• Advances in Energy Research
• /
• v.3 no.3
• /
• pp.181-194
• /
• 2015

In this work, an experimental study of the gasification on wood was carried out in downdraft type fixed bed Gasifier attached with 10 kW duel fuel diesel engine. The main objective of the study was to use wood as the biomass fuel for downdraft Gasifier and to evaluate the operating parameter of gasifier unit to predict its performance in terms of gas yield and cold gas efficiency. The influence of different biomass on fuel consumption rate, gas yield and cold gas efficiency was studied. Composition of producer gas was also detected for measuring the lower heating value of producer gas to select the feed stock so that optimum performance in the existing gasifier unit can be achieved. Under the experimental conditions, Lower heating value, of producer gas, cold gas efficiency and gas yields, using wood as a feed stock, are $4.85MJ/m^3$, 46.57% and $0.519m^3/kg$.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2000.11a
• /
• pp.347-352
• /
• 2000

Before investigating the performance of NA-Q additive oil, we have studied the properties of the commercial reference oil by using an engine dynamometer. Experimemts were conducted for 300 hours with 2,950rpm and 22kw and every 50 hours the used oil was sampled for analyzing its physical and chemical propreties. The reference oil shows stable but slightly increasing viscosities during the experiment. It has good agreements with the change of its TAN and TBN. Friction coefficients and anti-wear characteristics are compared with its ZDTP depletion factor and the diameters of wear scar. The concentrations of metal particles are analyzed with the results of ICP and spectrometer, However it is found that the concentrations by filtration method shows large difference with those by standard method in spectrometer.

• Membrane and Water Treatment
• /
• v.2 no.3
• /
• pp.137-145
• /
• 2011

Membrane processes are major breakthrough for the removal of organic pollutants in water remediation. The separations of solutes depend on nature of the membranes and solutes. The separation performance depends on the nature of the solutes (i.e., molecular volume, polarity, and hydrophobicity) for the same membrane. As 4-chlorophenol is of more dipolemoment compared to 2-chlorophenol, the orientation of the molecule enables it pass through the pores of the membrane, which is of negatively charged and thus separation order follows: 2-chlorophenol > 4-chlorophenol. Hydrophobicity factor also supports the order. Addition of sodium dodecyl sulfate (SDS) to chlorophenol solution shows remarkable increase in separation performance of the membrane. The improvement in separation is 1.8 and 1.5 times for 4- and 2- chlorophenol consecutively in case of 0.0082 M SDS (1cmc = 0.0082 M) in the solution. 4-chlorophenol has better attachment tendency with SDS because of its relatively more hydrophobic nature and thus reflects in performance i.e. the separation performance of 4-chlorophenol with SDS through the membrane is better compared to 2-chlorophenol.

• Journal of Biosystems Engineering
• /
• v.37 no.6
• /
• pp.365-372
• /
• 2012

Purpose: Performance of slurry composting and biofiltration with methane production (SCB-M) using swine manure and sawdust was evaluated. The suitable specific liquid input (SLI) was determined at lab-scale SCB. Method: In lab-scale SCB, the SLI test was performed at liquid input rate of 0.04, 0.09, $0.17cc/cm^3$ with constant sawdust volume. In pilot-scale SCB-M, the swine manure was fed to methane digester at organic loading rate (OLR) of 0.25-0.5 g VS/L/d. The effluent from methane digester was filtered using SCB. Results: The SLI at $0.04cc/cm^3$ showed good performance in terms of retention time. In pilot-scale SCB, the removal of $NH_3$-N and total nitrogen (T-N) was found to be around 59% and 28%, respectively. Similarly, volatile fatty acid (VFA) and total chemical oxygen demand (TCOD) removal was found be 56% and 43%, respectively. Conclusions: For SCB-M process, the SLI of $0.04cc/cm^3$ is recommended. The performance of swine manure treatment was improved more by using SCB-M system than using methane digester only.

• Membrane and Water Treatment
• /
• v.9 no.6
• /
• pp.385-392
• /
• 2018

Poly vinyl chloride (PVC) was chemically modified, and used for ultrafiltration to analyze the performance. Non-solvent induced phase separation (NIPS) method was used to prepare membranes. The neat PVC membrane was casted and used as a control membrane. Modified membrane was prepared by reacting PVC with ethanolamine (EA) in the casting solution (labeled as CM-PVC). Pure water permeability (PWP) was evaluated by measuring pure water flux. Humic acid was used as model foulant solute to analyze flux and rejection ability of membranes. Flux and rejection data of neat and modified membranes were compared to prove the improvement in the filtration performance. The experimental results showed that for PVC and CM-PVC, PWP was calculated to be ~64 and ${\sim}143L/m^2{\cdot}h$, respectively, and the rejection of humic acid was found to be 98% and 100%, respectively. TGA was carried out to analyze the effect of chemical modification on the thermal stability of polymer. FT-IR analysis was another characterization technique used for the comparative study.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.1
• /
• pp.207-218
• /
• 2013

One of the input parameters in the evaluation of seismic performance of rockfill dams is shear-wave velocity of rock debris and clay core. Reliable evaluation of shear-wave velocity by surface-wave methods requires overcoming the problems of rock-debris discontinuity, material inhomogeneity and sloping boundary. In this paper, for the shear-wave velocity investigation of rockfill dams, SBF (Short-Array Beamforming) technique was proposed using the principles of conventional beamforming technique and adopted to solve limitations of the conventional surface-wave techniques. SBF technique utilizes a 3- to 9-m long measurement array and a far-field source, which allowed the technique to eliminate problems of near-field effects and investigate local anomalies. This paper describes the procedure to investigate shear-wave velocity profile of rockfill dams by SBF technique and IRF (Impulse-response filtration) technique with accuracy and reliability. Validity of the proposed SBF technique was verified by comparisons with downhole tests and CapSASW (Common-Array-Profiling Spectral-Analysis-of-Surface-Waves) tests at a railroad embankment compacted with rock debris.

• Membrane and Water Treatment
• /
• v.7 no.4
• /
• pp.313-325
• /
• 2016

South Africa recognises piped water as the main source of safe drinking water supply. Remote areas do not have access to this resource and they rely solely on surface water for survival, which exposes them to waterborne diseases. Interim point of use solutions are not practiced due to their laboriousness and alteration of the taste. Bio-ultra low pressure driven membrane system has been noted to be able to produce stable fluxes after one week of operation; however, there is limited literature on South African waters. This study was conducted on three rivers namely; Umgeni, Umbilo and Tugela. Three laboratory systems were setup to evaluate the performance of the technology in terms of producing stable fluxes and water that is compliant with the WHO 2008 drinking water guideline with regards to turbidity, total coliforms and E.coli. The obtained flux rate trends were similar to those noted in literature where they are referred to as stable fluxes. However, when further comparing the obtained fluxes to the normal dead-end filtration curve, it was noted that both the Umbilo and Tugela Rivers responded similarly to a normal dead-end filtration curve. The Umgeni River was noted to produce flux rates which were higher than those obtainable under normal dead-end. It can be concluded that there was no stabilisation of flux noted. However, feed water with low E.coli and turbidity concentrations enhances the flux rates. The technology was noted to produce water of less than 1 NTU and 100% removal efficiency for E.coli and total coliforms.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.9
• /
• pp.656-661
• /
• 2011

The performance of a domestic ceramic membrane with pore size of $0.1{\mu}m$ was evaluated to produce drinking water. A pilot-scale ceramic membrane filtration plant with a capacity of $1m^3/d$ was operated at the filtration flux of $3.0m^3/m^2{\cdot}d$ to investigate the effect of both backwash interval and pre-ozonation on TMP (trans-membrane pressure) increasing rate. The TMP increased with increasing the backwash interval. However, the application of pre-ozonation reduced the TMP increasing rate remarkably. When 1 mg/L of ozone was dosed with contact time of 5 min, TMP increasing rate at the backwash interval of 1 hr was reduced by 30%. This result indicated that pre-ozonation was very effective in reducing membrane fouling. There was almost no change in TMP increasing rate when the ozone contact time was maintained in the range of 5 to 15 min. Increasing ozone concentration up to 3 mg/L showed beneficial effect on TMP increasing rate.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.5
• /
• pp.599-608
• /
• 2009

This manuscript covers the results of field investigation and lab-scale experiments to design a double-layered biofilter system to control urban storm runoff. The biofilter system consisted of a coarse soil layer (CSL) for filtration and fine soil layer (FSL) for adsorption and biological degradation. The variations of flow rate and water quality of runoff from a local expressway were monitored for seven storm events. Laboratory column experiments were performed using seven kinds of soil and mulch to maximize pollutants removal. The site mean concentration (SMC) of storm runoff from the drainage area (runoff coefficient: 0.92) was measured to be 203 mg/L for SS, 307 mg/L for $TCOD_{Cr}$, 12.3 mg/L for TN, 7.3 mg/L for ${NH_4}^+-N$, and 0.79 mg/L for TP, respectively. This study employed a new design concept, to cover the maximum rainfall intensity with one month recurrence interval. Effective storms for last ten years (1998-2007) in seoul suggested the design rainfull intensity to be 8.8 mm/hr Single layer soil column showed the maximum removal rate of pollutants load when the uniformity coefficient of CSL was 1.58 and the silt/clay contents of FSL was virtually 7%. The removal efficiency during operation of double layer soil column was 98% for SS and turbidity, 75% for TCODCr, 56% for ${NH_4}^+-N$, 87% for TP, and 73-91% for heavy metals. The hydraulic conductivity of the soil column, 0.023 cm/sec, suggested that the surface area of the biofilter system should be about 1% of the drainage area to treat the rainfall intensity of one month recurrence interval.

• Korean Chemical Engineering Research
• /
• v.47 no.2
• /
• pp.258-261
• /
• 2009

In this work, we the ettect on extraction amounts and general composition content of phytoestrogen genistein and formononetin extracted from Sophoraflavescens Aiton by various ultrasonic waves(35, 72, and 170 KHz) and extraction time(30, and 60 min) were compared using extraction solvent water 100%. The pretreatment step was composed of ultrasonic waves extraction, filtration, concentration, and membrane filtration. The extracted sample was analyzed by reversed-phase high performance liquid chromatography(RP-HPLC). And the mobile phase applied was linearly changed with A/B of 80/20~65/35 vol% for 60 min(A water/acetic acid, 99.9/0.1 vol%, B acetonitrile/acetic acid, 99.9/0.1 vol%). The experimental results, general composition carbohydrate(0.255 to 0.413%) excepts, other ingredients was confirmed almost similarly. Also, The highest yield of extraction amount 3.17g was obtained by ultrasonic waves with a frequency of 170 KHz and an extraction time of 60 min. This work offers would be useful for chemical and biological studies of natural plants and its products.