반탄화 목분과 폐활성탄 혼합물의 복합연료활용을 위한 연료적 특성에 관한 연구

이창구 ( Chang Goo Lee ),강석구 ( Seog Goo Kang ) 한국목재공학회 2015 목재공학 Vol.43 No.1

This study evaluated fuel properties of composite materials which were prepared by mixing a waste activated carbon from the used purifier filter with torrefied wood powder. Wood species of the raw material of torrefied wood powder are oak wood (Quercus serrata Thunb. ex Murray) and pine wood (Pinus densiflora Siebold & Zucc). And the treatment conditions used for this study were 300 s, 450 s, and 600 s at 200℃ for the wood roaster. Also, the mixing ratios are 5 : 95, 10 : 90, 15 : 85, 20 : 80, 40 : 60, 60 : 40 and 80 : 20 (waste activated carbon : torrefied wood powder). The fuel properties such as highly heating value (HHV), elementary analysis and ash content were evaluated. The results obtained are followings; 1. Despite the same treatment condition of wood roasting, pine wood has higher carbon contents than oak wood. Therefore, pine wood indicated the optimum carbonization at low temperature and short treatment times. 2. The gross calorific value and ash content increased as the mixing ratio of waste activated carbon increased. 3. Mixtures of the waste activated carbon and torrefied wood powder showed greater gross calorific value than those of the mixtures of waste activated carbon and the untreated wood powder. Also, the pine wood resulted in higher heating value that thaose of the oak wood. 4. When composite fuels that were composed waste activate carbon and wood powder are used, higher temperature conditions are required because the combustion is incomplete at 800℃ and 4 hours. 5. The increasing rate of the gross calorific value of mixtures of waste activated carbon and untreated wood powder is higher than does the mixtures of waste activated carbon and torrefied wood powder. Also, this phenomenon is more obvious for pine woods. Therefore, an optimal mixing ratio of waste activated carbon was determined to be between 5% and 10% (wt%). Also, this condition satisfied the requirement of the No.1 grade of wood pellet.

반탄화 목분을 이용한 계면활성제의 흡착 및 생태독성에 관한 연구

이석언(Seok Eon Lee),오영환(Young Hwan Oh),이학주(Hak Joo Lee),한현조(Hyun Jo Han),남정빈(Jeong Bin Nam),양승민(Seung Min Yang),강석구(Seog Goo Kang) 한국펄프·종이공학회 2017 펄프.종이技術 Vol.49 No.6

The area with damaged wood by pest in Korea currently covers about 10.1 thousand hectares, which is annually increasing. In this study, an application possibility of torrefied wood flour made from those damaged wood as a water treatment agent has been examined as compared with activated carbon, the existing one. Torrefied wood flour has been manufactured out of damaged wood by pest under the condition of high heat treatment, and an experiment with surfactant on the effect of water treatment has been conducted using to the torrefied wood flour through this study. While surfactant is a major cause of water pollution, it is being used in various ways such as medicine, detergent and agricultural chemicals, which brings about many social problems. In the experiment, adsorbent was mixed with C-PAM, torrefied wood flour and activated carbon in a ratio of ten to one respectively. Also, activated carbon, a current water treatment agent, was to be used as comparative material. Biodegradability, adsorption performance according to the change of concentration, and ecotoxicity value of surfactant has been tested in this study to figure out its possibility as an adsorbent. It has been confirmed that the surfactant degraded by about 90% within 15 days. In the light of the change in concentration of surfactant, both torrefied wood flour and activated carbon have the adsorption capacity as surfactant. It appeared that the adsorption performance of torrefied wood flour was about 20% higher than that of activated carbon when its dosage condition was 2%. In addition, the TU value in ecotoxicity from the filtrate of the processed torrefied wood flour with the highest adsorption. In conclusion of the study, it has been confirmed that, based on the result of ecotoxicity value and adsorption performance of surfactant, torrefied wood flour has an application possibility as a water treatment agent which can replace activated carbon.

고열처리 반탄화 목재 및 지방산을 활용한 성형 숯 착화물질 대체 가능성 평가

이현재,양승민,강석구 한국폐기물자원순환학회 2023 한국폐기물자원순환학회지 Vol.40 No.5

The study explores the potential of torrefied wood powder combined with fatty acids as an alternative ignition material for molded charcoal. The viability of this alternative was confirmed by evaluating its fuel properties, including the combustion rate, fixed carbon content, calorific value, ignition time, and combustion rates. The optimal torrefaction conditions for the wood flour were identified as a 20-minute treatment at 350oC, leading to the best fuel performance and the increased fixed carbon content from 10% to roughly 19%. Although torrefied wood powder has a lower fixed carbon and calorific value than charcoal, it has superior ignition capabilities and a higher combustion rate. When the charcoal-to-torrefied wood powder ratio reaches 7:3, the calorific value exceeds 6400 Cal/g, with a fixed carbon content of 65%. This also allows for a reduction in ignition time by approximately 12 seconds. Notably, the ignition efficiency of the torrefied wood powder is considerably enhanced when combined with fatty acids. The most significant improvement in ignition performance is observed when the fatty acid is melted and blended with the torrefied wood powder. Furthermore, when the standard barium nitrate and sodium nitrate mixture is substituted with torrefied wood powder combined with molten fatty acid, there is a notable increase in the fixed carbon content. This results in a rapid decrease in ash content, thereby improving the fuel's properties. The ignition time reduces significantly from 17 to 9 seconds, showcasing its potential as a novel ignition material substitute.

과열증기처리 반탄화목분을 이용한 나무연탄 개발 및 혼합비에 따른 연료특성에 관한 연구

강찬영,유승민,강석구 한국가구학회 2018 한국가구학회지 Vol.29 No.4

This study was carried out to develop wood briquettes by torrefied oak wood chips and anthracite coal by mixing ratio. For this purpose, the oak wood chips were torrefied at 300°C with the superheated steam and then mixed with wood powder, anthracite coal and gelatin binder by mixing ratio And then physical, thermal, fuel and microscope characteristics of the briquettes were analyzed. As the physical characteristics, the compression ratio of wood briquettes was higher than that of conventional briquettes. As the thermal properties, the higher the content of torrefied powder, the higher the calorific value but the lower the ash content. As a result of combustion test, 100% Torrefied wood briquette monoxide emission amount by mixing ratio was about 55% lower than conventional briquettes. Also, It was found that the shorter the combustion duration, the higher the content of torrefied powder. As a result of SEM observation, It can be found that the torrefied powder and the anthracite coal powder are physically. chemically bonded to each other due to the adhesion of gelatine. In conclusion, wood briquettes have a high initial temperature rise as the content of torrefied wood powder is high, but burnning time is shortter, so it is considered to be suitable for the case where it is necessary to heat up quickly or to use energy-consuming equipment in a short time.

강우 시 흙탕물 발생 하천의 수질 개선을 위한 반탄화 목재 분말혼합응집제 활용 가능성 연구

이현재,양승민,강석구 한국폐기물자원순환학회 2023 한국폐기물자원순환학회지 Vol.40 No.5

This study investigates a Torrefied wood flour mixed coagulant prepared by mixing torrefied wood flour with a strong negative charge and a cationic polyacrylamide. The effectiveness of the prepared coagulant in improving muddy water quality was verified by comparing turbidity, pH, dissolved solids content, total phosphorus (T-P), and total nitrogen (TN) removal rates for different coagulant types and injection amounts. Due to the water quality characteristics of each water treatment agent, the torrefied wood powder mixed coagulant led to a marginal PH reduction. Conversely, PAC showed a large pH drop, a decrease in turbidity improvement effect, and an increase in dissolved solids around pH 4.3. In terms of turbidity improvement effect, the torrefied wood powder mixed coagulant showed the best performance. However, with PAC, the turbidity improvement effect varied depending on the input amount and was about 13% compared to the maximum turbidity improvement effect under the 0.75 mL/L input condition. The torrefied wood powder mixed coagulant showed no substantial difference in turbidity improvement effect with varying input amounts and achieved a turbidity improvement effect and sedimentation rate about 10 times faster than PAC. Similar to the turbidity improvement effect, the T-N and T-P removal performance of PAC decreased rapidly compared to the 0.1 mL/L input condition under the input conditions between 0.25 mL/L and 1 mL/L. For an input amount of 0.75 mL/L or less, the torrefied wood powder mixed coagulant had better T-N removal efficiency. In the case of T-P, the torrefied wood powder mixed coagulant showed a higher removal rate than PAC at an input amount of 0.5-0.75 mL/L, with a removal rate of 65-85% compared to the PAC input in other ranges.

A Study on the Applicability of Torrefied Wood Flour Natural Material Based Coagulant to Removal of Dissolved Organic Matter and Turbidity(용존성 유기물질 및 탁도 제거를 위한 반탄화목분 천연재료 혼합응집제의 적용성에 관한 연구)

( Hae Keum Park ),( Seog Goo Kang ) 한국목재공학회 2020 목재공학 Vol.48 No.4

With the emergence of abnormal climate due to the rapid industrialization, the importance of water quality management and management costs are increasing every year. In Korea, for the management of total phosphorus and total nitrogen, the major materials causing the water quality pollution, coagulants are injected in sewage treatment plants to process organic compounds. However, if the coagulant is injected in an excessive amount to PAC (Poly Aluminium Chloride), a secondary pollution problem might occur. As such, a study on the applicability of natural material-based coagulant is being conducted in Korea. Thus, this study aimed to evaluate the applicability of a mixed coagulant developed by analyzing water quality pollutants T-P, T-N as well as their turbidity, in order to derive the optimum mixing ratio between PAC and torrefied wood flour for the primary settling pond effluent. Under the condition where the content of PAC (10%) and torrefied wood flour is 1%, T-P showed the maximum removal efficiency of 92%, and T-N showed approximately 22%. This indicates that removal of T-N which includes numerous positively charged organic compounds that are equivalent to mixed coagulant is not well accomplished. Turbidity showed the removal efficiency of approximately 91%. As such, 1% of torrefied wood flour was determined to be the optimum addition. As a result of analyzing the removal efficiency for organic compounds by reducing PAC concentration to 7%, T-P showed a high maximum removal efficiency of 91%, T-N showed 32%, and turbidity showed the maximum of 90%. In addition, a coagulation process is performed by using the mixed coagulant based on 1% content of torrefied wood flour produced in this study by performing a coagulation performance comparative experiment with PAC (10%). As a result, PAC concentration was reduced to 30-50%, a similar performance with other coagulants in market was secured, PAC injection amount was reduced that an economic effect can be achieved, and it is considered to perform a stable water treatment that reduces the secondary pollution problem.

비등온 열중량분석법을 이용한 급속 반탄화 참나무 목분의 열적 특성과 활성화 에너지 연구

이단비 ( Dan Bee Lee ),김범준 ( Birm June Kim ) 한국목재공학회 2016 목재공학 Vol.44 No.1

This study investigated thermal properties and activation energy (Ea) of torrefied oak wood powders treated with various torrefaction times (0, 5, 7.5, 10 min) by using non-isothermal thermogravimetric analysis at heating rates of 10, 20, 40℃/min to check the feasibility of rapidly torrefied oak wood powders as a fuel. As the torrefaction time increases, onset of thermal decomposition temperature, lignin content, and the amount of final residue of torrefied oak wood powders were accordingly increased with reduced hemicellulose content. Ea was determined by using Friedman and Kissinger models and respective R-square values were over 0.9 meaning very good availability of calculated Ea values. The Ea values of the samples were decreased with the increase of torrefaction time and the lowest Ea value observed in the torrefied oak wood powders treated for 7.5 min showed high feasibility of rapidly torrefied oak wood powder as a biomass-solid refuse fuel.

Evaluation of Antioxidant Activities of Water Extract from Microwave Torrefied Oak Wood

( Jeong Bin Nam ),( Geun Hye Oh ),( Seung Min Yang ),( Seok-eon Lee ),( Seog-goo Kang ) 한국목재공학회 2018 목재공학 Vol.46 No.2

The aim of this study was to assess the in vitro potential of water extract from torrefied oak wood as a natural antioxidant. The antioxidant potential of the extracts was assessed by employing different in vitro assays, including reducing power, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)], and FRAP (ferric reducing antioxidant potential) assays. The DPPH activity of the extract was increased in a dosedependent manner. Measurement of total flavonoid content of water extract from torrefied oak wood was achieved using an aluminum chloride colorimetric assay; the extract contained 192.12 mg/g flavonoid, which was significantly high when compared with standard quercetin. The results obtained in this study indicate that water extract from torrefied oak wood has significant potential for use as a natural antioxidant agent.

Coagulation Treatment of Wastewater Using Torrefied Wood Powder

Jeong Bin Nam,Seung Min Yang,Geun Hye Oh,Seog-Goo Kang 한국펄프·종이공학회 2018 펄프.종이技術 Vol.50 No.6

Water quality pollution is becoming a serious social problem due to the improvement of living standards due to economic and population growth in cities. Many researches have been carried out for the efficient treatment of municipal sewage and new research is underway. In particular, as the demand for products used in physico-chemical treatment increases, the research for the development of a more safe and efficient water treatment agent is needed. This study investigated the coagulation characteristics of superfine steamed torrefied wood powder for application to domestic sewage and investigated the possibility of its use as a better coagulant or flocculant than the existing ones. Since torrefied wood flour is an eco-friendly material that is harmless to the environment, it can be used more safely than the conventional flocculants and will help improve treatment efficiency in the water treatment process as a flocculant or a coagulant. The aim of this study was to investigate nutrient reduction using torrefied wood powder (TWP) as a flocculant for wastewater treatment. The TWP flocculant were successfully removed over 96% of the turbidity. COD in the wastewater at the following optimal TWP dosage: 10% for COD and TP. Therefore, TWP can be a promising flocculants due to its high efficiency and low dose requirements. In addition, TWPs including C-PAM do not contaminate treated wastewater, which can be recycled to reduce not only the cost and the demand for treated water, but also the extra operational costs for fresh reusing wastewater.

Development and Assessment of Harmful Gases Reducing Molded Fuel Using Torrefied Wood(반탄화목재를 이용한 유해가스 저감형 성형연료의 개발 및 평가)

( Chang-goo Lee ),( Chang-deuk Eom ),( Min-ji Kim ),( Seog-goo Kang ) 한국목재공학회 2020 목재공학 Vol.48 No.5

In this study, a torrefaction of Quercus serrata to manufacture a molded charcoal was performed, investigated material properties, fuel characteristics, and performed a quantitative analysis of hazardous gases which occur during a combustion process. In addition, a molded charcoal in market was selected as a control group, and a comparative analysis was performed. As a result, the higher heating value (HHV) of the torrefied specimen was about 14% higher than that of molded charcoal, and its ash content was about 51 times lower. Moreover, after performing a quantitative assessment of hazardous gases (carbon monoxide, nitrogen oxide, and sulfur dioxide) which were produced when each specimen was combusted for 900 seconds in an enclosed chamber, it was confirmed that the maximum value of generated amount of carbon monoxide on the torrefied specimen was about 50 times lower than that of the existing molded charcoal. Therefore, it was shown that the torrefied specimen produced in this study had a higher heating value than the molded charcoal in the market, and a very low amount of carbon monoxide generated during the combustion process.