The effect of temperature and compression during pyrolysis on the density of charcoal made from Australian eucalypt wood

Abstract

a b s t r a c tCharcoal produced from sustainably grown biomass can be used to reduce the net CO 2 emissions from iron and steel making operations. However careful control of pyrolysis conditions is required to produce charcoal with the necessary properties to optimise substitution for coal and coke in specific applications. The density of charcoal is an important property to control in order to minimise transport and handling costs as well as control of charcoal reactivity and strength.In this work the density of charcoal has been increased through compression of Blackbutt wood chips during pyrolysis. The true density of charcoal prepared under compression of 0.5 MPa and at a heating rate of 2 C/min was found to increase with pyrolysis temperature, especially at temperatures higher than 450 C. This increase in true density is likely to be due to restructuring of the graphitic structure at high temperatures. The true density of charcoal was found to be independent of compressive pressure during pyrolysis (0.056e4.0 MPa). The porosity of charcoal increased linearly with pyrolysis temperature and ranged from 0.24 at 300 C to about 0.46 at 700 C. The apparent density of charcoal prepared under a compressive pressure of 0.5 MPa was about 1000 kg/m 3 and had minimum between 400 and 600 C. This is similar to the apparent density of metallurgical coke. The results suggest that specially prepared charcoal could be a viable substitute for coal and coke in steelmaking applications which require a dense carbon product.

Slow pyrolysis of bamboo: an approach on quality of charcoal and greenhouse gases emission

“…Materials that present a basic carbon in its constitution, when submitted to pyrolysis temperatures higher than 500 °C, have a characteristic to connect the carbons, resulting in structures with more organization. This fact, associated with the reduction in the volatilization of organic matter and the increase of the apparent relative density, greater mechanical resistance of the charcoal, thus contributing to reduce the friability of charcoal at a temperature of 700 °C (Somerville & Jahanshahi, 2015). Table 3 shows the adjustments of the equations referring to the model that best fitted to the data dispersion.…”

“…Pyrolysis temperature is an important parameter to define the quality of the solid fuel, since it affects the yields, as well as the physical, chemical, anatomical and mechanical properties of charcoal (Dhyani & Bhaskar, 2018). Among the charcoal properties that vary according to the pyrolysis temperature, we can cite the apparent density, friability, high heating value, energetic density, fixed carbon content, volatile matter and ashes (Somerville & Jahanshahi, 2015).…”

Clonal selection of Corymbia for energy and charcoal production

“…Higher charcoal density lead to greater use in blast furnaces, since the material has longer residence time and greater use of the furnace's volume (Alfaro & Jones 2018). Nevertheless, this property is also dependent of the carbonization process, once major degradation of the material can lead to lower apparent density and resistance (Somerville & Jahanshahi 2015).…”

Mass Transfer Behavior of Phosphorus from the Liquid Slag Phase to Solid 2CaO·SiO2 in the Multiphase Dephosphorization Slag

“…In addition, the density of each sample was detected through the true density analyzer (3H-2000TD) as illustrated in Figure 18. [23] Finally, their cross sections were observed through the SEM under the same magnification, which is displayed in Figure 19.…”