Pyrolysis is one alternative to reduce the amount of waste, both composite and inorganic waste such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polypropylene (PP), and many other types. To produce optimum energy, the energy needed for the production process needs to be minimized. In the process of pyrolysis there is a process of changing the form of steam into liquid, namely a heat exchanger. This research was carried out with plastic material, which is PET, and with size of 15mm x 15mm, as well as reaction temperatures from 400° to 600 °C with increment of 50°C and held for 2 hours. To reduce energy use in the production process of pyrolysis products, this research was conducted using heat exchanger with straight heat pipes, while the cold section used flowing ambient water. It was found the optimal temperature in this research is at 450°C, where the specific energy obtained 31.36 Watts/gram, whereas the wax produced is at 23.52%wt. The main product of this pyrolysis is Benzoic Acid, after being tested by the GC-MS method, the composition is 77.73%.