3 for precipitation; CanESM2, GISS, and MPI-ESM-L-R for T_max; and GFDL, MRI-CGCM3, and CanESM2 for T_min. However, the top 3 performing GCMs for CMIP6 are MRI-ESM2-0, BCC_CSM, and GFDL for precipitation; MIROC6, BCC_CSM, and MRI-ESM2-0 for T_max, and GFDL, MPI_ESM_HR, and MRI-ESM2-0 for T_min. Meanwhile, the multi-model ensembles (an average of top 3 GCMs) performed better in simulating historical precipitation and T_min for both CMIP5 and CMIP6 compared with multi-model ensembles (an average of all the GCMs), which only performed slightly better for simulating T_max. This study provides an insightful findings on the selection of appropriate GCMs to generate reliable climate projections for local climate in Chungcheong region of South Korea.

A Test of Relative Removal Properties of Various Offensive Odors by Zeolite

Adedeji A. Adelodun,Kowsalya Vellingiri,전병훈,오종민,Sandeep Kumar,김기현 한국대기환경학회 2017 Asian Journal of Atmospheric Environment (AJAE) Vol.11 No.1

The adsorptive removal properties of synthetic A4 zeolite were investigated against a total of 16 offensive odors consisting of reduced sulfur compounds (RSCs), nitrogenous compounds (NCs), volatile fatty acids (VFAs), and phenols/indoles (PnI). Removal of these odors was measured using a laboratory-scale impinger-based adsorption setup containing 25 g of the zeolite bed (flow rate of 100 mL min-1). The high est and lowest breakthrough (%) values were shown for PnIs and RSCs, respectively, and the maximum and minimum adsorption capacity (μg g-1) of the zeolite was observed for the RSCs (range of 0.77-3.4) and PnIs (0.06-0.104), respectively. As a result of sorptive removal by zeolite, a reduction in odor strength, measured as odor intensity (OI), was recorded from the minimum of approximately 0.7 OI units (indole [from 2.4 to 1.6]), skatole [2.2 to 1.4], and p-cresol [5.1 to 4.4]) to the maximum of approximately 4 OI units (methanethiol [11.4 to 7.5], n-valeric acid [10.4 to 6.5], i-butyric acid [7.9 to 4.4], and propionic acid [7.2 to 3.7]). Likewise, when removal was examined in terms of odor activity value (OAV), the extent of reduction was significant (i.e., 1000-fold) in the increasing order of amy acetate, ibutyric acid, phenol, propionic acid, and ammonia.