Ilman Nuran Zaini

Municipal solid waste processing and separation employing wet torrefaction for alternative fuel production and aluminum reclamation

This study employs wet torrefaction process (also known as hydrothermal) at low temperature. This process simultaneously acts as waste processing and separation of mixed waste, for subsequent utilization as an alternative fuel. The process is also applied for the delamination and separation of non-recyclable laminated aluminum waste into separable aluminum and plastic. A 2.5-L reactor was used to examine the wet torrefaction process at temperatures below 200°C. It was observed that the processed mixed waste was converted into two different products: a mushy organic part and a bulky plastic part. Using mechanical separation, the two products can be separated into a granular organic product and a plastic bulk for further treatment. TGA analysis showed that no changes in the plastic composition and no intrusion from plastic fraction to the organic fraction. It can be proclaimed that both fractions have been completely separated by wet torrefaction. The separated plastic fraction product obtained from the wet torrefaction treatment also contained relatively high calorific value (approximately 44MJ/kg), therefore, justifying its use as an alternative fuel. The non-recyclable plastic fraction of laminated aluminum was observed to be delaminated and separated from its aluminum counterpart at a temperature of 170°C using an additional acetic acid concentration of 3%, leaving less than 25% of the plastic content in the aluminum part. Plastic products from both samples had high calorific values of more than 30MJ/kg, which is sufficient to be converted and used as a fuel.

Hydrothermal treatment of palm oil empty fruit bunches: an investigation of the solid fuel and liquid organic fertilizer applications

ABSTRACT In this study, the investigation of hydrothermal treatment (HTT) of palm oil empty fruit bunches (EFB) on both solid product and liquid residue characteristics was conducted. The effects of HTT were investigated at temperatures of 100, 150, 180 and 220°C with 30 minutes holding time. Hydrochars were characterized by elemental analysis, SEM, ash analysis and TGA, while liquid products were analyzed by micro- and macronutrient analysis, and germination test. The results showed that the HTT treated EFB has an increased carbon content, lowered ash content, and lowered deposition tendency compared to the raw EFB. Moreover, the maximum of 37% of nitrogen, 65% of potassium and less than 10% of phosphorus in EFB were solubilized into the liquid residue which positively correlated with the temperature. The produced liquid was found unsuitable as a fertilizer due to low pH value, low N content, and low germination index, hence needing improvement when applied as fertilizer. These results demonstrated the possibility of employing the HTT for producing solid fuel as well as nutrient cycling in the plantation.