• 펄프종이기술
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• 제44권4호
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• pp.32-42
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• 2012

Wood biomass including forest residues, waste wood, and construction residuals has been widely generated in Korea, but forest biomass from the National Forest Management Operation Project plays a big role in generating wood biomass. Unfortunately the promotion policy of woody energy organized by the Forest Service in Korea concentrates more on demand creation rather than on supply expansion. Therefore, in order to utilize insufficient wood resources effectively, it is greatly required to develop uses for maximizing their added value. In particular, more attention to the use of the second generation biomass has been paid in foreign countries because there is a threshold that the first generation biomass cannot produce enough biofuel without threatening food supplies and biodiversity. In Korea, wood pellets are regarded as the alternative clean fuels to oils and coals that emit green house gases into the atmosphere. However, using wood as pellet raw materials can not be an economic way because the value of wood disappears right after burning in the boiler in spite of its contribution to the decrease of carbon emission. Differently from wood pellets, kraft pulping process using woody biomass produces black liquor as a by-product which can be used to generate electricity, bioenergy and biochemicals through gasification. Thus, it can be more economical to make a torrefaction of lignocellulosic biomass such as low-quality wood and agricultural leftovers as raw materials of pellets.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.137-148
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• 2010

The high costs for ethanol production with lignocellulosic biomass as a second generation energy materials 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 sugar 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 the enhancement of enzymatic hydrolysis for lignocellulosic biomass after pretreatment in bioethanol production process.

• 한국육종학회지
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• 제42권2호
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• pp.121-128
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• 2010

Finding alternative and renewable energy sources has become an important goal for plant scientists, especially with the demand for energy increasing worldwide and the supply of fossil fuel being depleted. The most important biofuel to date is bioethanol which is produced from sugars (sucrose and starch) found in corn and sugarcane. Second generation bioethanol is targeting studies that would allow the use of the cell wall (lignocellulose) as a source of carbon by non-food plants. Plant scientists, including breeders, agronomists, physiologists and molecular biologists, are working towards the development of new and improved energy crops especially, how to design crops for bioenergy production and increased biomass generation for biofuel purposes. This review focuses on: i) the current status of first generation bioenergy production, ii) the limitations of first and second generation bioenergy, and iii) ongoing research to overcome challenging issues in second generation bioenergy.

• 에너지공학
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• 제26권1호
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• pp.76-83
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• 2017

In this paper, the carbon resources recycling of the overview of coffee waste generation in Vietnam. Since few years, there has been a significant research studies was done in the areas of coffee waste generation areas and also waste water generation from coffee production. The coffee residue (solid) and waste water (liquid) both are caused the underground water contamination and also soil contamination. These residues contain high organic matter and acid content leads to the severe threat to environment. In second stage of coffee production process, the major solid residue was generated. Various solid residues such as spent coffee grounds, defective coffee beans and coffee husks) pose several environmental concerns and specific problems associated with each type of residue. Due to the unlimited usage of coffee, the waste generation is high. At the same time, some researchers have been investigated the spent coffee wastes are the valuable sources for various valuable compounds. Biodiesel or biomass productions from coffee waste residues are the best available utilization method for preventing the landfill problems of coffee waste residues.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.588-598
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• 2017

현재 수송용 연료 첨가제로 유통되고 있는 바이오에탄올은 주로 옥수수와 사탕수수와 같은 식용(1세대) 바이오매스를 활용하여 생산된 것으로 농산물 가격상승 및 윤리적인 차원에서 다양한 문제점을 유발할 수 있다. 이를 해결하기 위해 비식용 자원인 목질계 바이오매스를 활용할 수 있는데, 그 예로 짚과 Bagasse (사탕수수 찌꺼기)와 같은 농업부산물과 목재가공 산업에서 발생하는 톱밥 등의 임업 부산물 등이 있다. 따라서 목질계 바이오에탄올 생산은 2세대 바이오매스의 효과적인 활용 경로가 될 수 있으며, 그 원료는 1세대 자원보다 풍부하며 저렴한 원료의 확보가 가능하다. 이러한 바이오연료를 사용함으로써 얻게 되는 가장 큰 장점으로는 화석연료와 달리 환경에 미치는 영향을 최소화하여 온실가스 감축에 기여하는 것을 들 수 있다. 본 연구에서는 목질계 바이오에탄올 활용을 통해 이루어질 수 있는 온실가스 감축효과와 ASEAN 국가(인도네시아, 말레이시아, 태국, 필리핀)에서 현재 시행되고 있는 재생에너지에 대한 정부 정책을 연구하였다. 이러한 네 국가에서는 바이오연료에 관한 많은 정책과 인센티브 등이 발전되어 왔으며, 이산화탄소 배출 감축 목표와 바이오연료 의무 혼합률을 점차 증가시킬 것으로 조사되었다.

• Elastomers and Composites
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• 제56권3호
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• pp.136-151
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• 2021

Biomass lignin, a waste produced during the paper and bio-ethanol production process, is a cheap material that is available in large quantities. Thus, the interest in the valorization of biomass lignin has been increasing in industrial and academic areas. Over the years, lignin has been predominantly burnt as fuel to run pulping plants. However, less than 2% of the available lignin has been utilized for producing specialty chemicals, such as dispersants, adhesives, surfactants, and other value-added products. The development of value-added lignin-derived co-products should help make second generation biorefineries and the paper industry more profitable by valorizing lignin. Another possible approach towards value-added applications is using lignin as a component in plastics. However, blending lignin with polymers is not simple because the polarity of lignin molecules results in strong self-interactions. Therefore, achieving in-depth insights on lignin characteristics and structure will help in accelerating the development of lignin-based products. Considering the multipurpose characteristics of lignin for producing value-added products, this review will shed light on the potential applications of lignin and lignin-based derivatives on polymeric composite production. Moreover, the challenges in lignin valorization will be addressed.

• 청정기술
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• 제23권4호
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• pp.435-440
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• 2017

바이오 연료 생산을 위한 3세대 바이오매스, 즉 미세조류 및 거대조류의 급속 열분해는 최근 1 세대 및 2 세대 바이오매스와 비교하여 실험적으로 연구된 바 있다. 하지만 거대조류의 경우 스케일업을 위한 공정모사 및 공정설계 연구는 거의 전무한 실정이다. 이 연구에서는 갈조류 급속 열분해의 벤치 스케일 실험 데이터에 근거하여 갈조류로부터 최종적으로 디젤을 생산하는 산업 규모의 공정을 상용 공정모사기를 이용하여 설계하고 모사하였다. 이때 육상 바이오매스 대비 갈조류의 조성 차이를 수용하기 위해 공정 설계에 특별한 주의를 기울였다. 연간 380,000톤의 건조 갈조류 원료를 바이오 디젤로 전환하는 전체 공정을 경제적으로 평가하고 최소 (디젤) 판매 가격 또한 산정하였다.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• Korean Chemical Engineering Research
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• 제61권3호
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• pp.412-418
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• 2023

The surge in the oil prices, increasing global population, climate change, and waste management problems are the major issues which have led to the development of biofuels from lignocellulosic wastes. Cellulosic or second generation (2G) bioethanol is produced from lignocellulosic biomass via pretreatment, hydrolysis, and fermentation. Pretreatment of lignocellulose is of considerable interest due to its influence on the technical, economic and environmental sustainability of cellulosic ethanol production. In this study, furniture waste sawdust was subjected to alkaline peroxide (H₂O₂) for the production of reducing sugars. Sawdust was pretreated at different concentrations from 1-3% H₂O₂ (v/v) loadings at a pH of 11.5 for a residence time of 15-240 min at 50, 75 and 90 ℃. Optimum pretreatment conditions, such as time of reaction, operating temperature, and concentration of H₂O₂, were varied and evaluated on the basis of the amount of total reducing sugars produced. It was found that the changes in the amount of lignin directly affected the yield of reducing sugars. A maximum of 50% reduction in the lignin composition was obtained, which yielded a maximum of 75.3% total reducing sugars yield and 3.76 g/L of glucose. At optimum pretreatment conditions of 2% H₂O₂ loading at 75 ℃ for 150 min, 3.46 g/L glucose concentration with a 69.26% total reducing sugars yield was obtained after 48 hr. of the hydrolysis process. Pretreatment resulted in lowering of crystallinity and distortion of the sawdust after the pretreatment, which was further confirmed by XRD and SEM results.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.349-352
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• 2007

The Fourth Assessment Report of IPCC predicted that global warming is already happening and it should be caused from the increase of greenhouse gases by the extension of human activities. These global changes will give a serious influence for human society. Global environment can be monitored by the earth observation using satellite. For the observation of global climate change and resolving the global warming process, satellite should be useful equipment and its detecting data contribute to social benefits effectively. JAXA (former NASDA) has made a new plan of the Global Change Observation Mission (GCOM) for monitoring of global environmental change. SGLI (Second Generation GLI) onboard GCOM-C (Climate) satellite, which is one of this mission, provides an optical sensor from Near-DV to TIR. Characteristic specifications of SGLI are as follows; 1) 250 m resolutions over land and area along the shore, 2) Three directional polarization observation (red and NIR), and 3) 500 m resolutions temperature over land and area along shore. These characteristics are useful in many fields of social benefits. For example, multi-angular observation and 250 m high frequency observation give new knowledge in monitoring of land vegetation. It is expected that land products with land aerosol information by polarization observation are improved remarkably. We are studying these possibilities by ground data and satellite data.