Upgrade of bio-oil produced from the sisal residue composting

Abstract

The present work studies the composting effects on the chemical characteristics of bio-oil produced by pyrolysis of sisal residue. Three systems were composted with sisal residue proportions to sisal fiber powder of 100:0, 90:10, and 75:25, respectively. The systems showed reductions of 33%–48% (extractive), 70%–80% (hemicellulose), and 80%–90% (cellulose) after composting. An increase in lignin content was observed in all systems. The pyrolysis of the composted systems was performed at 450°C and 550°C. At both temperatures, this process was selective in producing a large concentration of hydrocarbons (>160% increase), mainly alkanes and alkenes, reducing the concentrations of ketones, aldehydes, and phenolics (>50%) and eliminating esters, furans, and acetic acid to composted biomasses. The higher temperature favored aromatics and cyclic hydrocarbon production from the pyrolysis of composted samples. In addition to these results, composting helped reduce the oxygenated bio-oil species by approximately 44%–75% at the lowest and ~69% at the highest temperatures. These results indicate that composted sisal residue can produce bio-oils that are more suitable for biorefineries since they are rich in aliphatic hydrocarbons and non-oxygenated species.