Pyrolysis apparatus and methods using same

Abstract

An apparatus and methods of using the apparatus are described to decompose plastic to form a fuel for use in generating energy such as electricity.

1 . A thermal conversion pyrolysis reactor apparatus including:
 a. a pyrolysis reactor vessel with a heat source to heat plastic material in bottom vessel;   b. a conveyer for transporting char and/or plastic from the vessel; and   c. a condensing seal through which decomposed gas travels and wherein the condensing seal prevents entry of oxygen into the vessel and egress of heavier compounds out of the vessel.   
     
     
         2 . The apparatus as claimed in  claim 1  wherein the heat source is electricity. 
     
     
         3 . The apparatus as claimed in  claim 1  wherein the conveyer inlet is sealed by use of a cooling tube around a portion of the conveyer prior to entry of the conveyer into the reactor and wherein molten plastic and/or char in the reactor bottom enters the cooling tube or tubes and solidifies on or cools in the conveyer. 
     
     
         4 . The apparatus as claimed in  claim 1  wherein the conveyer outlet is sealed by use of a cooling tube around a portion of the conveyer as the conveyer exits the reactor and wherein molten plastic and/or char in the reactor bottom enters the cooling tube and solidifies on or in the chain conveyer. 
     
     
         5 . The apparatus as claimed in  claim 3  wherein the cooling tube abuts the reactor vessel. 
     
     
         6 . The apparatus as claimed in  claim 3  wherein water is used as a coolant in the cooling tube. 
     
     
         7 . The apparatus as claimed in  claim 1  wherein the condensing seal includes a cooling jacket surrounding an outlet of the reactor through which decomposed gas is conveyed from the reactor. 
     
     
         8 . The apparatus as claimed in  claim 1  wherein the condensing seal creates a layer of cool gas and gases of a higher density or molecular weight condense in the layer and return to the reactor. 
     
     
         9 . The apparatus as claimed in  claim 1  wherein water is used as a coolant in the condensing seal. 
     
     
         10 . The apparatus as claimed in  claim 2  wherein the heat source is sufficient to heat plastic material in the bottom of the apparatus to a temperature from 100° C. to 800° C. 
     
     
         11 . The apparatus as claimed in  claim 1  wherein the decomposition gas includes hydrocarbon chains with a length of less than 25 carbon atoms. 
     
     
         12 . The apparatus as claimed in  claim 1  wherein the decomposition gas includes hydrocarbon chains with a length of less than 15 carbon atoms. 
     
     
         13 . The apparatus as claimed in  claim 1  wherein the apparatus processes plastic material as a batch process with plastic raw material being added to the reactor in one step. 
     
     
         14 . The apparatus as claimed in  claim 1  wherein the apparatus processes plastic material as a semi-continuous process with plastic raw material being added in stages to the reactor. 
     
     
         15 . The apparatus as claimed in any  claim 1  wherein the apparatus processes plastic material as a continuous process with plastic raw material being added to the reactor as a continuous feed. 
     
     
         16 . The apparatus as claimed in  claim 1  wherein the reactor vessel has a V-shaped bottom. 
     
     
         17 . The apparatus as claimed in  claim 1  wherein the reactor vessel has an aspect ratio of 2:1 to 10:1 height to width. 
     
     
         18 . The apparatus as claimed in  claim 1  wherein the apparatus is transportable. 
     
     
         19 . The apparatus as claimed in  claim 1  wherein the plastic raw material is selected from thermoplastic wastes of polyolefinic and/or polyaromatic nature that does not have heteroatoms. 
     
     
         20 . The apparatus as claimed in  claim 1  wherein the plastic includes heteroatoms and the apparatus includes an additional stage of low temperature pyrolysis to remove the heteroatoms prior to full decomposition. 
     
     
         21 . A method of completing thermal conversion pyrolysis of plastic by the steps of:
 a. adding plastic to a thermal conversion pyrolysis reactor apparatus including;
 i. a pyrolysis reactor vessel with a heat source to heat plastic material in bottom of the vessel; 
 ii. a conveyer for transporting char and/or plastic from the vessel; and 
 iii. a condensing seal through which decomposed gas travels and wherein the condensing seal prevents entry of oxygen into the vessel and egress of heavier compounds out of the vessel. 
   b. heating the plastic sufficient to cause pyrolysis of the plastic;   c. collecting the resulting hydrocarbon gas from the reactor vessel.   
     
     
         22 . (canceled) 
     
     
         23 . The apparatus as claimed in  claim 1  wherein the conveyor is a chain. 
     
     
         24 . The apparatus as claimed in  claim 1  wherein the apparatus is used in a two part process being:
 a. formation of dense plastic pellets by melting the raw plastic in the reactor at a low enough temperature to minimise decomposition but sufficient to melt the plastic in the reactor and then transport and harden the molten plastic into discrete pellets via the conveyor; and 
 b. subsequent pyrolysis of the discrete pellets to decompose the pellets into gas and char. 
 
     
     
         25 . The apparatus of  claim 24 , wherein the heat source is electricity. 
     
     
         26 . The apparatus as claimed in  claim 1  wherein the decomposition gas is used to generate energy. 
     
     
         27 . The apparatus as claimed in  claim 26  wherein the energy may be selected from electricity and/or heat. 
     
     
         28 . A method for producing electricity by the step of:
 a. adding plastic to a thermal conversion pyrolysis reactor apparatus including
 i. a pyrolysis reactor vessel with a heat source to heat plastic material in bottom of the vessel; 
 ii. a conveyer for transporting char and/or plastic from the vessel; and 
 iii. a condensing seal through which decomposed gas travels and wherein the condensing seal prevents entry of oxygen into the vessel and egress of heavier compounds out of the vessel, 
   b. heating the plastic sufficient to cause pyrolysis of the plastic;   c. collecting the resulting hydrocarbon gas from the reactor vessel; and   d. using the hydrocarbon gas to drive a generator to generate electricity.