• 한국응용과학기술학회지
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• 제37권6호
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• pp.1678-1686
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• 2020

본 논문은 농업부산물인 왕겨를 사용하여 목제펠릿 이용 가능성을 도출하고자 하였으며 왕겨의 낮은 발열량은 팽연화 기술과 연소첨가제를 통해 개선하고자 하였다. 왕겨의 물리?화학적 분석 시 염소 함유량이 0.09%로 목재펠릿 품질 기준에 부합하지 않는 결과를 얻을 수 있었다. 팽연화 기술을 통해 왕겨를 팽연왕겨로 제작 시 염소 함유량이 감소하여 목재펠릿 기준에 준하는 0.02%의 생성물을 얻을 수 있었으며 발열량 역시 기존 3,780 kcal/kg 대비 4,280 kcal/kg로 증가된 생성물을 얻을 수 있었다. 5,000 kcal/kg 이상의 생성물을 얻기 위해 연소촉진제로 붕사, 과산화수소, 수산화나트륨을 사용했지만 발열량 개선은 미비하게 나타났다. 폐자원 바이오매스인 커피찌꺼기를 사용하여 커피유로 전환 후 팽연왕겨에 혼합하여 생성물 분석 시 커피유 15 wt% 혼합 생성물이 4,949 kcal/kg의 발열량을 나타냈다. 농업부산물인 왕겨를 목제펠릿으로 사용할 시 발열량 개선을 위해 폐자원을 사용하는 것이 바람직하다 판단되며, 본 연구의 결과에 따라 커피유를 혼합할 시 왕겨를 목제펠릿으로 충분히 사용 가능할 것이라 사료된다.

• 한국토양비료학회지
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• 제17권3호
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• pp.283-288
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• 1984

동계(冬季)에 볏짚, 왕겨와 인축분뇨(人畜糞尿)를 원료(原料)로하여 재료별(材料別)로 퇴적(堆積)하고 부숙과정(腐熟過程)에서 발생(發生)되는 퇴비온도(堆肥溫度) 및 퇴비성상(堆肥性狀)의 변화(變化)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 볏짚, 왕겨 1:1 혼합구(混合區)가 볏짚 단용구(單用區)에 비(比)하여 퇴비부숙발열기간(堆肥腐熟發熱期間)이 연장(延長)되었다. 2. 인산첨가구(燐酸添加區)의 퇴비온도(堆肥溫度)는 대조구(對照區)에 비(比)하여 발효초기(醱酵初期)에는 급격(急激)히 상승(上昇)하였으나 발효(醱酵) 30일(日) 이후(以後)에는 낮아지는 경향(傾向)이었다. 3. pH는 발효초기(醱酵初期)에 5.5이었으나 퇴비온도(堆肥溫度)의 급상승(急上昇)과 더불어 10일경(日傾)에 8.8까지 올라갔으며 30일 이후(日以後)부터는 거의 변화(變化)가 없었다. 4. 퇴비온도(堆肥溫度)가 $30{\sim}65^{\circ}C$로 유지(維持)되는 기간(其間)은 볏짚+계분구(鷄糞區)가 39일(日), 볏짚+왕겨+계분구(鷄糞區)가 69일(日), 볏짚+왕겨+돈분구(豚糞區)가 56일(日), 볏짚+왕겨+우분구(牛糞區)가 66일(日), 볏짚+왕겨+인분구(人糞區)가 21일(日)로서 볏짚+왕겨+계분구(鷄糞區)가 가장 길었다.

• 한국토양비료학회지
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• 제43권4호
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• pp.484-489
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• 2010

작부체계내로의 녹비작물의 도입은 토양의 건전성 향상으로 농업생산성의 지속성 유지에 중요한 역할을 한다. 그러나 벼 재배를 위해 호밀 같은 화본과 녹비작물이 다량으로 투입 될 경우 환원장해 등의 부작용이 발생한다. 본시험은 녹비작물 헤어리베치와 호밀의 혼파를 이용하여 벼 재배 시 왕겨숯의 처리 효과를 구명하고 수행하였다. 시험장소는 농촌진흥청 국립식량과학원 답작시험 포장이었고 시험토양은 식양질인 신흥통이었다. 시험기간은 2007년 10월 녹비파종에서 벼 수확기인 2008년 10월까지였다. 시험처리는 왕겨숯 처리, 무처리 및 관행시비구를 두었고 왕겨숯 처리구는 혼파 녹비작물의 지상부제거와 전체 식물체의 투입구로 구분하였다. 이앙 후 8일과 37일의 산화환원전위는 왕겨숯 무처리에 비하여 처리한 구에서 증가하였다. 이앙 후 17일과 49일의 토양 암모니아태 질소의 함량은 전식물체 투입구의 왕겨숯 처리구에서 가장 높았다. 벼의 주요 생육특성인 초장과 경수도 토양의 산화환원전위와 암모니태질소 함량 영향으로 이앙 후 48일에 전식물체 투입한 왕겨숯 처리구에서 가장 양호하였다. 쌀 수량은 전식물체 투입구의 왕겨숯 처리 (5,290 kg $ha^{-1}$)와 무처리 (5,140 kg $ha^{-1}$)간 유의적 차이가 없었다. 그러나 벼 재배 후 왕겨숯 처리구에서 토양물리성인 공극률과 용적밀도가 개선되었다. 따라서 왕겨숯 처리는 쌀 수량의 유의적 증가에 기여하지는 못하였지만 벼 생육기간 및 벼 수확 후 토양 이화학성의 개선효과가 있어 토양개량제로 이용할 수 있을 것으로 판단된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.619-619
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• 2009

Recently, silica nanostructures are widely used in various applicationary areas such as chemical sensors, biosensors, nano-fillers, markers, catalysts, and as a substrate for quantum dots etc, because of their excellent physical, chemical and optical properties. Additionally, these days, semiconductor silica and silicon with high purity is a key challenge because of their metallurgical grade silicon (MG-Si) exhibit purity of about 99% produced by an arc discharge method with high cast. Tremendous efforts are being paid towards this direction to reduce the cast of high purity silicon for generation of photovoltaic power as a solar cell. In this direction, which contains a small amount of impurities, which can be further purified by acid leaching process. In this regard, initially the low cast rice-husk was cultivated from local rice field and washed well with high purity distilled water and were treated with acid leaching process (1:10 HCl and $H_2O$) to remove the atmospheric dirt and impurity. The acid treated rice-husk was again washed with distilled water and dried in an oven at $60^{\circ}C$. The dried rice-husk was further annealed at different temperatures (620 and $900^{\circ}C$) for the formation of silica nanospheres. The confirmation of silica was observed by the X-ray diffraction pattern and X-ray photoelectron spectroscopy. The morphology of obtained nanostructures were analyzed via Field-emission scanning electron microscope(FE-SEM) and Transmission electron microscopy(TEM) and it reveals that the size of each nanosphares is about 50-60nm. Using the Inductively coupled plasma mass spectrometry(ICP-MS), Silica was analyzed for the amount of impurities.

• 농업과학연구
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• 제51권3호
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• pp.271-281
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• 2024

The application of biochar to soil for sustainable agriculture has been considered to have a positive impact on soil fertility and crop productivity. In this study, biochar derived from rice husk and chicken manure was applied to the soil at rates of 1% and 3% by weight, respectively, for lettuce cultivation experiments. The results indicated that both rice husk biochar and chicken manure biochar were effective in improving soil fertility through soil pH correction and increased nutrient content. The nitrogen content and pH of the biochar increased the available nitrogen and phosphate in the soil, creating a soil environment conducive to the growth enhancement of lettuce. In particular, after the application of 3% chicken manure biochar, the soil exhibited the highest levels of available nitrogen and phosphate at 87.42 mg·kg^-1 and 69.07 mg·kg^-1, respectively. Plant fresh weight increased with rising biochar amount, with the 3% chicken manure biochar treatment (228.25 g·plant^-1 fresh weight [FW]) exhibiting superior fresh weight compared to 3% rice husk biochar treatment (120.88 g·plant^-1 FW). The nutrient content in lettuce, except for K₂O, was higher in the chicken manure biochar treatment compared to the same dosage of rice husk biochar. Therefore, for enhancing lettuce productivity and soil fertility, chicken manure biochar appears to be more effective than rice husk biochar, and increasing the application rate up to 3% showed improvement effects without adverse impacts. However, excessive application of chicken manure biochar may lead to an increase in soil pH and electrical conductivity (EC) beyond the optimal range, requiring further assessment of application rates.

• Computers and Concrete
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• 제10권6호
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• pp.631-647
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• 2012

This paper focuses on the application of Fuller's ideal gradation curve to theoretically design blended ratio of all solid materials of high performance concrete (HPC), with the aid of error function, and then to study the effect of rice husk ash (RHA) on the performance of HPC. The residual RHA, generated when burning rice husk pellets at temperatures varying from 600 to $800^{\circ}C$, was collected at steam boilers in Vietnam. The properties of fresh and hardened concrete are reviewed. It is possible to obtain the RHA concrete with comparable or better properties than those of the specimen without RHA with lower cement consumption. High flowing concrete designed by the proposed method was obtained without bleeding or segregation. The application of the proposed method for HPC can save over 50% of the consumption of cement and limit the use of water. Its strength efficiency of cement in HPC is 1.4-1.9 times higher than that of the traditional method. Local standards of durability were satisfied at the age of 91 days both by concrete resistivity and ultrasonic pulse velocity.

• 한국연소학회지
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• 제14권4호
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• pp.25-32
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• 2009

In commercial combustion systems, heavy oil is one of main hydrocarbon fuel because of its economical efficiency. Regarding heavy oil combustion, due to increasing concerns over environmental pollutants such as carbon monoxide, unburned hydrocarbon and nitrogen oxides, development of low pollutant emission methods has become an imminent issue for practical application to numerous combustion devices. Also a great amount of effort has been tried to developed effective methods for practical using of biomass. It is also an important issue to reduce carbon tax. In this paper, an experimental study has been conducted to evaluate the effect of biomass reburning on NOx formation in a heavy oil flamed combustion furnace. Experiments were performed in flames stabilized by a multi-staged burner, which was mounted at the front of the furnace. Experimental tests were conducted using air-carried rice husk powder and LNG as the reburn fuel and heavy oil as the main fuel. The paper reports data on flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. NOx concentration in the exhaust has decreased considerably due to effect of reburning. The maximum NOx reduction rate was 62% when the rice husk was used by reburn fuel, however it was 59% when the LNG was used by reburn fuel. The result shows the positive possibility of biomass reburning system for optimal NOx reduction.

• 콘크리트학회논문집
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• 제27권4호
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• pp.343-351
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• 2015

최근들어 $CO_2$ 증가에 따른 사회적, 공학적 문제가 증가하면서 시멘트 사용량을 줄이려는 연구가 진행되고 있다. 플라이 애쉬, 고로 슬래그, 실리카퓸 등의 혼화재료가 시멘트 대체재로 많이 사용되고 있는데, 최근 들어 Rice Husk Ash (RHA)를 혼화재료로 사용하여 콘크리트의 성능을 개선시키려는 연구가 활발하게 진행 중이다. 본 연구에서는 RHA와 가장 뛰어난 혼화재료로 알려진 실리카퓸을 혼입한 콘크리트를 제조하여 초기재령 콘크리트에 대한 염해저항성을 평가하였다. 이를 위해 10~30%의 RHA 치환률과 2~8%의 실리카퓸 치환률을 가진 콘크리트를 제조하여, 역학적 실험과 밀도, 공극률, 염화물 확산계수, 부식전류 측정등의 내구성 실험을 수행하였다. RHA 10~15% 수준의 치환은 SF 2~4% 수준보다 초기재령 콘크리트에서의 높은 강도 및 염해저항성을 확보하였으며, 미래에 유용하게 사용될 수 있는 혼화재료의 가능성을 나타내었다.

• 한국산업융합학회 논문집
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• 제20권5호
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• pp.351-357
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• 2017

Growing plant in potting media without soil is known as Soilless cultivation. This method is used mostly in greenhouse cultivation to increase horticultural commodities production. Peat moss is commonly utilized as potting media substrate because of its characteristic. However, peat moss price is high because of the quantity of peat moss in nature has been decreased. Recently, most of the research is conducted to find the alternative growing medium to cultivate horticulture plant in potting media. Perlite and rice husk ash were mentioned that had a potent as alternative growing media for seasonal plants to increase agriculture production due to the lack of production area. This study aimed to determine the effect of using different substrate and growth performance of chili. The method used was the soilless cultivation. The chili was planted in the pot with perlite media, rice husk ash media, and peat moss media. The chili was measured after 65 days after planting. The result showed that rice husk ash and perlite were more potentials in chili growth performance than peat moss. Rice husk ash had the significant result of plant height. While, Perlite effect on root length, plant weight, leaf length, and stem diameter. The best alternative for cultivation chili without substrate based on this research was perlite then rice husk ash and peat moss.

• Journal of Biosystems Engineering
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• 제31권1호
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• pp.33-38
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• 2006

This work was conducted to find the operating characteristics of an efficient wet grinding system designed to obtain fine rice husk ash powder. Once the rice husk was combusted and the thermal energy was recovered from the furnace, the ash was fed and pulverized in the grinding system resulting a fine powder to be used as a supplementary adding material to the portland cement. Grinding time (15, 30, 45 min), impeller speed (250, 500, 750 rpm), and mixed ratio (6.7, 8.4, 11.l, 20.9) were three operating factors examined for the performance of a wet-type stirred ball mill grinding system. For the operating conditions employed, mean diameter of fine ash powder, specific energy input, and grinding energy efficiency were in the range of $2.83{\sim}9.58{\mu}m,\;0.5{\sim}6.73kWh/kg,\;and\;0.51{\sim}3.27m^2/Wh$, respectively. With the wet-type stirred ball mill grinding system used in this study, the grinding energy efficiency decreased with the increase in total grinding time, impeller speed, and mixed ratio. The difference in specific surface area of powder linearly increased with logarithm in total number of impeller revolution and the grinding energy efficiency linearly decreased. Grinding time of 45 min, impeller speed of 500 rpm, and mixed ratio of 6.7 were chosen as the best operating condition. At this condition, mean particle diameter of the fine ash, grinding energy efficiency, grinding throughput, and specific energy input were $2.84{\mu}m,\;2.28m^2/Wh,\;0.17kg/h$, and 2.03kWh/kg, respectively. Wet fine grinding which generates no fly dust causing pollution and makes continuous operation easy, is appeared to be a promising solution to the automatization of rice husk ash grinding process.