• 신재생에너지
• /
• 제16권4호
• /
• pp.83-91
• /
• 2020

In this study, the reusability of the Fenton oxidation solution was evaluated to reduce the cost of the pretreatment process. Biomass was sequential subjected to Fenton oxidation-hydrothermal treatment and enzymatic hydrolysis to produce monosaccharides. The liquid solution recovered after Fenton oxidation contained OH radicals with a concentration of 0.11 mol/L. This liquid solution was reused for a new Fenton oxidation reaction. After Fenton oxidation, hydrothermal treatment was performed under the same conditions as before, and 9.34-13.63 g/L of xylose was detected. This concentration was slightly lower than that of a fresh Fenton oxidation solution (16.51 g/L) but was higher than that obtained by hydrothermal treatment without Fenton oxidation (2.72 g/L). The degradation rate during hydrothermal pretreatment involving Fenton oxidation was 36.02%, which decreased (29.24-31.05%) slightly when the liquid solution recovered after Fenton oxidation was reused. However, the degradation rate increased compared to that measured from hydrothermal treatment without Fenton oxidation (15.21%). Moreover, the yield after enzyme hydrolysis decreased in the following order: fresh Fenton oxidation-hydrothermal treatment (89.64%) > Fenton oxidation with reused solution-hydrothermal treatment (74.84%) > hydrothermal treatment without Fenton oxidation (32.05%).

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
• /
• pp.63-68
• /
• 2007

An experimental study was carried out to investigate gasification process of wood sawdust in the 1-dimensional downdraft fixed bed gasifier. The preheated air which was used oxidizer and steam were used as a gasifying agent. The downdraft fixed bed gasifier obtains more amount of hydrogen and methane by increasing residence time of supplied air. The operating parameters, the supplied air temperature and steam were used. The oxidizer temperature was varied from 500K to 620K and vapor was added. The gasification process was monitored by measuring temperature at three position near the biomass using R-type thermocouples and the syngas composition was analyzed by gas chromatograph. We get the sample gas at the end of gasifier and it was eonugh time to finishing the chemical reaction. Finally, the amount of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.

• 한국산림과학회지
• /
• 제102권4호
• /
• pp.484-490
• /
• 2013

본 연구는 낙엽송 개체목의 가공처리 과정에서 생산되는 제재목 및 제재 부산물의 양을 분석하기 위한 시뮬레이션 모델을 개발하고자 수행되었다. 이 모델에서는 수간곡선 추정식을 이용하여 개체목의 전간재적을 산출하고 절동된 원목에 대한 목재 가공 시뮬레이션을 통해 판재 및 각재, 원주목의 규격에 따른 최대 생산가능량을 예측하였다. 또한 제재목 가공처리 과정에서 생산되는 톱밥 및 죽데기의 잔존재적에 대한 분석을 수행하였다. 그 결과 흉고직경 12 cm 이상부터 제재목의 생산이 가능한 것으로 나타났고, 제재목의 생산이 가능한 경우에는 보다 큰 규격의 판재와 각재를 생산하는 것이 상대적으로 작은 규격의 판재와 각재 혹은 원주목을 생산하는 것에 비해 더 많은 생산량을 얻을 수 있었다. 향후 이 모델은 낙엽송의 이용재적 산출을 통한 산림의 경제적 가치평가는 물론, 최근 목질계 바이오에너지 자원으로서 그 중요성이 점차 높아지고 있는 톱밥과 같은 제재 부산물의 양을 예측하는 데에도 활용될 수 있을 것이다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 춘계학술대회
• /
• pp.482-486
• /
• 2005

Total forest growing stock and growing stock per ha in Korea are $470\times10^6m^3\;and\;73m^3$, respectively. Those figures mean that forest growing stock was increased 4.7 times more during last 30 years. The annual production of forest biomass comes from forest tending executed by Korea Forest Service was estimated about $1.07\times10^6m^3$ M/T, which was equivalent to $0.45\%$ of total imported crude oil of Korea at 2002. The production is expected to increase and reach up to $1.9\times10^6 M/T$ till 2008. The analysis of economic feasibility showed that the production cost of wood chip(134,786Won/T) was about 30,389 Won/T higher than heat value of wood chip, 104,397 Won/T estimated from that of kerosene. For the promotion of forest bioenergy utilization, more efforts need to be given for the education and public relations to induce publicity a willingness-to-pay for the environment friendly fuels under the good understanding for the use of bioenergy. In addition, we need to provide a community-based biomass utilization program by region to allocate the role of each participant and to increase the profitability of bioenergy.

• 펄프종이기술
• /
• 제48권1호
• /
• pp.53-60
• /
• 2016

Abiotic-stressed tobacco stems as a non-wooden biomass were analyzed for their chemical characteristics. Light-stressed tobacco stems (LST) have a relatively high nitrogen concentration, much more extractive content, and a similar amount of lignin and higher contents of acid sugars than those of Non stressed tobacco (NST). It also has low cellulose crystallinity and a high degree of condensation. Guaiacyl units having a lower molecular weight distribution consist of rich lignin. Tension stressed tobacco (TST) growth differentiation under tensile stress was significantly different between normal tissue and cell walls, with the exception of the slightly higher cellulose crystallinity observed for.

• Journal of the Korean Wood Science and Technology
• /
• 제46권4호
• /
• pp.309-314
• /
• 2018

Size reduction is an important pre-processing operation for utilizing biomass as a sustainable resource in industrial-scale energy production and as a raw material for other industries. This work investigates the size reduction characteristics of air-dried Miscanthus sacchariflorus Goedae-Uksae 1 (Amur silver grass) via image processing and identifies the morphological characteristics of comminuted and screened M. sacchariflorus. At chopping lengths of 18, 40, 80, and 160 mm, 81%, 77%, 78%, and 76% of the particles, respectively, passed through a 4-mm sieve. Even a knife mill with a very small screen aperture (>1 mm) admitted over 10% of the particles. The average circularity and aspect ratio of the particles were <0.30 and >10, respectively. These results confirm that in all preparation modes, most M. sacchariflorus particles were needle-like in shape, irrespective of the type of preparation.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2011년도 춘계학술발표회 논문집
• /
• pp.171-178
• /
• 2011

During the last decades, global warming from the increased amount of greenhouse gases, mainly carbon dioxide has become a major political and scientific issue. Burning fossil fuels (natural gas, coal and oil) releases $CO_2$, which is also a major cause of global warming. Among the clean environment, wood pellets are considered as promising renewable fossil fuels because of clean burning characteristics, reduction of particulate and NOx emission from combustion. In Korea, more than 50% pellets have to be imported every year because of shortage of feedstocks. On the other hand, about 80% of wood pulps are greatly dependent upon overseas products due to limited forest resources. Under this situation, this study explored how efficiently we have to use forest biomass instead of total dependence on wood as raw materials for pellets.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2005년도 학술발표논문집
• /
• pp.586-591
• /
• 2005

Syngas or fuel gas production through biomass gasification is a century old technology. Biomass gasification is getting more and more interest recently as one of competitive renewable energy technologies. It does not contribute to increasing greenhouse gases(GHG). A down-draft gasifier was designed and tested for syngas quality using different fuel sets in this study. The gasifier was of about 100kW capacity. Tests were conducted at air flow rates ranging from 10 to $60m^3/hr$. Fuels tested included wood chips and wood char. The results showd that gas quality in terms of flammability was reasonably good when the temperatures were over $600^{\circ}C$ inside the gasifier. Although $800^{\circ}C$ or higher is recommended, gas quality was reasonably good. If insulation was provided outside the gasifier, the temperature would increase. When wood chips were used, the temperature was below $600^{\circ}C$ and gas quality was not good. It seemed that calorific values of fuel and height of reduction zone in the gasifier are very important. The results of the tests would provide important information for designing more improved gasifier and its operation.

• Journal of the Korean Wood Science and Technology
• /
• 제47권4호
• /
• pp.442-450
• /
• 2019

Despite its potential as a renewable source for fuels and chemicals, lignin valorization still faces technical challenges in many aspects. Overcoming such challenges associated with the chemical recalcitrance of lignin can provide many opportunities to innovate existing and emerging biorefineries. In this work, we leveraged a biomass genetic engineering technology to produce phenolic aldehyde-rich lignin structure via downregulation of cinnamyl alcohol dehydrogenase (CAD). The structurally altered lignin obtained from the Arabidopsis thaliana CAD mutant was pyrolyzed to understand the effect of structural alteration on thermal behavior of lignin. The pyrolysis was conducted at 400 and $500^{\circ}C$ using an analytical pyrolyzer connected with GC/MS and the products were systematically analyzed. The results indicate that aldehyde-rich lignin undergoes fragmentation reaction during pyrolysis forming a considerable amount of C6 units. Also, it was speculated that highly reactive phenolic aldehydes facilitate secondary repolymerization reaction as described by the lower yield of overall phenolic compounds compared to wild type (WT) lignin. Quantum mechanical calculation clearly shows the higher electrophilicity of transgenic lignin than that of WT, which could promote both fragmentation and recondensation reactions. This work provides mechanistic insights toward biomass genetic engineering and its application to the pyrolysis allowing to establish sustainable biorefinery in the future.

• 펄프종이기술
• /
• 제45권1호
• /
• pp.13-20
• /
• 2013

In this study, oil palm biomass such as empty fruit bunch (EFP) and palm kernel shell (PKS) was used as raw materials for making pellets. EFB and PKS are valuable lignocellulosic biomass that can be used for various purposes. If EFB and PKS are used as alternative raw materials for making pellets instead of wood, wood could be saved for making pulps or other value-added products. In order to explore their combustion characteristics, EFB and PKS were analyzed using thermal gravimetric analyzer (TGA) with ultimate and proximate analyses. From the TGA results, thermal decomposition of EFB and PKS occurred in the range of 280 to $400^{\circ}C$ through devolatilization and combustion of fixed carbon. After $400^{\circ}C$, their combustion were stabilized with combustion of residual lignin and char. PKS contained more fixed carbons and less ash contents than EFB, which indicated that PKS could be more active in combustion than EFB.