Torrefaction of densified empty fruit bunches with addition of plastics waste

ABSTRACT

The techniques of briquetting and torrefaction were applied to a mixture of pulverized empty fruit bunches (EFB) and shredded high-density polyethylene (HDPE) plastics with a weight ratio of 85:15. The briquettes, produced under controlled conditions, were torrefied at various torrefaction temperatures from 225 to 300°C for 30 min with a constant nitrogen flow rate of 1 L/min. The results indicate that the moisture content is reduced and calorific value is significantly improved due to torrefaction treatment. In addition, the compressive strength of the torrefied briquettes is also enhanced by the torrefaction treatment, thus revealing the important role of HDPE plastics as a good binding agent after the treatment. However, the density of the torrefied briquettes decreased with an increase in temperature. The ash content of the briquettes torrefied at 225 to 275°C can be considered competitive if compared to that of conventional solid fuels (< 5.8%). The physical and combustion properties of the torrefied briquettes are strongly affected by torrefaction temperature and mixture composition. Meanwhile, torrefaction at 300°C is not favourable due to significant physical degradation.

HIGHLIGHTS

• Densification and torrefaction were performed on pulverized EFB.

• Fixed operating conditions were used to produce all briquettes.

• Addition of HDPE plastics improves the physical and combustion properties.

• Torrefaction temperature is the most important parameter.

• Torrefaction temperature at 300°C is not favourable due to physical destruction.

KEYWORDS:

• Torrefaction
• empty fruit bunch
• high-density polyethylene
• torrefied briquettes
• plastics waste

Acknowledgements

The authors acknowledge the Ministry of Higher Education Malaysia and Universiti Teknologi Malaysia for their cooperation and full support for this research activity. The authors wish to thank the Research Management Center (RMC) for the Fundamental Research Grant Scheme (FRGS) research grant (Vote No.: R.J130000.7824.4F757) from the Ministry of Higher Education Malaysia and Universiti Teknologi Malaysia.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ministry of Higher Education Malaysia and Universiti Teknologi Malaysia [grant number R.J130000.7824.4F757].