Method and device for the destructive distillation of polyethylene and polypropylene waste

The device for destructive distillation of polyethylene and polypropylene waste, including at least two parallel heating units, each of which contains a destructive distillation reactor with top polymer feedstock feed (through the feeding unit) and bottom carbon residue discharge through the bottom side hatch of the reactor, each of the reactors contains a furnace designed to be detached from and attached to the reactor, and a fuel burner;

• decomposition unit for polymer feedstock destructive distillation products, which consists of the following items connected in sequence:
• water cooled heat exchanger with a downflow of a vapor-gas mixture of hydrocarbons, hydrocarbon receiver executed as a horizontal cylindrical container equipped with re-boiler heated by exhaust gases, dewaxing unit installed on the receiver, consisting of a bottom part with tubes and mass-exchanging packed beds filled with a catalyst, and a reflux column executed as a shell-and-tube heat exchanger installed at the top of the dewaxing unit;
• distillation column for separating diesel fuel and gasoline fractions, consisting of a reflux column installed at the top of the column, an enriching section with mass-exchanging packed beds filled with a catalyst, a feed section and a stripper, a heat exchanger for cooling the diesel fraction;
• a vertical shell-and-tube heat exchanger with downward gasoline vapors and hydrocarbon gas (gaseous fraction);
• a gas/water separator, vapor-gas mixture of hydrocarbons piping systems, exhaust gas piping systems with dampers installed before and after the hydrocarbon receiver;
• cooling systems installed on the piping of vapor-gas mixture of hydrocarbons from destructive distillation product receivers:
• diesel fuel fractions, gasoline fractions, gas fractions, wax fraction receiver;
• circulating water tank installed in the cooling system;
• coke receiver, separated water sump, is characterized by the fact that, each furnace is lined with refractory high-temperature ceramic fibers and installed on air cushions;
• the feeding unit of each reactor is vacuum;
• the reactors are connected to the vapor-gas mixture piping system by pipeline chainage with bypasses;
• there is a vacuum pump installed in the vapor-gas mixture piping system suitable for connecting to/disconnecting from each of the reactors;
• there is a carbon dioxide container installed in the vapor-gas mixture piping system suitable for connecting to/disconnecting from each of the reactors;
• a water-cooled heat exchanger with a downflow of a vapor-gas mixture of hydrocarbons is equipped with a vapor discharge piping with an exit branch for steam smothering;
• each reactor is connected to the vapor-gas mixture piping system by separate sections equipped with gate valves with bypasses cut before and after with pressure control valves in the phased vapor-gas mixture release system;
• there are boilers installed in exhaust gas piping system;
• there is a wax fraction trap installed at the top of the receiver under the water-cooled heat exchanger, that is suitable for extracting and feeding the wax fraction through the wax fraction cooler to the wax fraction trap;
• there is a droplet separator in the form of a funnel tube installed at the top of the receiver under the dewaxing unit to prevent foaming in the receiver;
• there is a hatch at the end of the receiver on the exhaust gases inlet to connect the receiver with the cooler for draining heavy waxes into the heavy wax receiver;
• there is a filter damping the vapor-gas mixture installed after the dewaxing unit's reflex column, tangentially connected at the outlet with the feed section of the distillation column to create eddying flow of the vapor-gas mixture in the distillation column;
• at least three column plates are installed in the stripper of the distillation column;
• automatic level controls with a discharge valve are installed under the receiver before the wax fraction cooler, after the stripper before the diesel fraction cooling heat exchanger, after the gas/water separator;
• titanium-free nickel-containing alloys with at least 20% nickel are used as a catalyst in the mass-exchanging packed beds;
• the device is additionally equipped with a gas separator at the outlet of the gas/water separator.