왕겨/모래/왕겨 회재의 유동 및 혼합 특성 연구

김보화 ( Bo Hwa Kim ),서명원 ( Myung Won Seo ),국진우 ( Jin Woo Kook ),최희망 ( Hee Mang Choi ),라호원 ( Ho Won Ra ),윤상준 ( Sang Jun Yoon ),문태영 ( Tae Young Mun ),김용구 ( Yong Ku Kim ),이재구 ( Jae Goo Lee ),이영우 ( Young Wo 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.4

We investigate fluidization characteristics of the mixture of rice husk, silica sand and rice husk ash as a preliminary study for valuable utilization of rice husk ash obtained from gasification of rice husk in a fluidized bed reactor. As experiment valuables, the blending ratio of rice husk and sand (rice husk: sand) is selected as 5:95, 10:90, 20:80 and 30:70 on a volume base. Rice husk ash was added with 6 vol% of rice husk for each experiment and air velocity to the reactor was 0~0.63 m/s. In both rice husk/sand and rice husk/sand/ash mixture, the minimum fluidization velocity (Umf) is observed as 0.19~0.21 m/s at feeding of 0~10 vol.% of rice husk and 0.30 m/s at feeding of 20 vol.% of rice husk. With increasing the amount of rice husk up to 30 vol. %, Umf can not measure due to segregation behavior. The mixing index for each experiment is determined using mixing index equation proposed by Brereton and Grace. The mixing index of the mixture of rice husk/sand and rice husk/sand/ash was 0.8~1 and 0.88~1, respectively. The optimum fluidization condition was found for the good mixing and separation of rice husk ash.

Development of Cyclone Combustor for Producing Carbonized Rice Husk

No, Soo Young,Kim, Won Tae 충북대학교 한국과학재단 지정 첨단원예기술개발 연구센터 1997 연구보고서 Vol.2 No.-

Carbonized rice husk is highly recommended for raising soil/water temperature, keeping moisture and aerating the roots of plants. The objective of this study is the development of a non-slagging, vertical cyclone combustor for producing carbonized rice husk effectively. Isothermal and mixed firing with LPG and rice husk were undertaken in order to characterize the system. Inert rice husk was used during the isothermal test to find the mass of rice husk collected. It was impossible to ignite rice husk itself over the experimental conditions considered in this experiment. Cyclone combustor was operated at temperatures of 1273-1473K. Detailed combustion data were obtained from a pilot unit with the air flow rate of 70m³/h and rice husk feed of 2kg. The equivalence ratio ranged from 0.66 to 3.48. The auxiliary gas flow rate was varied from 3.22 to 12.86ℓ/min. The weight reduction, pH and particle size distribution of carbonized rice husk were measured to evaluate the quality of carbonized rice husk. An analysis of exhaust gas emission was conducted to characterize the combustor. The required carbonized rice husk could be obtained at equivalence ratio of 1.68-2.17, combustor temperature of 1273-1373K, and auxiliary gas flow rate of 3.22-6.43ℓ/min. A method to reduce CO emissions should be employed.

Rice Husk as a Food Carrier Forselective Enrichment of Tea Catechins

Meng Shi,Long-Yue Huang,Rong-Rong Han,Qiao Lin, Jian-Hui Ye,Yue-Rong Liang,Jian-Hui Ye 한국차학회 2015 한국차학회지 Vol.- No.S

The potentials of rice husk, oat bran and soya milk cake as food carriers for tea catechins(TC) were studied. Adsorption properties, contact time and temperature effects and the concentration of tea catechins, as well as digestive stability were investigated in this paper. The result showed that the adsorption capacity of rice husk for tea catechins was 32.04 mgg-1 which was 28.1 % and 17.7 % higher than those of oat bran and soya milk cake and no obvious adsorbability to caffeine was observed for these materials. The selectivity coefficient K of EGCg to TC for rice husk was 4.44 in comparison with 1.87 and 1.96 of oat husk and soya milk cake. This guarantees rice husk a selective food carrier to tea catechins with enrichment of EGCg. Also, 20 min contact time and tea extract concentration above 1.75 g L-1 are recommended in order to obtain a high loading amount of tea catechins onto rice husk, and low temperature is favorable for the adsorption processof tea catechins onto rice husk. Digestive study showed that combination of tea catechins with rice husk was propitious to increase the digestive stability of tea catechins in simulated gastrointestinal fluids. Thus, rice husk is a promising food carrier for tea catechins. Further studies would be focusing on the identification and separation of the functional constituent of rice husk and its interaction mechanism with tea catechins.

Preparation and Characterization of Silicon composite from Rice Husk Ash

송시내,반가람,김희택 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Rice as the main grain in Asia, including Republic of Korea, has been produced about 424 ton in 2014(National Statistical Office, 2014). The Rice Husk, by-product generated after milling of rice, typically contains approximately 20% of rice in weight ratio and Rice Husk would be supplied about 85 ton as by-product through milling process in domestic. It could be resource of Biomass to utilize for practical use. Silica is relatively included in Rice Husk comparing with other crops. In case of Silica included Rice Husk, high purity Silica is obtained because of `Natural selectivity` process from roots of rice. In this study, we purpose to produce high purity Silica through Rice Husk separation process in by optimized experimental factors and then compound Silicon composite by using certain polymer.

Monitoring of arsenic contents in domestic rice and human risk assessment for daily intake of inorganic arsenic in Korea

Lee, Seul Gi,Kim, Da Hyun,Lee, Young Seok,Cho, Seung-Yong,Chung, Myung-Sub,Cho, MinJa,Kang, YoungWoon,Kim, HyeJung,Kim, DongSul,Lee, Kwang-Won Elsevier 2018 Journal of food composition and analysis Vol.69 No.-

<P><B>Abstract</B></P> <P>Rice can be the major contributor to exposure of inorganic arsenic (iAs). A total of 485 domestic rice (polished rice, n = 368; husked rice, n = 117) samples produced in 2014 were determined for total arsenic (tAs) and As species. The determination of As species was conducted by HPLC-ICP-MS. AsIII was the major detected species. AsV, DMA, and MMA were occurred in lower level in both types of rice. In polished rice, iAs represented 43–91% of tAs: tAs = 0.088 ± 0.021 mg/kg; iAs = 0.060 ± 0.013 mg/kg. In husked rice, iAs ranged from 55% to 91% of tAs; tAs = 0.160 ± 0.042 mg/kg, iAs = 0.114 ± 0.029 mg/kg. The iAs level of polished rice samples was below the current maximum limit of the Chinese and German standard (0.2 mg/kg for inorganic arsenic in milled rice). Also, husked rice samples did not exceed the standard for iAs. Average dietary exposure to iAs from polished rice consumption was calculated as 0.17 ± 0.21 μg/kg·bw/day which was 8.09% level of Provisional Tolerable Weekly Intake. The result obtained in the present study provide a reference data of iAs in Korean rice for the establishment of safety standards.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Korean polished and husked rice were analyzed for total and inorganic arsenic. </LI> <LI> In rice AsIII was the major detected species, and iAs represents 43–91%. </LI> <LI> The level of iAs of polished rice was below the current maximum limit of standard. </LI> <LI> Safety standards depend on the As characteristic in rice and other foods. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effect of composition on the ability to form SiC/SiO2-C composite from rice husk and silica gel

Do Quang Minh,Tran Van Khai,Huynh Ngoc Minh,Nguyen Vu Uyen Nhi,Kieu Do Trung Kien 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.2

Rice husk is a waste product of agricultural production of rice. Every year, the agricultural production of Vietnam emits about10 million tons of rice husks. Rice husks are usually treated by burning method or discharged into rivers, causing manynegative impacts on the environment. In this study, the rice husk/silica gel ratio components were investigated to form SiC/SiO2-C composite in a CO2 environment at 1000 oC for 60 min. The products after pyrolysis were determined SiC, SiO2, andfree C contents according to ISO 21068-2: 2008 standards. The functional groups and mineral composition of composites wereanalyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The microstructure and elementdistribution of them were observed by scanning electron microscope (SEM) and Energy-dispersive X-ray (EDX) mapping. Theresults showed that the optimum rice husk/silica gel ratio to form SiC/SiO2-C was 1.4/1. The sample after pyrolysis hadchemical composition including 14% SiC, 63% SiO2, 23% free C (%wt.) and the phase composition including amorphouscarbon, β-SiC, 6H-SiC, 4H-SiC, cristobalite. Composite SiC/SiO2-C can apply to advanced friction systems. This can be seenas an effective method to treat rice husk waste and improved the economic value of rice plants.

이산화염소 전처리가 왕겨 실리카 추출에 미치는 영향

김동섭(Dong-Seop Kim),성용주(Yong Joo Sung) 한국펄프·종이공학회 2016 펄프.종이技術 Vol.48 No.6

The pretreatments of rice husk with chlorine dioxide were conducted in order to increase the silica extraction efficiency of rice husk. The temperature of chlorine dioxide treatment had significant effects on the morphological properties and the chemical composition of treated rice husk. The severer treatment conditions resulted in the higher loss in the yield and the lignin of treated rice husk. The ash contents of the treated rice husk were increased, which showed the chlorine dioxide treatment had no significant effects on the silica in rice husk. The reduction in the organic components including the lignin of rice husk and the changes in the structure by the pretreatment leaded to the increase in the alkali extraction of silica from the treated rice husk. Those results showed the silica extraction efficiency could be improved by the chlorine dioxide pretreatment.

국내 육성 신품종 현미 및 백미에 함유된 수용성 비타민 티아민, 리보플라빈 및 니아신 함량

전진수(Jinsoo Jeon),이상훈(Sang Hoon Lee),최용민(Young Min Choi),정명근(Myoung-Gun Choung) 한국식품영양과학회 2020 한국식품영양과학회지 Vol.49 No.9

한국인이 주식으로 섭취하는 쌀에 함유된 수용성 비타민의 함량 정보는 국민 식생활 개선에 중요한 요소이다. 본 연구는 국내 육성 신품종 쌀 10품종을 현미와 백미로 가공하여 함유된 수용성 비타민인 티아민, 리보플라빈 및 니아신의 함량을 HPLC/DAD 및 HPLC/FLD법으로 정밀 분석하였다. 사용된 HPLC 분석 조건은 우수한 감도, 선택성, 직선성, 재현성, 정밀성 및 정확성을 나타내었다. 국내 육성 10품종에 함유된 티아민, 리보플라빈 및 니아신의 함량 분석 결과, 현미는 각각 0.131~0.319 mg, 0.019~0.030 mg, 0.310~0.407 mg/100 g의 범위를 나타내었고 백미의 경우 각각 0.074~0.177 mg, 0.003~0.013 mg, 0.256~0.303 mg/100g의 범위를 나타내었다. 현미 및 백미의 각 품종 간 통계적 차이가 인정되었고, 현미가 백미 대비 약 1.3~2.7배 함량이 높은 양상을 나타내었다. 주성분 분석 결과, loading plot에서 티아민, 리보플라빈 및 니아신 성분은 크게 2그룹으로 구분되었고, scores plot에서도 티아민, 리보플라빈 및 니아신 성분의 함량에 따라 현미와 백미가 완전히 구분됨을 알 수 있다. Information on the contents of water-soluble vitamins in rice is an essential factor for improving the Korean diet. In this study, 10 Korean new rice cultivars were processed into husked and milled rice, respectively, and precisely analyzed based on the contents of thiamine, riboflavin, and niacin according to the high-performance liquid chromatography/diode array detector (HPLC/DAD) and high-performance liquid chromatography/fluorescence detector (HPLC/FLD) methods. HPLC analysis conditions showed good sensitivity, selectivity, linearity, reproducibility, precision, and accuracy. The amounts of thiamine, riboflavin, and niacin in husked rice ranged from 0.131∼0.319 mg, 0.019∼0.300 mg, and 0.310∼0.407 mg/100 g, respectively, and in the case of milled rice, 0.074∼0.007 mg, 0.003∼0.013 mg, and 0.256∼0.300 mg/100 g, respectively. There was a statistical significance between husked and milled rice, as husked rice showed a higher content of about 1.3∼2.7 times than that of thiamine, riboflavin, and niacin in milled rice. As a result of the principal component analysis, thiamine, riboflavin, and niacin were divided into two groups in the loading plot. The husked and milled rice were entirely classified according to thiamine, riboflavin, and niacin components in the scores plot.

Effects of hydrophilic compounds in purple rice husk on AFB1-induced mutagenesis

Angkhana Nilnumkhum,Charatda Punvittayagul,Arpamas Chariyakornkul,Rawiwan Wongpoomchai,R. Wongpoomchai 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.2

Rice husk has been shown to possess cancer chemopreventive activity. This study focused on mutagenicity and antimutagenicity of the crude acidified methanolic extract of purple rice husk and its solvent- partitioned fractions using a Salmonella mutation assay and rat liver micronucleus test. The purple rice husk extracts were not mutagenic in S. typhimurium strain TA98, but were mutagenic in TA100 (crude extract and its hydrophilic fractions). There was no significant mutagenicity of purple rice husk extracts in rat liver. The rice husks possessed antimutagenicity against AFB1-induced mutagenesis in both bacterial and animal models. The dichloromethane-partitioned fraction (DPF) showed the highest antimutagenicity. Vanillic acid, a major phenolic compound found in DPF, exhibited antimutagenicity against AFB1 in both bacterial and rat models. The inhibitory mechanism was associated with the induction of detoxifying enzymes in AFB1 metabolism of rat liver. These findings suggested that vanillic acid may be a principal antimutagenic compound in purple rice husk.

Rice husk-originating silicon–graphite composites for advanced lithium ion battery anodes

Kim Hye Jin,Choi Jin Hyeok,Choi Jang Wook 나노기술연구협의회 2017 Nano Convergence Vol.4 No.24

Rice husk is produced in a massive amount worldwide as a byproduct of rice cultivation. Rice husk contains approximately 20 wt% of mesoporous SiO2. We produce mesoporous silicon (Si) by reducing the rice husk-originating SiO2 using a magnesio-milling process. Taking advantage of meso-porosity and large available quantity, we apply rice husk-originating Si to lithium ion battery anodes in a composite form with commercial graphite. By varying the mass ratio between these two components, trade-off relation between specific capacity and cycle life was observed. A controllable pre-lithiation scheme was adopted to increase the initial Coulombic efficiency and energy density. The series of electrochemical results suggest that rice husk-originating Si–graphite composites are promising candidates for high capacity lithium ion battery anodes, with the prominent advantages in battery performance and scalability.