Catalytic pyrolysis of Eremurus spectabilis for bio-oil production in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and character

Abstract

Conventional slow pyrolysis of Eremurus spectabilis samples has been performed in a fixed-bed tubular reactor with (tincal, colemanite and ulexite) and without catalyst in the temperature range between 350 and 550 °C with heating rates of 10, 30, 50 °C/min. The yields of bio-char, bio-oil and gas produced, as well as the compositions of the resulting bio-oils were determined by elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and gas chromatography/mass spectrometry (GC–MS). The effects of pyrolysis parameters such as heating rate, temperature, catalyst type, sweeping gas flow rate and particle size (Dp) on product yields were investigated. The results show that temperature and catalyst are the main factors that effect the conversion of E. spectabilis into solid, liquid and gaseous products. The highest liquid yield of 38.14% including aqueous phase was achieved with ulexite catalyst at 500 °C temperature at a heating rate of 50 °C/min when 0.224 > Dp > 0.150 mm particle size raw material and 100 mL/min of sweeping gas flow rate were used. Ninety-one and ninety-seven different compounds have been identified by GC–MS in bio-oils obtained at 350 and 550 °C respectively.