• Membrane and Water Treatment
• /
• v.8 no.6
• /
• pp.529-541
• /
• 2017

A multi-effect air gap membrane distillation (ME-AGMD) module for pesticide wastewater treatment is studied with internal heat recovery, sensible heat of brine recovery, number of stages and the use of fresh feed as cooling water in a single module is implemented in this study. A flat sheet polytetrafluroethylene (PTFE) membrane was used in the 4-stage ME-AGMD module. The maximum value of permeate flux could reach $38.62L/m^2h$ at feed -coolant water temperature difference about $52^{\circ}C$. The performance parameter of the module like, specific energy consumption and gain output ratio (GOR) was investigated for the module with and without heat recovery. Also, the module performance was characterized with respect to the separation efficiency of several important water quality parameters. The removal efficiency of the module was found to be >98.8% irrespective water quality parameters. During the experiment the membrane fouling was caused due to the deposition of the salt/crystal on the membrane surface. The membrane fouling was controlled by membrane module washing cycle 9 h and also by acidification of the feed water (pH=4) using 0.1M HCl solution.

• Korean Chemical Engineering Research
• /
• v.46 no.4
• /
• pp.739-746
• /
• 2008

The aim of this study is finding the optimal design parameters and the optimal operation variables of a reactive distillation column. Different from steady state optimization, dynamic optimization makes it possible considering operation ability as well as design problems at process design step. For performing dynamic optimization, dynamic simulation should be done first. If dynamic simulation is already finished, dynamic optimization can be performed with less effort than that of dynamic simulation.Reactive distillation systems involving reaction and separation in a single unit have the potential to reduce capital and operating costs, particularly when reaction have conversion constraint or when azeotropes exist making conventional separation difficult and expensive. This study here present work on the continuous distillation process, the homogeneous catalyzed esterification of methanol and acetic acid, the synthesis of methyl acetate. Based on an equilibrium stage model of a reactive distillation column a dynamic optimization problem was formulated and solved. And the results were verified by performing dynamic simulation and showing the variation of conversion and purity as the variation of the operation variables. As the results of dynamic optimization, this study found optimal feed ratio, reflux ratio and reboiler duty of this system. And as this study applied it to dynamic simulations the dynamic characteristics of a reactive distillation column are showed under optimal operating condition.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.250-255
• /
• 2009

This study was analyzed the long term performance of the demonstration system for solar energy desalination in Jeju. we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as $2m^3$ a $120m^2$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. Through the operation during about 3 years, In a clear day more than $400W/m^2$, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to March, 2009 for 3 years, solar irradiance daily averaged was measured $370W/m^2$, the daily fresh water yield showed that can be produced about 330liter.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.04a
• /
• pp.221-226
• /
• 2008

This study was carry out evaluation of seasonal performance for the decentralized desalination system with the solar thermal system and the photovoltaic power system. First operating demonstration system was set up in Cheju in 2006. These system comprises the desalination unit with designed daily fresh water capacity of $2m^3$ and is supplied by a $120m^2$ evacuated tubular solar collector, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation supply the electricity for hydraulic pumps to move the working fluids. In a spring season day average $392W/m^2$, the daily fresh water showed to produce about 340liter. In a summer season day average $296W/m^2$, the daily fresh water showed to produce about 328liter. In a autumn season day average $349W/m^2$, the daily fresh water showed to produce about 277liter. In a winter season day average $342W/m^2$, the daily fresh water showed to produce about 271liter.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.11a
• /
• pp.172-177
• /
• 2008

This study was carry out evaluation of long-term performance for the decentralized desalination system with the solar thermal system and the photovoltaic power system. First operating demonstration system was set up in Cheju in 2006. These system comprises the desalination unit with designed daily fresh water capacity of $2m^3$ and is supplied by a $120m^2$ evacuated tubular solar collector, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation supply the electricity for hydraulic pumps to move the working fluids. In a clear day more than 400W/$m^2$, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to October, 2008 for 2 years, solar irradiance daily averaged was measured 370W/$m^2$, the daily fresh water yield showed that can be produced about 330liter.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.10
• /
• pp.1510-1516
• /
• 2015

The objective of this study was to investigate the quality and sensory characteristics of sweet persimmon mashes and spirits fermented by three different yeasts [Saccharomyces species, labeled as LB (Lalvin BM $4{\times}4$), LD (Lalvin DV10), and UC (Uvaferm CM)]. In the production of sweet persimmon wines, UC had the highest alcohol content of 10.20% (v/v) after 9 days of fermentation (P<0.05). The range of pH after fermentation was 3.63~3.75. The total aerobic bacteria and yeast contents increased until day 3 and then continuously decreased to approximately 8.60 log CFU/mL and 8.20 log CFU/mL, respectively. Reducing sugar contents were 3.37% in UC, 3.91% in LD, and 4.05% in LB after fermentation. Total sugar contents were 4.89% in UC, 6.24% in LD, and 5.47% in LB after fermentation. Two-stage single-pot distillation was conducted to produce sweet persimmon spirits. While conducting second distillation, spirits were collected every 100 mL fraction. The alcohol contents gradually decreased as more fractions were collected. The amounts of acetaldehyde were 226 mg/L for LD, 225 mg/L for LB, and 310 mg/L for UC in the first fraction. LD produced the highest volume (677.8 mL) of alcohol in its body part in comparison with LB (408.0 mL) and UC (445.4 mL). In the descriptive analysis, UC had stronger intensities of sweet aroma, sour aroma and taste, and persimmon flavor (P<0.05). Persimmon characteristics seemed to be well characterized by UC. In conclusion, LD was the most efficient in terms of production cost, whereas UC would be used to produce a more flavorful sweet persimmon spirit.