Ethanol production from various agricultural and forest residues has been widely researched, but there is limited information available on the use of mixed hardwood for ethanol production. The main objective of this study is to assess the impact of time on the steam explosion pretreatment of waste wood (mixed hardwood) and to determine the convenience of a delignification step with respect to the susceptibility to enzymatic hydrolysis of the cellulose residue and the recoveries of both cellulose and hemicellulosic sugars. Delignification did enhance enzymatic hydrolysis yields of steam exploded waste wood. For steam explosion pretreatment times of 3 and 5 min, the recovery yield of hemicellulosic-derived sugars decreased. The effective hemicellulose solubilization does not always result in high recoveries of hemicellulose-derived sugars in the liquid fractions due to sugar degradation. In the steam explosion pretreatment times of 3 and 5 min, where hemicellulose solubilization exceeded 95%, but sugar recoveries in the liquid fraction remained below 30%. Cellulose to glucose yield losses were less significant than hemicellulosic-sugar losses, with a maximum loss of 24% at 5 min. Up to 80% of the lignin in the original wood was solubilized, leaving a cellulose-rich residue that led to a concentrated cellulose to glucose yield solution (about 50 g/L after 72 h enzymatic hydrolysis in the best case). The maximum overall process yield, taking into account both sugars present in the liquid from steam explosion pretreatment and cellulose to glucose yield from the steam exploded, delignified and hydrolyzed solid was obtained at the lowest steam explosion pretreatment time assayed.

There is a large amount of radioactive waste in waste storage in the Korea Atomic Energy Research Institute. Some of the radioactive waste was generated during the dismantling process due to Korea Research Reactor 1&2 and it accounts for 20% of the total waste. Radioactive waste must be reduced by appropriate disposal methods to secure storage space and to reduce disposal costs. Research Reactor wastes include wastes that are below the acceptable criteria for selfdisposal and non-contaminated wastes, so they can be treated as wastes subject to self-disposal through contamination analysis and reclassification. In order to deregulation radioactive waste, it is necessary to meet the self-disposal standards stipulated in the Domestic Nuclear Act and the treatment standards of the Waste Management Act. The main factors of deregulation are surface contaminant, radionuclide activity and dose assessment. To confirm the contamination of waste, surface contaminant and gamma nuclide analysis were performed. After homogenizing the waste sample, it was placed in 1 L Mariinelli beaker. When collecting waste samples, 1 kg per 200 kg of waste was collected. The concentrations of the major radionuclides Co-60, Cs-134, Cs-137, Eu-152, and Eu-154 were analyzed using HPGe detector. To evaluate radiation dose, various computational programs were used. A dose assessment was performed with the analyzed nuclide concentration. The concentrations of representative nuclides satisfied the deregulation acceptance criteria and the results of the dose assessment corresponding to self-disposal method was also satisfied. Based on this results, KAERI submitted the report on waste self-disposal plan to obtain approval. After final approval, Research Reactor waste is to be incinerated and incineration ash is to be buried in the designated place. Some metallic waste has been recycled. In this study, the suitability of deregulation for self-disposal was confirmed through the evaluation of the surface contaminant analysis, radionuclide concentration analysis and dose assessment.

In KAERI, Waste storage facility in the radiation management area has stored a large amount of wood waste. The amount of waste is approximately 27,000 kg, it accounts for 17% of the total waste in waste storage facility. Proper disposal of wood waste improves the fire resistance performance, secure storage space and reduce disposal costs. In order to self-disposal of wood waste, it is necessary to satisfy the self-disposal standards stipulated by the domestic Atomic Energy Act and the treatment standards of the Waste Management Act. The main factors of standards are surface contaminant, radionuclide activity and radiation dose effects. To confirm the contamination of wood waste, direct indirect measurement methods and gamma nuclide analysis were performed. To evaluate radiation dose, various computational programs were used. The results of the analysis were satisfied with domestic regulations on the classification and self-disposal of radioactive wastes. Based on this results, KAERI submitted the report on wood waste self-disposal plan to obtain approval. After final approval, wood waste is to be incinerated and incineration ash is to be buried in the designated place. The objective of this study is to provide total procedure of wood waste self-disposal and effective representative sampling method.

최근 탄소 중립 정책에 따른 신재생에너지 활용을 위한 노력이 가속화되고 있다. 이를 위하여 본 연구에서는 바이오매스 작물 중 하나인 케나프 (Hibiscus cannabinus L.)를 연료화하기 위하여, 미이용 목재 자원과 폐목재 자원을 혼합하여 고형연료인 펠릿을 제조하고 품질을 분석하였다. 품질을 평가하기 위해 목재 펠릿, 비목재 펠릿과 Bio-SRF의 품질기준을 통해 성형한 펠릿의 품질을 파악하였다. 케나프 펠릿의 경우 겉보기밀도, 발열량 등에서는 목재 펠릿 품질기준을 만족하였으나 회분의 함량이 기준을 초과하였다. 이를 보완하기 위해 목재 자원인 폐목재를 혼합하여 제조한 펠릿의 특성을 조사한 결과, 질소 및 겉보기밀도, 회분, 발열량 등에서 오히려 품질을 저하시키는 경향을 보이는 것으로 나타났다. 한편, 미이용 목재를 혼합하여 성형된 펠릿의 품질을 조사한 결과, 겉보기밀도, 함수율, 질소, 황, 발열량의 조건에서 대부분 목재 펠릿의 품질기준을 만족하였다. 다만 회분함량의 경우 비목재 펠릿 및 Bio-SRF의 15% 이하 기준을 만족하고 있지만, 목재 펠릿의 최저 기준인 B등급 2.0% 이하 기준의 경우 만족하는 경우와 만족하지 못하는 경우가 발생하였다. 함수율 15%(w.b.)에서 케나프와 미이용 목재의 혼합비가 2:8인 경우와 함수율 20%(w.b.)에서 케나프와 미이용 목재의 혼합비가 6:4 및 2:8인 경우에 기준을 만족하였고, 그 이외에는 기준을 만족하지 못하였다. 특히, 케나프만을 사용하거나 폐목을 섞은 경우는 모두 기준을 만족하지 못하므로, 목재 펠릿의 기준을 만족하는 연료 이용을 위해서는 케나프와 미이용 목재 자원을 혼합 활용하는 것이 바람직할 것으로 판단된다.

Sustainable biomass-derived porous carbons demonstrate excellent capacitive properties owing to their heteroatom-rich nature and distinct textural feature. Herein, a series of nitrogen-/phosphorus-/oxygen-containing microporous carbons (CWWN/ P/O-MPCs) have been successfully fabricated by etching in H2O2 solution, pre-treatment of camphor wood wastes with KOH solution and subsequent carbonization. As an electrode material for supercapacitors, the typical microporous carbon (CWW-N/P/O-MPCs-0.5) exhibits a remarkably high specific capacitance of 245 F g− 1 at 0.5 A g− 1, corresponding to an impressively large volumetric capacitance of 208 F m− 3, and excellent long-term stability over 10,000 cycles. The excellent electrochemical performance can be ascribed to the optimal combination of heteroatom groups and ultrafine micropores.

바이오매스는 지속가능한 에너지원의 일종으로 다양한 공정에 따라 바이오 에탄올, 바이오 디젤, 바이오 가스 등으로 회수하여 석유자원의 대체제로 사용 가능하다. 그 중 목질계 바이오매스는 주로 셀룰로오스, 헤미셀룰로오스, 리그닌으로 이루어져 있으며, 셀룰로오스는 바이오 에탄올 등의 연료화를 통해 이용되고 있으나, 리그닌의 경우 펄프 공정 내 부산물로 여겨져 단순 연소를 통한 열에너지원으로서의 역할을 하고 있다. 하지만 리그닌은 자연에서 가장 많이 존재하는 페놀성 고분자 화합물의 일종으로, 이를 이용한 페놀 수지, 에폭시 수지, 접착제 등의 화학약품화 및 탄소섬유로 소재화하는 등의 리그닌 부가가치화 연구사례가 많아지고 있다. 본 연구 대상인 폐목재는 2015년 기준 연간 약 170만 톤이 발생하고 있으며 약 70%가 재활용되어지고 있으나, 3등급 폐목재의 경우 가공과정에서 페인트, 기름, 방부제, 접착제 등 다량의 불순물이 함유되어 재활용 시 많은 제약을 두고 있다. 이러한 폐목재의 특성을 고려한 재활용 방안에 대한 연구의 필요성이 존재한다. 본 연구는 3등급 폐목재를 대상으로 organosolv 전처리법을 이용한 최적 리그닌 분해 조건 도출 및 UF/NF 멤브레인 시스템 적용을 통한 폐목재 내 목적으로 하는 분자량을 가진 리그닌의 고순도 분리 추출을 목적으로 하고 있다. 또한 분리된 리그닌의 FT-IR, NMR, TGA 분석을 통해 폐목재 리그닌의 재활용 가능성을 검토해보고자 한다.

최근 세계적으로 신재생에너지에 대한 관심이 커지고 있으며, 국내의 경우 폐바이오매스를 이용하는 친환경적인 에너지원으로써 활용할 수 있는 연료화 기술이 각광받고 있다. 국내 폐바이오매스는 크게 식품폐기물, 축산폐기물, 농산부산물, 임산부산물 및 하수슬러지 등으로 구분할 수 있으며, 이를 에너지원으로 전환하는 공정은 생물학적, 열화학적 공정으로 크게 구분할 수 있다. 국내 하수슬러지의 경우, 해양투기가 금지된 이후 에너지로 전환하여 재활용하기 위한 연구가 활발히 진행되고 있으며, 2014년 환경부에 따르면 전국 하수슬러지 처리시설은 98개 지자체에서 96개의 하수슬러지 처리시설이 운영되고 있고, 추가적으로 18개의 시설이 설계 및 건설되고 있다. 이 중 대부분의 시설은 고화 및 건조연료화를 통해 하수슬러지 처리량 저감을 하고 있으나, 고화 및 건조 연료화를 통한 하수슬러지 저감은 슬러지 자체의 높은 수분함량으로 인해 상대적으로 많은 에너지를 필요로 한다. 본 연구는 하수슬러지의 연료화를 위해 열화학적 공정 중 하나인 반탄화 공정을 이용하여 10 TPD급 폐바이오매스 반탄화 반응 시스템을 구성하였다. 원료물질인 하수슬러지의 높은 수분함량에 따른 열량 부족 문제를 극복하기 위해 폐목재를 혼합하여 사용하였으며, 반응온도(250-350℃)와 하수슬러지와 폐목재 혼합물의 혼합비(6:4, 4:6)에 대하여 운전 조건의 최적화 연구를 수행하였으며, 결과적으로 반탄화물 수율 70% 이상, 생성된 탄화물의 고위발열량 4,000 kcal/kg 이상의 운전조건을 도출할 수 있었다. 이와 더불어 생산된 반탄화물의 원소분석에 따른 C, H, O의 구성비는 저품위 석탄과 유사하게 나타남을 확인할 수 있었다.

Global increase in energy consumption has been known to cause the depletion of fossil fuels, and results in the increase of coal and oil price. Recently, waste to energy policy has received attention more and more, Korea imports approximately 97% of its total energy consumed, and there is an urgent necessity for the development of alternative energy source. Domestic waste management policy aims at zero waste community, which can be explained as the concept of 4R. The 4R consists of existing 3R (Reduce, Reuse and Recycle) and Recovery policies. Conversion of waste to energy, a form of renewable energy, has been known as an effective alternative for the increasing energy crisis. In this study, waste wood generated in D city was investigated as one of the alternative energy source. Expecially, the conversion of waste wood to solid refuse fuel (SRF) as an energy source was focused on. As an initial step to evaluate the applicability of waste wood as the alternative energy source, the waste wood sample were characterized by a proximate analysis and element and heavy metal contents analyses. In addition, heating values of the waste wood were calculated by presumption equation and Dulong's equation, and measured by bomb calorimeter. In summary, waste wood can be considered as one of the alternatives for effective energy source by meeting Korea standards for the quality and grade of SRF such as in lowheating values, contents of moisture, sulfur, and chlorine, and heavy metal contents

Hydrothermal carbonization (HTC) is a highly effective technique for treating lignocellulosic biomass and organic waste of various shapes and moisture content. The solid product of HTC is friable, hydrophobic, and increased in mass and energy densification compared to the raw biomass. also solid product is similar regardless of the type of biomass used. A liquid solution of five carbon and six carbon sugars, along with various organic acids and 5-HMF, is also produced from HTC of lignocellulosic biomass. The gaseous phase product consists mostly of CO2. Solid product has the similar characteristics to low rank coal. The solid fuel characteristics of feedstock was increased with reaction temperature and time via HTC process. However, mass yield was decreased with increasing temperature and time. Therefore, it is necessary to optimize the reaction temperature and time for HTC. The HTC process produces the solid product and a large amount of water. Thus the reuse or treatment techniques of liquid product is necessary. Therefore, potential of biological treatment of HTC liquid product was evaluated.

According to the quality standards of the BIO-SRF(Bio-Solid Fuel Products) in Act on the Promotion of Saving and Recycling of Resources enforcement regulations, chloride is regulated to less than 0.5wt.%. The reason why chloride was regulated may generate HCl and dioxin when bio-solid fuel was burnt. Chloride and chloride compounds can be presented the characteristic of corrosiveness. These materials is reacted with iron to produce ferric chloride. Ferric chloride is oxidized to ferric oxide and ferric oxide can cause a pipe corrosion to short boiler life in combustion facility. There are several reactions to reduce Cl concentration in organic wastes and some wastes can be used in nucleophile reaction as reductive agents. Nucleophile(Nu) material can be represented by phosphate, nitrate, sulfate etc. Nu materials can substitute them for chlorine-based compounds(X-: Cl-, Br-, I-). Nu materials can reduce the harmfulness and chlorine concentration by substituting them for chlorine-based compounds of the solid fuel product produced by carbonization. In order to produce solid fuel product from organic wastes, carbonization among pyrolysis processes is suitable because nucleophile reaction should be an endothermic reaction, which heat must be entered to solid fuel product from outside. In this study, sewage sludge is used as a reductive agent to evaluate the characteristics of the reduction reaction in carbonization process because a large amount of Nu material is contained in sewage sludge. In order to evaluate the effect of Nu materials to control chloride in the residue of carbonization, waste wood mixed with sewage sludge was used in carbonization process.

Recently, the energy supply uses mostly fossil fuels such as coal, petroleum, natural gas etc... however, they are limited and they present an issue for the environment. Biomass derived energy is considered promising for reducing the emissions of CO2, the significant contributor to global warming. Also it can be converted to various forms of energy through thermochemical conversion processes. In this study, a screw gasifier has been engineered for wood biomass gasification. Waste wood chip was used as biomass and the producer gas, tar; char were then achieved by gasification in the presence of CO2. The results showed that with the increase of the gasification temperature, the producer gas increased and the tar decreased. Also, due to thermal cracking, the light tar increased by the decomposition of the gravimetric tar. And a development of char pore structure was confirmed by SEM. The gasification of biomass in the presence of CO2 at 800oC produced an increase in the concentration of carbon monoxide according to the Boudoudard reaction and an increase in the char pore surface as well as its adsorption capacity. Thus the biomass gasification in the presence of CO2 was confirmed to be effective for the production of CO and the development of char.

The IPCC methodology for estimating methane emissions from a solid waste landfill is based on the first order decay (FOD) method. One emission factor in the model is the methane generation potential (L0) that is estimated from the amount of decomposable degradable organic carbon (DOC) in a solid waste landfill. L0 is estimated based on the fraction of DOC in the waste, the fraction of the degradable organic carbon that decomposes under anaerobic conditions (DOCf), methane correction factor (MCF), and the fraction of methane in generated landfill gas (F). The other emission factor is the methane generation rate constant (k). The IPCC recommended that every country needs to develop country-specific key parameters (DOC, DOCf, k) more appropriate for its circumstances and characteristics. The objective of this research was to investigate the greenhouse gas emission factor (k) and parameters (DOC, DOCf) for wood wastes in a solid waste landfill. To investigate DOC, DOCf, and k for wood wastes, the biodegradable rate of wood wastes was determined by comparing the composition of excavated samples (L-1, L-2) with their fresh ones (F-1, F-2). The DOC values were found to be 48.36% and 45.27% for F-1 and F-2, respectively. It showed that the IPCC default value of DOC for wood wastes is appropriate for estimating methane emission. The maximum DOCf (0.17 and 0.18) or each wood waste excavated from G landfill was found to be lower compared with those for IPCC. The IPCC provided that default values of DOCf 0.5. The k values were found to be 0.0055 and 0.0058 year−1 for F-1 and F-2, respectively. The result confirmed that the biodegradation rate of wood wastes was very slow due to its lignin.

In order to utilize waste wood chip for pavement, a polyurethane resin that is both eco-friendly and suitable for bindingwood chip was developed as the binder, and workability was examined through laboratory experiment for characteristicsof waste wood chip mixture using the polyurethane resin and through test pavement on the field. The new resin was aVOC reduction type free from plasticizer and solvent classified as endocrine-disrupting chemicals and environmentalhazardous substances, and NCO equivalents were set at 8, 9, 10 and 11% by modifying the polyisocyanate-polyol ratio.Laboratory experiment showed that polyurethane resin with NCO equivalent of 9% and 10% had excellent characteristicsas binder for waste wood chip. In the field experiment applying waste wood chip and polyurethane resin in the massratio of 1:0.8, tensile strength of the pavement system was about 30% higher than that using polyurethane resin currentlybeing sold, and permeability coefficient and elasticity thereof were the same as that using the resin currently being sold.Also, examination of compaction methods for waste wood chip pavement system showed that non-heating hand rollerand compactor had the problem of the “waste wood chip - resin mixture” sticking to the roller during the compaction but that heating hand roller had excellent workability and could achieve good planation surface relatively easily.

SLC has installed and operated a 50 tons/day scale pilot plant of construction & demolition waste (c&d waste) separation/ selection pilot plant in order to utilize wood wastes among construction wastes carried into landfill sites as energy sources, etc. In the present study, for optimized operation of the aforementioned pilot plant, the characteristics of operation of the plant were assessed in relation to changes in operation conditions and the characteristics of inputted wastes. Based on the results of an experiment conducted to select sieves of vibrating screens for the discharge of incombustible materials, wood waste recovery rates were the highest when 8mm sieves were applied but the purity of wood wastes and combustible materials was higher when 20 mm sieves were applied. By supplementing the shape of the overflower of the wet separator, combustible materials stagnant in the water tank were reduced and the rate of recovery of combustible materials including wood was improved by around 10%. It was identified that not only the amounts of wood wastes and combustible materials among inputted wastes but also the ratio of coarse combustible materials to entire combustible materials could affect operation time. Therefore, if processes to select or smash coarse combustible materials in advance are added and bottle neck points are supplemented to be prepared for an increases in the amount of inputted combustible materials, construction wood waste selection/separation facilities could be stably operated even when the characteristics of inputted wastes are changed.