• Journal of the Korean Wood Science and Technology
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• v.40 no.3
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• pp.194-203
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• 2012

1-Ethyl-3-methylimidazolium acetate known as efficient biomass pretreatment reagent was used for the extraction of lignin from rigida pine wood (pitch pine), which was called to ionic liquid lignin (ILL), and chemical structural features of ILL were compared with the corresponding milled wood lignin (MWL). The amounts of phenolic hydroxyl groups (Phe-OH) was determined to 10.0% for ILL and 7.2% for MWL, respectively, where those of methoxyl groups (OMe) were 4.9% for ILL and 11.0% for MWL, respectively. The weight average molecular weight (Mw) of ILL (3,995) were determined to ca. 1/2 of that of MWL (8,438) and polydispersity index (PDI: Mw/Mn) suggested that the lignin fragments were more uniform in the ILL (PDI 1.36) than in the MWL (PDI 2.64). The temperature (Tm) corresponding to maximum decomposition rate (Vm) of ILL ($306.6^{\circ}C$) was ca. $35^{\circ}C$ lower than that of MWL ($341.9^{\circ}C$), suggesting that ILL was thermally unstable than MWL, as evidence from the lower Tm for ILL. Moreover, the structural characteristics of ILL and MWL were confirmed by spectroscopic analyses (FT-IR and $^{13}C$-NMR), and these results indicated ionic liquid (1-ethyl-3-methylimidazolium acetate) was chemically or physically bound to ILL.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.601-608
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• 2008

The objective of this study was to evaluate the effect of ozonation as pretreatment on the removal of dissolved or biodegradable organic matter(DOM or BOM), the variance of DOM fractionation, and microbial regrowth by pilot-scale granular activated carbon processes in which adsorption and biodegradability was proceeding due to long time operation. Regardless of point of ozonation applied, GAC processes with ozonation(i.e., Ozonation combined with GAC Filter-adsorber; Pre O$_3$ + F/A, Ozonation combined with GAC adsorber; Post O$_3$ + GAC) compared with GAC processes without ozonation(i.e., GAC Filter-adsorber; F/A, GAC adsorber; GAC) removed approximately 10 to 20% more of DOC, hydrophilic DOM(HPI), BDOC and AOC after long period of operation that biological activity was assumed to happen. Ozonation was not found to have a significant effect on the removal of DOC, but caused the decrease of AOC by approximately 20%. It was found that the fixed bacterial biomass on GAC media did not show a significant difference between the GAC with ozonation and GAC without ozonation as pre-treatment, whereas the HPC of column effluent was more biostable at Post O$_3$ + GAC compared with F/A or GAC.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.404-406
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• 2009

This study note wished to introduce special-purpose ship for algae removal that is developed by core technology of our country. The ship is consisted of main frame and adjuvant that can attach and detach as cross (+) shape of a character. The characteristics of ship are super light weight and low draft. That is consisted of four devices as suction, collection, filtration and recovering units. Among these, filtration used screen filter (mesh size 30 ${\mu}m$). Also, can separate and remove water and algae by compression air participle notion. Percentage of moisture content of concentrated algal particle was 85%. Water parted with algae finally is exhausted to water area. Removal efficiency that compare by chlorophyll-$\alpha$ concentration was about 57% (inflow: 83.2 ${\mu}g\;L^{-1}$, outflow: 35.8 $[\mu}g\;L^{-1}$) without physical and chemical pretreatment. Forward, need to achieve effect test in various conditions (algal biomass, flow etc.) for efficiency and technological elevation of exclusion device. We wished to contribute in presuppression system construction of massive algal development that manage blue-green algae occurrence area effectively, and prevents spread as lower part of reservoir.

• KSBB Journal
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• v.23 no.6
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• pp.499-503
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• 2008

The bioethanol for use as a liquid fuel by fermentation of renewable biomass as an alternative to petroleum is important from the viewpoint of global environmental protection. Recently, many scientists have attempted to increase the productivity of bioethanol process by developing specific microorganism as well as optimizing the process conditions. In the present study, which is based on our previous investigation on the pretreatment process, theproductivity of bioethanol obtained from simultaneous saccharification and fermentation (SSF) process was compared between various domestic materials including barley, brown rice, corn and sweet potato. Additionally, Solid glucoamylase (SGA; developed in Changhae Co.), from modified strain with UV, was used. The result was compared to commercial glucoamylase (GA). It was observed that the fermentation rate was increased together with the yield which can be derived from the final ethanol concentration. Especially, in the case of brown rice, compared to the experimental results using GA, the final ethanol concentration was 1.25 times higher and 18.4 g/L of the yield was increased. Also, the time required for reaching 95% of the maximum ethanol concentration is significantly reduced, which is approximately 36 hours, compared to 88 hours using GA. It means that SGA has excellent saccharogenic power.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.414-422
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• 2022

The objective of this work was to investigate the feasibility of acid-catalyzed hydrothermal fractionation for maximum solubilization of the hemicellulosic portion of two typical agricultural residues. The fractionation conditions converted into combined reaction severity (CS) in the range of 1.2-2.9 was used to establish a simple reaction criteria at glance. The hemicellulosic sugar yield of 56.6% was shown when rice straw was fractionated at the conditions at the conditions; 160 ℃ of temperature 0.75% (w/v) of H₂SO₄, 20 min of reaction time, 1:15 solid/liquid ratio. The hemicellulosic sugar yield of 83.0%, however, was achieved when barley straw was fractionated at the conditions at the conditions; 150 ℃ of temperature 0.75% (w/v) of H₂SO₄, and 15 min of reaction time, 1:10 solid/liquid ratio. For barley straw, acid-catalyzed hydrothermal fractionation could be effectively performed. After the fractionation process, the remaining fractionated solids were 48.5% and 57.5% from raw rice and barley straws, respectively. The XMG contents in the solid residues decreased from 17.3% and 17.6% to 6.0% and 2.6%, which corresponded to 16.7% and 8.5% on the basis of the raw straws, respectively. In another way, only 5.6% of cellulose and 8.5% of XMG were lost due to excessive decomposition during the acid-catalyzed hydrothermal fractionation of barley straw, compared to cellulose and XMG losses of 6.4% and 26.6% in rice straw. Hemicellulosic sugars from the rice straw were considered more over-decomposed due to the somewhat higher reaction severity at the acid-catalyzed hydrothermal fractionation.

• Clean Technology
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• v.25 no.2
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• pp.129-139
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• 2019

Bamboo is an evergreen perennial plant, and it is known as one of the most productive and fastest-growing plants in the world. It grows quickly in moderate climates with only moderate water and fertilizer. Traditionally in Asia, bamboo is used for building materials, as a food source, and as versatile raw materials. Bamboo as a biomass feedstock can be transformed to prepare activated carbon using the thermal treatment of pyrolysis. The effect of process variables such as carbonization temperature, activation temperature, activation time, the amount of steam, and the mixing ratio of phosphoric acid and bamboo were systematically investigated to optimize the preparation conditions. Steam activation was proceeded after carbonization with a vapor flow rate of $0.8{\sim}1.8mL-H_2O\;g-char^{-1}\;h^{-1}$ and activation time of 1 ~ 3 h at $700{\sim}900^{\circ}C$. Carbon yield and surface area reached 2.04 ~ 20.59 wt% and $499.17{\sim}1074.04m^2\;g^{-1}$, respectively, with a steam flow rate of $1.4mL-H_2O\;g-char^{-1}\;h^{-1}$ for 2 h. Also, the carbon yield and surface area were 24.67 wt% and $1389.59m^2\;g^{-1}$, respectively, when the bamboo and phosphoric acid were mixed in a 1:1 weight ratio ($700^{\circ}C$, 2 h, $1.4mL-H_2O\;g-char^{-1}\;h^{-1}$). The adsorption of methylene blue into the bamboo activated carbon was studied based on pseudo first order and second order kinetics models. The adsorption kinetics were found to follow the pseudo second order model, which is governed by chemisorption.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.4
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• pp.13-28
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• 2023

This study assessed the biochemical methane potential (B_u-P) of three grass species-Poa pratensis (PP), Zoysia japonica (ZJ), and Agrostis stolonifera (AS). B_u-P values were determined as 0.330 Nm³/kg-VS_added for PP, 0.297 Nm³/kg-VS_added for ZJ, and 0.261 Nm³/kg-VS_added for AS. Notably, PP exhibited superior suitability for methane production. The investigation also examined the impact of silage storage duration on PP grass clippings, revealing a 19% decline in B_u-P from an initial value of 0.269 Nm³/kg-VS_added on day 0 to 0.217 Nm³/kg-VS_added on day 180. Throughout the storage period, there were significant increases in neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) contents, rising from 67.59%, 39.68%, and 3.02% on day 0 to 77.12%, 54.65%, and 6.24% on day 180, respectively. These findings highlight the influence of storage duration on the anaerobic digestibility of PP grass clippings. To effectively utilize grass clippings as a renewable resource for methane production, further studies considering factors such as initial moisture content, pretreatment methods, and potential effects of residual pesticides are necessary to optimize anaerobic digestion efficiency for herbaceous biomass.