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IEA-CFBC 모델을 이용한 저급탄의 순산소 연소 특성 분석
곽유라 ( You Ra Gwak ),김예빈 ( Ye Bin Kim ),길상인 ( Sang In Keel ),윤진한 ( Jin Han Yun ),이시훈 ( See Hoon Lee ) 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.5
에너지 공급 안정과 온실가스 저감이라는 목표를 달성하기 위해 저등급 석탄의 순산소 순환유동층 보일러의 적용이 새롭게 모색되고 있다. 아직까지 실증 단계의 개발이 진행되고 있기에 순산소 순환유동층 보일러에서의 저급탄 이용을 위해 주입 공기량, 조업 온도, 연료 공급량 등의 변화에 따른 연소 특성이 고찰되어야 상용 모델을 위한 설계 기준을 선정할 수 있다. 이에 본 연구에서는 공기 연소로 개발된 IEA-CFBC 모델을 순산소 연소를 전산모사하도록 개조하였고 새로운 순산소 순환유동층 모델을 이용하여 온도(800 ℃~900 ℃), 산소 농도(21%~41%), 석탄 주입량, Ca/S 비율(1.5~4.0) 등의 다양한 조건에서 순산소 연소 특성을 고찰하였다. 공기 연소와 비교하여, 순산소 조건에서의 보일러 온도가 높았으나 산소 농도가 증가함에 따라 보일러의 온도구배는 감소하는 경향을 나타냈다. 더불어 Ca/S 비율, 산소농도가 높을수록 탈황 효율이 증가하는 것으로 나타났다. The application of an oxy-combustion circulating fluidized bed combustor (Oxy-CFBC) for low grade coals has recently developed in the world to meet the continuous increase of energy demand and to achieve the reduction of greenhouse gases. Since demo plants for Oxy-CFBC have been developed, the combustion properties of Oxy- CFBC in various operation conditions, such as gas flow rates, combustion temperature, fuel, and so on, should be investigated to develop design criteria for a commercial Oxy-CFBC. In this study, a computational simulation tool for Oxy- CFBC was developed on the basis of the IEA-CFBC (International Energy Agency Circulating Fluidized Bed Combustor) model. Simulation was performed under various conditions such as reaction temperature (800 ℃~900 ℃), oxygen contents (21%~41%), coal feeding rate, Ca/S mole ratio (1.5~4.0), and so on. Simulation results show that the combustion furnace temperature is higher in oxy 1 than air fired. However, the temperature gradient tended to decrease with increasing oxy mixing percent. In case of SO<sub>x</sub>, the higher the Ca/S mole ratio and oxy mixing percent, the higher the desulfurization efficiency.
Economic evaluation of synthetic ethanol production by using domestic biowastes and coal mixture
Gwak, You Ra,Kim, Ye Bin,Gwak, In Seop,Lee, See Hoon Elsevier 2018 Fuel Vol.213 No.-
<P><B>Abstract</B></P> <P>Biowastes, such as cow manure, waste paper, and wood waste, are recognized as an essential source of renewable energy, and their importance increased significantly over time. However, the insufficient supply of biowastes for commercial thermochemical conversion processes is a major problem that needs to be addressed. Therefore, the co-utilization of biowastes and coal has been developed globally. In this study, we investigated the feasibility of biowaste and coal mixtures in an ethanol conversion process. A commercial-scale thermochemical process consisting of a dual fluidized bed gasifier, compressor, tar reformer, catalytic reactor, and auxiliary facilities was used and analyzed. In particular, the effects of material costs including both transportation and collection costs of biowastes and mix percentages on the economic value of synthetic ethanol were analyzed. In addition to the limitations of biowaste collection, the scale of co-utilization processes could be a critical factor for the commercialization of converting biowaste and coal mixtures to ethanol.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biowaste-coal mixtures to synthetic ethanol conversions were investigated. </LI> <LI> The economic efficiency of synthetic ethanol process increased due to increasing final products. </LI> <LI> Mixing coal could be a solution for biowastes to energy conversion. </LI> </UL> </P>
결착제 종류에 따른 식물소재기반 패티 제조 및 품질특성
임수빈(Su-Bin Lim),문태휘(Tae-Hwi Moon),임선구(Sun-goo Yim),유예림(Ye-Lim You),한정아(Jung-Ah Han) 한국식품과학회 2023 한국식품과학회지 Vol.55 No.3
본 연구에서는 1% 히알루론산과 카라기난, 구아검을 결착제로 첨가한 식물성 패티를 제조하고 그 특성을 평가하였다. 색도평가시, 명도와 황색도에서 시료 간의 유의적인 차이는 없었으나 적색도는 대조군이 결착제 첨가군보다 유의적으로 높은 값을 나타냈다. pH는 검을 첨가한 시료군이 대조군과 HA 첨가군보다 유의적으로 낮은 값을 보였다. 수분함량과 가열수율은 HA, GG, HA+GG 첨가군에서 유의적으로 높은 값을 보였으며 직경감소율은 HA, GG, HA+GG군이 유의적으로 낮은 값을 보여 서로 상응하는 결과를 보였다. 전자현미경을 이용하여 패티의 미세구조를 관찰한 결과 결착제 첨가군에서 결착제의 친수성 상호작용으로 인해 대조군에 비해 표면공극의 수가 감소하여 표면 개선에 도움을 준 것을 확인할 수 있었으나 GG 첨가군은 높은 점성으로 인해 큰 공극이 형성되면서 불규칙한 구조를 확인할 수 있었다. 조직감 측정결과 결착제를 첨가한 패티가 대조군보다 유의적으로 낮은 경도와 씹힘성, 그리고 높은 탄력성을 보였다. 시제품 2종과 GG, HA+CG, HA+GG 첨가군을 대상으로 관능검사를 실시한 결과 외관은 시제품 2종과 GG첨가군에서 유의적으로 높은 평가를 받았으며 향도 시제품 2종에서 유의적으로 높은 평가를 보였다. 맛과 부드러움은 HA+GG 첨가군이 유의적으로 높은 값을 보였으며, 전반적인 기호도 또한 HA+GG와 HA+CG가 유의적으로 높은 평가를 받았다. 강도평가에서 촉촉함은 HA+GG, HA+CG 첨가군이 가장 높았고 시제품 2종은 상대적으로 낮은 평가를 받았으며, 조직감은 시료 간의 유의적인 차이를 보이지 않았다. 이상의 결과로 식물성 패티 제조 시 히알루론산과 구아검을 결착제로 첨가하는 경우 패티의 수분함량과 가열수율은 향상시키고 직경감소율을 감소시켜 제품의 촉촉함과 부드러움을 개선시킬 수 있을 것으로 보인다. Plant-based patties with different binders were developed as meat analogues, and their properties were compared. Hyaluronic acid, carrageenan (CG), guar gum (GG), and a mixture of the gums (HA+CG and HA+GG) were used as binders. Samples with HA, GG, and HA+GG showed significantly higher moisture content and cooking yield and lower reduction in diameter after cooking than the control samples. In addition, microstructure analysis using scanning electron microscopy showed that the samples with binders had an improved surface structure and smaller pores than the control, except for those with GG. Patties with binders also exhibited lower hardness and higher springiness than the controls. In the sensory evaluation, patties with HA+GG showed significantly higher values for taste, moistness, tenderness, and overall acceptability than others. These results indicate that HA+GG can be used as an effective binder to improve the quality of plant-based meat analogue.
Drying characteristics of low rank coals in a pressurized flash drying system
Gwak, In Seop,Gwak, You Ra,Kim, Ye Bin,Lee, See Hoon THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.57 No.-
<P><B>Abstract</B></P> <P>Drying characteristics of low rank coals were examined and determined using a pressurized flash drying system which consisted of a pressurized feeder, rolled tubes (maximum of 6m), a cyclone, and a back pressure regulator. The effect of the operating conditions, such as pressure (maximum of 40bar), gas outlet temperature (maximum of 300°C), particle sizes (212–300 and 300–355μm) and residence time (maximum of 1s) on the drying ratio was investigated and analyzed. The study results show that temperature is a more effective factor than pressure. A correlation equation to predict the drying ratio of coals was suggested based on operation conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The characteristics of pressurized flash drying of low rank coal were investigated. </LI> <LI> The drying ratio mostly increased with temperatures and pressures. But the drying ratio did not increase at high pressure conditions because of increasing boiling temperature. </LI> <LI> The empirical equation to predict drying ratio was suggested as follows: <SUB> D r </SUB> = 2.82 × <SUP> R 0.63 </SUP> × <SUP> S 0.02 </SUP> × <SUP> P 0.28 </SUP> × <SUP> T 0.65 </SUP> . </LI> </UL> </P>