Reaction rate analysis of CO₂ gasification for Indonesian coal char Impact of Internal/External diffusion at high temperature and elevated pressure

Kevin Yohanes Lisandy(케빈),Ryang-Gyoon Kim(김량균),Chan-Won Hwang(황찬원),Yeon-Kyung Lee(이연경),Chung-Hwan Jeon(전충환) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.5

Pressurized wire mesh heating reactor (PWMR) can provide high pressure and temperature experimental conditions up to 50 bar and 1750 K respectively. This equipment was developed to evaluate intrinsic reaction kinetics of CO2 gasification. PWMR utilize platinum (Pt) wire mesh resistance to generate heat with direct current (DC) electricity supply. This DC power supply then can be controlled by computer software to reach exact expected terminal temperature as well as heating period. In this study, Berau (sub-bituminous Indonesian coal) was pulverized then converted into char which has 90-150 micrometers particle size experimented with variable pressure condition (1-40 bar) and variable temperature (1373-1673 K) on atmospheric condition. The internal/external effectiveness factor was analyzed to determine the effects of high pressure The intrinsic reaction kinetics of Berau char was obtained using nth order reaction rate equations. The value was determined to be 203.8kJ/mol.

Enhanced Accuracy of the Reaction Rate Prediction Model for Carbonaceous Solid Fuel Combustion

Lisandy, Kevin Yohanes,Kim, Gyeong-Min,Kim, Jin-Ho,Kim, Gyu-Bo,Jeon, Chung-Hwan American Chemical Society 2017 ENERGY AND FUELS Vol.31 No.5

<P>Combustion of carbonaceous solid fuels was modeled using a number of methods, and the employed models were further improved by thoroughly studying the physical and chemical interactions between carbonaceous solid fuels and oxidizers. Simulation accuracy was improved by using special techniques to reduce the fitting errors of earlier models; e.g., errors in the isothermal coal char combustion rate model were reduced by modifying the well-established random pore model, with increased model flexibility generally considered vital for improvement. Thermogravimetric analyses were performed for four categories of carbonaceous fuels: semi-anthracite coals, bituminous coals, sub-bituminous coals, and biomass. Scanning electron microscopy imaging was employed to understand correlations between the fuel structure and model parameters. The obtained results were used to confirm the hypotheses of the used models, and a general model of carbonaceous solid fuel combustion, termed 'flexibility-enhanced random pore model', was established, improving correlation coefficients from 0.7 to 0.98 and decreasing deviations from 20 to 3%.</P>

Sensitivity test of low rank Indonesian coal utilization using steady state and dynamic simulations of entrained-type gasifier

Lisandy, Kevin Yohanes,Kim, Ryang-Gyoon,Hwang, Chan-Won,Jeon, Chung-Hwan Elsevier 2016 Applied Thermal Engineering Vol.102 No.-

<P><B>Abstract</B></P> <P>Gasification is a process in which a solid fuel is transformed into a gas, which acts as a useful energy source. Coal gasification provides a wide range of products such as chemical, power, liquid, and gaseous fuels. A simulation study was undertaken to calculate the composition, mass flow rate, temperature, pressure of syngas, ash slag layer thickness, heat dissipation from the reactor, and carbon conversion of the coal under steady state conditions. The effect of changes in the input parameters such as the changes in the O<SUB>2</SUB> and H<SUB>2</SUB>O to coal ratios, operating temperature, and most importantly the change in the fuel, was considered. Besides steady state simulations, dynamic simulations were also conducted to predict the starting and shutdown conditions of the gasifier. The g-proms process modeling software was utilized to conduct the simulations based on mathematical equations, which are capable of calculating time dependent derivatives. In order to obtain the actual physical and chemical properties of coal and its ash, as well as the reaction kinetics of coal, some experiments were performed. Proximate analysis, elemental analysis, and coal pyrolysis, combustion and gasification kinetics were conducted using thermogravimetry (TGA), elemental analysis method (EA), and a pressurized wire mesh heating reactor (PWMR), respectively. Ash viscosity and ash mineral composition were determined using rheometer and X-ray fluorescence (XRF), respectively. The results of these experiments were fitted into the model and served as input for the calculations. Berau and Kideco are low rank Indonesian coals with different characteristics. The results showed major problems associated with slag tapping in the case of Kideco coal. On the other hand, Berau coal performed without any issues.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The de-volatilization and char reaction kinetics for simulation input were analyzed. </LI> <LI> The viscosity variations over temperature was obtained by utilizing a rheometer. </LI> <LI> Considering diffusion effect and RPM, the intrinsic reaction kinetics was obtained. </LI> <LI> The numerical model for gasifier slag mechanism was developed. </LI> <LI> Dynamic simulation for the shell entrained-type gasifier were developed. </LI> </UL> </P>

고온, 고압조건에서의 인도네시아 석탄촤의 CO₂ 가스화 반응

리산디케빈요하네스(Kevin Yohanes Lisandy),김량균(Ryang-Gyoon Kim),황찬원(Chan-Won Hwang),전충환(Chung-Hwan Jeon) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.9

PWMR(Pressurized wire mesh heating reactor)는 Intrinsic CO₂ 가스화 반응속도 해석에 필요한 활성화에너지와 빈도상수를 도줄하기 위해서 고안되었으며, 고압 및 고온(50atm, 1750K)조건 하에서 실험을 수행하였다. 본 연구에서는 고온조건에서의 실험을 위해 백금(Pt) 메쉬를 가열체로 사용하였고 직류전원공급기를 통해 백금메쉬로 전류를 인가하여 석탄 입자를 가열시킨다. 가열시 정확한 온도제어 및 반응시간 조절을 위해 직류전원공급기는 컴퓨터로 제어된다. 본 연구에서는, 인도네시아 아역청탄인 BERAU 를 사용하였으며 입자크기는 90-150 μm, 압력과 온도조건은 각각 1-40atm 및 1373-1673K 에서 실험을 진행하였다. 고압에서의 압력의 영향을 구분하기 위해 Internal/external effectiveness factor 를 고려하였다. 최종적으로 BERAU 촤의 Intrinsic 가스화 반응속도론 을 n<SUP>th</SUP> order 반응식을 통해 도출하였으며 그 값은 203.8kJ/mol 의 값을 가졌다. A pressurized wire mesh heating reactor (PWMR) can provide high pressure and temperature experimental conditions up to 50 atm and 1750 K, respectively. This equipment was developed to evaluate the intrinsic reaction kinetics of CO₂ gasification. A PWMR utilizes a platinum (Pt) wire mesh resistance to generate heat with a direct current (DC) electricity supply. This DC power supply can then be controlled by computer software to reach the exact expected terminal temperature and heating period. In this study, BERAU (sub-bituminous Indonesian coal) was pulverized then converted into char with a particle size of 90-150 μm. This was used in experiments with various pressures (1-40 atm) and temperatures (1373-1673 K) under atmospheric conditions. The internal and external effectiveness factor was analyzed to determine the effects of high pressure. The intrinsic reaction kinetics of BERAU char was obtained using n<SUP>th</SUP> order reaction rate equations. The value was determined to be 203.8kJ/mol.

Effect of coal blending ratio on CO2 coke gasification

김진호,김경민,Kevin Yohanes Lisandy,전충환 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.11

Coke gasification is largely influenced by the raw coal, catalyst, and blending ratios, pore structure, and specific surface area of the raw coal. In this study, several properties of cokes related to their reactivity were measured using coke reactivity test apparatus (CRTA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmet-Teller (BET) surface area analysis, and energy dispersive X-ray spectroscopy (EDS) to investigate the characteristics of coke gasification. The results indicated that the reactivity of coke in the temperature range from 950 to 1,050 oC was affected by the type of coke and its specific surface area rather than the general properties of the coke, although the overall reactivities at the other temperatures were uniform. EDS analysis showed that the catalyst acted on the reactivity of cokes at low temperatures, whereas the BET analysis indicated that the reactivity at high temperature was influenced by the specific surface area.

Investigation into the effects of ash-free coal binder and torrefied biomass addition on coke strength and reactivity

Kim, Gyeong-Min,Lisandy, Kevin Yohanes,Isworo, Yanuar Yudhi,Kim, Jin-Ho,Jeon, Chung-Hwan Elsevier 2018 Fuel Vol.212 No.-

<P><B>Abstract</B></P> <P>The effects of adding ash-free coal (AFC) as a binder on the physical and chemical properties of coke were investigated to understand the mechanism of coke strength increase and to measure CO conversion reactivity. Two AFC samples (AFC_P and AFC_E) were first extracted from Indonesian low-rank coal. Torrefied biomass was also produced from woody biomass for use as an additive to AFC samples. Coke samples were then prepared by adding 3% AFC and 3% AFC + torrefied fuel. The coke strength was investigated by performing indirect tensile tests and <SUP>13</SUP>C NMR analyses. Coke reactivity was examined using thermogravimetric analysis and a coke reactivity test apparatus. The use of AFC as a binder increased the tensile strength of coke between 39% and 48%. Specifically, coke tensile strength was 2.32 MPa with AFC_P and 2.16 MPa with AFC_P + torrefied fuel; and 2.17 MPa with AFC_E and 2.10 MPa with AFC_E + torrefied fuel. The reactivity of the coke containing AFC + torrefied fuel was higher than that of the coke containing AFC alone. The coke produced with AFC_E + torrefied fuel had the highest reaction rate and average CO emission of 257,543 ppm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The effects on coke strength of ash-free coal and torrefied fuel were investigated. </LI> <LI> Added torrefied fuel may realize a reduction in CO<SUB>2</SUB> emissions from steelworks. </LI> <LI> The tensile strength of coke is related to the average number of aromatic rings. </LI> <LI> The reactivity of coke produced using TGA and CRTA via CO concentrations. </LI> </UL> </P>

코크스 기공 형성과 사용 촉매가 코크스 CO<SUB>2</SUB> 가스화에 미치는 영향

전기태,김진호,김경민,Kevin Yohanes Lisandy,송주헌 한국에너지학회 2017 한국에너지공학회 학술발표회 Vol.2017 No.4

고온, 고압조건에서의 인도네시아 석탄촤의 CO₂ 가스화 반응

리산디케빈요하네스,김량균,황찬원,전충환,Lisandy, Kevin Yohanes,Kim, Ryang-Gyoon,Hwang, Chan-Won,Jeon, Chung-Hwan 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.9

A pressurized wire mesh heating reactor (PWMR) can provide high pressure and temperature experimental conditions up to 50 atm and 1750 K, respectively. This equipment was developed to evaluate the intrinsic reaction kinetics of $CO_2$ gasification. A PWMR utilizes a platinum (Pt) wire mesh resistance to generate heat with a direct current (DC) electricity supply. This DC power supply can then be controlled by computer software to reach the exact expected terminal temperature and heating period. In this study, BERAU (sub-bituminous Indonesian coal) was pulverized then converted into char with a particle size of $90-150{\mu}m$. This was used in experiments with various pressures (1-40 atm) and temperatures (1373-1673 K) under atmospheric conditions. The internal and external effectiveness factor was analyzed to determine the effects of high pressure. The intrinsic reaction kinetics of BERAU char was obtained using $n^{th}$ order reaction rate equations. The value was determined to be 203.8kJ/mol. PWMR(Pressurized wire mesh heating reactor)는 Intrinsic $CO_2$ 가스화 반응속도 해석에 필요한 활성화에너지와 빈도상수를 도줄하기 위해서 고안되었으며, 고압 및 고온(50atm, 1750K)조건 하에서 실험을 수행하였다. 본 연구에서는 고온조건에서의 실험을 위해 백금(Pt) 메쉬를 가열체로 사용하였고 직류전원공급기를 통해 백금메쉬로 전류를 인가하여 석탄 입자를 가열시킨다. 가열시 정확한 온도제어 및 반응시간 조절을 위해 직류전원공급기는 컴퓨터로 제어된다. 본 연구에서는, 인도네시아 아역청탄인 BERAU 를 사용하였으며 입자크기는 $90-150{\mu}m$, 압력과 온도조건은 각각 1-40atm 및 1373-1673K에서 실험을 진행하였다. 고압에서의 압력의 영향을 구분하기 위해 Internal/external effectiveness factor를 고려하였다. 최종적으로 BERAU 촤의 Intrinsic 가스화 반응속도론 을 $n^{th}$ order 반응식을 통해 도출하였으며 그 값은 203.8kJ/mol 의 값을 가졌다.

고온/고압 조건에서의 석탄 촤 내부 및 외부 가스화 반응효과

김경민(Gyeong-Min Kim),김진호(Jin-Ho Kim),리산디케빈요하네스(Kevin Yohanes Lisandy),김량균(Ryang-Gyoon Kim),김규보(Gyu-Bo Kim),전충환(Chung-Hwan Jeon) 한국연소학회 2016 한국연소학회지 Vol.21 No.4

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 CO₂ 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<SUP>th</SUP> order reaction rate equations.

무회분 석탄(AFC)을 바인더로 이용한 코크스의 물리적 및 화학적 특성

김경민 ( Gyeong Min Kim ),김진호 ( Jin Ho Kim ),리잔디케빈요하네스 ( Kevin Yohanes Lisandy ),김규보 ( Gyu Bo Kim ),최호경 ( Ho Kyung Choi ),전충환 ( Chung Hwan Jeon ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.3

본 연구에서는 무회분 석탄을 바인더로 첨가한 코크스의 물리적 및 화학적 성질들을 실험적으로 분석하고 강도 향상 메커니즘에 대해 고찰하였다. 또한 제철소에서의 CO₂저감을 위해 반탄화 과정을 거친 바이오매스 연료를 이용하였다. 무회분 석탄과 함께 팽윤현상(Swelling)이 일어나지 않는 발전용 석탄을 함께 탄화시켜서 전자현미경(SEM)을 이용하여 인터페이스를 관찰하였다. 또한 코크스의 강도 분석을 위하여 I.T.T (Indirect Tensile Test)와 함께, 화학적 구조 고찰을 위하여 ¹H NMR 및 ¹³C NMR 분석을 사용하였다. 무회분 석탄의 ¹H NMR 및 ¹³C NMR 분석으로 도출된 분자 구조와 코크스 강도의 관계를 도출하였으며, 그 결과 코크스의 강도는 무회분 석탄을 바인더로 첨가함으로써 증가될 수 있음을 확인하였다. Coke strength was increased by adding ash-free coal (AFC) binder. In this study, the effect of the AFC binder on the physical and chemical properties of coke was experimentally investigated to understand the molecular mechanism for the improved coke strength. For reduced CO₂ emission in steelmaking industry, torrefied biomass fuel mixed with coal binder is also considered. The interface between the base coal and AFC was thus examined using Scanning Electron Microscope (SEM). The coke strength was commonly measured by performing the indirect tensile test and Nuclear Magnetic Resonance (NMR) spectroscopy in ¹H and ¹³C modes. For comprehensive mechanism study of the enhanced coke strength thus obtained, ordinary coal for thermal power plant use was carbonized with AFC for subsequent SEM examination. The NMR spectroscopy results of coke samples positively revealed that the tensile strength was proportional to the average number of aromatic rings.