Process for converting plastic into gases, liquid fuels and waxes by cracking

Abstract

The present invention relates to a process for converting a mixture comprising plastic and at least one oxygenated compound into gases, liquid fuels and waxes by cracking. The process comprises a deoxygenation step and subsequently a cracking step during which the mixture is subjected to cracking conditions for obtaining a product stream containing said gases, liquid fuels and waxes.

1 . A process for converting a mixture comprising plastic and at least one oxygenated compound into gases, liquid fuels and waxes by cracking, the process comprising:
 a deoxygenation step which is conducted by heating the mixture to a temperature of at least 200° C. for a period until the condensate of the gas stream obtained from the heated mixture has a density of about 0.94 g/cm 3  or lower;   and subsequently to the deoxygenation step a cracking step during which the mixture is subjected to cracking conditions for obtaining a product stream containing said gases, liquid fuels and waxes.   
     
     
         2 . The process according to  claim 1 , wherein the deoxygenation step is conducted until the condensate of the gas stream obtained from the heated mixture has a density in the range of 0.90 g/cm 3  to 0.93 g/cm 3 . 
     
     
         3 . The process according to  claim 1 , wherein the temperature in the deoxygenation step is in the range of 250° C. to 400° C. 
     
     
         4 . The process according to  claim 1 , wherein the gas stream obtained during the deoxygenation step and the product stream are kept separate from each other. 
     
     
         5 . The process according to  claim 1 , wherein the gas stream obtained in the deoxygenation step is removed for a time sufficient to remove at least 50% by weight, based on the total weight of the at least one oxygenated compound being present in the mixture prior to the deoxygenation step. 
     
     
         6 . The process according to  claim 1 , wherein the plastic comprises waste plastic. 
     
     
         7 . The process according to  claim 1 , wherein the plastic comprises more than 50% by weight of polystyrene and/or polyolefin based on the total weight of plastic. 
     
     
         8 . The process according to  claim 1 , wherein the cracking step is conducted in the presence of a catalyst. 
     
     
         9 . The process according to  claim 8 , wherein the deoxygenation step and the cracking step are conducted in the presence of a catalyst. 
     
     
         10 . The process according to  claim 8 , wherein the catalyst is a zeolite-type catalyst and/or an amorphous-type catalyst. 
     
     
         11 . The process according to  claim 8 , wherein the catalyst is fresh catalyst, equilibrated catalyst, or a mixture thereof. 
     
     
         12 . The process according to  claim 1 , wherein the deoxygenation step and the cracking step are conducted in two different reactors. 
     
     
         13 . The process according to  claim 1 , wherein the deoxygenation step and the cracking step are conducted in the same reactor. 
     
     
         14 . The process according to  claim 1 , which wherein the process is conducted batchwise, semi-batchwise or continuously. 
     
     
         15 . A process for removing oxygenated compounds from a mixture comprising plastic and at least one oxygenated compound, the process comprising: 
       heating the mixture to a temperature of at least 200° C. for a period until the condensate of the gas stream obtained from the heated mixture has a density of about 0.94 g/cm 3  or lower. 
     
     
         16 . The process according to  claim 2 , wherein the deoxygenation step is conducted until the condensate of the gas stream obtained from the heated mixture has a density in the range of 0.91 g/cm 3  to 0.93 g/cm 3 . 
     
     
         17 . The process according to  claim 3 , wherein the temperature in the deoxygenation step is in the range of 250° C. to 380° C. 
     
     
         18 . The process according to  claim 5 , wherein the gas stream obtained in the deoxygenation step is removed for a time sufficient to remove at least 70% by weight, based on the total weight of the at least one oxygenated compound being present in the mixture prior to the deoxygenation step. 
     
     
         19 . The process according to  claim 6 , wherein the plastic comprises mixed waste plastic. 
     
     
         20 . The process according to  claim 10 , wherein the catalyst is silica, alumina, kaolin, or a mixture thereof.