Plastic Recycling by Pyrolysis

Founded in 1996 as “Get Energy Research,” the company is active in the field of research, development, and construction of energy production plants. Today named “Get Energy Prime Italia” and based in Rome, Italy, the company specializes in engineering and construction of Pyrolysis plants for plastics and rubber.

The process that GET ENERGY conducts in its plants consists of the thermal cracking, or pyrolysis, of the Secondary Solid Fuel (SSF). The objective of the process is the production of a fuel oil based on hydrocarbons, mainly in view of its use for energy production in stationary engines. Beyond the fuel oil as by-products a gas will be obtained, mainly consisting of hydrocarbons, and fuel, and a solid, carbon-based for plastics (called pyrolysis coke) and carbon-based for End of Life Tyres (ELTs) called carbon black 774.

The plants operate in continuous mode and their core element is made up of a fixed cylindrical tubular reactor, in which the finely shredded waste is introduced. The reactor waste supply system is equipped with a system of guillotine or pneumatic piston valves operating in mode to limit the entry of "parasitic" air and therefore to minimize the risk of oxidation / combustion reactions. Moreover, the reactor is equipped with two oxygen detectors that in real time guide and control the safety system, providing nitrogen blowing if the oxygen concentration should expect 4% on a volumetric basis. The reactor is equipped with an induction heating system, whose modular power will allow temperatures of between 350 ° and 700 ° C to be reached. Always within the reactor is cochlea, which serves for the advancement of the waste to be treated.

The heating of the treated material will cause a series of chemical reactions that will break the long hydrocarbon chains which constitute the polymers present in the treated waste. The majority part of the waste will then be converted into a mixture of medium / low molecular weight hydrocarbons which, at the temperatures at which cracking reactions occur, will be in the vapor phase. A smaller fraction will instead remain in the solid phase, going to constitute the waste of the process. The flow of steam produced in the cracking reactor will be subsequently cooled, so as to determine the condensation of its heaviest fraction, which will form a liquid mainly consisting of hydrocarbons at boiling temperatures (and therefore high molecular weight) included between the cut of gasoil and that of heavy gas oil. Vice versa, the fraction with lower molecular weight will remain in gaseous form even downstream of cooling, and will therefore constitute a further product, distinct from the aforementioned liquid, composed partly of light products deriving from cracking reactions, as molecular hydrogen (H2), light hydrocarbons (methane, CH4, ethane, C2H6, propane, C3H8 etc.), and partly from non-condensable gases deriving from very little air that inevitably enters the plant during the loading phase (and therefore fundamentally from molecular nitrogen, N2, oxide of carbon, CO, and carbon dioxide, C0 2), in addition to, at least in principle, traces of volatile compounds deriving from impurities possibly present in the feeding matrix (hydrochloric acid, HCl, ammonia, NH3, etc.).

It is worth underlining explicitly that, to the extent that the process in question converts a waste into an oil and a combustible gas (as well as a solid waste), the same can be classified in the R3 type (Recycling / recovery of organic substances no solvents were used, including composting and other biological transformations). In principle, for this oil and combustible gases, once the classification has been clearly defined within the specifications set by European legislation, the waste qualification is outlined, and its use is expected to be fuel in a stationary engine for electricity production.