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Effect of holding time on fuel properties of biochars prepared from the torrefaction of coffee residue

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Abstract

Decomposition reactions during torrefaction start at 563 K, as shown by thermogravimetric analysis (TGA), as determined by pretests. Based on these findings, different biochars were produced by torrefaction at 563 K, combined with increasing holding times (10–40 min). The fuel properties of biochar products were investigated by means of calorific value, ultimate analysis, true density, and scanning electron microscopy (SEM). The maximal increase in the calorific value of biochar occurred at about 20 min, which correlated positively with its carbon contents. More consistently, the true densities of the resulting biochar end products increased mostly within the holding time ranging from 10 to 20 min, which we proposed as the best process window for torrefaction of coffee residue. At longer holding time (>20 min), we observed a shrinking of biochar by SEM, making it more friable or brittle. It may involve more hemicellulose depolymerization, leading to a porous and corrugated structure.

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References

  1. Demirbas A (2001) Biomass resource facilities and biomass conversion processing for fuels and chemicals. Energy Convers Manag 42:1357–1378

    Article  Google Scholar 

  2. Demirbas A (2008) Hazardous emissions from combustion of biomass. Energy Source A 30:170–178

    Article  Google Scholar 

  3. Acar S, Ayanoglu A (2012) Higher heating values (HHVs) of biomass fuels. Energy Educ Sci Technol A 28:749–758

    Google Scholar 

  4. Klass DJ (1998) Biomass for renewable energy, fuels, and chemicals. Academic Press, San Diego

    Google Scholar 

  5. McKendry P (2002) Energy production from biomass (part 2): conversion technologies. Bioresour Technol 83:47–54

    Article  Google Scholar 

  6. Basu P (2010) Biomass gasification and pyrolysis: practical design and theory. Academic Press, San Diego

    Google Scholar 

  7. Brewer CE, Schmidt-Rohr K, Satrio JA, Brown RC (2009) Characterization of biochar from fast pyrolysis and gasification systems. Environ Prog Sustain Energy 28:386–396

    Article  Google Scholar 

  8. Cantrell KB, Hunt PG, Uchimiya M, Novak JM, Ro KS (2012) Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar. Bioresour Technol 107:419–428

    Article  Google Scholar 

  9. Lee Y, Eum PRB, Ryu C, Park YK, Jung JH, Hyun S (2013) Characteristics of biochar produced from slow pyrolysis of Geodae-Uksae 1. Bioresour Technol 130:345–350

    Article  Google Scholar 

  10. Ronsse F, Hecke SV, Dickinson D, Prins W (2013) Production and characterization of slow pyrolysis biochar: influence of feedstock type and pyrolysis conditions. GCB Bioenergy 5:104–115

    Article  Google Scholar 

  11. Deng J, Wang GJ, Kuang JH, Zhang YL, Luo YH (2009) Pretreatment of agricultural residues for co-gasification via torrefaction. J Anal Appl Pyrolysis 86:331–337

    Article  Google Scholar 

  12. Pimchuai A, Dutta A, Basu P (2010) Torrefaction of agriculture residues to enhance combustible properties. Energy Fuels 24:4638–4645

    Article  Google Scholar 

  13. Ciolkosz D, Wallace R (2011) A review of torrefaction for bioenergy feedstock production. Biofuels Bioprod Bioref 5:317–328

    Article  Google Scholar 

  14. Acharya B, Sule I, Dutta A (2012) A review on advances of torrefaction technologies for biomass processing. Biomass Converg Bioref 2:349–369

    Article  Google Scholar 

  15. 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

    Article  Google Scholar 

  16. Tsai WT, Liu SC, Hsieh CH (2012) Preparation and fuel properties of biochars from the pyrolysis of exhausted coffee residue. J Anal Appl Pyrolysis 93:63–67

    Article  Google Scholar 

  17. Bustin RM, Mastalerz M, Wilks KR (1993) Direct determination of carbon, oxygen, and nitrogen content in coal using the electron microprobe. Fuel 72:181–185

    Article  Google Scholar 

Download references

Acknowledgments

Sincere appreciation was expressed to acknowledge the Instrumentation Centers at National Chung Hsing University and National Pingtung University of Science and Technology for the assistances in the elemental analysis and SEM observation, respectively.

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Correspondence to Wen-Tien Tsai.

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Liu, SC., Tsai, WT., Li, MH. et al. Effect of holding time on fuel properties of biochars prepared from the torrefaction of coffee residue. Biomass Conv. Bioref. 5, 209–214 (2015). https://doi.org/10.1007/s13399-014-0139-1

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  • DOI: https://doi.org/10.1007/s13399-014-0139-1

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