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 preparing a stable blend of petroleum and the selected plastic. The amount of plastic in the blend comprises no more than 20 wt. % of the blend. The blend is passed to a refinery hydrocracking unit. A liquid petroleum gas C.sub.3 olefin/paraffin mixture is recovered from the hydrocracking unit. The C.sub.3 paraffins and C.sub.3 olefins are separated into different fractions with the C.sub.3 olefin fraction passed to a propylene polymerization reactor, and the C.sub.3 paraffin fraction passed optionally to a dehydrogenation unit to produce additional propylene. A heavy fraction can also be recovered from the hydrocracking unit and passed to an isomerization dewaxing unit to prepare base oil.

The present disclosure provides a method of treating waste plastic pyrolysis oil. The method includes a first step of washing waste plastic pyrolysis oil with water and then removing moisture; a second step of mixing the waste plastic pyrolysis oil from which the moisture is removed and a sulfur source to prepare a mixed oil; a third step of hydrotreating the mixed oil with hydrogen gas in the presence of a hydrotreating catalyst; a fourth step of separating the hydrotreated mixed oil into a liquid stream and a gas stream to obtain liquid pyrolysis oil; and a fifth step of recovering hydrogen gas from the separated gas stream and recycling the recovered hydrogen gas to the third step.

The present disclosure provides a method of treating waste plastic pyrolysis oil. The method includes a first step of washing waste plastic pyrolysis oil with water and then removing moisture; a second step of mixing the waste plastic pyrolysis oil from which the moisture is removed and a sulfur source to prepare a mixed oil; a third step of hydrotreating the mixed oil with hydrogen gas in the presence of a hydrotreating catalyst; a fourth step of separating the hydrotreated mixed oil into a liquid stream and a gas stream to obtain liquid pyrolysis oil; and a fifth step of recovering hydrogen gas from the separated gas stream and recycling the recovered hydrogen gas to the third step.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

The present invention is based on the use of a two-step hydrocracking process comprising a step of hydrogenation placed upstream of the second hydrocracking step, the hydrogenation step treating the unconverted liquid fraction separated in the distillation step in the presence of a specific hydrogenation catalyst. Furthermore, the hydrogenation step and second hydrocracking step are carried out under specific operating conditions and in particular under very specific temperature conditions.

The present invention is based on the use of a two-step hydrocracking process comprising a step of hydrogenation placed upstream of the second hydrocracking step, the hydrogenation step treating the unconverted liquid fraction separated in the distillation step in the presence of a specific hydrogenation catalyst. Furthermore, the hydrogenation step and second hydrocracking step are carried out under specific operating conditions and in particular under very specific temperature conditions.

The invention relates to the implementation of a multi-stage hydrocracking process comprising a hydrogenation stage located downstream of the second hydrocracking stage, said hydrogenation stage treating the effluent produced in the second hydrocracking stage, in the presence of a specific hydrogenation catalyst. In addition, the hydrogenation and second hydrocracking stages are implemented under specific operating conditions and particularly under very specific temperature conditions.

The invention relates to the implementation of a multi-stage hydrocracking process comprising a hydrogenation stage located downstream of the second hydrocracking stage, said hydrogenation stage treating the effluent produced in the second hydrocracking stage, in the presence of a specific hydrogenation catalyst. In addition, the hydrogenation and second hydrocracking stages are implemented under specific operating conditions and particularly under very specific temperature conditions.

A method of dosing a system with HCL is provided. The method includes at least two parallel trains. The method utilizes a first operating mode, wherein at least one primary train is actively providing HCL to an end user, and at least one secondary train is either inactive or also providing HCL to the end user. The method utilizes a second operating mode, wherein the least one primary train is evacuating the contents of the train to a disposal system, and the at least one secondary train is providing HCL to the end user. And the system utilizes a third operating mode, wherein the at least one primary train is purging the train, and the at least one secondary train is providing HCL to the end user. The first operating mode, the second operating mode, and the third operating mode are controlled by an electronic monitoring and control system.