Influence of nano powder on rheological behavior of bimodal feedstock in powder injection molding

Oh, Joo Won,Lee, Won Sik,Park, Seong Jin Elsevier Sequoia 2017 Powder technology Vol.311 No.-

<P><B>Abstract</B></P> <P>Rheological behavior of feedstock, which highly affects the condition of green body, is substantial issue in powder injection molding process. In this paper, the influence of nano powder contents in bimodal feedstock on solids loading and rheological behavior has been investigated. The bimodal powders were fabricated with 100nm and 4μm sized 316L stainless steel powders, and mixed with wax-based binder system. The critical solids loading for each powder was measured by torque rheometer. In order to analyze net effect of nano powder ratio, all feedstocks were formulated as solids loading of 42vol.%. Feedstock homogeneity was evaluated by rotational rheometer. Capillary rheometer test was conducted to measure the viscosity of feedstock with different temperatures, shear rates and nano powder ratios. Rheological parameters, like flow index, flow activation energy and moldability index, were calculated based on the capillary rheometer test. The results indicated the critical solids loading and feedstock homogeneity decreased as nano power ratio increased in bimodal feedstock. Rheological parameters were also affected by nano powder ratio, and the optimal mixing ratio of nano powder for moldability index was investigated as 12vol.%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nano powder effect in bimodal feedstock on rheological properties was analyzed. </LI> <LI> Bimodal feedstocks with various nano powder ratios were fabricated. </LI> <LI> Nano powder decreased the critical solids loading and feedstock homogeneity. </LI> <LI> Bimodal feedstocks showed better rheological characteristic than micro feedstock. </LI> <LI> 12vol.% nano powder in bimodal feedstock was determined as the optimal ratio. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

다양한 자원을 활용한 가스화 특성 연구 : 폐기물 가스화 적용 가능성 평가

박세원 ( Se-won Park ),이상엽 ( Sang-yeop Lee ),정연욱 ( Yean-ouk Jeong ),한건호 ( Gun-ho Han ),서용칠 ( Yong-chil Seo ) 한국폐기물자원순환학회 2019 한국폐기물자원순환학회지 Vol.36 No.7

In this study, the gasification process was operated using various feedstocks, including biomass, waste, and fossil fuel. Sawdust, waste solid refuse fuel, and coal were selected as the representative for the feedstocks. In the case of waste fuel, it must be utilized as a new and renewable energy, rather than a disposed target. A comparative study on feedstock type was conducted, and the feedstocks were applied to a lab-scale downdraft fixed bed gasification process. The experimental conditions were maintained for the assessment of the gasification process’s applicability, and the deduction of the optimum equivalent ratio of feedstock. The results of the study revealed that the waste solid refuse fuel was more applicable to the gasification process than coal and sawdust, with an optimal equivalent ratio of 0.4 in all feedstocks, and the highest cold gas and carbon conversion efficiency. Detailed results showed that cold gas efficiency was 50.94%, and carbon conversion ratio was 54.66% from waste gasification. In further studies or researches, gasification technologies using waste, biomass or coal were continuously conducted for development of high efficient technology. This study could potentially be used as reference data for gasification operations at commercial plants.

원료조건에 따른 하향식 가스화 효과 분석

왕용 ( Long Wang ),홍성구 ( Seong Gu Hong ) 한국농공학회 2013 한국농공학회 학술대회초록집 Vol.2013 No.-

Biomass is a promising renewable energy resource. It can be converted into fuels, heat or power through thermo chemical processes. Gasification is a popular technology convert biomass into synthesis gas which composited of carbon monoxide, hydrogen and methane. Syngas can directly used as fuel or materials to produce chemicals or power generation to meet the need of ever-increasing energy in the world and reduce CO2 emission. The composition of syngas usually depend on feedstock conditions. In this study RDF, woodchip and charcoal was used as feedstock in downdraft gasification process. RDF and charcoal mixed with woodchip as some certain proportions. woodchip used as two different sizes- 0.7~0.9 cm size and 2~3 cm size. The results presented that methane composition was as high as 10% and LHV as high as 1600kacl/Nm³ when use RDF mixed with woodchip as feedstock. LHV was low as 683kcal/Nm³ use charcoal. The H₂ composition usually more than 10% and LHV usually keep in 1100~1200kacl/Nm³ when use woodchip as feedstock. The cold gas efficiency reach to 65% when use 0.7~0.9 cm size woodchip. It is presented that small size woodchip is a good feedstock for downdraft gasification as lower reaction temperature, higher cold gas efficiency and carbon conversion.

바이오에탄올 보급에 대한 사회적 수용성 분석: 바이오에탄올 원료 속성을 중심으로

이드미트리 ( Dmitriy D. Li ),배정환 ( Jeong Hwan Bae ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2021 자원·환경경제연구 Vol.30 No.1

본 연구는 선택실험법을 이용하여 바이오에탄올 원료유형, 바이오에탄올 혼합율, 바이오에탄올 비용, 정부지원 정책과 같은 속성들이 바이오에탄올 보급정책에 대한 사회적 수용성에 영향을 미치는지를 분석하였다. 바이오에탄올 속성 계수를 추정하기 위해 조건부로짓모형, 혼합로짓모형, 개별계수추정모형을 적용하였다. 추정 결과에 따르면, 소비자들은 국산원료와 비식량원료를 사용한 바이오에탄올을 선호하고 지원정책 가운데는 면세정책을 선호하는 것으로 나타났다. 혼합로짓모형과 개별계수추정모형에 의하면 모든 속성들이 관찰불가능한 이질성을 갖고 있는 것으로 나타났다. 또한 속성별 지불용의액을 추정한 결과, 유전자조작기반 바이오 에탄올임을 사전에 인지한 응답자일수록 그렇지 못한 응답자보다 바이오에탄올에 대한 지불용의액이 더 낮게 나타났다. 추정결과를 종합하면, 우리나라에서 바이오에탄올을 보급하기 위해서는 국산원료 및 비식량원료에 기반한 바이오에탄올을 중점적으로 보급해야 하고, 특히 유전자 조작 기반 바이오에탄올에 대한 수용성이 낮게 나타나므로 보급시 이를 충분히 고려해야 할 것이다. This study uses a choice experiment approach to examine whether different types of feedstocks as well as other attributes such as the cost of bioethanol, bioethanol blending ratio, and government support policies affect consumers’ biofuel preferences. We apply a standard conditional logit model, a mixed logit model (MLM), and individual coefficient estimation model (ICM) to estimate the parameters of the investigated attributes. The results show that people prefer domestic and non-food feedstock, along with tax exemption as a support policy. All the attributes show unobservable preference heterogeneity in the MLM and ICM. In particular, willingness to pay for attributes are higher in the genetically modified (GM) feedstock-unknown group than in the known one. We show the importance of using domestic and non-food feedstocks and managing GM feedstocks carefully to avoid consumer resistance when producing bioethanol in South Korea.

휴경지를 활용한 바이오에탄올연료 생산의 경제성 비교분석

이종인,최호준,정해동,최윤상 한국국제농업개발학회 2009 韓國國際農業開發學會誌 Vol.21 No.2

This study attempts to evaluate economic feasibility of domestic bio-ethanol production based on fallow fields. The results suggest that barley for paddy fields and corn and sweet potato for dry fields are the most suitable domestically-produced feedstocks for bio-ethanol production because of their relatively low input crop costs. Suppose those feedstocks are produced in fallow fields, total bio-ethanol production is estimated at 8,600 (barley)~29,100 tons (sweet potato), depending on feedstocks. Then, evaluating economic inducement effects from bio-ethanol production based on fallow fields, its production inducement effects would be 91 billion won (barley)~508 billion won (sweet potato) and its employment inducement effect would be 4,100 (barley)~17,900 heads (sweet potato), depending on feedstocks. 본 연구에서는 국내 유휴 농업자원인 휴경지를 활용한 국내 바이오에탄올연료 생산의 경제성을 분석하고 경제적 가치를 평가함으로써 국내에서 생산된 원료작물을 활용한 바이오에탄 올연료 생산의 가능성을 제시하고자 하였다. 이를 위해 국내 바이오에탄올연료 생산에 가장 적합한 원료작물을 선정하고 휴경지에서 선정된 원료작물을 생산할 경우 생산 가능한 바이 오에탄올연료의 생산량을 추정했다. 이와 함께 이러한 과정을 통해 이루어지는 바이오에탄올연료의 생산이 국가경제에 미치 는 파급효과를 추정하여 국내생산 원료작물을 이용한 바이오 에탄올연료 생산의 경제적 가치를 도출하였다. 생산성 비교 결과 논에는 보리쌀, 밭에는 옥수수와 고구마 가 가장 경제성이 있는 원료작물로 선정되었다. 그러나 이러 한 결론은 기존의 생산방식에 기초한 결과이기 때문에 미활용 자원인 유휴지를 이용하거나 식용이 아닌 산업원료로서의 생 산과정에서 생산비용을 절감할 수 있고 또한 품질은 떨어지지 만 단수를 높일 수 있는 산업원료용 품종을 개발할 경우 경제 성을 상당부분 향상시킬 수 있을 것으로 판단된다. 다음으로 현재 활용 가능한 유휴지에 경제성분석에서 선정 된 원료작물을 재배할 경우 생산 가능한 바이오에탄올연료의 양을 두 가지의 원료작물과 바이오에탄올 간 전환율(이론적인 전환율과 연구사례에 의한 전환율)에 기초하여 산정해 보았다. 이론적인 전환율을 적용한 경우, 생산 가능한 최대 바이오에탄 올의 양은 보리쌀의 경우 약 200억원(8,750톤), 옥수수의 경우 약 410억원(19,911톤), 고구마의 경우 약 570억원(29,089톤)인 것으로 추정되었다. 반면 연구사례에 의한 전환율을 적용할 경 우에는, 생산 가능한 최대 바이오에탄올의 양은 보리쌀의 경우 약 150억원(8,555톤), 옥수수의 경우 약 290억원(19,911톤), 고 구마의 경우 약 180억원(9,670톤)인 것으로 추정되었다. 마지막으로 휴경지를 활용한 바이오에탄올연료 생산의 경제 파급효과를 산정해 본 결과, 보리쌀의 경우 총생산유발액은 911억원이며 총취업유발인원은 4,169명, 옥수수의 경우에는 총 생산유발액은 1,591억원이며 총취업유발인원은 4,839명, 그리 고 고구마의 경우에는 총생산유발액은 5,083억원이며 총취업 유발인원은 17,944명인 것으로 나타났다. 생산유발효과의 크 기를 비교해 보면 각 원료작물별로 바이오에탄올연료 생산액 의 3.1~8.1배인 것으로 나타나 바이오에탄올연료 생산이 생산 유발효과가 큰 것을 알 수 있다. 그리고 원료작물별로 비교해 보면 고구마의 생산유발효과와 취업유발효과가 가장 큰 것으 로 나타났다. 이상과 같이 국내산 작물을 원료로 바이오에탄올을 생산하 여 연료로 활용할 경우 일반적으로는 휘발유에 비해 경제성이 없는 것으로 보고되고 있으나 분석결과에서도 보는 바와 같이 석유수입 감소, 대기오염 개선, 유휴지와 같은 유휴 농업자원 의 활용, 경제파급효과(생산유발효과, 취업유발효과) 등의 사 회적 편익이 큰 것으로 나타나 바이오에탄올 생산을 단순한 경제성 논리로만 접근해서는 안 된다. 따라서 국내 여건에 맞는 바이오에탄올 생산에 대한 사회적 합의를 도출하고 이를 기준으로 외국(미국, 중국 등)에서와 같 이 자국 내에서 원료를 조달하여 생산하는 경우 정부보조금을 통해 바이오에탄올의 경제성을 보장하고 제도적으로 사용을 의무화 하여 ...

발전용 바이오중유용 원료물질의 품질특성 연구

장은정(Eun-Jung Jang),이미은(Mi-Eun Lee),박조용(Jo-Yong Park),민경일(Kyung-Il Min),임의순(Eui-Soon Yim),하종한(Jong-Han Ha),이봉희(Bong-Hee Lee) 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.1

신재생에너지 공급 의무화제도(Renewable Portfolio Standard(RPS))가 시행됨에 따라, 발전 사업자들은 의무공급량 이행을 위해 발전용 바이오중유를 사용하고 있다. 본 연구에서는 발전용 바이오중유의 원료물질별 물성과 원료 조성에 따른 발전용 바이오중유의 품질특성을 알아보았다. 발전용 바이오중유와 원료유지의 연료특성은 전산가, 동점도, 금속분 등 고시 상 품질기준 항목을 분석하였으며, 적외선 분광광도계와 고성능 액체크로마토그래피를 이용하여 조성분포를 분석하였다. 팜유계열의 저가의고산가 유지는 유리지방산 함량이 높아 전산가가 높고, 금속분에 의한 회분함량이 높았으며, 바이오디젤 공정부산물은 점도가 높았다. 동점도, 전산가, 금속분과 같은 발전용 바이오중유의 연료특성은 원료물질의 조성 및 혼합비와 관련이 깊다. As it carry out RPS(Renewable Portfolio Standards), power producers are using the power bio-fuel oil to meet their RPS quota. In this study, we test the quality characteristics of raw materials for power bio-fuel oil and the property changes of power bio-fuel oil by the kind of feedstocks. The power bio-fuel oil and feedstocks were analyzed for item of quality standard such as acid number, viscosity and metal contents. And it was analyzed for composition distribution by FT-IT and HPLC. Such as low priced palm oil series has high acid number and ash contents due to high free-fatty acid and metal contents. And by-product of biodiesel have a tendency of high viscosity. The fuel properties of power bio-fuel oil, such as viscosity, acid number and metal contents are correlated with the constituent and the mixing ratio of the feedstocks.

방사선·알칼리 전처리 볏짚 당화액 및 당밀 활용Desmodesmus sp. KAERI-NJ5의 지질 생산성 비교 평가

조민호,김동호,배석 (사)한국방사선산업학회 2019 방사선산업학회지 Vol.13 No.3

Depending on species, microalgae can produce fatty acids more efficiently byusing organic carbon sources than by using the phototrophic cultivation mode. In this study,Desmodesmus sp. KAERI-NJ5 was grown in heterotrophic (HT) and mixotrophic (MT) modesusing enzymatic hydrolysate of rice straw pretreated with radiation and alkali solution to enhancebiodiesel feedstock productivity. In addition, biomass and lipid productivities were comparedwith the results from molasses based medium. Firstly, carbon source preference of the microalgawas determined. Although the presence of light caused a slight difference in the carbon sourcepreference, glucose was the most preferred carbon source in both types of cultivation. The ricestraw hydrolysate (RSH) was used as a carbon source and successfully utilized by the microalga. The biomass and lipid yield was higher in the HT cultivation mode than those from the MTcultivation mode. The final biomass and lipid yield of 6.0 and 3.4 g·l-1 was achieved, respectively,in HT cultivation. In addition, the conversion yield of consumed sugars to lipid and fatty acidmethyl esters (FAMEs) were 34.2 and 31.4%, respectively, which is even higher than that grownwith corresponding pure sugars. Analysis of the FAMEs composition revealed that palmitic, oleic,and stearic acids were the main FAMEs, and the FAMEs content was 52.19% in the HT cultivationmode corresponding to a 1.51-fold higher content than with MT cultivation. In addition, 92.52%of FAMEs consisted of saturated and monounsaturated fatty acids indicating good qualitybiodiesel feedstock. In addition, the productivities of biomass, total lipid and FAMEs were also evaluated when the microalga was grown with molasses, a representative low-cost carbon source,in both cultivation modes. The highest total lipid yield was 3.9 g·l-1 in the HT cultivation modecorresponding to 1.15-fold higher than that of the RSH grown microalga. However, the lipidproductivity was negligible considering the quality as a biodiesel feedstock, regional availabilityand sustainability of carbon sources. Thus, the RSH could be used as a carbon source for biodieselfeedstock production by Desmodesmus sp. KAERI-NJ5.

발전용 바이오중유용 원료물질의 품질특성 연구

장은정,이미은,박조용,민경일,임의순,하종한,이봉희 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.1

신재생에너지 공급 의무화제도(Renewable Portfolio Standard(RPS))가 시행됨에 따라, 발전 사업자들은 의무공급량 이행을 위해 발전용 바이오중유를 사용하고 있다. 본 연구에서는 발전용 바이오 중유의 원료물질별 물성과 원료 조성에 따른 발전용 바이오중유의 품질특성을 알아보았다. 발전용 바이 오중유와 원료유지의 연료특성은 전산가, 동점도, 금속분 등 고시 상 품질기준 항목을 분석하였으며, 적 외선 분광광도계와 고성능 액체크로마토그래피를 이용하여 조성분포를 분석하였다. 팜유계열의 저가의 고산가 유지는 유리지방산 함량이 높아 전산가가 높고, 금속분에 의한 회분함량이 높았으며, 바이오디젤 공정부산물은 점도가 높았다. 동점도, 전산가, 금속분과 같은 발전용 바이오중유의 연료특성은 원료물질 의 조성 및 혼합비와 관련이 깊다. As it carry out RPS(Renewable Portfolio Standards), power producers are using the power bio-fuel oil to meet their RPS quota. In this study, we test the quality characteristics of raw materials for power bio-fuel oil and the property changes of power bio-fuel oil by the kind of feedstocks. The power bio-fuel oil and feedstocks were analyzed for item of quality standard such as acid number, viscosity and metal contents. And it was analyzed for composition distribution by FT-IT and HPLC. Such as low priced palm oil series has high acid number and ash contents due to high free-fatty acid and metal contents. And by-product of biodiesel have a tendency of high viscosity. The fuel properties of power bio-fuel oil, such as viscosity, acid number and metal contents are correlated with the constituent and the mixing ratio of the feedstocks.

대기 열플라즈마를 이용한 NiCr-Cr₂O₃-Ag-BaF₂/CaF₂ 코팅미세조직과 상조성에 대한 고찰

한창민,최한신,김길영,이창희,황순영 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.6

A blended NiCr-Cr₂O₃-Ag-CaF₂/BaF₂ feedstock was sprayed using an atmospheric plasma spraying. Physical and thermophysical properties of each constituent phase are quiet different and resulting interactions of each constituent with the plasma jet can be expected to be different. Thus, an attempt to change the plasma jet characteristics by changing the hydrogen gas flow rate in view of the thermophysical properties of the plasma jet was tried. According to the hydrogen gas flow rate, phase compositions and microstructures were evaluated. The effects of phase composition and microstructure on the Vickers microhardness and bond strength were also evaluated. For empirically tracing the each constituent particle trajectory, spot spraying bead was produced. Finally, particle temperature and velocity according to the hydrogen gas flow rate was measured using alumina-titania particle instead of the blended feedstock. (Received January 19, 2004)

Porous Al2O3 catalyst carrier by 3D additive manufacturing for syngas reforming

N.C. Fan,Y.Y. Chen,K.Y. Chen,W.C.J. Wei,B. H. Liu,A.B. Wang,R. C. Luo 한양대학교 세라믹연구소 2017 Journal of Ceramic Processing Research Vol.18 No.9

A disk-shaped ceramic catalyst made by 3D printing (3DP) is used to reform syngas. We select two Al2O3 powders (α- andhigh-surface-area θ-Al2O3) and polymeric binders for preparing the 3DP feedstock. Catalyst stacked Al2O3 disks are made bykneading the polymers with ceramic powders and extruding to produce filaments, which are melted and used for 3D additivemanufacturing (AM). The processing parameters (sequence of addition, viscosity of the feedstock, etc.), the phasetransformation of the θ-powder, and catalytic properties of the made carrier are examined. The made alumina disks weredensified to a relative density (RD) of 40% −65%. Two porous disks were coated with catalyst NiO and CeO2, and used toreform syngas made from waste paper. The best case reforms the CH4 content in the syngas from 25.7% down to 0.15% orlower. The reformed gaseous fuel is suitable for solid oxide fuel cells (SOFCs).