Apparatus and processes herein provide for converting hydrocarbon feeds to light olefins and other hydrocarbons. The processes and apparatus include, in some embodiments, feeding a hydrocarbon, a first catalyst and a second catalyst to a reactor, wherein the first catalyst has a smaller average particle size and is less dense than the second catalyst. A first portion of the second catalyst may be recovered as a bottoms product from the reactor, and a cracked hydrocarbon effluent, a second portion of the second catalyst, and the first catalyst may be recovered as an overhead product from the reactor. The second portion of the second catalyst may be separated from the overhead product, providing a first stream comprising the first catalyst and the hydrocarbon effluent and a second stream comprising the separated second catalyst, allowing return of the separated second catalyst in the second stream to the reactor.

Recycle content pyoil is cracked in a cracker furnace to make olefins and the coil outlet temperature of the r-pyoil fed coils can he lowered by adding r-pyoil to the cracker feedstock, or alternatively, the coil outlet temperature of the r-pyoil fed tubes can rise if the mass flow rates of the combined cracker stream containing r-pyoil are kept the same or lowered. Further, increasing the hydrocarbon mass flow rate by addition of r-pyoil can be achieved to also increase the output of ethylene and propylene in the cracker effluent. The cracker furnace can accept ethane and/or propane feedstocks in vapor form along with a liquid and/or vapor feed of r-pyoil.

Methods for operating a system having two downflow high-severity FCC units for producing products from a hydrocarbon feed includes introducing the hydrocarbon feed to a feed separator and separating it into a lesser boiling point fraction and a greater boiling point fraction. The greater boiling point fraction is passed to the first FCC unit and cracked in the presence of a first catalyst at 500° C. to 700° C. to produce a first cracking reaction product and a spent first catalyst. The lesser boiling point fraction is passed to the second FCC unit and cracked in the presence of a second catalyst at 500° C. to 700° C. to produce a second cracking reaction product and a spent second catalyst. At least a portion of the spent first catalyst or the spent second catalyst is passed back to the first FCC unit, the second FCC unit or both.

Methods for operating a system having two downflow high-severity FCC units for producing products from a hydrocarbon feed includes introducing the hydrocarbon feed to a feed separator and separating it into a lesser boiling point fraction and a greater boiling point fraction. The greater boiling point fraction is passed to the first FCC unit and cracked in the presence of a first catalyst at 500° C. to 700° C. to produce a first cracking reaction product and a spent first catalyst. The lesser boiling point fraction is passed to the second FCC unit and cracked in the presence of a second catalyst at 500° C. to 700° C. to produce a second cracking reaction product and a spent second catalyst. At least a portion of the spent first catalyst or the spent second catalyst is passed back to the first FCC unit, the second FCC unit or both.

A process for the production of polymers from waste plastics feedstocks includes: providing a hydrocarbon stream A obtained by treatment of a waste plastics feedstock; optionally providing a hydrocarbon stream B; supplying a feed C comprising a fraction of the hydrocarbon stream A and a fraction of the hydrocarbon stream B to a thermal cracker furnace comprising cracking coil(s); performing a thermal cracking operation in the presence of steam to obtain a cracked hydrocarbon stream D; supplying the cracked hydrocarbon stream D to a separation unit; performing a separation operation in the separation unit to obtain a product stream E comprising a monomer; supplying the product stream E to a polymerisation reactor; and performing a polymerisation reaction to obtain an polymer. The process allows for optimisation of the quantity of waste plastic material that finds its way back into a polymer that is produced as outcome of the process.

A method for producing alkene gases from a cracked product effluent, the method comprising the steps of introducing the cracked product effluent to a fractionator unit, separating the cracked product effluent in the fractionator to produce a cracked light stream and a cracked residue stream, wherein the cracked light stream comprises the alkene gases selected from the group consisting of ethylene, propylene, butylene, and combinations of the same, mixing the cracked residue stream and the heavy feed in the heavy mixer to produce a combined supercritical process feed, and upgrading the combined supercritical process feed in the supercritical water process to produce a supercritical water process (SWP)-treated light product and a SWP-treated heavy product, wherein the SWP-treated heavy product comprises reduced amounts of olefins and asphaltenes relative to the cracked residue stream such that the SWP-treated heavy product exhibits increased stability relative to the cracked residue stream.

According to one more embodiments, petrochemical products may be produced from a hydrocarbon material by a process that may comprise separating the hydrocarbon material into at least a lesser boiling point fraction, a medium boiling point fraction, and a greater boiling point fraction. The process may further comprise cracking at least a portion of the lesser boiling point fraction and the medium boiling point fraction in a second reactor unit in the presence of a second catalyst at a reaction temperature of from 500° C. to 700° C. to produce a second cracking reaction product, wherein the lesser boiling point fraction enters the second reactor unit upstream of wherein the medium boiling point fraction enters the second reactor.

The invention is directed to a process to prepare propylene from a mixture of hydrocarbons having an olefin content of between 5 and 50 wt. % and boiling for more than 90 vol. % between 35 and 280° C. or from a hydrocarbon feed comprising paraffins, naphthenics, aromatics and optionally up to 10 wt. % of olefins, by first contacting the feed with a low acidic density cracking catalyst in a fixed bed reactor, separating propylene and subsequently contacting the residue with a high acidic density cracking catalyst in a fixed bed reactor at a more elevated temperature, separating propylene and recycling the residue to first and second cracking reactors. Aromatics may be added to first and second cracking step to improve cycle length.

A method for processing a hydrocarbon feed to produce olefins may comprise introducing the hydrocarbon feed to a first fluid catalytic cracking system, which may cause at least a portion of the hydrocarbon feed to undergo catalytic cracking and produce a spent first cracking catalyst and a first cracked effluent comprising one or more olefins. The method may further comprise passing the first cracked effluent to a separation system downstream of the first fluid catalytic cracking system, which may separate the first cracked effluent to produce at least a naphtha effluent comprising one or more olefins. Additionally, the method may comprise passing the naphtha effluent to a second fluid catalytic cracking system downstream of the separation system, which may cause at least a portion of the naphtha effluent to undergo catalytic cracking and produce a spent cracking catalyst mixture and a second cracked effluent comprising one or more olefins.

Provided is a continuous process for converting waste plastic into a feedstock for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and then passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is then separated into offgas, a pyrolysis oil comprising a naphtha/diesel/heavy fraction, and char. The pyrolysis oil is passed to a crude unit in a refinery from which a naphtha fraction (C.sub.5-C.sub.8), or a propane and butane (C.sub.3-C.sub.4) fraction, is recovered. The naphtha fraction, or propane and butane (C.sub.3-C.sub.4) fraction, is then passed to a steam cracker for ethylene production.