Application of MgO-Titanomagnetite mixture in high-temperature catalytic pyrolysis of radiata pine

Abstract

AbstractThis study aimed to investigate the effect of MgO and titanomagnetite mixture on the high-temperature pyrolysis of radiata pine wood in a fluidised bed reactor at 850 °C. The catalytic performance of the MgO-titanomagnetite (MgO-TM) mixture was experimentally evaluated based on product distribution, gas composition, gas properties, and tar composition. The results revealed that addition of MgO-titanomagnetite resulted in a decrease in gas yield (67.2 wt.%) compared to addition of titanomagnetite (TM) alone (72.9 wt.%), but an improvement was found compared to addition of MgO alone (63.9 wt.%). The hydrogen concentration in the gas product was significantly enhanced (23.2 vol.%) compared to titanomagnetite alone (12.8 vol.%) or to non-catalytic (NC) pyrolysis (14.1 vol.%) but was similar to that with addition of MgO alone (22.6 vol.%). However, the addition of MgO and titanomagnetite mixture resulted in a reduction in CO concentration to 2.7 vol.% in the gas product whereas increased the CO2 and light olefins formation. It was also found that the addition of the MgO and titanomagnetite mixture significantly increased the total concentration of ethylene and propylene (18.3 vol.%) compared to addition of titanomagnetite (5.8 vol.%), MgO (9.0 vol.%), or non-catalytic pyrolysis (12.0 vol.%). The lower heating value of the gas product and the H2 to CO ratio (17.5 MJ/Nm3 and 8.7) were also improved with addition of the MgO-titanomagnetite mixture. These findings demonstrate that application of physically mixed MgO and titanomagnetite as catalyst is a promising method for converting biomass into a H2-rich gas product via high-temperature pyrolysis. This study offers a useful reference for the development of novel catalytic systems for biomass conversion. Graphical Abstract