A process for upgrading a plastic derived oil includes providing the plastic derived oil comprising hydrocarbons and greater than or equal to 100 ppmw halogen-containing compounds and contacting the plastic derived oil with an MMO catalyst in a first reactor at reaction conditions to remove halogens from the plastic derived oil to produce a first reactor effluent with less than 100 ppmw halogen-containing compounds. The process includes contacting the first reactor effluent with an adsorbent to produce a treated first reactor effluent, passing the treated first reactor effluent to a second reactor, and contacting the treated first reactor effluent with a cracking catalyst in the second reactor. Contacting with the cracking catalyst may cause hydrocarbons in the treated first reactor effluent to undergo catalytic cracking to produce a second reactor effluent comprising light olefins, naphtha range hydrocarbons, or combinations thereof.

A pyrolysis process comprises introducing one or more chemical reactants into a reactor containing a liquid maintained at a high temperature, producing chemical products in the liquid based on the high temperature, allowing the solid product to grow in particle size, accumulating the solid product in the liquid, and removing the solid product from the reactor while retaining a substantial portion of the liquid within the reactor. The chemical products comprise a solid chemical product that is mixed with the liquid.