• Environmental and Resource Economics Review
• /
• v.16 no.3
• /
• pp.653-682
• /
• 2007

In this study, multi-sectoral partial equilibrium and computable general equilibrium models of Taiwan are used to investigate the direct and indirect effects of energy price increases on overall economies and agro-food sector in Taiwan. The results suggest that agricultural prices, production cost would increase between 0.27% to 1.88%, and a reduction in GDP around 0.39% to 0.54 %. The negative impact on livestock sector is slightly higher than that on the crop sector. Negative impacts are also observed in the employment and wages. The rising oil price has the potential to discourage production of energy-intensive activity because of the possibility of substitution and adaptations. The growth rate of real GDP will shrink by 0.64% to 1.06% and CPI will increase by 1.17% to 1,95%. Both the agriculture and non-agricultural sector also respond by raising output prices by 0.80% to 1.33%. The rising international oil price has urged the government to take policy actions like using alternative fuels such as biodiesel, bioethanol, and adopting measures to cut down on energy consumptions mainly in transportation sectors in response to public concern over economic shocks.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.3
• /
• pp.146-153
• /
• 2011

American NREL (National Renewable Energy Laboratory) reported that BDF20 could reduce PM, CO, SOx, and cancerogenic matters by 13.6%, 9.3%, 17.6%, and 13% respectively, compared to diesel fuel. BDF20 has been being tested on garbage trucks and official vehicles at Seoul City, which is positive on air environment, but negative on combustion by higher viscosity in winter season. This study investigated the combustion characteristics by applying pilot injection for improving the deterioration of combustibility caused by the higher viscosity of the BDF20 with the combustion flames taken by a high-speed camera and the cylinder pressure diagram. A 4-cycle single-cylinder diesel engine was remodeled to a visible 2-cycle engine taking the flame photographs, which has a common-rail injection system. The test was done laboratory temperature at $5{\sim}6^{\circ}C$. The results obtained are summarized as follows, (1) In the case of without pilot injection, the flame propagation speed was slowed and the maximum combustion pressure became lower. The phenomena became further aggravated as the fuel viscosity gets higher. (2) In the case of with pilot injection, early stage of combustion such as rapid ignition timing and flame propagation was activated since intermediate products formed by pilot injection act as a catalyst for combustion of main fuel.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.2
• /
• pp.133-145
• /
• 2017

Palm oil production is among the highest worldwide, and it has been mainly used in the food industry and other commodities. Currently, a lot of palm oil production has been destined for the synthesis of biodiesel; however, its use in applications other than the food industry has been questioned. Thereby for a sustainable development, in this paper the use of palm oil of low quality for corrosion inhibitors synthesis is proposed. The performance of the synthesized inhibitors was evaluated by using electrochemical techniques such as open circuit potential measurements, linear polarization resistance and electrochemical impedance spectroscopy. The results indicate that the fatty amides from palm oil are excellent corrosion inhibitors with protection efficiencies greater than 98%. Fatty amides molecules act as cathodic inhibitors decreasing the anodic dissolution of iron. When fatty amides are added, a rapid decrease in the corrosion rate occurs due to the rapid formation of a molecular film onto carbon steel surface. During the adsorption process of the inhibitor a self-organization of the hydrocarbon chains takes place forming a tightly packed hydrophobic film. These results demonstrate that the use of palm oil for the production of green inhibitors promises to be an excellent alternative for a sustainable use of the palm oil production.

• Fire Science and Engineering
• /
• v.33 no.5
• /
• pp.1-6
• /
• 2019

The recent development of biofuel production technology facilitates the widespread use of bioethanol and biodiesel by mixing them with fossil fuels. However, the use of these new blended fuels in combustion could result in severe safety problems, such as fire and explosion. In this study, numerical simulation was performed on the well-stirred reactor (WSR) to simulate the autoignition temperature (AIT) in homogeneous combustion and clarify the effect of ethanol addition on the AIT, the most important property for assessing the potential for fire and explosion. Response surface methodology (RSM) was introduced as a design of experiment (DOE), enabling the AIT to be predicted and optimized systematically with respect to three independent variables: ethanol mole fraction, equivalence ratio, and pressure. The results show that the autoignition temperature primarily depends on the ethanol mole fraction and pressure, while the effects of the equivalence ratio are independent of the AIT. RSM accurately predicted the experimental AIT, indicating that this method can be used to effectively predict the key properties involved in fires and explosions.

• Journal of Marine Bioscience and Biotechnology
• /
• v.6 no.2
• /
• pp.118-122
• /
• 2014

The ocean provide great benefits for microalgal mass cultures with maintaining stable temperature due to high specific heat, mixing by wave energy, and providing large area for large-scale microalgae cultures. In this study, we cultivated a marine green microalga, Tetraselmis sp. KCTC12432BP, using marine photobioreactors on the ocean for investigating the effect of $NaHCO_3$ concentration on the biomass productivities and evaluating the potential of ocean microalgae culture. The culture medium consist of three fold concentrated f/2-Si with 4 g/L of $NaHCO_3$, which is dissolved in natural seawater. After 11 days of cultivation, the cultures reached stationary phase at biomass concentration of 1.6 g/L. At that time, $NaHCO_3$ concentration of 0, 2, and 4 g/L were fed to the cultures. The daily productivities of 0.11, 0.19, 0.30 g/L/day were attained with feeding rate of 0, 2, and 4 g/L $NaHCO_3$, respectively. Biomass productivity of Tetraselmis sp. KCTC12432BP was a function of the $NaHCO_3$ feeding rate as expected. This research shows that the microalgae can grow with $NaHCO_3$ as carbon source in marine photobioreactors on the ocean while exploiting various benefits of ocean cultivation.

• Journal of Marine Bioscience and Biotechnology
• /
• v.6 no.2
• /
• pp.110-117
• /
• 2014

Recently microalgae have been proposed as a promising biodiesel feedstock, owing to their higher lipid productivity and non-arable land based cultivation system. Biomass and lipid productivities of microalgae are largely affected by various environmental and nutritional factors. In this study, the effects of nitrogen (nitrate and ammonium) and organic carbon (glucose and glycerol) sources on the cell growth and lipid production of Chlorella sp. KR-1 were examined in flask cultures. Under autotrophic culture conditions for 15 days, overall cell growth and lipid (fatty acid methyl ester, FAME) production with nitrate were better than those of ammonium, resulting in 1.06 g cell/L and 333 mg FAME/L, respectively. Maximal intracellular lipid contents (348 - 352 mg FAME/g cell) were observed at low concentrations of 1 mM for both nitrate and ammonium. In the supply of light, addition of glucose in the range of 1 - 20 g/L showed higher cell densities than the autotrophic cell growth condition. Higher lipid accumulation of 375 mg FAME/g cell could achieved at 5 g glucose/L albeit of relatively short incubation of 7 days. With glycerol, intracellular lipid contents were ~1.9 times lower than glucose cases although similar cell growths were observed for both carbon sources.

• Korean Chemical Engineering Research
• /
• v.45 no.3
• /
• pp.286-290
• /
• 2007

The esterification efficiency of several ionic liquids has been investigated to determine the feasibility for the conversion of free fatty acids to alkylester. Five ionic liquid catalysts having strong acidity, BPC[$AlCl_3$], BMIM[$Bf_4$], BMIM[$Pf_6$], EMIM[$Ntf_2$], BMIM[Otf], have been employed in this work. BPC[$AlCl_3$] has the highest esterification efficiency among the ionic liquid catalysts. Over 90% conversion efficiency has been achieved in the esterification of the simulated used cooking oil by BPC[$AlCl_3$] with two hours reaction time. Since BPC[$AlCl_3$] has several advantages such as high esterification activity, ease of separation from reaction mixture and reusability after treatment procedure, it will be a promising catalyst for the conversion of free fatty acids to esters in waste fats.

• Korean Chemical Engineering Research
• /
• v.56 no.2
• /
• pp.275-280
• /
• 2018

Methyl ester derived from coconut oil is very interesting to study since it contains free-fatty acid with chemical structure of medium carbon chain ($C_{12}-C_{14}$), so the methyl ester obtained from its part can be a biodiesel and another partially into biokerosene. The use of heterogeneous catalysts in the production of methyl ester requires severe conditions (high pressure and high temperature), while at low temperature and atmospheric conditions, yield of methyl ester is relatively very low. By using microwave irradiation trans-esterification reaction with heterogeneous catalysts, it is expected to be much faster and can give higher yields. Therefore, we studied the production of methyl ester from coconut oil using CaO catalyst assisted by microwave. Our aim was to find a kinetic model of methyl ester production through a transesterification process from coconut oil assisted by microwave using heterogeneous CaO catalyst. The experimental apparatus consisted of a batch reactor placed in a microwave oven equipped with a condenser, stirrer and temperature controllers. Batch process was conducted at atmospheric pressure with a variation of CaO catalyst concentration (0.5; 1.0; 1.5; 2.0, 2.5%) and microwave power (100, 264 and 400 W). In general, the production process of methyl esters by heterogeneous catalyst will obtain three layers, wherein the first layer is the product of methyl ester, the second layer is glycerol and the third layer is the catalyst. The experimental results show that the yield of methyl ester increases along with the increase of microwave power, catalyst concentration and reaction time. Kinetic model of methyl ester production can be represented by the following equation: $-r_{TG}=1.7{\cdot}10^6{_e}{\frac{-43.86}{RT}}C_{TG}$.

• Journal of Radiation Industry
• /
• v.4 no.3
• /
• pp.277-283
• /
• 2010

Rape (Brassica napus L.) plants are one of the major oilseed crops. The main components of rapeseed are oil (35 to 47%) and protein (15 to 32%). For the biodiesel production, the development of a new variety of rape plant with high biomass and/or oleic acid contents is required. In order to determine the optimum dose of gamma-ray irradiation, the rape seeds of cvs. Hanra (Hr), Youngsan (Ys), Tammi (Tm), and Tamra (Tr) were irradiated with a 100~4,000 Gy dose range of gamma-rays. Considering the growth factors, the optimum doses were determined to be within the range of 600~1,000 Gy for the selection of useful mutant lines. Six-hundred and eighty-eight (688) $M_2$ mutant lines were obtained from 600~1,000 Gy gamma-ray-irradiated $M_1$ plants through selfing. The growth characteristics, leaf shape, early flowering, and flower color were all investigated. The selected mutant numbers of early flowering, leaf shape, and flower color were 34, 52, and 3 from the four cultivars, respectively. These mutant lines will be used for the development of a new variety of rape plant with high biomass and oleic acid contents.

• Journal of Forest and Environmental Science
• /
• v.27 no.3
• /
• pp.151-156
• /
• 2011

Seeds of Xanthoceras sorbifolia Bunge were collected from two plantations and two superior trees in Inner Mongolia: and one plantation and one superior tree in Liaoning, China in late August, 2011. Yellowhorn or goldenhorn is an important tree species, from the aspects of source of edible oil and biodiesel and pioneering capacity of degraded and desert land. Characteristics investigated were seed length, width, and weight: weight and volume of 1,000 seeds: and weight and volume of one-liter seeds. The seeds of Qingsonglingxiang No. 1, growing alone in an open space, showed the highest values in seed length (16.08 mm), width (14.48 mm) and weight (1.40 g), while those of Tree No. 160 in Ar Khorqin Banner were the lowest ones: that is, 11.48mm for length, 11.81 mm for width, and 0.73 g for weight, respectively. Traits of seeds varied quite much between trees and among areas; for example, Tree No. 38 and No. 160 produced quite different seeds in several traits, although they are adjacent to each other in the same farm. Weight of 1,000 seeds varied from 718.0 g to 1,010.1 g and volume from 0.76 L to 1.52 L. Weight of one-liter seeds were 522.3 g to 688.2 g, while the number of seeds were 603 to 935. Seeds which were soaked in the water at $4^{\circ}C$ for 2 days showed the highest germination rate (89%) in a 30-day test, which was about 10% to 40% higher than those of non-treatment and dipping treatment at $36^{\circ}C$ followed by keeping under room temperature for 2 days. 81% of seeds in the wet sand at room temperature germinated, while 23% of seeds deprived of seed coat germinated. It is necessary to understand seed traits to select superior clones or provenances for the increased, unfluctuating production of seed.