• Journal of Energy Engineering
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• v.23 no.3
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• pp.241-246
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• 2014

This study is to compare characteristics of saccharification reactions applying to enzymatic hydrolysis of pretreated fallen leaves for bio-ethanol production. It experimented pretreatment of acid, alkaline in the chemical. This experiment includes preteatment of acid and alkaline in chemical, soaking, shaking and autoclaving method, which were applied to biomass. In result, the glucose production from alkaline-NaOH method was 263 mg glucose/ g biomass comparing with them of acid-HCl method. Thus, alkaline-NaOH method is superior than the acid-HCl method for chemical preteatment of fallen leaves. Also, when various chemical treatments were compared, they were all. Based on the results of this study, we found that leaves, one of biomass, are possible in pretreatment and enzymatic hydrolysis process, and they are likely to affect bio-ethanol production in the future.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.96-102
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• 2009

The effect of ultrasonic and alkaline pre-treatments on waste activated sludge (WAS) disintegration was investigated for improved anaerobic digestion. As WAS was treated by either methods, longer capillary suction time (CST) was required due to the break-up of cell walls, and its supernatant demonstrated increase in soluble chemical oxygen demand (SCOD), protein content and turbidity. Ultrasonic process combined with alkaline pre-treatment demonstrated higher SCOD and protein content in the supernatant as compared with ultrasonic pre-treatment only. However, the degree of disintegration (DDCOD) of WAS decreased with increasing solid concentration as both WAS disintegration methods employed simultaneously.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.255-264
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• 2009

To evaluate the effects of chemical pretreatments of lignocellulosic biomass on enzymatic hydrolysis process, Populus euramericana was pretreated for 1 hr with 1% sulfuric acid ($H_2SO_4$) at $150^{\circ}C$ and 1% sodium hydroxide (NaOH) at $160^{\circ}C$, respectively. Before the enzymatic hydrolysis, each pretreated sample was subjected to drying process and thus finally divided into four subgroups; dried or non-dried acid pretreated samples and dried or non-dried alkali pretreated samples and chemical and physical properties of them were analyzed. Biomass degradation by acid pretreatment was determined to 6% higher compared to alkali pretreatment. By the action of acid ca. 24.5% of biomass was dissolved into solution, while alkali degraded ca. 18.6% of biomass. However, reverse results were observed in delignification rates, in which alkali pretreatment released 2% more lignin fragment from biomass to the solution than acid pretreatment. Unexpectedly, samples after both pretreatments were determined to somewhat higher crystallinity than untreated samples. This result may be explained by selective disrupture of amorphous region in cellulose during pretreatments, thus the cellulose crystallinity seems to be accumulated in the pretreated samples. SEM images revealed that pretreated samples showed relative rough and partly cracked surfaces due to the decomposition of components, but the image of acid pretreated samples which were dried was similar to that of the control. In pore size distribution, dried acid pretreated samples were similar to the control, while that in alkali pretreated samples was gradually increased as pore diameter increased. The pore volume which increased by acid pretreatment rapidly decreased by drying process. Alkali pretreatment was much more effective on enzymatic digestibility than acid pretreatment. The sample after alkali pretreatment was enzymatically hydrolyzed up to 45.8%, while only 26.9% of acid pretreated sample was digested at the same condition. The high digestibility of the sample was also influenced to the yields of monomeric sugars during enzymatic hydrolysis. In addition, drying process of pretreated samples affected detrimentally not only to digestibility but also to the yields of monomeric sugars.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.441-446
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• 2018

Herbaceous biomass is easier at chemical conversion than woody biomass. However, pretreatment must be needed because it has substantially lignin. Organsolv is good at fractionation of enzymatic hydrolysis inhibitors such as lignin and it is reusable by distillation when it has low molecular weight. Flow-through process can prevent recondensation of fractionated components and easily separate liquid from the biomass. In this study, the pretreatment was performed for decreasing additional process by using ethanol without catalyst because this process has a lot of operation expense at bio-alcohol production process. Flow-through pretreatment was performed at $150{\sim}190^{\circ}C$ with 30~99.5 wt% ethanol during 20~60 minutes. Also the phsyco-chemical pretreatment was performed for decreasing reaction time and temperature.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.34-41
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• 2000

Recently many scientists have tried to synthesize biodegradable polymers due to durable and non-biodegradable products of conventional synthetic plastics when these were wasted in nature. So to reuse the wastepapers for biodegradable polymer resources, ONP (old newsprint), OCC (old corrugated containerbpard) were carried out by the pretreatment of chlorinite, hypochlorite and oxygen-alkali treatment conditions. For manufacturing of biodegradable polymer with wastepaper, this study performed to investigate change of chemical components and optimal pretreatment condition. The summarized results in this study were as follows: Lignin content in ONP and OCC was was higher than in MOW and ash content was the highest in MOW. More amount of ash components were reduced by wet defiberation than by dry defiberation. Wet defiberation fiber are better than dry defiberated fiber in chemical pretreatment condition for wastepapers, and the best result was obtained in the condition of sodium chlorite at $70^{\circ}C$, because it has high delignification ratio, ${\alpha}$-cellulose contents and degree of polymerization in this treatment condition. Oxygen-alkali treatment condition is the worst method because of low yield, low degree of polymerization in this pretreatments.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.177.2-177.2
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• 2011

세계적인 자원고갈과 지구온난화와 같은 환경문제가 발생됨에 따라 대체에너지 개발에 대한 연구가 활발히 이루어지고 있다. 섬유소 기질을 이용한 바이오에탄올 생산은 세계적으로 막대한 자원이 있으며 광합성에 의해 재생산되는 무한한 재원으로서 환경적으로도 대기오염물질을 적게 배출하여 유용한 에너지원으로 각광받고 있다. 하지만 섬유소 기질은 cellulose, hemicellulose, lignin과 같은 고분자 화합물이 유기적으로 결합된 단단한 결정구조로 이루어져 있어 이를 분해하여 원하는 물질을 얻기 위해서는 전처리 과정이 필요하다. 전처리 공정은 바이오에탄올을 생산하는 당화 및 발효공정의 효율 및 반응시간 단축에 기여하며, 특히 섬유소 기질일 경우에는 필수불가결한 공정이다. 전처리 공정은 물리적, 화학적, 생물학적 방법으로 나누어지며, 이러한 방법들 중 기질의 특성과 처리효율에 따라 기술들을 병합하여 사용하기도 한다. 이에 본 연구에서는 산 처리, 암모니아 처리, 과산화수소 처리 및 효소를 이용한 생물학적 처리를 단독 또는 병행하여, 전환된 당 성분 및 함량을 조사함으로서 섬유소계 기질인 채소 음식물류 쓰레기를 대상으로 바이오에탄올을 경제적으로 생산하기 위한 적합한 전처리법을 검토하였다. 전처리 방법별 당화율을 살펴보면, 산 처리와 암모니아-과산화수소-계면활성제 처리가 각각 65.3 % 및 65.7 %로 가장 높았으며, 과산화수소 처리는 16.2 %로 가장 낮았다. 반면 전처리 공정 없이 효소를 이용한 당화만을 실시한 경우에는 4.3 %의 낮은 당화율을 나타내었다. 섬유소계 기질의 전처리 효율을 향상시키기 위해 첨가하는 계면활성제의 효과는 암모니아-과산화수소 및 암모니아-과산화수소-계면활성제 처리의 당화율을 비교한 결과, 뚜렷한 효과를 확인할 수 없었다. 전처리 방법별 당의 성분 및 함량을 비교한 결과 육탄당은 암모니아-과산화수소-계면활성제 전처리에서 가장 많이 검출되었다. 오탄당은 산 처리 후 그 함량이 현저히 높았으며, 오탄당 중 xylose의 함량이 60.49 mg/g로 가장 많이 차지하고 있었다. 이 결과로부터 전처리 방법에 관계없이 당화율은 유사한 수준을 보이지만, 당화된 당의 성분 및 함량에는 큰 차이가 있음을 알 수 있었다. 이당류의 경우 과산화수소 및 암모니아-과산화수소 처리를 제외한 나머지 전처리 방법에서 유사한 수준을 나타내었다. 암모니아 처리 및 과산화수소 처리를 순차적으로 병행한 암모니아-과산화수소 처리에서는 각각의 처리시보다 육탄당의 함량은 증가하였으나 암모니아 처리시보다 이당류의 함량은 감소한 것으로 나타났다.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.129-130
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• 2000

기존에 발표된 논문에서 섬유를 고해하기 전에 물리적 전처리를 함으로써 같은 여수도에서 섬유길이의 손상없이 섬유의 WRV 가 증가하는 사실을 발표한 바 있다. 이러한 Hobart m mixer를 이용한 섬유의 전처리가 과연 화학펄프섬유의 건조시 발생하는 각질화 ( (Homification)를 역전시킬 수 있는지를 본 연구에서 알아보았다. 현재까지의 실험결과 침 엽수 표백화학펄프의 경우 건조시 각질화가 많이 일어나지 않은 경우 (섭씨 80도의 저온에 서의 건조) 에는 거의 완벽한 각질화의 역전이 일어났지만 건조온도가 높아져서 심한 각질 화가 예상되는 경우 (섭씨 110도) 에는 물리적 전처리의 효과가 나타나지 않았다. 따라서 H Hobart mixer를 이용한 물리적 전처리는 각질화가 많이 진행되지 않은 경우에는 섬유의 불 리적 특성올 회복시킬 수 있는 수단이 될 수 있다고 판단되었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.82-90
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• 2009

Disintegration of sewage sludge (SS) was investigated by batch experiments using mechanical pre-treatment. Mechanical disintegration of SS increased the amount of soluble chemical oxygen demand (SCOD), protein and carbohydrate due to the break-up of cell walls. The mechanical disintegration incorporated with alkaline pre-treatment demonstrated higher amount of SCOD compared with mechanical one only. In terms of anaerobic biodegradability, mechanical pretreatment enhanced the anaerobic biodegradation of SS, leading to the methane production improvement. The improvement in BMP for SS treated with mechanical and alkaline-mechanical pre-treatments were 24.1% and 44.5%, respectively. This result suggested that disintegration of SS was effective for improving anaerobic biodegradability.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.274-286
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• 2009

Lignocellulosic biomass is the most abundant raw material for bioconversion in many country. However the high costs for pretreatment and enzymatic hydrolysis currently deter commercialization of lignocellulosic biomass, especially wood biomass which is considered as the most recalcitrant material for enzymatic hydrolysis mainly due to the high lignified structure and the nature of the lignin component. Therefore, overcoming recalcitrance of lignocellulosic biomass for converting carbohydrates into intermediates that can subsequently be converted into biobased fuels and biobased products is the primary technical and economic challenge for bioconversion process. This study was mainly reviewed on the research trend of pretreatment with lignocellulosic biomass in bioethanol production process.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.371-371
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• 2010

탄소나노튜브(CNT)는 기계적인 특성이 뛰어나며, 화학적으로 안정하고, 전기적으로 도체 및 반도체성을 가지고 있을 뿐만이 아니라 직경이 최소 1nm 수준으로 종횡비 및 비표면적이 매우 큰 특성을 가지고 있다. CNT는 투명전극, 유연성 디스플레이, 전자종이 분야 등 투명 전극 응용 분야에서 ITO 대체 신소재로 각광을 받고 있다. 본 발표에서는 SWCNT 전도막의 특성을 향상시키기 위해 PET 기판에 다양한 전처리 방법을 적용하여 SWCNT의 부착력 및 접착력, 투명전극의 면저항, 투과도 및 균일도 향상을 통해 SWCNT 투명전극 특성향상 연구를 진행했다. 접촉각과 표면에너지 제어를 통한 박막특성과의 상관관계 분석, 전처리 방법에 따른 표면에너지 및 제타포텐셜 변화와 박막특성과의 관계를 규명, Roughness 조절을 통한 기판의 면저항과 투과도 향상, 플라즈마 및 polymer 처리를 통해 물리적, 화학적 기판 전처리에 따른 SWCNT 투명전극 특성 향상을 목적으로 실험을 진행했다. 플라즈마 처리 후 polymer 처리된 박막에서는 친,소수 작용기 양의 변화에 따른 상관관계를 보이지 않았지만, 플리즈마 처리 후 친,소수 작용기 양과 Roughness 변화정도에 대해서는 면저항과 투과도의 변화를 보였다.