A plastic catalytic pyrolysis process that can produce high yields of ethylene, propylene and other light olefins from waste plastics is disclosed. The catalytic product stream is quenched to below catalytic pyrolysis temperature quickly after exiting the reactor or bulk separation from the catalyst. Quench preserves selectivity of light olefinic monomers. The catalytic pyrolysis process can be operated in a single stage or a two-stage process.

A system for hydrogenation C.sub.3 and C.sub.4 acetylenes contained within a hydrocarbon stream generated in a stream cracker unit where a debutanizer is placed upstream of a depropanizer for more economical processing of the hydrocarbon stream to produce lighter hydrocarbons, where the system requires only one stripper tower downstream of hydrogenation to remove residual hydrogen.

Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and 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 separated into offgas, a pyrolysis oil and optionally wax comprising a naphtha/diesel and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC unit from which a liquid petroleum gas C.sub.3-C.sub.5 olefin/paraffin mixture fraction is recovered. The liquid petroleum gas C.sub.3-C.sub.5 olefin/paraffin mixture fraction is passed to a refinery alkylation unit, with a propane and butane fraction recovered from the alkylation unit. The propane and butane fraction is then passed to a steam cracker for ethylene production. In another embodiment, a naphtha fraction (C.sub.5-C.sub.8) is recovered from the alkylation unit and passed to the steam cracker. In another embodiment, a propane/propylene fraction (C.sub.3-C.sub.3) is recovered from the FCC and passed to the steam cracker.

A process for increasing conversion and selectivity to normal paraffins is achieved by reducing the hydrogen to hydrocarbon ratio for paraffin feeds with substantial butanes. A separator may be used to remove excess hydrogen from a first isomerate before a second isomerization step that may isomerize additional butanes perhaps generated in the first isomerization step.

Methods for cracking a hydrocarbon feed stream include contacting a hydrocarbon feed stream with a catalyst system in a catalytic cracking unit having a flowing gas stream to obtain a cracking product containing light olefins. The catalyst system includes at least a base catalyst. The base catalyst includes a pentasil zeolite. The pentasil zeolite includes from 0.01% to 5% by mass lithium atoms, as calculated on an oxide basis, based on the total mass of the pentasil zeolite. The flowing gas stream comprises hydrogen and, optionally, at least one additional carrier gas.

A high-pressure steam stream produced from the waste heat recovery system of a syngas producing unit may be superheated and then supplied to a steam turbine in a hydrocarbon production plant to produce an expanded steam stream and shaft power. A portion of the expanded stream can be fed into the reforming reactor in the syngas producing unit. The shaft power can be used to drive compressors and pumps in an olefins production plant. Considerable energy efficiency and capital investment savings can be realized by such steam integration compared to running the olefins production plant separately.

Methods and systems are provided for the conversion of waste plastics into various useful downstream recycle-content products. More particularly, the present system and method involves integrating a pyrolysis facility with a cracker facility by introducing at least a stream of r-pyrolysis gas into the cracker facility. In the cracker facility, the r-pyrolysis gas may be separated to form one or more recycle content products, and can enhance the operation of the facility.

A hydrocarbon conversion process comprises pyrolysing at a temperature ≥700° C. a feedstock comprising hydrocarbon to produce a pyrolysis effluent comprising at least one C.sub.2 to C.sub.4 olefin and C.sub.5+ aliphatic and aromatic hydrocarbons. The pyrolysis effluent is contacted with an oleaginous quench stream to reduce the temperature of the pyrolysis effluent to ≤400° C. At least first and second streams are separated from the cooled effluent. The first stream comprises at least one C.sub.2 to C.sub.4 olefin, and the second stream comprises a quench oil having an average boiling point at atmospheric pressure of at least 120° C. At least a portion of the second stream is catalytically hydroprocessed to produce a hydroprocessed stream, which is combined with at least a portion of any remainder of the second stream to form the quench stream.

Integrated pyrolysis and hydrocracking systems and processes for efficiently cracking of hydrocarbon mixtures, such as mixtures including compounds having a normal boiling temperature of greater than 450° C., 500° C., or even greater than 550° C., such as whole crudes for example, are disclosed.

A catalyst composition includes a metal catalyst dispersed in a molten eutectic mixture of alkali metal or alkaline earth metal carbonates or hydroxides. A process for the catalytic cracking of hydrocarbons includes contacting in a reactor system a carbon-containing feedstock with at least one catalyst in the presence of oxygen to generate olefinic and/or aromatic compounds; and collecting the olefinic and/or aromatic compounds; wherein: the at least one catalyst includes a metal catalyst dispersed in a molten eutectic mixture of alkali metal or alkaline earth metal carbonates or hydroxides. A process for preparing the catalyst includes mixing metal catalyst precursors selected from transition metal compounds and rare-earth metal compounds and a eutectic mixture of alkali metal or alkaline earth metal carbonates or hydroxides and heating it. A use of the catalyst in the catalytic cracking process of hydrocarbons.