Recycling method system and container
Nitrogen is fed into a sealed container ( 18 ) to expel oxygen (step 1) and, in such a state, the inside temperature of the container ( 18 ) is incrementally raised step by a heater built into the container ( 18 ). In sequential steps 2 through 5, Water content, chlorine, and high-molecular gases are extracted. Reusable carbon and metal remain in the container ( 18 ) in step 6, or when left standing for a prescribed time or more. Gases extracted in steps 2 to 5 can be liquefied for recycling. No carbon dioxide or dioxins are produced because heating is performed in an oxygen-free atmosphere. A furnace is not required because the heater is installed in the container ( 18 ), and treatment efficiency is high. A space-saving, energy-efficient, and low-cost treatment system, by which carbon (e.g., inert carbon), metals, and the like can be recovered in a reusable state without producing carbon dioxide or dioxins, is obtained. The obtained inert carbon can be subjected to an activation treatment to continuously mass-produce carbon nanotubes and activated carbon.
1. A recycling method, comprising:
a first step of injecting inert gas through an inert gas supply apparatus into a container containing agricultural wastes as an object to be treated and replacing the atmosphere in the container with an oxygen-free atmosphere;
a second step of heating the object in the container to a temperature between the boiling temperature of water and 150° C. using a heater preinstalled in the container
and controlling the heater so as to provide the temperature of about 150° C. for a period of time sufficient to substantially complete extraction of the water content of the object, while maintaining the oxygen-free atmosphere in the container in order to liberate vapor from the object, and guiding the liberated vapor as a first product to a device outside the container;
a third step of heating the object from which all water content has been extracted in the container to a temperature of about 200-350° C. using the heater preinstalled in the container while maintaining the oxygen-free atmosphere in the container in order to liberate chlorine from the object, and guiding the liberated chlorine gas to a device outside the container while maintaining the chlorine gas in a state isolated from the air to obtain the chlorine gas in a fluid state;
a fourth step of heating the object in the container to a temperature of no higher than 450° C. using the heater preinstalled in the container while maintaining the oxygen-free atmosphere in the container in order to liberate other gas from the object, and guide the liberated gas to a device outside the container while maintaining the gas in a state isolated from the air to obtain the gas in a fluid state;
a fifth step of maintaining the temperature in the container at no higher than 450° C. for a period of time sufficient for providing carbonized object while maintaining the oxygen-free atmosphere in the container; and
a sixth step of cooling the inside of the container to a temperature lower than the temperature at which carbonized object will burn while continuously maintaining the oxygen-free atmosphere in the container and obtaining a residue remaining in the container as a second product.
2. The recycling method according to claim 1 , wherein:
a heating temperature of the object in each of the plurality of steps from the second step to the fourth step is determined so that the heating temperature in a following step is higher than that in the preceding step and according to the gas to be liberated in that step, and then the vapor liberating process is performed before the chlorine liberating process is performed; and
a guiding route and a guided destination for acquisition of the first product are separately determined for each of the plurality of processes performing the second step.
3. A recycling method according to claim 1 , wherein:
the first step is performed with a first device for feeding at least a reducing gas or an inert gas connected to the container through a first pipeline;
the steps from the second step to the fourth step are performed with the first device connected to the container through the first pipeline and a second device as an outside device of the container connected to the container through a second pipeline; and
the container is placed in a sealed state when it is necessary to disconnect the pipeline between the container and the first or second device in order to move the container from one step to a next step.
4. A recycling method according to claim 3 , wherein a different implementation location is determined for each step, and a pipeline required for implementation of each step at the individual implementation locations is extended to the implementation location so as to allow simultaneous treatment of a plurality of containers in an assembly-line method by sequentially moving the containers from one step to a next step.
5. A recycling system according to claim 3 , wherein the implementation locations of at least the steps from the first step to the fourth step are designed to be a common location to enable the performance of at least the first and second steps without moving the container, and all pipelines required for the first and second steps are extended to said common location.