H2-Rich and Tar-Free Downstream Gasification Reaction of EFB by Using the Malaysian Dolomite as a Secondary Catalyst

In this study, Malaysian dolomites as secondary catalysts are placed at the downstream of the fluidized-bed gasifier. Three types of Malaysian dolomites with different elemental ratios of CaO-MgO content denoted as P1, P2, and P3 are investigated with EFB gasification reaction at different cracking temperatures (700–900 °C). The performance of the catalysts with a variation of catalyst to biomass weight ratio (C/B) (0.05 to 0.30 w/w) is evaluated. The findings showed that the total gas yield increased by 20%, hydrogen increased by 66%, along with an almost 99% reduction in tar content with P1 catalyst with the following reaction conditions: gasification temperature of 850 °C, equivalence ratio (ER) of 0.25, and cracking temperature of 900 °C. Malaysia dolomite could be a secondary catalyst to provide a better alternative, tar-free hydrogen-rich gas with the possibility of regeneration and re-use.

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Influence of O2/C molar ratio and coal feeding rate on sulfur release during CFB gasification

E3S Web of Conferences ◽

10.1051/e3sconf/202019404044 ◽

2020 ◽

Vol 194 ◽

pp. 04044

Author(s):

Shengxian Xian ◽

Denghao Jiang ◽

Yanqi Fan ◽

Haixia Zhang ◽

Zhen Chai ◽

...

Keyword(s):

Fluidized Bed ◽

Coal Gasification ◽

Feeding Rate ◽

Circulating Fluidized Bed ◽

Molar Ratio ◽

Release Behavior ◽

Far From Equilibrium ◽

Gaseous Sulfur ◽

Fluidized Bed Gasifier ◽

Gasification Temperature

The release behavior of sulfur during coal gasification was studied in a bench-scale self-heated circulating fluidized bed gasifier. With the increase of the O2/C molar ratio, gasification temperature increases, which promotes sulfur release rate and the formation of H2S. The conversion reaction between H2S and COS is far from equilibrium and the yield of COS is excessive. Under the same molar ratio of O2/C, the increase of coal feeding rate can elevate the gasification temperature, promote the release of sulfur and the transformation of gaseous sulfur to H2S.

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Effects of Temperature and Equivalence Ratio on Pine Syngas Primary Gases and Contaminants in a Bench-Scale Fluidized Bed Gasifier

Industrial & Engineering Chemistry Research ◽

10.1021/ie404401n ◽

2014 ◽

Vol 53 (14) ◽

pp. 5767-5777 ◽

Cited By ~ 30

Author(s):

Nourredine Abdoulmoumine ◽

Avanti Kulkarni ◽

Sushil Adhikari

Keyword(s):

Fluidized Bed ◽

Equivalence Ratio ◽

Bench Scale ◽

Effects Of Temperature ◽

Fluidized Bed Gasifier

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Steam–air fluidized bed gasification of distillers grains: Effects of steam to biomass ratio, equivalence ratio and gasification temperature

Bioresource Technology ◽

10.1016/j.biortech.2008.10.011 ◽

2009 ◽

Vol 100 (6) ◽

pp. 2062-2068 ◽

Cited By ~ 127

Author(s):

Ajay Kumar ◽

Kent Eskridge ◽

David D. Jones ◽

Milford A. Hanna

Keyword(s):

Fluidized Bed ◽

Equivalence Ratio ◽

Distillers Grains ◽

Biomass Ratio ◽

Gasification Temperature

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The Design and Operation of a New Clapboard-Type Internal Circulating Fluidized-Bed Gasifier

18th International Conference on Fluidized Bed Combustion ◽

10.1115/fbc2005-78062 ◽

2005 ◽

Author(s):

Zhengshun Wu ◽

Chuanfang Zhu ◽

Long-Long Ma ◽

Chuangzhi Wu

Keyword(s):

Fluidized Bed ◽

High Velocity ◽

Circulating Fluidized Bed ◽

Wood Chip ◽

Low Velocity ◽

Fuel Gas ◽

Fluidized Bed Gasifier ◽

Gasification Efficiency ◽

Gasification Reaction ◽

Velocity Region

The design and operation of a new clapboard-type Internal Circulating Fluidized-Bed gasifier is introduced in this paper. By setting clapboard in the middle of gasifier, bed layer in gasifier is divided into two regions that have different fluidization velocity, the incompletely reacted fuel or carbon in the high velocity region flows to the low velocity region companying with bed medium, and gasification reaction takes place in this region; still incompletely reacted fuel or carbon returns to the high velocity region in the bottom of gasifier, then gasification reaction further occurs. By this way, internal circulation in the gasifier was formed, gasification reaction time and efficiency increased. The experimental results indicate that gas yield (1.6 ∼ 1.9Nm3/kg fuel), gas heat values (5340kJ/Nm3 for wood chip fuel and 4880kJ/m3 for rice husk), and gasification efficiency (70%) can be obtained using this kind of gasifier in the optimal operational temperature range of 790∼850°C.

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Effects of Fluidization Velocity and Equivalence Ratio on the Energy and Exergy of the Syngas Produced from Wheat Straw in A Dual-distributor Type Fluidized Bed Gasifier

Advances in Research ◽

10.9734/air/2015/7751 ◽

2015 ◽

Vol 3 (1) ◽

pp. 20-35 ◽

Cited By ~ 2

Author(s):

Yaning Zhang ◽

Abdel Ghaly ◽

Ali Ergudenler ◽

Bingxi Li

Keyword(s):

Wheat Straw ◽

Fluidized Bed ◽

Equivalence Ratio ◽

Fluidization Velocity ◽

Energy And Exergy ◽

Fluidized Bed Gasifier

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CFD-DEM simulation of air-blown gasification of biomass in a bubbling fluidized bed gasifier: Effects of equivalence ratio and fluidization number

Energy ◽

10.1016/j.energy.2020.119533 ◽

2021 ◽

Vol 219 ◽

pp. 119533

Author(s):

In Sik Hwang ◽

Jungho Sohn ◽

Uen Do Lee ◽

Jungho Hwang

Keyword(s):

Fluidized Bed ◽

Equivalence Ratio ◽

Dem Simulation ◽

Bubbling Fluidized Bed ◽

Fluidized Bed Gasifier

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Numerical study of fluid dynamics and heat transfer property of dual fluidized bed gasifier

Energy ◽

10.1016/j.energy.2021.121246 ◽

2021 ◽

pp. 121246

Author(s):

Feihu Fan ◽

Min Zheng ◽

Shiliang Yang ◽

Hua Wang

Keyword(s):

Heat Transfer ◽

Fluid Dynamics ◽

Fluidized Bed ◽

Numerical Study ◽

Transfer Property ◽

Heat Transfer Property ◽

Dual Fluidized Bed ◽

Fluidized Bed Gasifier

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Parametric Study on the Adjustability of the Syngas Composition by Sorption-Enhanced Gasification in a Dual-Fluidized Bed Pilot Plant

Energies ◽

10.3390/en14020399 ◽

2021 ◽

Vol 14 (2) ◽

pp. 399

Author(s):

Selina Hafner ◽

Max Schmid ◽

Günter Scheffknecht

Keyword(s):

Fluidized Bed ◽

Ghg Emissions ◽

Space Velocity ◽

Synthesis Process ◽

Wood Pellets ◽

High Hydrogen ◽

Syngas Production ◽

Dual Fluidized Bed ◽

Bed Material ◽

Gasification Temperature

Finding a way for mitigating climate change is one of the main challenges of our generation. Sorption-enhanced gasification (SEG) is a process by which syngas as an important intermediate for the synthesis of e.g., dimethyl ether (DME), bio-synthetic natural gas (SNG) and Fischer–Tropsch (FT) products or hydrogen can be produced by using biomass as feedstock. It can, therefore, contribute to a replacement for fossil fuels to reduce greenhouse gas (GHG) emissions. SEG is an indirect gasification process that is operated in a dual-fluidized bed (DFB) reactor. By the use of a CO2-active sorbent as bed material, CO2 that is produced during gasification is directly captured. The resulting enhancement of the water–gas shift reaction enables the production of a syngas with high hydrogen content and adjustable H2/CO/CO2-ratio. Tests were conducted in a 200 kW DFB pilot-scale facility under industrially relevant conditions to analyze the influence of gasification temperature, steam to carbon (S/C) ratio and weight hourly space velocity (WHSV) on the syngas production, using wood pellets as feedstock and limestone as bed material. Results revealed a strong dependency of the syngas composition on the gasification temperature in terms of permanent gases, light hydrocarbons and tars. Also, S/C ratio and WHSV are parameters that can contribute to adjusting the syngas properties in such a way that it is optimized for a specific downstream synthesis process.

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