Product gas composition for steam-oxygen fluidized bed gasification of dried sewage sludge, straw pellets and wood pellets and the influence of limestone as bed material

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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Atmospheric fluidized bed gasification of promising biomass fuels in southern European regions

Thermal Science ◽

10.2298/tsci0701005p ◽

2007 ◽

Vol 11 (1) ◽

pp. 5-15 ◽

Cited By ~ 1

Author(s):

Kyriakos Panopoulos ◽

Lydia Fryda ◽

Emmanuel Kakaras

Keyword(s):

Fluidized Bed ◽

Lignin Content ◽

Giant Reed ◽

Co2 Production ◽

European Regions ◽

Biomass Fuels ◽

Product Gas ◽

Sorghum Bagasse ◽

Bed Material ◽

The Impact

Three promising biomass fuels from southern European regions were gasified atmospherically with air in a lab-scale fluidized bed reactor with quartz or olivine as bed material. The fuels used were an agro-industrial residue (olive bagasse) and the energy crops giant reed and sweet sorghum bagasse. Varying air ratios and temperatures were tested to study the impact on the product gas composition and tar load. Tars were higher in the case of olive bagasse, attributed to its higher lignin content compared to the other two biomasses with higher cellulose. Giant reed gasification causes agglomeration and defluidisation problems at 790?C while olive bagasse shows the least agglomeration tendency. The particular olivine material promoted the destruction of tars, but to a lesser level than other reported works; this was attributed to its limited iron content. It also promoted the H2 and CO2 production while CO content decreased. Methane yield was slightly affected (decreased) with olivine, higher temperatures, and air ratios. Air ratio increase decreased the tar load but at the same time the gas quality deteriorated. .

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CO2 gasification in a dual fluidized bed reactor system: Impact on the product gas composition

Fuel ◽

10.1016/j.fuel.2019.04.168 ◽

2019 ◽

Vol 253 ◽

pp. 1605-1616 ◽

Cited By ~ 14

Author(s):

A.M. Mauerhofer ◽

J. Fuchs ◽

S. Müller ◽

F. Benedikt ◽

J.C. Schmid ◽

...

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactor ◽

Reactor System ◽

Gas Composition ◽

Co2 Gasification ◽

Product Gas ◽

Dual Fluidized Bed ◽

System Impact

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Two-stage gasification of dried sewage sludge: Effects of gasifying agent, bed material, gas cleaning system, and Ni-coated distributor on product gas quality

Renewable Energy ◽

10.1016/j.renene.2021.12.069 ◽

2021 ◽

Author(s):

Yong-Seong Jeong ◽

Tae-Young Mun ◽

Joo-Sik Kim

Keyword(s):

Sewage Sludge ◽

Two Stage ◽

Gas Cleaning ◽

Cleaning System ◽

Product Gas ◽

Bed Material

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Experimental investigation of synthetic gas composition in a two-stage fluidized bed gasification process: effect of activated carbon as bed material

Environmental Technology ◽

10.1080/09593330.2016.1220430 ◽

2016 ◽

Vol 38 (9) ◽

pp. 1169-1175

Author(s):

Jia-Hong Kuo ◽

Chiou-Liang Lin ◽

Tsung-Jen Chang ◽

Wang-Chang Weng ◽

JingYong Liu

Keyword(s):

Experimental Investigation ◽

Activated Carbon ◽

Fluidized Bed ◽

Gas Composition ◽

Two Stage ◽

Gasification Process ◽

Synthetic Gas ◽

Bed Material

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Hydrogen-Rich Gas Production by Cogasification of Coal and Biomass in an Intermittent Fluidized Bed

The Scientific World JOURNAL ◽

10.1155/2013/276823 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Li-Qun Wang ◽

Zhao-Sheng Chen

Keyword(s):

Fluidized Bed ◽

Production Efficiency ◽

Gas Production ◽

Gas Composition ◽

Mass Ratio ◽

Product Gas ◽

Higher Temperature ◽

Operation Parameters ◽

Weak Influence ◽

Gasification Temperature

This paper presents the experimental results of cogasification of coal and biomass in an intermittent fluidized bed reactor, aiming to investigate the influences of operation parameters such as gasification temperature (T), steam to biomass mass ratio (SBMR), and biomass to coal mass ratio (BCMR) on hydrogen-rich (H2-rich) gas production. The results show that H2-rich gas free of N2dilution is produced and the H2yield is in the range of 18.25~68.13 g/kg. The increases of T, SBMR, and BCMR are all favorable for promoting the H2production. Higher temperature contributes to higher CO and H2contents, as well as H2yield. The BCMR has a weak influence on gas composition, but the yield and content of H2increase with BCMR, reaching a peak at the BCMR of 4. The H2content and yield in the product gas increase with SBMR, whilst the content of CO increases first and then decreases correspondingly. At a typical case, the relative linear sensitivity coefficients of H2production efficiency to T, SBMR, and BCMR were calculated. The results reveal that the order of the influence of the operation parameters on H2production efficiency is T > SBMR > BCMR.

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Characterizing devolatilized wood pellets for fluidized bed applications

Biomass Conversion and Biorefinery ◽

10.1007/s13399-021-01486-x ◽

2021 ◽

Author(s):

Kolja Jarolin ◽

Shen Wang ◽

Timo Dymala ◽

Tao Song ◽

Stefan Heinrich ◽

...

Keyword(s):

Mechanical Behavior ◽

Fluidized Bed ◽

Large Scale ◽

Pore Network ◽

Wood Pellets ◽

Tomographic Images ◽

Computed Tomographic ◽

Before And After ◽

Primary Fragmentation ◽

Bed Material

AbstractWe investigated devolatilized wood pellets to characterize their mechanical behavior and their microstructure. The work’s aim is to increase the understanding and modeling capabilities for the application in fluidized bed gasification as a sustainable alternative to generate synthesis gas. Our experiments showed that devolatilized wood pellets are a stable but highly porous and fragile structure. Computed tomographic images of the same pellets before and after devolatilization showed that the existing pore network in raw conditions characterizes the final structure. Along with the pores, the reaction rate likely increases and the pores massively enlarge, and internal cavities are formed. The resulting pore network dominates the mechanical behavior and leads to micro fragmentations already at low static loads or slow dynamic impacts. This results in the creation of fines or breakage already at low impact velocities. For fluidized bed devolatilization, the large-scale open pore network of the biochar pellets allows the penetration of bed material into the pellet leading to an estimated increase in the pellet’s mass of up to 45%. However, an increase in pore size caused by the penetration was not apparent. Due to the pellet’s porous structure, breakage and attrition induced by mechanical stresses are likely to be as or even more important than primary fragmentation caused by the devolatilization process itself in a reactor.

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