Study on the Pyrolysis and Co-pyrolysis of Shenmu bitumite and Plastics

摘要

This paper demonstrates the pyrolysis and co-pyrolysis of Shenmu bitumite(SMB) with plastics (PE and PP). SMB was crushed and then sieved using a screen of 6mm size. PE and PP used were pellets of about 2- 4mm in diameter.Mixtures of SMB and different plastics were pyrolyzed in an atmospheric fixed-bed reactor with the temperature programmed heating under 0.1 MPa of nitrogen. The flow velocity was 0.4L/min measured at ambient temperature and atmospheric pressure. The weight percentages of various plastics in the mixtures were 1%, 3%, 5%,8% and 10 %. The chars obtained were poured out and weighed, and the mixtures of tar and water were cooled down by cold trap and separated by toluene distillation to get water and tar. The result of pyrolysis of SMB showed that when the flow velocity of carrier gas is 0.4L/min and the residence time is 20min, the tar yield has the maximum of 14.22wt% at 540 °C. The result of co-pyrolysis of SMB with PE and PP showed that the tar yield of SMB-PE mixtures has the maximum of 17.27wt% and that of SMB-PP mixtures has the maximum of 18.88wt% both at 520 °C. When PP was added into SMB, the tar yield increased which was higher than the theoretic calculation and the water yield decreased but the case was just negligible for PE.However, synergism between SMB and PP became weak when the weight percent of PP in the mixtures was above 5%. Co-pyrolysis of coal with plastics could be a worthwhile future technology for the conversion of plastics.