Orange Peel Liquefaction Monitored by FTIR

The aim of this work was to test polyalcohol liquefaction for processing orange peel into value added products such as adhesives, foams, chemicals or even as liquid fuel. Dry orange peel was liquefied using a mixture of ethyleneglycol and glycerol (50/50) as solvents catalysed by sulphuric acid (SA). A ratio of 9:1 solvent/lignocellulosic material (LM) was used and 3% of sulphuric acid (SA) was added based on the solvent mass. The liquefaction temperatures tested were 160ºC, 180ºC and 200ºC. The time ranged between 60-120 min. The Initial peel, the liquefied material and the resulting solid residue were analysed by FTIR-ATR. The liquefaction yield ranged from 79% to 92%. The results showed that it is possible to achieve a high liquefaction yield even at low temperatures. The solid residue and the original material have similar spectra, the main differences are observed between the original orange peel and the liquefied material.