• Title/Summary/Keyword: Green Hydrogen

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EV Energy Convergence Plan for Reshaping the European Automobile Industry According to the Green Deal Policy (그린딜 정책에 따른 유럽자동차 산업재편의 EV 에너지 융합방안)

  • Seo, Dae-Sung
    • Journal of Convergence for Information Technology
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    • v.11 no.6
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    • pp.40-48
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    • 2021
  • The paper dealt with the fact that the green deal took place when the demand for electrical energy surged. However, the procurement of electric vehicles and much of the electric energy of the future still depends on fossil fuels. Accordingly, the importance of the IT industry is highlighted, and the demand for hydrogen-electric vehicles and related industries increases. The method of this study investigated the relevance of EV charging as a future next-generation power source rather than the electric energy demand of the IT industry. This study derives the correlation between industrial electricity and household energy PPP according to economic growth through empirical regression analysis. As the result, it was found that the amount of change, including electric and next-generation electric vehicles, was significant for on thirds of the countries in the change in purchasing power compared to GDP. This affects overall purchasing power as twelve out of thirty two countries with EV demand (Italy, Canada, Switzerland, Poland, Slovenia, Germany, Slovakia, Finland, Sweden, Czech Republic, Estonia, Denmark) are more sensitive to electric energy. This is related to the charging of EVs or hydrogen as the next-generation power of the future rather than the electric energy demand of the IT industry. By preventing waste of unused electricity of IT-electric energy sources and charging-preserving hydrogen electricity, it seems indispensable to prepare for the national IT power conservation buffer facility for supply and demand in future growth.

Microbial Reduction of Fresh Vegetables by Treatment of Sanitizing Reagents (살균제의 처리에 의한 신선엽채류의 미생물 감소)

  • Park Heon-Kuk;Kim Sang-Bum
    • The Korean Journal of Food And Nutrition
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    • v.17 no.4
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    • pp.436-441
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    • 2004
  • As the production of agricultural products showing high quality and environmental safety is required increasingly these days, it is really necessary to study on technology for producing agricultural products which are safe microbiologically. Among several sanitizing reagents contacted easily, we investigated the most effective and useful method for reducing microorganisms by sanitizer treatment. From this study, it was showed that treatment of 3% hydrogen peroxide solution over 1 minute, which decreased microbiological level less than one tenth of natural state(no sanitizer treatment) in all microorganisms tested, was the most effective sanitizing method to green vegetables, especially raw lettuce used in this study, for reducing microorganisms. By utilizing this sanitizing method in farming step, the improvement of safety and added value of agricultural products, especially raw green vegetables, is expected.

Effects of Calcination Temperature on Characteristics of Electrospun TiO2 Catalyst Supports for PEMFCs (열처리 온도가 전기방사방법을 이용하여 제조한 PEMFC용 TiO2 담체의 물리적 특성에 미치는 영향)

  • Kwon, Chorong;Yoo, Sungjong;Jang, Jonghyun;Kim, Hyoungjuhn;Kim, Jihyun;Cho, Eunae
    • Journal of Hydrogen and New Energy
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    • v.24 no.3
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    • pp.223-229
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    • 2013
  • Polymer Electrolyte Membrane Fuel Cell (PEMFC) is a power generation system to convert chemical energy of fuels and oxidants to electricity directly by electrochemical reactions. As a catalyst support for PEMFCs, carbon black has been generally used due to its large surface area and high electrical conductivity. However, under certain circumstances (start up/shut down, fuel starvation, ice formation etc.), carbon supports are subjected to serve corrosion in the presence of water. Therefore, it would be desirable to switch carbon supports to corrosion-resistive support materials such as metal oxide. $TiO_2$ has been attractive as a support with its stability in fuel cell operation atmosphere, low cost, commercial availability, and the ease to control size and structure. However, low electrical conductivity of $TiO_2$ still inhibits its application to catalyst support for PEMFCs. In this paper, to explore feasibility of $TiO_2$ as a catalyst support for PEMFCs, $TiO_2$ nanofibers were synthesized by electrospinning and calcinated at 600, 700, 800 and $900^{\circ}C$. Effects of calcination temperature on crystal structure and electrical conductivity of electrospun $TiO_2$ nanofibers were examined. Electrical conductivity of $TiO_2$ nanofibers increased significantly with increasing calcination temperature from $600^{\circ}C$ to $700^{\circ}C$ and then increased gradually with increasing the calcination temperature from $700^{\circ}C$ to $900^{\circ}C$. It was revealed that the remarkable increase in electrical conductivity could be attributed to phase transition of $TiO_2$ nanofibers from anatase to rutile at the temperature range from $600^{\circ}C$ to $700^{\circ}C$.

Biohydrogen Production from Food Waste by Two-Stage (Lactate+Photo)-Fermentation Process (2단(유산발효+광발효) 발효공정을 통한 음식물쓰레기로부터의 수소생산)

  • Kim, Ok-Sun;Son, Han-Na;Kim, Dong-Hoon;Jeon, Dong-Jin;Rhee, Young-Woo;Kim, Mi-Sun
    • Journal of Hydrogen and New Energy
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    • v.22 no.3
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    • pp.333-339
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    • 2011
  • In the present work, it was attempted to produce $H_2$ from food waste by the two-stage fermentation system. Food waste was acidified to lactate by using indigenous lactic acid bacteria under mesophilic condition, and the lactate fermentation effluent (LFE) was subsequently converted to $H_2$ by photo-fermentation. $Rhodobacter$ $sphaeroides$ KD131 was used as the photo-fermenting bacteria. The optimal conditions for lactate fermentation were found to be pH of 5.5 and substrate concentration of 30 g Carbo. COD/L, under which yielded 1.6 mol lactate/mol glucose. By filtering the LFE and adding trace metal, $H_2$ production increased by more than three times compared to using raw LFE, and finally reached the $H_2$ yield of 3.6 mol $H_2$/mol lactate. Via the developed two-stage fermentation system $H_2$ yield of 5.8 mol $H_2$/mol glucose was achieved from food waste, whose value was the highest that ever recorded.

A Study on the NOx Emission Characteristics of HCNG Engine (HCNG 엔진의 NOx 배출특성에 관한 연구)

  • Park, Cheol-Woong;Kim, Chang-Gi;Choi, Young;Won, Sang-Yeon;Lee, Sun-Youp
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.4
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    • pp.78-83
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    • 2011
  • Natural gas is one of the most promising alternatives to gasoline and diesel fuels because of its high thermal efficiency and lower harmful emissions, including $CO_2$. Although the high octane value of natural gas increases engine output and efficiency due to the high compression ratio, this fuel is prone to such difficulties as a narrow limit of inflammability and a slow combustion speed in the lean burn operation domain, leading to unstable combustion and higher emissions of harmful exhaust gases. Hydrogen blended with natural gas can extend the lean burn limit while maintaining stable, efficient combustion and achieving lower NOx, hydrocarbon and green house gas emissions. In this study, the effect of hydrogen addition on an engine performance and NOx emission characteristics was investigated in a heavy duty natural gas engine. The results showed that thermal efficiency was increased and NOx emissions were reduced due to the expansion of lean operation range under stable operation. NOx emission can be significantly reduced with the retard of spark advance timing.

Antioxidant Activity of Solubilized Tetraselmis suecica and Chlorella ellipsoidea by Enzymatic Digests

  • Lee, Seung-Hong;Chang, Dong-Uk;Lee, Bae-Jin;Jeon, You-Jin
    • Preventive Nutrition and Food Science
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    • v.14 no.1
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    • pp.21-28
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    • 2009
  • In this study, we focused on natural water-soluble antioxidants from Tetraselmis suecica (T. suecica) and Chlorella ellipsoidea (C. ellipsoidea). They were prepared by enzymatic digestion using five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Alcalase, Flavourzyme, Neutrase, and Kojizyme), and the potential antioxidant activity of each was assessed. Most enzymatic digests from T. suecica had a higher radical scavenging activity than those from C. ellipsoidea. Among the enzymatic digests, Kojizyme digest from T. suecica exhibited the highest effect on DPPH radical scavenging. Viscozyme (30.2%) and Neutrase (34.6%) digests from T. suecica exhibited higher hydroxyl radical scavenging activity. Kojizyme digest from T. suecica (81.5%) had strong alkyl radical scavenging activity. Neutrase (61.9%) and Kojizyme (61.5%) digest from T. suecica possessed the highest effects on hydrogen peroxide scavenging. Among the tested samples, Neutrase (TN) and Kojizyme (TK) digests from T. suecica showed the highest antioxidant activity (DPPH, alkyl radical, hydrogen peroxide). Therefore, TN and TK digests were selected for use in the further experiments. Those digests showed enhanced cell viability against $H_2O_2$-induced oxidative damage, and relatively good hydrogen peroxide scavenging activity in an African green monkey kidney (Vero) cell line. These results suggested that an enzymatic digestion will be an effective way for the production of a potential water-soluble antioxidant from a microalgae, T. suecica.

Fabrication and Properties of Porous Tungsten by Freeze-Drying Process (동결건조 공정을 이용한 텅스텐 다공체의 제조 및 특성)

  • Lee, Young-Sook;Oh, Sung-Tag
    • Korean Journal of Materials Research
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    • v.21 no.9
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    • pp.520-524
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    • 2011
  • Porous W with controlled pore characteristics was fabricated by a freeze-drying process. $WO_3$ powder and camphene were used as the source materials of W and sublimable vehicles, respectively. Camphene slurries with $WO_3$ contents of 10 and 15 vol% were prepared by milling at $50^{\circ}C$ with a small amount of oligomeric polyester dispersant. Freezing of a slurry was done in a Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$ while the growth direction of the camphene was unidirectionally controlled. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $800^{\circ}C$ for 30 min and sintered in a furnace at $900^{\circ}C$ for 1 h under a hydrogen atmosphere. Microstructural observation revealed that all of the sintered samples were composed of only W phase and showed large pores which were aligned parallel to the camphene growth direction. The porosity and pore size increased with increasing camphene content. The difference in the pore characteristics depending on the slurry concentration may be explained by the degree of powder rearrangement in the slurry. The results strongly suggest that a porous metal with the required pore characteristics can be successfully fabricated by a freeze-drying process using metal oxide powders.

Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide

  • Abdel-Monaim, Montaser Fawzy
    • Mycobiology
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    • v.41 no.1
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    • pp.47-55
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    • 2013
  • Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination between biocontrol agents and chemical inducers recorded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in field.

Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

  • Sarkar, Shuranjan;Moon, Do-Hyun;Lah, Myoung-Soo;Lee, Hong-In
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3173-3179
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    • 2010
  • New complex $[Mn(II)H_{1.5}L]_2[Mn(II)H_3L]_2(ClO_4)_5{\cdot}3H_2O$ (1), where $H_3L$ is tris {2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of $[Mn(II)H_{1.5}L]^{0.5+}$ complex ions are extended to build a 2D puckered network with trigonal voids. $[Mn(II)H_3L]^{2+}$ complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of $ABTS^{+{\cdot}}$ was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

Fabrication of Porous Ni by Freeze Drying and Hydrogen Reduction of NiO/Camphene Slurry (NiO/camphene 슬러리의 동결건조 및 수소환원 공정에 의한 Ni 다공체 제조)

  • Jeong, Jae-Hun;Oh, Sung-Tag;Hyun, Chang-Yong
    • Journal of Powder Materials
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    • v.26 no.1
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    • pp.6-10
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    • 2019
  • In this study, freeze drying of a porous Ni with unidirectionally aligned pore channels is accomplished by using a NiO powder and camphene. Camphene slurries with NiO content of 5 and 10 vol% are prepared by mixing them with a small amount of dispersant at $50^{\circ}C$. Freezing of a slurry is performed at $-25^{\circ}C$ while the growth direction of the camphene is unidirectionally controlled. Pores are generated subsequently by sublimation of the camphene during drying in air for 48 h. The green bodies are hydrogen-reduced at $400^{\circ}C$ and then sintered at $800^{\circ}C$ and $900^{\circ}C$ for 1 h. X-ray diffraction analysis reveals that the NiO powder is completely converted to the Ni phase without any reaction phases. The sintered samples show large pores that align parallel pores in the camphene growth direction as well as small pores in the internal walls of large pores. The size of large and small pores decreases with increasing powder content from 5 to 10 vol%. The influence of powder content on the pore structure is explained by the degree of powder rearrangement in slurry and the accumulation behavior of powders in the interdendritic spaces of solidified camphene.