Provided is a continuous process for converting waste plastic into recycle for polypropylene 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 naphtha/diesel fraction, a heavy fraction, and char. Pyrolysis oil and wax, comprising the naphtha/diesel fraction and heavy fraction, is sent to a refinery FCC unit. A liquid petroleum gas C.sub.3-C.sub.5 olefin/paraffin mixture is recovered from the FCC unit and passed to a refinery alkylation unit. A propane fraction is recovered from the alkylation unit and passed to a dehydrogenation unit to produce propylene. The propylene is passed to a propylene polymerization reactor.

A method and system for separating light hydrocarbons are disclosed, wherein the method comprises compression, cooling, absorption, desorption, rectification, cracking, and recycling cracked gas to the compression step.

The invention relates to various nonlimiting embodiments that include methods, apparatuses or systems for processing natural gas comprising a heavies removal column processing natural gas and light oil reflux. The overhead stream goes to heavies treated natural gas storage. The heavies removal column reboiler bottoms stream product is input to a debutanizer column. The debutanizer column overhead lights are input to a flash drum where the bottoms is pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the debutanizer reboiler bottoms product is stored as stabilized condensate. Alternatively, debutanizer column overhead lights are sent to heavies treated gas storage and the bottoms stream product goes to a depentanizer column, the overhead lights are pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the depentanizer reboiler bottoms product is stabilized condensate.

The invention relates to various nonlimiting embodiments that include methods, apparatuses or systems for processing natural gas comprising a heavies removal column processing natural gas and light oil reflux. The overhead stream goes to heavies treated natural gas storage. The heavies removal column reboiler bottoms stream product is input to a debutanizer column. The debutanizer column overhead lights are input to a flash drum where the bottoms is pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the debutanizer reboiler bottoms product is stored as stabilized condensate. Alternatively, debutanizer column overhead lights are sent to heavies treated gas storage and the bottoms stream product goes to a depentanizer column, the overhead lights are pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the depentanizer reboiler bottoms product is stabilized condensate.

This disclosure relates to the production of chemicals and plastics using pyrolysis oil from the pyrolysis of plastic waste as a co-feedstock along with a petroleum-based or fossil fuel co-feed, or as a feedstock in the absence of a petroleum-based or fossil fuel co-feed. A mass balance accounting approach is employed to attribute the pounds of pyrolyzed plastic products derived from pyrolysis oil to any output stream of a given unit, which permits assigning circular product credit to product streams. In an aspect, the polymers and chemicals produced according to this disclosure can be certified under International Sustainability and Carbon Certification (ISCC) provisions as circular polymers and chemicals at any point along complex chemical reaction pathways.

A process can be used for purifying a hydrocarbon stream containing at least Cx alkanes, Cx olefins, low boilers such as Cx−1 hydrocarbons, and high boilers such as Cx+1 hydrocarbons, with x=3 or 4. The process involves separating off low boilers and separating off high boilers, wherein the separating-off of high boilers is performed in the presence of hydrogen and hence a hydrogenation of the olefins present takes place.

This disclosure relates to the production of chemicals and plastics using pyrolysis oil from the pyrolysis of plastic waste as a co-feedstock along with a petroleum-based, fossil fuel-based, or bio-based feedstock. In an aspect, the polymers and chemicals produced according to this disclosure can be certified under International Sustainability and Carbon Certification (ISCC) provisions as circular polymers and chemicals at any point along complex chemical reaction pathways. The use of a mass balance approach which attributes the pounds of pyrolyzed plastic products derived from pyrolysis oil to any output stream of a given unit has been developed, which permits ISCC certification agency approval.

A method and system for separating light hydrocarbons are disclosed, wherein the method comprises compression, cooling, absorption, desorption, rectification, cracking, and recycling cracked gas to the compression step.

A method of recovering gaseous hydrocarbons from tank headspace as fuel on-site includes flowing a hydrocarbon gas composition from headspace of a tank fed by a secondary separator into a compressor to form a compressed mixture. The method includes flowing the compressed mixture into a cooling unit to cool the compressed mixture, to form a cooled composition including liquid hydrocarbons. The method includes flowing the cooled composition to a buffer tank to form a buffered fuel composition. The method includes removing a fuel gas composition from headspace of the buffer tank. The method also includes combusting the fuel gas composition as an on-site fuel.

The present invention relates to a process and system for forming a hydrocarbon feedstock from a biomass material, and the hydrocarbon feedstock formed therefrom. The present invention also relates to a process and system for forming a bio-derived LPG fuel from a hydrocarbon feedstock, and the bio-derived LPG fuel formed therefrom, as well as intermediate treated hydrocarbon feedstocks formed during the process.