Kinetic analysis of catalytic coal gasification process in fixed bed condition using Aspen Plus

Abstract With the help of Aspen Plus, a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier. A developed and validated two dimensional CFD model for coal gasification has been used to predict and assess the viability of the syngas generation from coal gasification employing the updraft fixed bed gasifier. The process rate model and the sub-model of gas generation are determined. The particle size variation and char burning during gasification are also taken into account. In order to verify the model and increase the understanding of gasification characteristics, a set of experiments and numerical comparisons have been carried out. The simulated results in the bed are used to predict the composition of syngas and the conversion of carbon. The model proposed in this paper is a promising tool for simulating the coal gasification process in a fixed bed gasifier.

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Modelling Test of Autothermal Gasification Process Using CFD

Archives of Mining Sciences ◽

10.1515/amsc-2017-0019 ◽

2017 ◽

Vol 62 (2) ◽

pp. 253-268

Author(s):

Tomasz Janoszek ◽

Krzysztof Stańczyk ◽

Adam Smoliński

Keyword(s):

Numerical Model ◽

Coal Gasification ◽

Energy Transport ◽

Fluid Dynamic ◽

Fixed Bed ◽

Complex Model ◽

Ex Situ ◽

Underground Coal Gasification ◽

Gasification Process ◽

Physical And Chemical

AbstractThere are many complex physical and chemical processes, which take place among the most notable are the chemical reactions, mass and energy transport, and phase transitions. The process itself takes place in a block of coal, which properties are variable and not always easy to determine in the whole volume. The complexity of the phenomena results in the need for a construction of a complex model in order to study the process on the basis of simulation. In the present study attempts to develop a numerical model of the fixed bed coal gasification process in homogeneous solid block with a given geometry were mode. On the basis of analysis and description of the underground coal gasification simulated in the ex-situ experiment, a numerical model of the coal gasification process was developed. The model was implemented with the use of computational fluid dynamic CFD methods. Simulations were conducted using commercial numerical CFD code and the results were verified with the experimental data.

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Catalytic Coal Gasification Process Simulation with Alkaline Organic Wastewater in a Fluidized Bed Reactor Using Aspen Plus

Energies ◽

10.3390/en12071367 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1367 ◽

Cited By ~ 1

Author(s):

Xiao ◽

Wang ◽

Zheng ◽

Qin ◽

Zhou

Keyword(s):

Process Simulation ◽

Equivalence Ratio ◽

Coal Gasification ◽

Aspen Plus ◽

Operating Conditions ◽

Catalytic Gasification ◽

Gasification Process ◽

Cold Gas Efficiency ◽

Gas Efficiency ◽

Organic Wastewater

A co-gasification process was proposed both for treating alkaline organic wastewater and to promote coal gasification by the alkaline substances in situ. A catalytic gasification model was developed by introducing a catalytic correction factor to describe the catalytic effects quantitatively. An integrated process simulation was carried out using Aspen Plus equipped with FORTRAN subroutines. The model was verified using the root mean square error between the simulation results and experimental data from the literature. Syngas composition, cold gas efficiency, and carbon conversion efficiency were analyzed with respect to different operating conditions (reaction temperature, steam/coal ratio, and equivalence ratio). The optimal conditions are summarized based on a self-sufficient system by using sensitivity analysis: Gasification temperature of 700 °C, steam/coal ratio = 1.0, and equivalence ratio = 0.4.

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Pemanfaatan gasifikasi batubara untuk unit pengeringan teh

Jurnal Teknik Kimia Indonesia ◽

10.5614/jtki.2006.5.2.6 ◽

2018 ◽

Vol 5 (2) ◽

pp. 443

Author(s):

Ari Susandy Sanjaya ◽

S Suhartono ◽

Herri Susanto

Keyword(s):

Coal Gasification ◽

Fixed Bed ◽

Calorific Value ◽

Diesel Oil ◽

Fuel Oil ◽

Dual Fuel ◽

Processing Unit ◽

Producer Gas ◽

Downdraft Gasifier ◽

Gasification Process

Coal gasification utilization for tea drying unit. Anticipating the rise of fuel oil, the management of a tea plantation and drying plant has considered to substitute its oil consumption with producer gas (gaseous fuel obtained from gasification process). A tea drying unit normally consumes 70 L/h of industrial diesel oil and is operated 10 hours per day. The gasification unit consisted of a down draft fixed bed gasifier (designed capacity of about 100 kg/h), gas cooling and cleaning systems. The gas producer was delivered to the tea processing unit and burned to heat the drying oil: Low calorific value coal (4500 kcal/kg) and wood waste (4000 kcal/kg) have been used as fuel. The gasification unit could be operated as long as 8 hours without refueled since the coal hopper on the toppart of gasifier has a capacity of 1000 kg. Sometimes, the gasification process must be stopped before coal completely consumed due to ash melting inside the gasifier. Combustion of producer gas produced a pale-blue flame, probably due to a lower calorific value of the producer gas or too much excess air. Temperature of heating-air heated by combustion of this producer gas was only up to 96 oC. To achieve the target temperature of 102 oC, a small oil burner must he operated at a rate ofabout 15 L/h. Thus the oil replacement was about 78%.Keywords: Fuel oil, Producer gas, Downdraft gasifier, Dual fuel, Calorific value, Burner. AbstrakKenaikan harga bahan bakar minyak untuk industri pada awal 2006 telah mendorong berbagai pemikiran dan upaya pemanfaatan bahan bakar alternatif. Sebuah unit gasifikasi telah dipasang di pabrik teh sebagai penyedia bahan bakar alternatif. Unit gasifikasi tersebut terdiri dari gasifier, pendingin, pembersih gas, dan blower. Unit gasifikasi ini ditargetkan untuk dapat menggantikan konsumsi minyak bakar 70 L/jam. Gasifier dirancang untuk kapasitas 120 kg/jam batubara, dan memiliki spesifikasi sebagai berikut: downdraft gasifier; diameter tenggorokan 40 cm, diameter zona reduksi 80 cm. Bunker di bagian atas gasifier memiliki kapasitas sekitar 1000 kg batubara agar gasifier dapat dioperasikan selama 8 jam tanpa pengisian-ulang. Bahan baku gasifikasi yang telah diuji-coba adalah batuhara kalori rendah (4500 kcal/kg) dan limbah kayu (4000 kcal/kg). Gas produser (hasil gasifikasi) dibakar pada burner untuk memanaskan udara pengering teh sampai temperatur target 102 oC. Pembakaran gas produser ternyata menghasilkan api biru pucat yang mungkin disebabkan oleh rendahnya kalor bakar gas dan tingginya udara-lebih. Temperatur udara pengering hasil pemanasan dengan api gas produser hanya mencapai 96 oC. Dan untuk mencapai temperatur udara pengering 102 oC, burner gas prod user harus dibantu dengan burner minyak 15 L/jam. Jadi operasi dual fued ini dapat memberi penghematan minyak bakar 78%.Kata kunci: Minyak bakar, Gas produser, Downdraft gasifier, Dual fuel, Kalor bakar, Burner.

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Fractionation of coal through organo-separative refining for enhancing its potential for the CO2-gasification

International Journal of Coal Science & Technology ◽

10.1007/s40789-020-00348-7 ◽

2020 ◽

Vol 7 (3) ◽

pp. 504-515 ◽

Cited By ~ 2

Author(s):

Heena Dhawan ◽

Rohit Kumar ◽

Sreedevi Upadhyayula ◽

K. K. Pant ◽

D. K. Sharma

Keyword(s):

Sugarcane Bagasse ◽

Coal Gasification ◽

Ambient Pressure ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Inert Gas ◽

Coal Structure ◽

Gasification Reactivity ◽

Gasification Process ◽

Residual Coal

Abstract Coal gasification has already been extensively studied earlier under varying conditions of steam, CO2, O2, inert conditions. Belbaid coal and its e, N and NMP-DETA SCC products recovered through organo-refining under milder ambient pressure conditions were subjected to CO2-gasification in a fixed bed reactor under varying conditions. CO2 being an inert gas becomes the most challenging to be utilized during the gasification process. The SCCs showed better CO2-gasification reactivity than the raw Belbaid coal at 900 °C. The use of the catalyst K2CO3 tremendously increased the gasification reactivity for both raw coal and the SCCs. The use of sugarcane bagasse for CO2-gasification along with raw coal as well as with residual coal was also studied. Gasification under CO2 atmosphere conditions was used to structurally understand the coals as the coal structure gets loosened after extraction.

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Experimental Study and Thermodynamic Analysis of Hydrogen Production through a Two-Step Chemical Regenerative Coal Gasification

Applied Sciences ◽

10.3390/app9153035 ◽

2019 ◽

Vol 9 (15) ◽

pp. 3035 ◽

Cited By ~ 2

Author(s):

Li ◽

He ◽

Li

Keyword(s):

Hydrogen Production ◽

Production Process ◽

Coal Gasification ◽

Fixed Bed ◽

H2 Production ◽

Steam Gasification ◽

Air Separation ◽

The Novel ◽

Separation Unit ◽

Gasification Process

Hydrogen, as a strategy clean fuel, is receiving more and more attention recently in China, in addition to the policy emphasis on H2. In this work, we conceive of a hydrogen production process based on a chemical regenerative coal gasification. Instead of using a lumped coal gasification as is traditional in the H2 production process, herein we used a two-step gasification process that included coking and char-steam gasification. The sensible heat of syngas accounted for 15–20% of the total energy of coal and was recovered and converted into chemical energy of syngas through thermochemical reactions. Moreover, the air separation unit was eliminated due to the adoption of steam as oxidant. As a result, the efficiency of coal to H2 was enhanced from 58.9% in traditional plant to 71.6% in the novel process. Further, the energy consumption decreased from 183.8 MJ/kg in the traditional plant to 151.2 MJ/kg in the novel process. The components of syngas, H2, and efficiency of gasification are herein investigated through experiments in fixed bed reactors. Thermodynamic performance is presented for both traditional and novel coal to hydrogen plants.

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Pilot verification of a low-tar two-stage coal gasification process with a fluidized bed pyrolyzer and fixed bed gasifier

Applied Energy ◽

10.1016/j.apenergy.2013.10.052 ◽

2014 ◽

Vol 115 ◽

pp. 9-16 ◽

Cited By ~ 44

Author(s):

Xi Zeng ◽

Fang Wang ◽

Hongling Li ◽

Yin Wang ◽

Li Dong ◽

...

Keyword(s):

Fluidized Bed ◽

Coal Gasification ◽

Fixed Bed ◽

Two Stage ◽

Gasification Process

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Green energy technology from buriti (Mauritia flexuosa L. f.) for Brazilian agro-extractive communities

SN Applied Sciences ◽

10.1007/s42452-021-04278-0 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

Munique Gonçalves Guimarães ◽

Rafael Benjamin Werneburg Evaristo ◽

Augusto César de Mendonça Brasil ◽

Grace Ferreira Ghesti

Keyword(s):

Lignin Content ◽

Fixed Bed ◽

Thermal Conversion ◽

Volatile Matter ◽

Matter Content ◽

Green Energy ◽

Fixed Bed Reactor ◽

Gasification Process ◽

Mauritia Flexuosa ◽

Immediate Analysis

AbstractThe present work analyzed the energy generation potential of Buriti (Mauritia flexuosa L. f.) by thermochemical reactions. The experimental part of the study performed immediate analyses, elemental analyses, lignocellulosic analysis, thermogravimetric analysis, calorific values, and syn gas concentrations measurements of the gasification of Buriti in a fixed-bed reactor. Additionally, numerical simulations estimated the syn gas concentrations of the gasification reactions of Buriti. The immediate analysis showed that Buriti has the highest ash content (4.66%) and highest volatile matter content (85%) compared to other Brazilian biomass analyzed, but the higher heating value was only 18.28 MJ.kg−1. The elemental analysis revealed that the oxygen to carbon ratio was 0.51 while hydrogen to carbon ratio was 1.74, indicating a good thermal conversion efficiency. The Lignocellulosic analysis of Buriti resulted in a high content of holocellulose (69.64%), a lignin content of 28.21% and extractives content of 7.52%. The thermogravimetry of the Buriti indicated that the highest mass loss (51.92%) occurred in a temperature range between 150 °C and 370 °C. Lastly, the experimental gasification study in a fixed-bed updraft gasifier resulted in syn gas concentrations of 14.4% of CO, 11.5% of CO2 and 17.5% of H2 while the numerical simulation results confirmed an optimal equivalence ratio of 1.7 to maximize CO and H2 concentrations. Therefore, based on the results presented by the present work, the gasification process is adequate to transform Buriti wastes into energy resources. Graphic abstract

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Changes in properties of tar obtained during underground coal gasification process

International Journal of Coal Science & Technology ◽

10.1007/s40789-021-00440-6 ◽

2021 ◽

Author(s):

Marian Wiatowski ◽

Roksana Muzyka ◽

Krzysztof Kapusta ◽

Maciej Chrubasik

Keyword(s):

Coal Gasification ◽

Coal Tar ◽

Liquid Product ◽

Coke Oven ◽

Underground Coal Gasification ◽

Gasification Process ◽

Dominant Component ◽

Process Gas ◽

High Volatility ◽

Product Separator

AbstractIn this study, the composition of tars collected during a six-day underground coal gasification (UCG) test at the experimental mine ‘Barbara’ in Poland in 2013 was examined. During the test, tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven (coal) tar. The obtained results were compared with each other and with the data for coal tar. As gasification progressed, a decreasing trend in the water content and an increasing trend in the ash content were observed. The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline. All tested samples were characterized by very high distillation losses, while for samples starting from the third day of gasification, a clear decrease in losses was visible. A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar. The content of polycyclic aromatic hydrocarbons (PAHs) in UCG tars is several times lower than that in coal tar. No light monoaromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes—BTEX) were found in the analysed tars, which results from the fact that these compounds, due to their high volatility, did not separate from the process gas in the liquid product separator.

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