The catalytic copyrolysis of torrefied cork oak (TOak) and high density polyethylene (HDPE) over mesoporous HY catalysts was performed using a tandem mu-reactor-gas chromatograph/mass spectrometry/flame ionization detector. Two types of mesoporous HY catalysts with different acidity, MesoHY-1 and MesoHY-2, were prepared by pseudomorphic synthesis with various surfactant ratios. For comparison, a commercial microporous HY was also used as a catalyst. The properties of the catalysts were measured by N-2-sorption, X-ray diffraction, and NH3-temperature programmed desorption. Compared to the catalytic pyrolysis of cork oak (Oak), that of TOak produced a larger amount of mono aromatic hydrocarbons (MAHs) over all HY catalysts. The catalytic copyrolysis of TOak and HDPE over micropore HY and MesoHY-1 produced a larger amount of MAHs than that over MesoHY-2 due to the higher acidities. Although both micropore HY and MesoHY-1 have similar acidity, MesoHY-1 showed stronger synergy for the formation of MAHs on catalytic copyrolysis than micropore HY owing to its larger pore, which allows the easier diffusion of HDPE reaction intermediates into the pore of the catalysts. (C) 2017 Elsevier B.V. All rights reserved.