Effects of reaction conditions on the phenol liquefaction of peanut shells

Peanut shells were liquefied in phenol using sulfuric acid as the catalyst. The effects of the liquefaction conditions, such as the phenol/peanut shells ratio, catalyst loading, reaction temperature, and time, on the residue ratio, percent combined phenol, and formaldehyde reactivity of the liquefied products were investigated. The results showed that increasing the phenol/peanut shells ratio decreased the residue ratio and increased the combined phenol and formaldehyde reactivity. Increasing the catalyst loading decreased the residue ratio and increased the combined phenol, but a higher catalyst loading caused the formaldehyde reactivity to decrease. A higher reaction temperature and prolonged reaction time did not lead to a further decrease in the residue ratio and it further increased the combined phenol and formaldehyde reactivity. Fourier transform infrared spectroscopy and gas chromatography-mass spectroscopy showed that the liquefied products contained a large amount of polyphenol compounds and a small quantity of furan compounds and furfural. The SEM images showed small particles were the main portion of the liquefaction products and cellulose fibers could still be clearly seen.