Comparison between the “one-step” and “two-step” catalytic pyrolysis of pine bark

► The bio-oil yields from two-step thermal pyrolysis of pine bark were more than that from one-step thermal pyrolysis. ► The catalytic effect on bio-oil yield was pronounced in two step pyrolysis, leading to decrease in the bio-oil yield. ► The ZSM-5 catalyst was the most effective for decreasing in bio-oil yield followed by ReUS-Y and red mud.