Gwi-Taek Jeong

Optimization of transesterification of animal fat ester using response surface methodology

In an effort to optimize the reaction conditions of biodiesel production from lard, response surface methodology was applied, and the effects of five-level-three-factors and their reciprocal interactions were assessed. A total of 20 individual experiments were conducted, and were designed to study reaction temperature, catalyst amount, and oil-to-methanol molar ratio. A statistical model predicted that the highest conversion yield of lard biodiesel would be 98.6%, at the following optimized reaction conditions: a reaction temperature of 65 degrees C, a catalyst amount of 1.26%, and an oil-to-methanol molar ratio of 7.5:1, with a 20-min reaction time. Using these optimal factor values under experimental conditions in three independent replicates, an average content of 97.8+/-0.6% was achieved, and this value was well within the range predicted by the model. The quality of biodiesel produced from lard at the optimum reaction conditions satisfied the relevant quality standards, with the exception of cold filter plugging point.

Lipase-Catalyzed Transesterification of Rapeseed Oil for Biodiesel Production with tert-Butanol

Biodiesel is a fatty acid alkyl ester that can be derived from any vegetable oil or animal fat via the process of transesterification. It is a renewable, biodegradable, and nontoxic fuel. In this paper, we have evaluated the efficacy of a transesterification process for rapeseed oil with methanol in the presence of an enzyme and tert-butanol, which is added to ameliorate the negative effects associated with excess methanol. The application of Novozym 435 was determined to catalyze the transesterification process, and a conversion of 76.1% was achieved under selected conditions (reaction temperature 40 °C, methanol/oil molar ratio 3:1, 5% (w/w) Novozym 435 based on the oil weight, water content 1% (w/w), and reaction time of 24h). It has also been determined that rapeseed oil can be converted to fatty acid methyl ester using this system, and the results of this study contribute to the body of basic data relevant to the development of continuous enzymatic processes.

Production of biodiesel fuel by transesterification of rapeseed oil

Fatty acid methyl esters (FAMEs) show large potential applications as diesel substitutes, also known as biodiesel fuel. Biodiesel fuel as renewable energy is an alternative that can reduce energy dependence on petroleum as well as air pollution. Several processes for the production of biodiesel fuel have been developed. Transesterification processes under alkali catalysis with short-chain alcohols give high yields of methyl esters in short reaction times. We investigated transesterification of rapeseed oil to produce the FAMEs. Experimental reaction conditions were molar ratio of oil to alcohol, concentration of catalyst, type of catalyst, reaction time, and temperature. The conversion ratio of rapeseed oil was enhanced by the alcohol:oil mixing ratio and the reaction temperature.

Enhancement of growth and secondary metabolite biosynthesis: Effect of elicitors derived from plants and insects

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration inP. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture ofP. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor andd-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at 1% (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

Batch (one- and two-stage) production of biodiesel fuel from rapeseed oil.

Biodiesel fuel is an alternative and renewable energy source, which may help to reduce air pollution, as well as our dependence on petroleum for energy. Several processes have already been developed for the production of biodiesel. Alkali-catalyzed transesterification with short-chain alcohols, for example, generates high yields of methyl esters in short reaction times. In this study, we have evaluated the efficacy of batch (one- and two-stage) transesterification of rapeseed oil in the production of rapeseed methyl ester. The conversion of rapeseed oil exhibited similar reaction patterns and yields in 30- and 1-L reaction systems. Approximately 98% of the rapeseed oil was converted at 400 rpm within 20 min, under the following conditions: 1% (w/w) KOH, 1:10 methanol molar ratio, and at 60 degrees C. In the 30-L, two-stage transesterification process, approx 98.5% of the rapeseed oil was converted at a 1:4.5 molar ratio and 1% (w/w) KOH at 60 degrees C for 30 min (first reaction condition), and at a 1:1 molar ratio and 0.2% (w/w) KOH at 60 degrees C for 30 min (second reaction condition).Biodiesel fuel is an alternative and renewable energy source, which may help to reduce air pollution, as well as our dependence on petroleum for energy. Several processes have already been developed for the production of biodiesel. Alkali-catalyzed transesterification with short-chain alcohols, for example, generates high yields of methyl esters in short reaction times. In this study, we have evaluated the efficacy of batch (one- and two-stage) transesterification of rapeseed oil in the production of rapeseed methyl ester. The conversion of rapeseed oil exhibited similar reaction patterns and yields in 30- and 1-L reaction systems. Approximately 98% of the rapeseed oil was converted at 400 rpm within 20 min, under the following conditions: 1% (w/w) KOH, 1∶10 methanol molar ratio, and at 60°C. In the 30-L, two-stage transesterification process, approx 98.5% of the rapeseed oil was converted at a 1∶4.5 molar ratio and 1% (w/w) KOH at 60°C for 30 min (first reaction condition), and at a 1∶1 molar ratio and 0.2% (w/w) KOH at 60°C for 30 min (second reaction condition).

Effect of plant growth regulators on growth and biosynthesis of phenolic compounds in genetically transformed hairy roots ofPanax ginseng C. A. Meyer

In this study, morphological alterations, biomass growth, and secondary metabolite production of genetically transformed hairy roots ofPanax ginseng C. A. Meyer, were evaluated after administration of plant growth regulators. The addition of benzylamino purine and kinetin to the culture media increased biomass formation and phenolic compound biosynthesis in the hairy roots. α-Naphthaleneacetic acid and indole-3-butyric acid inhibited hairy root growth, however, low concentrations of indole-3-acetic acid slightly increased hairy root growth. Low concentrations of 2,4-Dichlorophenoxyacetic acid profoundly inhibited growth of hairy roots. The addition of plant growth regulators, such as auxin, did not increase total phenolic compounds in hairy roots that did not contain gibberellic acid and cytokinins. Callus formation was induced in cultures suspended in liquid medium amended with benzylamino purine and kinetin. Hairy roots regenerated from these calluses exhibited an active growth pattern with extensive lateral branching in non-amended medium, similar to the growth pattern of the original hairy roots.

Emission Profile of Rapeseed Methyl Ester and Its Blend in a Diesel Engine

Fatty acid methyl esters, also known as biodiesel, have been shown to have a great deal of potential as petro-diesel substitutes. Biodiesel comprise a renewable alternative energy source, the development of which would clearly reduce global dependence on petroleum and would also help to reduce air pollution. This paper analyzes the fuel properties of rapeseed biodiesel and its blend with petro-diesel, as well as the emission profiles of a diesel engine on these fuels. Fuels performance studies were conducted in order to acquire comparative data regarding specific fuel consumption and exhaust emissions, including levels of carbon monoxide (CO), carbon dioxide (CO2), smoke density, and NOx, in an effort to assess the performance of these biodiesel and blend. The fuel consumption amount of oil operations at high loads was similar or greater than that observed during petro-diesel operation. The use of biodiesel is associated with lower smoke density than would be seen with petro-diesel. However, biodiesel and its blend increased the emission of CO, CO2, and nitrogen oxides, to a greater degree than was seen with petro-diesel. The above results indicate that rapeseed biodiesel can be partially substituted for petro-diesel under most operating conditions, regarding both performance parameters and exhaust, without any modifications having to be made to the engine.

Evaluation of pilot-scale modified A2O processes for the removal of nitrogen compounds from sewage

In this study, pilot-scale experiments for the removal of nitrogen from sewage obtained from a county Y sewer system were performed using modified A(2)O processes. Using this approach, the total amount of nitrogen discharged during denitrification of the influent was average 38.6 mg/L and a level of average 10.8 mg/L was maintained throughout the denitrification process, which resulted in an average removal efficiency that was greater than 72%. The nitrogen components in the effluent water consisted of 22% ammonia nitrogen, 6% nitrite nitrogen and 72% nitrate nitrogen, reaching a nitrification efficiency of 94%. In conclusion, since these advanced treatment methods, which involve modified A(2)O processes, were successfully employed to remove nitrogen from sewage discharge, they hold promise for wide spread use by treatment plants.

Response Surface Methodological Approach for Optimization of Free Fatty Acid Removal in Feedstock

Fatty acid methyl esters, also referred to as biodiesel, have been determined to have a great deal of potential as substitutes for petro-diesel. In order to optimize conversion yield in the biodiesel production process, feedstocks were previously recommended to be anhydrous, with a free fatty acid content of less than 0.5%. In this study, we removed free fatty acid from feedstock through the use of solid catalysts and response surface methodology. In order to optimize free fatty acid removal, response surface methodology was applied to delineate the effects of five-level-four-factors and their reciprocal interactions on free fatty acid removal. A total of 30 individual experiments were conducted, each of which was designed to study reaction temperature, reaction time, catalyst amounts, or methanol amounts. A statistical model was used to estimate that the optimal free fatty acid removal yield would be 100%, under the following optimized reaction conditions: a reaction temperature of 66.96°C, a catalyst amount of 12.66% (w/v), and a reaction time of 37.65 min. Using these optimal factor values under experimental conditions in three independent replicates, an average conversion yield was well achieved within the values predicted by the model.

Comparison of growth characteristics of Panax ginseng hairy roots in various bioreactors

This study investigated the effects of flask-to-liquid volume ratio on the growth of Panax ginseng hairy root, transformed by Agrobacterium rhizogenes, in flask cultures and compared the characteristics of various bioreactors for scale-up. The flask-to-liquid volume ratio was optimum at 1.5 mL of air/mL of medium in flask cultures, and hairy root growth was not affected above the optimum ratio. In 500-mL flask culture, hairy root showed two growth phases. After the first exponential growth, specific growth rate decreased. The growth characteristics of P. ginseng hairy root in various bioreactors were investigated. Hairy root growth was about 55-fold of inoculum after 39 d in a 5-L bioreactor and about 38-fold of inoculum after 40 d in a 19-L bioreactor. Carbon yield was higher in a 19-L bioreactor than in others, but it did not show any linear relationship to the growth rate of hairy roots in bioreactors.