An indigenous reactor with a capacity to hold a maximum temperature of 1,000°C was developed for investigating the co-pyrolysis of Juliflora (JF) and low-density polyethylene (LDPE). The length of the reactor was 1.49 m and width was 0.49 m. A screw feeder of 1.5 m, with a 0.051-m circular pipe, delivered the feed along the length of the reactor. Thermogravimetric (TG) analysis reported that the optimum temperature of LDPE and JF was 450 and 600°C, respectively. Fast pyrolysis is conducted to investigate the effect of oil quality and quantity from JF biomass and LDPE. Different blend of the feedstock 1:0, 1:1, 1:2, 2:1, and 0:1 of JF and LDPE was tested for co-pyrolysis. Experiments were conducted at varying temperature of 450, 500, 550, 600, 650, and 700°C. The optimum heating rate was found to be 10°C min−1. The elemental analysis of the biomass and plastic was performed. JF and LDPE at the blend of 1:2 yielded maximum liquid content. Increase in ratio of LDPE increased the calorific value and lowered oxygen content in the bio-oil. The pyrolytic oil is characterized and analyzed by GC–MS and FT-IR. The calorific value of the oil produced was found to be 27.14 MJ kg−1. The energy and exergy of JF, LDPE, and blend of both were 76.45, 92.15, 101.25, 73.48, 80.46, and 93.97 MJ, respectively. © 2019 Taylor & Francis Group, LLC.