Technical Note: Evaluation of a Crucible Furnace Retort for Laboratory Torrefactions of Wood Chips


  • Thomas L. Eberhardt
  • Karen G. Reed


Biofuels, biomass, moisture, particle size, pyrolysis, thermal degradation


Torrefaction is a thermal process that improves biomass performance as a fuel by property enhancements such as decreased moisture uptake and increased carbon density. Most studies to date have used very small amounts of finely ground biomass. This study reports the testing of a crucible furnace retort that was fabricated to produce intermediate quantities of torrefied material and to allow processing of wood chips. Yields ranging from 51 to 96% were impacted to a greater extent by differences in temperature than time of treatment. Although temperature-control issues (gradients, slow heating) were experienced with the crucible furnace retort, this equipment proved to be useful for its intended purpose.


Arias B, Pevida C, Fermoso J, Plaza MG, Rubiera F, Pis JJ (2008) Influence of torrefaction on the grindability and reactivity of woody biomass. Fuel Process Technol 89:169-175.nChen W-H, Kuo P-C (2011) Torrefaction and co-torrefaction characterization of hemicellulose, cellulose and lignin as well as torrefaction of some basic constituents in biomass. Energy 36:803-811.nCiolkosz D, Wallace R (2011) A review of torrefaction for bioenergy feedstock production. Biofuel Bioprod Bior 5:317-329.nMedic D, Darr M, Shah A, Potter B, Zimmerman J (2012) Effects of torrefaction process parameters on biomass feedstock upgrading. Fuel 91:147-154.nMeng J, Park J, Tilotta D, Park S (2012) The effect of torrefaction on the chemistry of fast-pyrolysis bio-oil. Biores Technol 111:439-446.nPentananunt R, Rahman ANMM, Bhattacharya SC (1990) Upgrading of biomass by means of torrefaction. Energy 15(12):1175-1179.nPhanphanich M, Mani S (2011) Impact of torrefaction on the grindability and fuel characteristics of forest biomass. Biores Technol 102:1246-1253.nPimchuai A, Dutta A, Basu P (2010) Torrefaction of agriculture residue to enhance combustible properties. Energy Fuels 24:4638-4645.nSingh T, Singh AP, Hussain I, Hall P (2013) Chemical characterisation and durability assessment of torrefied radiata pine (Pinus radiata) wood chips. Int Biodeter Biodegr 85:347-353.nStelte W, Clemons C, Holm JK, Sanadi AR, Ahrenfeldt J, Shang L, Henriksen UB (2011) Pelletizing properties of torrefied spruce. Biomass Bioenerg 35:4690-4698.n






Research Contributions