Comparison of steam gasification reactivity of algal and lignocellulosic biomass: Influence of inorganic elements

Hognon, Céline; Dupont, Capucine; Grateau, Maguelone; Delrue, Florian

doi:10.1016/j.biortech.2014.04.111

Cited by 92 publications

(63 citation statements)

References 22 publications

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“…It was emphasized that the surface area of biochar increased with conversion, suggesting the formation of new pores and/or opening of closed pores as a result of steam activation during gasification. Besides the effect of the carbon structure evolution, the inhibiting effect of some inorganic components such as Si and P was also discovered by Hognon et al (2014), where K would tend to be encapsulated by P and Si with carbon conversion, and would then be unable to act as a catalyst.…”

Section: Effect Of Alkali and Alkaline Metallic (Aaem) Speciesmentioning

confidence: 95%

Steam gasification of a refuse derived char: Reactivity and kinetics

Kolaczkowski

2015

Chemical Engineering Research and Design

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a b s t r a c tA char was obtained from a commercial pilot-scale gasifier, which had been operating with a refuse derived fuel (RDF). Using this char, steam gasification experiments were then performed in a 15.6 mm i.d. packed bed tubular reactor. The effect of reaction temperature was studied (800 • C to 900 • C), and also the partial pressure of steam were in the range 33.3 kPa to 66.7 kPa. With the aid of the Shrinking-Core and the Uniform-Reaction models, kinetic parameters were estimated (apparent activation energy varied from 96 kJ mol −1 to 162 kJ mol −1 ). It was also found that at lower carbon conversions (e.g. 10% to 60%) the RDF-derived char appeared to be more reactive than other bio-chars reported in the literature. However, at higher conversions (>60%), its apparent reactivity decreased with carbon conversion, thereby behaving in a similar manner to chars derived from coal.

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Section: Effect Of Alkali and Alkaline Metallic (Aaem) Speciesmentioning

confidence: 95%

Steam gasification of a refuse derived char: Reactivity and kinetics

Kolaczkowski

2015

Chemical Engineering Research and Design

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“…This is an area of ongoing investigation 11,19 . The uniform conversion model is assumed as in previous works 5, 41 where F j (X) is taken as invariant with conversion; although an arbitrarily complex function could be applied in the context of this numerically integrated model.…”

Section: Char Gasification Reactivity Modelingmentioning

confidence: 99%

“…Second, the reactivity itself can either increase or decrease 11 significantly throughout the conversion-phenomena attributed to the catalytic impact of the ash and changes in the pore morphology 12 . The latter is usually accounted for using some form of semi-empirical structural profile model (e.g.…”

Section: Introductionmentioning

confidence: 99%

Modeling of Biomass Char Gasification, Combustion, and Attrition Kinetics in Fluidized Beds

2016

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Char conversion is one of the most pivotal factors governing the effectiveness of fluidized bed gasification systems. Gasification-assisted attrition is a phenomenon whereby heterogeneous reactions progressively weaken a char's structure throughout its lifetime leading to enhanced attrition and the production of a significant fraction of fines that exit the reactor unconverted.While this effect has been observed and measured experimentally, few models have been developed to quantitatively account for it, particularly for biomass chars. In this study, a transient gasification and combustion particle model is presented to describe primary fragmentation, attrition, and heterogeneous reactions of a single batch of particles. A conversion-dependent structural function is proposed to describe gasification-assisted attrition and the model parameters are fitted to published experimental data ref [2]. The fragile structure of char derived from wood chips contributes to a higher initial attrition rate than char from wood pellets, but the hardness of both feedstocks is shown to deteriorate rapidly as they convert. A 2 shrinking particle combustion model which accounts for variable feedstock properties is comprehensively presented and validated against the aforementioned data set. The combustion behaviors of both feedstocks are found to strongly depend on particle size/geometry because of significant mass transfer limitations. Using a residence time distribution approach, the model is extended to describe a continuously fed system in order to examine the sensitivity of steady state outputs (conversion and residence time) to the operating temperature, pressure, and kinetics. As the temperature increases, the char reactivity also increases but the coupled and competing effect of gasification-assisted attrition acts to shorten the residence time of the char particles making complete char conversion very difficult even at 900 ○ C-the upper operating temperature limit for most single stage fluidized bed gasification systems. Low operating temperatures result in longer average residence times and higher steady-state char inventories, and slower kinetics lowers the overall conversion. Because of inhibition effects, elevated operating pressures have a smaller impact on improving conversion compared to higher temperature. The steady model further provides a rigorous method for estimating the maximum stable biomass feeding rates as a function of relevant independent parameters including reactor temperature, pressure, volume, and feedstock characteristics.3

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“…The world's reliance on the use of fossil fuels and the consequent concerns around climate change has stimulated interest in renewable fuels such as biomass [1]. Thermal conversion of biomass, including combustion, pyrolysis and gasification are important technologies for biomass utilization [2].…”

Section: Introductionmentioning

confidence: 99%

Effect of interactions of biomass constituents on polycyclic aromatic hydrocarbons (PAH) formation during fast pyrolysis

Zhou

Meng

et al. 2014

Journal of Analytical and Applied Pyrolysis

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The interactions of biomass constituents (hemicellulose, cellulose and lignin) were investigated during fast pyrolysis at 800 °C in a fixed bed reactor. The formation of polycyclic aromatic hydrocarbons (PAH) as well as mass distribution and gas products is presented. The possible interactions of biomass constituents were compared with the results of the expected results based on the pyrolysis of single components. For the interaction of xylan and cellulose, the mass distribution was similar to that expected from calculation of single component addition, however, PAH were increased. The interaction of xylan and lignin produced a decrease in PAH concentration compared to that expected from single component data. There was evidence of strong interaction between cellulose and lignin, where gas and solid residue yield was decreased and tar/oil yield was increased. In addition, naphthalene, acenaphthylene, and chrysene/benzo[a]anthracene were decreased compared with the concentrations expected from the single component pyrolysis. However, the amounts of 1-methynaphthalene, 2-methynaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, and pyrene were increased.

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Comparison of steam gasification reactivity of algal and lignocellulosic biomass: Influence of inorganic elements

Cited by 92 publications

References 22 publications

Steam gasification of a refuse derived char: Reactivity and kinetics

Steam gasification of a refuse derived char: Reactivity and kinetics

Modeling of Biomass Char Gasification, Combustion, and Attrition Kinetics in Fluidized Beds

Effect of interactions of biomass constituents on polycyclic aromatic hydrocarbons (PAH) formation during fast pyrolysis

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