Effect of the Coal Particle Size on Pyrolysis and Char Reactivity for Two Types of Coal and Demineralized Coal

Zhu, Wenkui; Song, Wenli; Lin, Weigang

doi:10.1021/ef800143h

Cited by 70 publications

(35 citation statements)

References 18 publications

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“…Transport limitations during heating are reduced for smaller particles, resulting in a higher effective heating rate. Although research in this area has been limited, initial particle size has been observed to have an impact on morphology of biomass chars (Avila et al, 2011) and on reactivity of coal chars (Zhu et al, 2008). Experimental particle size distributions in the present study (given below) reflect the anticipated differences between torrefied and raw biomass that will occur in full-scale devices.…”

Section: Introductionmentioning

confidence: 75%

Combustion and gasification characteristics of chars from raw and torrefied biomass

Fisher

Dupont

Darvell

et al. 2012

Bioresource Technology

152

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Torrefaction is a mild thermal pretreatment (T<300°C) that improves biomass milling and storage properties. The impact of torrefaction on the gasification and oxidation reactivity of chars from torrefied and raw biomass was investigated. Thermogravimetric analysis was used to study the differences in O(2) and steam reactivity, between chars prepared from torrefied and raw willow, under both high- and low-heating-rate conditions. High-heating-rate chars were prepared at 900°C with a residence time of 2s. Low-heating-rate chars were prepared with a heating rate of 33°C/min, a maximum temperature of 850 or 1000°C, and a residence time of 30 min or 1h, respectively, at the maximum temperature. Pretreatment by torrefaction consistently reduced char reactivity. Torrefaction's impact was greatest for high-heating-rate chars, reducing reactivity by a factor of two to three. The effect of torrefaction on a residence time requirements for char burnout and gasification was estimated.

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Section: Introductionmentioning

confidence: 75%

Combustion and gasification characteristics of chars from raw and torrefied biomass

Fisher

Dupont

Darvell

et al. 2012

Bioresource Technology

152

View full text Add to dashboard Cite

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“…Different products are generated in the different steps of pyrolysis. The weight loss behavior and product composition of pyrolysis are affected by many factors, including temperature, heating rate, particle size, mineral, coal type and petrography (Ghetti, 1986;Özbas, 2003;Kizgut and Yilmaz, 2003;Zhu et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

A thermal behavior study of Chinese coals with high hydrogen content

Wang

Tang

Schobert

et al. 2010

International Journal of Coal Geology

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“…The positive effect of torrefaction on energy consumption during biomass size reduction can be captured only if the large particle size of biomass is utilized in the torrefaction process. A large particle size induces higher char production and lower liquid yield in the pyrolysis process [5][6][7]. However, how this affects the torrefaction process, or product yield and quality is not known.…”

mentioning

confidence: 99%

The Effects of Particle Size, Different Corn Stover Components, and Gas Residence Time on Torrefaction of Corn Stover

et al. 2012

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Large scale biofuel production will be possible only if significant quantities of biomass feedstock can be stored, transported, and processed in an economic and sustainable manner. Torrefaction has the potential to significantly reduce the cost of transportation, storage, and downstream processing through the improvement of physical and chemical characteristics of biomass. The main objective of this study was to investigate the effects of particle size, plant components, and gas residence time on the production of torrefied corn (Zea mays) stover. Different particle sizes included 0.85 mm and 20 mm. Different stover components included ground corn stover, whole corn stalk, stalk shell and pith, and corn cob shell. Three different purge gas residence times were employed to assess the effects of interaction of volatiles and torrefied biomass. Elemental analyses were performed on all of the samples, and the data obtained was used to estimate the energy contents and energy yields of different torrefied biomass samples. Particle density, elemental composition, and fiber composition of raw biomass fractions were also determined. Stalk pith torrefied at 280 °C and stalk shell torrefied at 250 °C had highest and lowest dry matter loss, of about 44% and 13%, respectively. Stalk pith torrefied at 250 °C had lowest energy density of about 18-18.5 MJ/kg, while cob shell torrefied at 280 °C had the highest energy density of about 21.5 MJ/kg. The lowest energy yield, at 59%, was recorded for stalk pith torrefied at 280 °C, whereas cob and stalk shell torrefied at 250 °C had highest energy yield at 85%. These differences were a consequence of the differences in particle densities, hemicellulose quantities, and chemical properties of the OPEN ACCESSEnergies 2012, 5 1200 original biomass samples. Gas residence time did not have a significant effect on the aforementioned parameters.

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Effect of the Coal Particle Size on Pyrolysis and Char Reactivity for Two Types of Coal and Demineralized Coal

Cited by 70 publications

References 18 publications

Combustion and gasification characteristics of chars from raw and torrefied biomass

Combustion and gasification characteristics of chars from raw and torrefied biomass

A thermal behavior study of Chinese coals with high hydrogen content

The Effects of Particle Size, Different Corn Stover Components, and Gas Residence Time on Torrefaction of Corn Stover

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