Process for the thermal degradation of rubber containing waste

A process for the non-oxidative thermal degradation of rubber containing waste, the process including:

• feeding the rubber containing waste through an inlet of and into a hermetically sealed cylindrical flow-through reactor having a heating zone, a cooling zone, and one or more thermal reaction zones arranged along a horizontal axis of the reactor between the inlet and an outlet of the reactor,
• wherein the one or more thermal reaction zones are located between the heating zone and the cooling zone, wherein the heating zone is located upstream of the one or more thermal reaction zones and the cooling zone is located downstream of the one or more thermal reaction zones,
• wherein each thermal reaction zone is provided with:
• one or more heating elements controllable to heat the thermal reaction zone to an operating temperature for mediating the non-oxidative thermal degradation of rubber in the rubber containing waste, and
• one or more gas outlets for withdrawing gas or gases evolved during the non-oxidative thermal degradation of the rubber;
• pre-heating the rubber containing waste to a temperature below the degradation temperature of the rubber containing waste of at least 300° C. prior to transporting the rubber containing waste through the one or more thermal reaction zones;
• operating the one or more thermal reaction zones at a temperature at or above the thermal degradation temperature of rubber, wherein a first thermal reaction zone of the one or more thermal reaction zones is operated at a temperature of from about 445° C. to 550° C.;
• operating a screw auger in both the forward and reverse directions to agitate the rubber containing waste within the reactor and to transport the rubber containing waste along the horizontal axis of the reactor, and through the reactor at a rate to provide a residence time in the one or more thermal reaction zones sufficient to heat the rubber containing waste to a temperature above the degradation temperature of rubber, and to degrade rubber in the rubber containing waste into a volatile gas or gases, fuel oil, and a char product, wherein flighting on the screw auger tracks the internal cylindrical surface of the reactor in close relationship to minimize or prevent the transport of the volatile gas or gases and/or the char product through a clearance space between outer edges of the flighting and the internal cylindrical surface of the reactor;
• applying a negative pressure to each thermal reaction zone and a cooling zone to withdraw volatile gas or gases that are formed in that thermal reaction zone from the non-oxidative thermal degradation of the rubber;
• cooling the char product to a temperature of no less than about 400° C. prior to discharging the char product from the reactor;
• and
• discharging the char product through the outlet of the reactor.

A hermetically sealed flow-through reactor for thermally degrading a rubber containing waste, the hermetically sealed flow-through reactor having an internal cylindrical surface, and the reactor including:

• an inlet and an outlet,
• a heating zone, a cooling zone, and one or more thermal reaction zones, wherein the one or more thermal reaction zones are arranged between the heating zone and the cooling zone and between the inlet and the outlet, wherein the heating zone is located upstream of the one or more thermal reaction zones and the cooling zone is located downstream of the one or more thermal reaction zones, and each thermal reaction zone is provided with:
• one or more heating elements controllable to heat the thermal reaction zone to an operating temperature for mediating non-oxidative thermal degradation of rubber in the rubber containing waste, wherein a first thermal reaction zone of the one or more thermal heating zones is operated at a temperature of from about 445° C. to about 550° C.;
• and
• one or more gas outlets with each of the one or more gas outlets being connected to an extraction pipe for withdrawing gas or gases evolved during the non-oxidative thermal degradation of the rubber;
• and
• a screw auger located within the reactor, the screw auger configured to rotate in both the forward and reverse directions to agitate and transport the rubber containing waste through the one or more thermal reaction zones in both the forward and reverse directions and to the outlet,
• wherein fighting on the screw auger tracks the internal cylindrical surface of the reactor in close relationship to minimize or prevent the transport of material through a clearance space between outer edges of the flighting and the internal cylindrical surface of the reactor,
• wherein the heating zone is operated to pre-heat the rubber containing waste to a temperature of at least 300° C. and less than the thermal degradation temperature of the rubber containing waste prior to transporting the rubber containing waste through the one or more thermal reaction zones,
• wherein the cooling zone is operated so as to cool the char product to a temperature of no less than about 400° C. prior to discharging the char product from the reactor, and
• wherein the cooling zone comprises one or more gas outlets for withdrawing gas or gases.