Waste processing process

Abstract

Waste processing system including a shredder, a grinder and a steam explosion device such as a cooking extruder. The waste processing system is used to process raw waste, such as consumer waste, into an end product such as pellets. One potential use for these pellets is pyrolization to form biogas. Because of the uniformity composition of the processing waste (see DEFINITIONS section), imparted by the shredder and grinder, and because of the uniformity of distribution of plastic in the processing waster, imparted by the steam explosion processing, the end-product made by systems according to the present invention are superior with respect to several physical characteristics and especially well suited for pyrolization to make biogas.

1 . A waste processing process for processing waste, the process comprising the steps of:
 performing an initial processing step to convert the waste into an end-product including both a plastic component and an organic matter component; and   pyrolyzing the end-product to form biogas.   
   
   
       2 . The process of  claim 1  wherein the waste is consumer waste that includes both a plastic component and an organic matter component. 
   
   
       3 . The process of  claim 2  wherein the plastic component of the consumer waste includes polyethylene. 
   
   
       4 . The process of  claim 2  wherein the plastic component of the consumer waste includes polyolefins. 
   
   
       5 . The process of  claim 2  wherein the organic component of the consumer waste includes cellulose. 
   
   
       6 . The process of  claim 1  wherein the initial processing step includes a steam explosion processing sub-step. 
   
   
       7 . The process of  claim 6  wherein the initial processing step includes a grinding sub-step, which is performed prior to the steam explosion processing sub-step. 
   
   
       8 . The process of  claim 7  wherein the initial processing step includes a shredding sub-step, which is performed prior to the grinding sub-step. 
   
   
       9 . The process of  claim 6  wherein the initial processing step includes a shape forming sub-step, which is performed subsequent to the steam explosion processing sub-step, wherein the processing waste is formed into a plurality of solid, discrete pieces. 
   
   
       10 . The process of  claim 9  wherein the plurality of solid, discrete pieces formed at the shape forming sub-step are pellets. 
   
   
       11 . The process of  claim 8  wherein the plurality of solid, discrete pieces are dry, inert and have a relative lack of friability. 
   
   
       12 . The process of  claim 1  wherein:
 the pyrolyzation step is performed in a pyrolyzation chamber; and   the plastic component of the end-product at least substantially prevents atmospheric gas from entering the pyrolyzation chamber.   
   
   
       13 . A waste processing process for processing waste, the process comprising the steps of:
 providing consumer waste that has both a plastic component and an organic matter component; and   performing steam explosion processing on the consumer waste.   
   
   
       14 . The process of  claim 13  wherein the steam explosion processing step is performed under a set of temperature and pressure conditions so that the plastic melts during the steam explosion processing step. 
   
   
       15 . The process of  claim 14  further comprising the step of, prior to the steam explosion processing step, dividing the consumer waste so that the organic matter component includes a fibrous mass, wherein the steam explosion processing is performed under a set of temperature and pressure conditions so that the melted plastic coats the fibrous mass during the steam explosion processing step. 
   
   
       16 . The process of  claim 13  wherein the plastic component of the consumer waste includes polyethylene. 
   
   
       17 . The process of  claim 13  wherein the plastic component of the consumer waste includes polyolefins. 
   
   
       18 . The process of  claim 13  wherein the organic component of the consumer waste includes cellulose. 
   
   
       19 . The process of  claim 13  further comprising, subsequent to the steam explosion processing step, a shape forming sub-step wherein the consumer waste is formed into an end-product of a plurality of solid, discrete pieces. 
   
   
       20 . A process for processing waste comprising the following steps:
 providing waste; and   performing steam explosion processing on the waste.   
   
   
       21 . The process of  claim 20  wherein the performing steam explosion processing step comprised the sub steps of: (i) increasing the temperature and pressure of the waste; and (ii) after the increasing step, subjecting the waste to a low pressure environment. 
   
   
       22 . The process of  claim 21  wherein, at the increasing sub-step, the temperature of the waste is increased to at least 370 degrees Fahrenheit. 
   
   
       23 . The process of  claim 21  wherein, at the increasing sub-step, the pressure of the waste is increased to at least 10 atmospheres. 
   
   
       24 . The process of  claim 21  wherein the increasing sub-step takes no more than 30 seconds. 
   
   
       25 . The process of  claim 20  wherein the performing steam explosion processing step is performed by feeding the waste from a primary extruder to a vacuum chamber. 
   
   
       26 . A process for processing waste into finished material, the process comprising the following steps:
 providing waste;   performing steam explosion processing on the waste to form an extrudate material; and   processing the extrudate material with a die to finished material.   
   
   
       27 . The process of  claim 26  wherein the die processes the extrudate material to form highly densified extrudate material. 
   
   
       28 . The process of  claim 26  wherein the die processes the extrudate material to form non-densified extrudate material. 
   
   
       29 . The method of  claim 26  further comprising the step of:
 sorting the waste to remove at least metal and obvious toxic material.   
   
   
       30 . The method of  claim 26  further comprising the step of:
 reducing particle size of the waste by shredding it.   
   
   
       31 . The method of  claim 30  wherein the reducing particle size step comprises the sub-steps of: (i) initial shredding of the waste with a primary shredder; and (ii) after the initial shredding sub-step, secondary shredding of the waste with a secondary shredder. 
   
   
       32 . The method of  claim 26  further comprising the step of:
 preconditioning the waste by exposing it to live steam while the waste is mixed.   
   
   
       33 . A process for processing waste into finished material, the process comprising the following steps:
 providing waste;   sorting the waste to remove at least metal and obvious toxic material;   reducing particle size of the waste by shredding it, wherein the reducing particle size step comprises the sub-steps of: (i) initial shredding of the waste with a primary shredder; and (ii) after the initial shredding sub-step, secondary shredding of the waste with a secondary shredder;   preconditioning the waste by exposing it to live steam while the waste is mixed;   performing steam explosion processing on the waste to form an extrudate material; and processing the extrudate material with a die to finished material.