Co-pyrolysis of walnut shell and tar sand in a fixed-bed reactor

► This work which is conducted on the pyrolysis of blended of walnut shell and tar sand is the first study. ► Highest bio-oil yield for the co-pyrolysis was 31.84 wt.% at ratio of 20 wt.% with the increase of 7.88 wt.%. ► Higher heating values for the bio-oil and its aliphatic subfraction were 27.45 and 38.52 MJ/kg. ► Bio-oil was richer with regard to the sum of aliphatic and aromatic contents compared to the other bio-oils reported. ► Tar sand as an additive was provided the significant contribution to the alkane content in the bio-oil from co-pyrolysis.