Methods for the decomposition of contaminated plastic waste

Abstract

This invention relates to the field of contaminated plastic waste decomposition. More specifically, the invention comprises methods and systems to decompose contaminated plastic waste and transform it into value-added products.

1 . A method for decomposing plastic waste, comprising:
 a. adding plastic waste to a reaction vessel;   b. adding aqueous nitric acid (HNO3) to the reaction vessel to give a mixture, wherein the wt. ratio of plastic waste to aqueous nitric acid is greater than 1:3; and   c. subjecting the mixture obtained in b. to conditions effective to decompose the plastic waste to produce decomposition products, wherein the decomposition products comprise:
 i. succinic acid, glutaric acid, adipic acid, pimelic acid, and azelaic acid; 
 ii. at least one of oxalic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, 2-octenedioic acid, 2-nonenedioic acid, 2-decenedioic acid, and 2-undecenedioic acid, or the salts or esters thereof; or at least one of C 8 -C 20  dicarboxylic acid substituted with a single nitro group, or the salts or esters thereof; and 
 iii. at least one anhydride of (i) and (ii). 
   
     
     
         2 . The method of  claim 1 , wherein the decomposition products comprise at least one of oxalic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, or the salts or esters thereof. 
     
     
         3 . The method of  claim 1 , wherein the decomposition products comprise at least one of C 8 -C 20  dicarboxylic acid substituted with a single nitro group, or the salts or esters thereof. 
     
     
         4 . The method of  claim 3 , wherein the at least one C 8 -C 20  dicarboxylic acid substituted with a single nitro group is (1) nitro-suberic acid, nitro-azelaic acid, nitro-sebacic acid, nitro-undecanedioic acid, nitro-dodecanedioic acid, nitro-brassylic acid, nitro-tetradecanedioic acid, nitro-pentadecanedioic acid, nitro-hexadecanedioic acid, nitro-heptadecanedioic acid, nitro-octadecanedioic acid, nitro-nonadecanedioic acid, or nitro-icosanedioic acid, or the salts or esters thereof; or (2) 2-nitro-suberic acid, 2-nitro-azelaic acid, 2-nitro-sebacic acid, 2-nitro-undecanedioic acid, 2-nitro-dodecanedioic acid, 2-nitro-brassylic acid, 2-nitro-tetradecanedioic acid, 2-nitro-pentadecanedioic acid, 2-nitro-hexadecanedioic acid, 2-nitro-heptadecanedioic acid, 2-nitro-octadecanedioic acid, 2-nitro-nonadecanedioic acid, or 2-nitro-icosanedioic acid, or the salts or esters thereof. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein the plastic waste comprises polyethylene. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The method of  claim 1 , wherein the nitric acid has a concentration of about 67 to about 70 wt %. 
     
     
         10 . The method of  claim 1 , wherein the weight ratio of plastic waste to nitric acid is 1:10 to 1:100. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 1 , wherein the conditions effective comprise a continuous process. 
     
     
         18 . The method of  claim 17 , wherein the continuous process comprises the continuous addition of plastic waste and aqueous nitric acid to the reaction vessel and the continuous removal of decomposition products. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . The method of  claim 1 , further comprising isolating the decomposition products. 
     
     
         24 . The method of  claim 23 , wherein the decomposition products are isolated by removal of insoluble products. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 24 , further comprising evaporation of solvent. 
     
     
         27 . (canceled) 
     
     
         28 . The method of  claim 1 , wherein the at least one anhydride is succinic anhydride. 
     
     
         29 . The method of  claim 1 , wherein the at least one anhydride is glutaric anhydride. 
     
     
         30 . (canceled) 
     
     
         31 . (canceled) 
     
     
         32 . A composition, comprising:
 a. succinic acid, glutaric acid, adipic acid, pimelic acid, and azelaic acid, or the salts or esters thereof; and   b. at least one of oxalic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, 2-octenedioic acid, 2-nonenedioic acid, 2-decenedioic acid, and 2-undecenedioic acid, or the salts or esters thereof; and
 at least one anhydride of (a) and (b). 
   
     
     
         33 . (canceled) 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . A composition, comprising:
 a. succinic acid, glutaric acid, adipic acid, pimelic acid, and azelaic acid, or the salts or esters thereof; and   b. at least one C 8 -C 20  dicarboxylic acid substituted with a single nitro group, or the salts or esters thereof; and   at least one anhydride of (a) and (b).   
     
     
         38 . The composition of  claim 37 , wherein the at least one C 8 -C 20  dicarboxylic acid substituted with a single nitro group is (1) nitro-suberic acid, nitro-azelaic acid, nitro-sebacic acid, nitro-undecanedioic acid, nitro-dodecanedioic acid, nitro-brassylic acid, nitro-tetradecanedioic acid, nitro-pentadecanedioic acid, nitro-hexadecanedioic acid, nitro-heptadecanedioic acid, nitro-octadecanedioic acid, nitro-nonadecanedioic acid, or nitro-icosanedioic acid, or the salts or esters thereof; or (2) 2-nitro-suberic acid, 2-nitro-azelaic acid, 2-nitro-sebacic acid, 2-nitro-undecanedioic acid, 2-nitro-dodecanedioic acid, 2-nitro-brassylic acid, 2-nitro-tetradecanedioic acid, 2-nitro-pentadecanedioic acid, 2-nitro-hexadecanedioic acid, 2-nitro-heptadecanedioic acid, 2-nitro-octadecanedioic acid, 2-nitro-nonadecanedioic acid, or 2-nitro-icosanedioic acid, or the salts or esters thereof. 
     
     
         39 . (canceled) 
     
     
         40 . The composition of  claim 37 , further comprising:
 c. at least one of oxalic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, 2-octenedioic acid, 2-nonenedioic acid, 2-decenedioic acid, and 2-undecenedioic acid, or the salts or esters thereof.   
     
     
         41 . (canceled) 
     
     
         42 . (canceled) 
     
     
         43 . (canceled) 
     
     
         44 . (canceled) 
     
     
         45 . (canceled) 
     
     
         46 . (canceled) 
     
     
         47 . (canceled) 
     
     
         48 . The composition of any one of  claim 32 , wherein the at least one anhydride is succinic anhydride. 
     
     
         49 . The composition of  claim 32 , wherein the at least one anhydride is glutaric anhydride. 
     
     
         50 . (canceled) 
     
     
         51 . (canceled)