Search

Interplays between microalgae and clay minerals enhance biologically mediated flocculation, thereby affecting the sedimentation and transportation of suspended particulate matter (SPM) in water and benthic environments. This interaction forms larger flocs with a higher settling velocity and enhances SPM sinking. The aim of this study was to investigate the flocculation kinetics of microalgae and clay in suspension and to elucidate the mechanisms associated with such interactions. Standard jar test experiments were conducted using various mixtures of kaolinite and microalgal samples from batch cultures (Chlorella vulgaris) to estimate biologically mediated flocculation kinetics. The organic matter (OM) composition secreted by the microalgae was characterized using a liquid chromatography - organic carbon detection system, and quantitative analysis of transparent exopolymer particles was conducted separately. A two-class flocculation kinetic model, based on the interaction between flocculi and flocs, was also adopted to quantitatively analyze the experimental data from flocculation. Results from the flocculation kinetic tests and OM analyses, in association with other data analyses (i.e., floc size distribution and flocculation kinetic model), showed that flocculation increased with OM concentration during the growth phase (10-20 d). However, on day 23 during the early stationary phase, flocculation kinetics started decreasing and substantially declined on day 30, even though the amount of OM (mainly biopolymers) continued to increase. Our results indicate that an adequate quantity of biopolymers produced by the microalgal cells in the growth phase enhanced floc-to-floc attachment and hence flocculation kinetics. In contrast, an excessive quantity of biopolymers and humic substances in the stationary phase enhanced the formation of polymeric backbone structures and flocculation via scavenging particles but simultaneously increased steric stabilization with the production of a large number of fragmented particles.

East Asian summer monsoon (EASM)-driven rapid hydroclimatic variation is a crucial factor with major socioeconomic impacts. Nevertheless, decadal- to centennial-scale EASM variability over the last two millennia is still poorly understood. Pollen-based quantitative annual precipitation (PqPann) and annual precipitation reconstructed by artificial neural networks (ANNs) for the period 650–1940 CE were reconstructed from a paleo-reservoir in South Korea. ANNs reconstruction was performed to compensate for a hiatus section. On a decadal timescale, 10 high-precipitation periods were identified, and PqPann and ANNs reconstructions were comparable to local instrumental rainfall and historic drought records. Biotic lags to rapid climatic changes ranging from 25 to 100 years were recognized by asynchronous pollen and speleothem responses to precipitation. We suggest that PqPann-based decadal- to centennial-scale climatic change reconstruction should take biotic lags into account, although the lags can be ignored on the millennial scale. The position of the EASM rainband influenced rainfall magnitude.

Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investig...

Lagoons are natural bodies of water that are isolated from the sea due to the development of a sand bar or spit. Each lagoon has distinct ecological characteristics, and these sites also serve as popular tourist attractions because they are common habitats for migratory birds and are characterized by beautiful natural scenery. Lagoons also have distinct ecological characteristics from those of their associated estuaries, and there are active research efforts to classify, qualify, and quantify the high biodiversity of lagoons. The lagoons in Korea are primarily distributed in the East Sea, and are represented by Hwajinpo, Yeongrangho, and Gyeongpoho. Here, we report the discovery of 11 unrecorded diatom species (Diploneis didyma, Mastogloia elliptica, Cosmioneis citriformis, Haslea crucigera, Pinnularia bertrandii, Pinnularia nodosa var. percapitata, Gyrosigma sinense, Gomphonema guaraniarum, Gomphonema italicum, Navicula freesei, Trybionella littoralis var. tergestina) among samples collected from the Hwajinpo, Hyangho, Maeho, Gapyeongri wetland, Cheonjinho, and Gyeongpoho lagoons in Korea during a survey from 2018–2020. We present the taxonomic characteristics, ecological information, habitat environmental conditions, and references for these 11 species.

Suncheonman Bay, Korea’s most representative estuary, is an invasive coastal wetland composed of 22.6 km2 of tidal flats surrounded by the Yeosu and Goheung Peninsulas. In January 2006, this region was registered in the Ramsar Convention list in Korea, representing the first registered wetland. Estuaries are generally known to have high species diversity. In particular, several studies have been conducted on planktonic and epipelic diatoms as primary producers. Suncheonman Bay has already been involved in many biological and geochemical studies, but fossil diatoms have not been evaluated. Therefore, we investigated fossil diatoms in Suncheonman Bay and introduced sub-fossil diatoms recorded in Korea. One sedimentary core has been extracted in 2018. We identified 87 diatom taxa from 52 genera in the SCW03 core sample. Of these, six species represent new records in Korea: Cymatonitzschia marina, Fallacia hodgeana, Navicula mannii, Metascolioneis tumida, Surirella recedens, and Thalassionema synedriforme. These six newly recorded diatom species were examined by light microscopy and scanning electron microscopy. The ecological habitats for all the investigated taxa are presented.

The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.

The dinoflagellate genus Scrippsiella is a common member of phytoplankton and their cysts are also frequently reported in coastal sediments worldwide. However, the diversity of Scrippsiella in Korean waters has not been fully investigated. Here, several isolates of Scrippsiella precaria collected from Korean waters and germinated from resting cysts were examined using light and scanning electron microscopy. The resting cysts were characterized by pointed calcareous spines and one or two red accumulation bodies, and the archeopyle was mesoepicystal, representing the loss of 2–4′ and 1–3a paraplates. Rounded resting cysts were found in culture, and an increase in spine length was observed until 8 days of development. Korean isolates of S. precaria had the plate formula of Po, X, 4′, 3a, 7″, 6C, 4S, 5‴, 2⁗. There were differences in the cell size and location of the red body between Korean isolates and previously described cells of S. precaria. In addition, the Korean isolates of S. precaria had two types of the 5″ plate that either contacted the 2a plate or not. Molecular phylogeny based on internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences revealed that the Korean isolates were nested within the subclade of PRE (S. precaria and related species) in the clade of Scrippsiella sensu lato, and that the PRE subclade had two ribotypes: ribotype 1 consisting of the isolates from Korea, China, and Australia, and ribotype 2 consisting of the isolates from Italy and Greece. Lineages between isolates of ribotype 1 were likely to be related to the dispersal by ocean currents and ballast waters from international shipping, and the two types of spine shapes and locations of the 5″ plates may be a distinct feature for ribotype 1.

The paleoenvironmental history of the artificial Reservoir Gonggeomji in Sangju City, Korea, was reconstructed using fossil diatom analysis of four sediment cores: GG01, 02, 03, and 04. Accelerator mass spectrometer (AMS) radiocarbon dating results suggest that Reservoir Gonggeomji was maintained from ca. 1350 to 150 cal year BP, and the diatom record in core sediment samples revealed well-defined hydrological changes and paleoenvironmental conditions during this period. The fossil diatom assemblages were predominantly benthic freshwater diatoms. The highest diatom concentrations in all cores were in diatom zone II, in which species richness and diversity were also very high. Cymbella, Eunotia, Gomphonema, Gyrosigma, Navicula, and Pinnularia were the dominant genera in all core sediments. The long-term trend in diatom species abundance and species diversity showed a stronger relationship to temperature anomalies in the northern hemisphere during the past 2000 years with changes in precipitation. These diatom changes could have been controlled by natural climate change, despite anthropogenic activities linked to construction of the dyke in the artificial reservoir.

As part of an effort to prepare a refrigerant with zero ozone depletion potential (ODP) and with a low global warming potential (GWP), the catalytic dehydrofluorination of 1,1,1,2,3-tetrafluoropropane (HFC-245eb) is performed to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf). Cr2O3 prepared by the sol-gel method (Cr2O3(SG)) exhibits good catalytic activity attributable to the formation of surface chromium oxyfluoride, which exhibits better catalytic activity with high-valent chromium and a larger fluorine content. The formation of chromium oxyfluoride from chromium oxide is achieved by in-situ fluorination in the early stage of dehydrofluorination, avoiding the conventional fluorination method using toxic HF.

Zn(OAc)2-catalyzed carbonylation and decarboxylation of glycerol and urea for the synthesis of glycidol were conducted at 150 °C, 2.7 kPa for 2 h and 170 °C, 2.0 kPa for 1.5 h, respectively. When the reaction conducted in a one-pot consecutive way, the yield of glycidol was 20%. However, when the formed zinc glycerolate (Zn(C3H6O3)) was filtered out after the carbonylation, the yield increased to 50% with respect to the amount of glycerol, whereas the yields of glycidol were very low when other zinc salts such as ZnCl2, ZnSO4 and Zn(NO3)2, were used as catalysts. The high catalytic activity of Zn(OAc)2 for this carbonylation and decarboxylation of glycerol and urea could be ascribed to the formation of Zn(NH3)x(OAc)2, which was determined from IR and TOF-SIMS studies.

Thalassiosira species are an important component of phytoplankton populations, and most species are considered cosmopolitan. Many authors have investigated the diversity of Thalassiosira species in order to understand their ecological roles in local areas. Our regional taxonomic study revealed the presence of 44 Thalassiosira species at 124 sites in Korean coastal waters. Of these, 14 species are newly reported in Korean waters and are described in detail with external and internal valve illustrations. Some morphologically confused taxa, such as the Thalassiosira s.s. group, T. curviseriata/T. tealata, T. simonsenii/Planktoniella blanda and T. proschkinae/T. spinulata, are clearly distinguished using additional morphological criteria. In addition, the full biogeographical distribution of Thalassiosira is described and compared with the Korean species. Korean waters seem to be the ‘Maginot Line' for the cold- and warm-water Thalassiosira species. Knowledge of Thalassiosira species diversity will ...

The effects of the addition of nutrients (nitrate: N, phosphate: P, and vitamin B1) and trace metals (iron: Fe, Copper: Cu, and selenium: Se) on the growth of Gymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The Korean isolate of G. catenatum grew under a wide range of concentrations of N and P. Whilst high concentrations of N (&gt, N: P ratio of 23.5) did not stimulate the growth rate, an enhanced growth rate and cell density were observed with the addition of P. The experimental addition of vitamin B1 revealed that G. catenatum is not dependent on vitamin B1 for growth. Moreover, the addition of Fe and Cu resulted in no significant differences in the growth patterns and rates of G. catenatum between the controls and treatments. It is thus possible that growth of the Korean isolate of G. catenatum does not require high concentrations of Fe and Cu. However, the cell densities were enhanced in the stationary phases of treatments upon addition of Se, and the maximum cell densities were higher than those in the culture experiments upon additions of other nutrient and trace metals. Our findings indicate that G. catenatum prefers P and Se for proliferation, rather than other nutritional sources.

Both DABCO (1,4-diazabicyclo[2.2.2]octane) and Merrifield resin-anchored DABCO ([p-DABCO]Cl), prepared from the reaction of DABCO and Merrifield resin, were found to exhibit high activities for the transesterification of dimethyl carbonate (DMC) with glycerol to produce glycerol carbonate (GLC). FT-IR and NMR spectroscopic results suggest that such a high transesterification activity of DABCO could be attributed to its superior ability to activate glycerol via a strong hydrogen bond formation between a hydroxyl group of glycerol and an amino group of DABCO. Meanwhile, the activation of glycerol by [p-DABCO]Cl proceeds mainly through the hydrogen bond interaction between a hydroxyl group or groups of glycerol and Cl− of [p-DABCO]Cl. The catalytic activity of [p-DABCO]Cl was maintained up to 5 reuses, demonstrating that [p-DABCO]Cl could be used as a recyclable heterogeneous catalyst.

Three kinds of lanthanum oxides (La2O3) were synthesized from different methods and used as a catalyst in the transesterification of dimethyl carbonate (DMC) with glycerol for the synthesis of glycerol carbonate (GLC). Lanthanum oxide synthesized using a surfactant (S-La) showed a much higher GLC yield of 89.9% compared to other lanthanum oxides synthesized by calcination (C-La) and precipitation (P-La) at the reaction conditions of 90 °C, DMC/glycerol = 2, and catalyst/glycerol = 5 wt %. The best catalyst was obtained when the surfactant/La weight ratio was 12. XRD study revealed that S-La has large amount of monoclinic and hexagonal La2O2CO3 phases, which are assumed as active sites of the catalyst for the reaction.

Our objective was to select setae ultrastructure characteristics as identification criteria for Chaetoceros subgenus Hyalochaete. We sampled 53 Korean coastal water locations and three Chukchi Sea, Arctic Ocean sites, and we studied 22 species using light microscopy and scanning electron microscopy. We selected 12 criteria for species-specific identification: (1) point of fusion of the sibling setae, (2) spine form, (3) poroid shape, (4) spine arrangement, (5) poroid arrangement, (6) number of poroid rows per μm along the setae, (7) special intercalary setae, (8) connecting bridge-like structure on the basal part of the intercalary setae, (9) siliceous capilli on the basal part of the setae, (10) setae cross-sectional shape, (11) silicification of the setae wall and (12) direction of setae to the chain axis. Using these criteria, we constructed a dichotomous key to aid species-specific identification in the subgenus Hyalochaete.

Chaetoceros atlanticus var. koreanus, a new variety of C. atlanticus, was collected from the East Sea of Korea on 20 August 2013. Its morphological characteristics were examined from wild material, and the new variety was compared with three closely related taxa, C. atlanticus var. atlanticus, C. atlanticus var. neapolitanus and C. atlanticus var. skeleton. The new taxon belongs to the subgenus Chaetoceros, which is characterized by numerous granular chloroplasts in the setae as well as the body of the cell and a rimoportula on each valve, and to the section Atlantica, which is characterized by a long tubular external rimoportula at the centre of each valve, terminal and intercalary setae differing in length and direction, and wide hexagonal apertures. Chaetoceros atlanticus var. koreanus shares its general morphological characteristics with three closely related species, but has rows of small poroids forming a grid pattern, a tetragonal cross-section, and perpendicular costae on the setae. These features...

As the seriousness of the global environment pollution is gaining our attention recently, researches on application of greenhouse gas emission of ship are being carried globally. However domestic study on greenhouse gas emission from ship was not carried out in various fields. In this study, quantitative data which was presented by greenhouse gas emission of training ship HANBADA and greenhouse gas emission was cal-culated by Tier 1 method based on total fuel consumption and amount of shore power. Actual voyage data for 1year in 2012 was used to analysis the greenhouse gas emission. This study showed how many weight of gases were exhausted per 1 gross tonnage and per 1trainee in the training ship. There is a need of further re-search to reduce pollutant and to respond to international environment regulation consistently. Keywords: Environment pollution, Greenhouse gas, Tier 1, Fuel consumption, Shore electricity 1. 서 론 기후변화에 관한 정부간 협의체(IPCC)는 제 4차 보고서 [1] 를 통해서 21세기 기후변화의 가속화 전망을 제시하고 있으며, 현재와 같이 지속적으로 화석연료를 사용한다면 21세기 말까지 지구평균기온이 2.4∼6.4℃ 상승하고, 해수면은 26~60cm 상승할 것으로 전망하고 있다

For floristic study on diatoms from the source of Han and Nakdong Rivers, we collected samples in February, April, and July 2016 from Geomryongso and Neodeolsam Ponds, South Korea. Geomryongso and Neodeolsam Ponds are sources of Han and Nakdong Rivers, respectively. Thirty-eight infrageneric taxa of freshwater diatoms were identified in the collected samples from study areas. The diatom species were classified into 25 genera, 17 families, 10 orders, 5 subclasses, and 2 classes based on the taxonomic system proposed by Round et al . (1990). Nine diatom taxa— Achnanthes sinaensis , Achnanthidium atomus , Edtheriotia guizhoiana , Fragilaria recapitellata , Gyrosigma procerum , Navicula nipponica , Pinnularia pseudotabellaria , Pinnularia rabenhorstii , and Platessa barhlsii —were newly recorded, whose taxonomic features have been described; they are indicated by asterisk. We presented the taxonomic information, including the systematics, and dimension in the source of two major rivers in Korea. This study might contribute to the understanding of diversity and flora of diatoms in various freshwater environments in Korea.

Since bio-diesel oil has a merit that it satisfies both demand of substitution for fossil fuel and reduction in carbon dioxide emission, it is widely used in diesel engines by blending in gas oil in small quantity. It is needed to reduce in NOx emission in some way or others if blending ratio of bio-diesel oil is going to increase, because it is demerit that bio-diesel oil emits more NOx emission than gas oil. In this study, it was accomplished to optimize 3 factors what effect on NOx emission as blending ratio of bio-diesel oil, injection timing and common rail pressure with an introduction of a design of experiments, in order to minimize a number of tests. It was cleared that to introduce the design of experiments was very available in NOx optimization. Key Words ：Bio-diesel Oil, NOx, Diesel Engine, Design of Experiments, Optimization ****†정석호(교신저자) : 부경대학교 기계시스템공학과E-mail : sukhojung@pknu.ac.kr, Tel : 051-629-6198 *이상득 : 한국해양대학교 실습운항원**김경현 : 부경대학교 탐양호***이한성 : 동주대학교 자동차·기계과****†Suk-Ho Jung(corresponding author) : Department of Mechanical System Engineering, PuKyong University.E-mail : sukhojung@pknu.ac.kr, Tel : 051-629-6198 *Sang-Deuk Lee : Sea training center **Kyong-Hyon Kim : TamYangHo, PuKyong University.***Han-Seong Lee : Department of Vehicle & Mechanical Engineering, DongJu University.

In environmental friendly aspects, the synthesis of glycerol carbonate from glycerol using carbon monoxide and oxygen gases which were produced in petrochemical plants was studied. The oxidative carbonylation of glycerol under batch reaction system was performed on parameter conditions such as effect of various metals (Cu, Pd, Fe, Sn, Zn, Cr), oxidizing agents, mole ratio of carbon monoxide to oxygen, catalyst amount, solvent types, reaction temperature and time and dehydrating agents. In particular copper chloride catalysts showed the excellent activities, and the glycerol carbonate yields over CuCl and CuCl2 catalysts were the maximum of 44% and 64%, respectively at the following reaction conditions: solvent as nitrobenzene, mole ratio of 1:3:0.15 (glycerol:carbon monoxide:catalyst), mole ratio of 2:1 (carbon monoxide:oxygen), the total pressure of 30 bar at 413 K for 4 hr. It was found that reactivity were significantly different depending on the oxidation number of Cu catalysts, and oxygen plays an important role as oxidizing agents in producing H2O during oxidation reaction after carbonylation of glycerol.

* Graduate School of Korea Maritime University, Busan, Korea** Department of Ship Operation, Korea Maritime University, Busan, Korea*** Korea Marin Equipment Research Institute, Busan, Korea**** Korean Register of Shipping, Busan, Korea***** Sea Training Center, Korea Maritime University, Busan, Korea****** Department of Power System Equipment, Kunsan National University, Jeonbuk, 573-701, Korea******* Division of Marine System Engineering, Korea Maritime University, Busan, Korea 요 약 : 본 연구에서는 국제해사기구(IMO)의 뜨거운 관심분야로 부상되고 있는 선박기인 입자상물질(PM)과 오염물질 배출에 관하여 한국해양대학교 실습선 한바다호를 이용하여 계측하였다. 특히, PM은 TEM 그리드를 이용해 채취하고 전자현미경으로 구조를 파악하였으며, NOx, CO

Many researches on green ship with increasing on economics, efficiency and convenience have been carried out consistently. One of them is development of diesel engines with electronic control. While small duty one for automobiles had been adopted mainly already, disseminating heavy duty one for ships has trouble due to safety and reliability. In order to solve these problem in this study, performance of electronic control and cam type engine installed in parallel on training ship HANBADA of korea maritime university was analyzed and compared. It is certain that specific fuel oil consumption of the electronic control type is lower than cam type and excellent at lower engine load, especially. And the electronic control type shows more effective characteristic at sea trial on specific fuel oil consumption.

Graduate School of Korea Maritime University, Busan, 606-791, Korea Department of Ship Operation, Korea Maritime University, Busan, 606-791, Korea Korean Register of Shipping, Busan, 618-814, Korea Division of Marine System Engineering, Korea Maritime University, Busan, 606-791, Korea 요 약 : 본 연구에서는 한국해양대학교 실습선 한바다를 이용하여 선박의 입 출항 및 약 150 rpm의 정속 운항 할 때 주기관에서 배출되는 배기가스를 실시간 계측하였다. 실측 결과 질소산화물의 농도는 정속 운항시 800ppm 에서 1,000ppm 사이인데 반해, 입 출항시에는 210ppm에서 1,230ppm까지 큰 범위에서 값이 변화하였다. 일산화탄소의 농도 역시 정속운항 상태 보다 입 출항시 측정값의 변화가 크게 나타났다. 이러한 결과는 입 출항시 가능한 한 주기관의 부하변동이 급격히 발생되지 않도록 하는 선박 조종 스킬이 필요하다는 것을 의미한다. 또한, 배기가스 저감 기술의 적용에 있어 입 출항시와 정속 운항할 때 그 차이를 고려할 필요가 있다는 것을 나타낸다.핵심용어 : 배기 배출물, 이산화탄소, 질소산화물, 주기관, 저감 기술Abstract : In this study, we conducted real-time measurement at the ship arrivals and departures at the port and at a constant speed of 150rpm for exhaust emissions from a main engine installed on the training ship, HANBADA, of Korea Maritime University. The result showed that the concentration of nitrogen oxide was measured in the range of 800ppm to 1,000ppm at constant speed mode . On the other hand, the concentration of nitrogen oxide during ship arrivals and departures was significantly fluctuated between 210ppm and 1,230ppm. And, the concentration of carbon oxide at the arrivals and departures was also larger than that of at constant speed mode. These results show that the ship maneuvering skills to prevent a sudden load change of main engine at the arrivals and departures of ship is needed. Additionally, it means that the difference of exhaust emissions generated between the constant speed mode and the arrival/departure has to be considered when invented many technologies are adopted into the reduction technologies of air pollutants from ships. Key Words : Exhaust emission, Carbon dioxide, Nitrogen Oxides, Main engine, Reduction technology

Many researches have been carried out consistently for the green ship owing to its economic increasement, efficiency and convenience. One of them is an electronic controlled marine diesel engine. However, we are suffered from dissemination of above engine, due to its anxiety about safety and reliability. In order to solve these problems in this study, emission characteristics test of main propulsive two-stroke diesel engine, equipped both electronic control and cam drive fuel injection systems, has been performed and evaluated under the various load conditions. From the test results, we have confirmed that exhaust gas emission characteristics of the electronic control system is similar to the cam drive system in eco-mode operation, but NOx in emission mode has been decreased 100ppm or more in full load condition. HC emission from the electronic control system is decreased 10~20ppm at 50% load, and 35~40ppm at 25% load in comparison to cam drive system. In fuel consumption, it is considered that 7g/kWh is decreased than the value of cam drive system at 700bar of injection pressure, which is 200bar higher than cam drive system.

In order to judge that non-esterified soybean oil could be used on diesel engine with electronic control of fuel injection system, The test of combustion performance using only gas oil, gas oil blended with esterified bio-diesel oil 5% and non-esterified soybean oil 5% were carried out. It is noticed that most performances of gas oil blended with esterified bio-diesel oil 5% and non-esterified 5% have similar characteristics but non-esterified bio-diesel oil 5% emitted smaller NOx, resulting from fuel NO. Keywords: Bio-diesel oil, Esterified, Non-esterified, Common rail direct injection, Diesel engine 1. 서 론 바이오 매스는 탄소의 증감이 0이 된다는 탄소중립(Carbon neutral)의 이점을 가지고 있다. 그래서탄소배출의 규제에 맞추어 탄소배출의 상당 부분을 차지하는 수송기계의 연료에 사용할 수 있는 바이오 연료에 대한 연구 [1]-[3] 가 활발하며 그 사용량 또한 증가되어 가고 있다. 특히, 디젤기관에사용되는 경유의 대체 바이오 연료인 바이오 디젤유는 2009년 우리나라 전체 디젤유의 1.5%가 될정도로 많이 사용되고 있고 장기적으로는 경유(GO)에 5% 혼합하여 사용할 계획을 세워 놓았다 [4] . 그러나 현재의 바이오 디젤유는 식물유 또는폐식용유를 메탄올과 반응시켜 에스테르화하는 공정 때문에 경제적 단점을 지니고 있다. 이에 폐식용유를 단순히 정제시켜 GO와 혼합한 비에스테르화 바이오 디젤유를 사용하여 캠타입 디젤기관에 이용, 경제적 측면에서의 장점을 부각시킨 연구가진행되었었다

Decarboxylation of glycerol carbonate (GLC) to produce 2,3-epoxy-1-propanol (glycidol) was conducted using various kinds of ionic liquids (ILs) as catalysts. ILs bearing an anion with medium hydrogen-bond basicity such as NO3- and I− exhibited the higher glycidol yields than those having an anion with low or strong hydrogen-bond. FT-IR spectroscopic analysis shows that both GLC and glycidol interact with anions of ILs through their hydroxyl groups. It was possible to improve the yield of glycidol when a zinc salt with a medium Lewis acidity was co-present along with an IL. The yield of glycidol was greatly increased up to 98% when the decarboxylation was conducted in the presence of a high-boiling aprotic solvent. Computational calculations on the mechanism using 1-butyl-3-methylimidazolium nitrate as a catalyst revealed that the first step is the NO3--assisted ring-opening of GLC followed by the ring closure, resulting in the formation of a 3-membered ring intermediate species.

The combination of a photovoltaic (PV) and an electrolytic cell into one single system, a monolithic PV-electrolytic cell, has been suggested as an efficient solar hydrogen generation system. In this study, we demonstrate an efficient prototype electrolysis system applied to a monolithic PV-electrolytic cell. Specifically, the relatively large unit cell (active area of 36 cm2) used in the study made it possible to directly measure in volume the amount of hydrogen and oxygen generated. To enhance the activity of the electrodes we introduced channels, Co3O4 film, and Pt particles on stainless steel (SUS) substrates. The highest hydrogen production rate was obtained in the system in which Co3O4 electrocatalytic film on a SUS foil and Pt particles on a SUS plate with channels were used as an anode and a cathode, respectively.