• 한국연소학회지
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• 제21권4호
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• pp.23-29
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• 2016

Reactivity of gasification defined by bouardard reaction is critical parameter in efficiency of the gasifier. In this study, char reactivity of the gasification was derived from the experiments using the intrinsic reaction kinetics model. Pressurized wire mesh heating reactor (PWMR) can produce high temperature and high pressure conditions up to 50 atm and 1750 K, respectively and PWMR was designed to evaluate the intrinsic reaction kinetics of $CO_2$ gasification. In this study, Kideco and KCH (sub-bituminous Indonesian coal) were pulverized and converted into char. Experiments used the PWMR were conducted and the conditions of the temperature and pressure were 1373~1673 K, 1~40 atm. To distinguish the pressure effect from high pressurized condition, internal and external effectiveness factors were considered. Finally, the intrinsic kinetics of the Kideco and KCH coal char were derived from $n^{th}$ order reaction rate equations.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.190-199
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• 2017

Air-blown Gasification of coal and torrefied biomass mixture is conducted on fixed-bed gasifier. The various ratio (9:1, 8:2, 7:3) of coal and torrefied biomass mixture are used. The contents of $H_2$, CO in the syngas were increased with gasification temperature. Carbon conversion tend to increase with temperature and equivalence ratio (ER). However, cold gas efficiency showed maximum point in ER range of 0.26-0.36. The torrefied biomass showed highest cold gas efficiency of 67.5% at $934^{\circ}C$, ER 0.36. Gasification of 8:2 mixture showed the highest carbon conversion and cold gas efficiency and synergy effect.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.425-434
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• 2010

Integrated gasification combined cycle (IGCC) is an efficient and environment-friendly power generation system which is capable of burning low-ranked coals and other renewable resources such as biofuels, petcokes and residues. In this study some process modeling on a conceptual entrained flow gasifier was conducted using the ASPEN Plus process simulator. This model is composed of three major steps; initial coal pyrolysis, combustion of volatile components, and gasification of char particles. One of the purposes of this study is to develop an effective and versatile simulation model applicable to numerous configurations of coal gasification systems. Our model does not depend on the hypothesis of chemical equilibrium as it can trace the exact reaction kinetics and incorporate the residence time calculation of solid particles in the reactors. Comparisons with previously reported models and experimental results also showed that the predictions by our model were pretty reasonable in estimating the products and the conditions of gasification processes. Verification of the accuracy of our model was mainly based upon how closely it predicts the syngas composition in the gasifier outlet. Lastly the effects of change oxygen are studied by sensitivity analysis using the developed model.

• 에너지공학
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• 제8권4호
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• pp.553-559
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• 1999

1 T/D 급 습식 분류상 석탄가스화 장치를 이용하여 외국의 각종탄에 대한 가스화 실험을 통해, 1) 석탄가스화를 위한 적절한 탄종을 선정하고 , 2) 탄종에 따른 가스화 반응식 데이터베이스를 구축하며, 3) 가스화 반응기에서 예상되는 문제점을 사전에 제거하고, 4) 습식분류상 가스화기술에 대한 요소기술 및 운소기술 및 운전기술을 확보하므로서 향후 IGCC Plant 설계, 건설시에 시행착오를 줄이는데 크게 기여하고저 하였다. 가스화 실험을 위해 미국산 Cyprus 및 Alaska 탄이 사용되었으며 , 실험결과 Cyprus 및 Alaska 탄은 국내발전용 탄인역청탄 및 갈탄으로 비교적 반응성은 양호하였으며, slag 의 용융온도 또한 약 129$0^{\circ}C$로서 비교적 낮게 나타났다. 석탄슬러리 농도는 Cyprus 탄의 경우 58, 62 , 65 %로 유지하였으며 가스화장치에 공급하는데는 점도 상승에 따른 큰 문제점이 없었으나, Alaska 탄의 경우엔 수분함량이 많아 슬러리 제조 및 feeding 상의 문제점을 고려하여 58%로 운전하였으며 , 60%이상 슬러리 농도를 유지할수 없었다. O2 coal ratio는 0.6에서 1.2까지 유지하면서 운전하였으며 갈탄인 Alaska탄의 경우 수분함량이 많아 산소소모가 많은 것으로 나타났다. 두 탄종에 대한 가스화실험을 통해, 생성된 합성가스(H2+ CO)는 40-62% 로나타났으며 , 생성가스의 열량은 1, 400-2,050kcal/N㎥(HHV)로 분석되었다.

• 한국연소학회지
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• 제4권1호
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• pp.1-15
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• 1999

In order to analyze the sensitivity on the pulverized coal flames of the several variables, a numerical study was conducted at the gasification process. Eulerian approach is used for the gas phase, whereas lagrangian approach is used for the solid phase. Turbulence is modeled using the standard $k-{\varepsilon}$ model. The turbulent combustion incorporates eddy dissipation model. The radiation was solved using a Monte-Carlo method. One-step two-reaction model was employed for the devolatilization of Kideco coal. In pulverized flame of long liftoff height, the initial turbulent intensity seriously affects the position of flame front. The radiation heat transfer and wall heat loss ratio distort the temperature distributions along the reactor wall, but do not influence the reactor performance such as coal conversion, residence time and flame front position. The primary/secondary momentum ratio affects the position of flame front, but the coal burnout is only slightly influenced. The momentum ratio is a variable only associated with the flame stabilization such as flame front position. The addition of steam in the reactor has a detrimental effect on all the aspects, particularly reactor temperature and coal burnout.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.746-754
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• 2015

본 연구는 이온교환법을 통해 Ni촉매를 담지한 저등급 석탄(인도네시아 Eco탄)과 바이오매스(대한민국 상록수)의 혼합물로부터 제조된 촤(char)를 $700{\sim}900^{\circ}C$ 등온조건에서 온도가 반응속도에 미치는 영향에 대해 알아보았다. $Char-CO_2$ 가스화 반응은 700, 750, 800, 850, $900^{\circ}C$의 온도에서 진행하였으며, 기-고체 반응의 가스화 거동특성을 알아보기 위하여 각각 다른 가정을 갖고 있는 shrinking core model(SCM), volumetric reaction model(VRM), random pore model(RPM), modified volumetric reaction model(MVRM)을 실험결과에 적용하여 비교하였다. Arrhenius equation를 이용하여 Ni-coal/biomass와 Non-catalyst coal/biomass의 활성화에너지를 구하였고 이를 비교하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.79-80
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• 2019

This study was intended to examine the possibility of reducing hydration heat by FA substitution and combination of slag (CGS) from coal gasification power generation (IGCC) with mixed aggregate for concrete. The analysis results showed good results if liquidity increases as the ratio of CGS increases, air volume decreases, and compressive strength is mixed up to 25% in the residual aggregate. The results showed that the heat of hydration was reduced compared to plain due to the boron content of CGS as the CGS substitution rate increased, but it was larger due to the combination with FA substitution. It was found that the heat of hydration was reduced.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.182-183
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• 2021

In this study, This is the result of thermal characteristics analysis to suggest an efficient method of using coal gasification slag(CGS) of byproduct from integrated gasification combined cycle(IGCC). In Specific Heat characteristics, CGS and CS showed similar values. Isothermal Conduction Calorimetry showed that the hydration reaction of cement was retarded when CGS was used. Therefore, it is expected that CGS will be used as an efficient alternative to reducing the hydration heat of mass concrete as a functional aggregate combination.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.460-469
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• 2010

To develop coal gasfication system, many studies have been actively conducted to describe the simulation of steady state. Now, it is necessary to study the gasification system not only in steady state but also in dynamic state to elucidate abnormal condition such as start-up, shut-down, disturbance, and develop control logic. In this study, a model was proposed with process simulation in dynamic state being conducted using a chemical process simulation tool, where a heat and mass transfer model in the gasifier is incorporated, The proposed model was verified by comparison of the results of the simulation with those available from NETL (National Energy Technology Laboratory) report under steady state condition. The simulation results were that the coal gas efficiency was 80.7%, gas thermal efficiency was 95.4%, which indicated the error was under 1 %. Also, the compositions of syngas were similar to those of the NETL report. Controlled variables of the proposed model was verified by increasing oxygen flow rate to gasifier in order to validate the dynamic state of the system. As a result, trends of major process variables were resonable when oxygen flow rate increased by 5% from the steady state value. Coal flow rate to gasifier and quench gas flow rate were increased, and flow rate of liquid slag was also increased. The proposed model in this study is able to be used for the prediction of gasification of various coals and dynamic analysis of coal gasification.

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.80-87
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• 2010

발열량이 낮은 저등급 석탄이나 황함량이 많은 petroleum-coke는 그 이용이 제한적이지만 공급이 풍부하여 잠재력이 큰 에너지원이므로, 가스화공정에 적용하여 고급연료인 수소나 액체연료를 생산할 수 있다. 본 연구에서는 상압의 열천칭 반응기(thermobalance)에서 wood chip, 저등급 석탄인 갈탄, 역청탄, 무연탄, pet-coke의 수증기 가스화 반응특성을 조사하였다. 가스화 온도 $600{\sim}850^{\circ}C$, 수증기 분압 30~90 kPa의 범위에서 조업변수들이 가스화반응속도에 미치는 영향을 조사하였다. 기체-고체 반응모델로서 modified volumetric reaction model을 적용하여 가스화반응의 거동을 묘사하고 가스화공정에 필수적인 kinetic 정보를 도출하였다. 저등급탄인 갈탄과 바이오매스인 wood chip은 휘발분 함량도 높고 비교적 높은 가스화반응속도를 보여 가스화반응공정에 적합한 연료이다. Arrhenius plot으로부터 활성화에너지는 wood chip, 갈탄, 역청탄, 무연탄, pet-coke에 대해 각각 260.3, 167.9, 134.6, 82.2, 168.9 kJ/mol으로 구해졌다. 각 연료에 대하여 수증기 가스화반응의 반응차수를 결정하였으며, 가스화공정 설계의 기초데이타로서 겉보기 반응속도식을 제시하였다.