Broadly, three technological steps of waste oil recycling process at the petroleum refinery with Cyclone Plasma Tube Reactor (capacity of one reactor = 40000 t/a) can be identified as follows:

1) Two-stage distillation. Preliminary the waste oil is filtrated and separated from water and mechanical sediments. Evaporation of water and light oil occurs in a first stage and prevaporization of gasoil - in a second stage. Obtained "dry" oil (Te >200°C) is transferred to the Cyclone Plasma Tube Reactor (CPT).

2) CPT with a length up to 2 km comprises several segments of different diameter. Every segment has its own heating temperature, which depends on the dry oil composition. Impact minimization conditions of oil evaporation in CPT allow to avoid the unfavorable processes like cracking and to increase the oil yield. Accordingly, a small amount of oil is loaded into CPT (approximate volume of reactor is 50 l) and heated up to 420°C under deep vacuum (10 mbar abs.). Whereas the entire mass is accelerated until 1700 km/h. High level of turbulence (Re>10000) and high-speed friction against reactor walls ensure transition of practically complete oil to reactive gas phase or so called condition of kinetic plasma. Evaluation of appropriate hold-up time depends on the waste oil composition as well as requirements for distillate and goes to achieve the optimal fractionation and decontamination. Special additives (for instance, NaOH) are directly injected into CPT and homogenized by using integrated mixer, if needed. Condensation consists of four steps. Initially, disk-bowl centrifuge separates residuum. Base oil of high and low viscosity condensates in the second and third steps correspondingly, while gasoil is selected in fourth step.

3) Presence of industrial oils of low quality in feed requires additional treatment of obtained base oil. Generally, there are three methods of base oil quality improvement: treatment with sulfuric acid/bleaching followed by distillation/rectification (achievement of base oil of group 1+, Sulfur 0,2 %, Viscosity index ~90); selective treatment with solvents (achievement of base oil of group 2, Sulfur 0,03 %, Viscosity index ~95) and hydro-treating (achievement of base oil of group 3, Sulfur 0,03 %, Viscosity index ~130).

Main advantages of CPT are: versatility (suitable for treatment of crude naphta and heavy waste from refineries as well as used oils), durability (absence of general maintenance over 10 years), corrosion free and thermal resistance of walls, compact size (12,5 х 7,5 х 13 м) and high profitability.