Plastic pyrolysis heating/reaction recipe

A process for pyrolyzing waste plastics, the process comprising:

• heating a waste plastic from an initial temperature to a first temperature in a reaction system and maintaining the waste plastic at the first temperature for a first time period, producing a first heated plastic;
• heating the first heated plastic to a second temperature in the reaction system and maintaining the first heated plastic at the second temperature for a second time period, producing a second heated plastic;
• pyrolyzing the second heated plastic by heating the second heated plastic to a third temperature in the reaction system and maintaining the second heated plastic at the third temperature for a third time period, producing a third heated plastic;
• pyrolyzing the third heated plastic by heating the third heated plastic to a fourth, peak, temperature in the reaction system, producing a fourth heated plastic;
• and
• pyrolyzing the fourth heated plastic by providing heat input sufficient to maintain a temperature of the fourth heated plastic at a fifth temperature in the reaction system and maintaining the fourth heated plastic at the fifth temperature for a fourth time period;
• recovering a pyrolyzed product from each of the pyrolyzing steps as a vapor and recovering a pitch as a liquid from the reaction system;
• wherein the first temperature is less than the second temperature, the second temperature is less than the third temperature, the third temperature is less than the fourth, peak, temperature, and the fifth temperature is less than the fourth, peak, temperature;
• and
• wherein heating the third heated plastic to a fourth, peak, temperature comprises:
• heating the third heated plastic at a rate of heating of greater than 50° C./min to an intermediate temperature;
• and
• heating the third heated plastic from the intermediate temperature to the fourth, peak, temperature at a rate of heating in a range of 15° C./min to 30° C./min.