A method for the aromatization of hydrocarbons, comprising: introducing a feed stream to an aromatization catalyst in a fixed bed reactor wherein the feed stream comprises a hydrocarbon having 2 to 4 carbon atoms, converting the hydrocarbon having 2 to 4 carbon atoms to form an outlet stream comprising an aromatic hydrocarbon; wherein the feed stream is introduced at a GHSV of greater than or equal to 4,000 milliliters per gram of catalyst per hour(ml.Math.g.sup.−1 Cat.Math.h.sup.−1), and a pressure of greater than or equal to 0.4 MPa. The feed stream can comprise hydrogen in an amount of at least 0.1 volume percent (vol %) up to 20 vol % based upon total volume of the feed stream.

Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization or for normal alpha olefins. 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 separated into offgas, a naphtha/diesel fraction, a heavy fraction, and char. The naphtha/diesel fraction is passed to a crude unit in a refinery from which is recovered a straight run naphtha fraction (C.sub.5-C.sub.8) or a propane/butane (C.sub.3-C.sub.4) fraction. The straight run naphtha fraction, or propane and butane (C.sub.3-C.sub.4) fraction, is passed to a steam cracker for ethylene production. The ethylene is converted to normal alpha olefin and/or polyethylene. Also, a heavy fraction from the pyrolysis reactor can be combined with a heavy fraction of normal alpha olefin stream recovered from the steam cracker. The combined heavy fraction and heavy fraction of normal alpha olefin stream can be passed to a wax hydrogenation zone to produce wax.

Processes and systems for making recycle content hydrocarbons, including olefins, are provided that integrate a cracker unit with one or more other processing units. For example, in some cases, a pyrolysis unit and cracking unit may share a common energy exchange zone so that energy from one unit may be transferred to the other. The energy exchange may be direct or indirect and may be present at one or more locations between the units.

Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization or for normal alpha olefins. 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 separated into offgas, a naphtha/diesel fraction, a heavy fraction, and char. The naphtha/diesel fraction is passed to a crude unit in a refinery from which is recovered a straight run naphtha fraction (C.sub.5-C.sub.8) or a propane/butane (C.sub.3-C.sub.4) fraction. The straight run naphtha fraction, or propane and butane (C.sub.3-C.sub.4) fraction, is passed to a steam cracker for ethylene production. The ethylene is converted to normal alpha olefin and/or polyethylene. Also, a heavy fraction from the pyrolysis reactor can be combined with a heavy fraction of normal alpha olefin stream recovered from the steam cracker. The combined heavy fraction and heavy fraction of normal alpha olefin stream can be passed to a wax hydrogenation zone to produce wax.

A process for commencing a continuous reaction in a reactor system includes introducing a catalyst to a catalyst processing portion of the reactor system, the catalyst initially having a first temperature of 500 C or less, and contacting the catalyst at the first temperature with a commencement fuel gas stream, which includes at least 80 mol % commencement fuel gas, in the catalyst processing portion. Contacting of the catalyst with the commencement fuel gas stream causes combustion of the commencement fuel gas. The process includes maintaining the contacting of the catalyst with the commencement fuel gas stream until the temperature of the catalyst increases from the first temperature to a second temperature at which combustion of a regenerator fuel source maintains an operating temperature range in the catalyst processing portion.

Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization. In one embodiment, 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. The naphtha/diesel fraction is passed to a crude unit distillation column in a refinery where a straight run naphtha (C.sub.5-C.sub.8) fraction or a propane/butane (C.sub.3-C.sub.4) fraction is recovered. The straight run naphtha fraction (C.sub.5-C.sub.8) or the propane/butane (C.sub.3-C.sub.4) fraction is passed to a steam cracker for ethylene production. The heavy fraction from the pyrolysis unit can also be passed to an isomerization dewaxing unit to produce a base oil.

The invention provides a process for preparing a fluid having a boiling point in the range of from 150 to 260° C. and comprising more than 80% by weight of isoparaffins and less than 50 ppm of aromatics, comprising the step of catalytically hydrogenating a feed comprising more than 85% by weight of oligomerized olefins, at a temperature from 115 to 195° C. and at a pressure from 30 to 70 bars. The invention also provides the fluid obtainable by the process of the invention and the use of said fluid.

A composition of fuel gas that when mixed with spent catalyst and oxygen has an induction time that allows bubbles to break up while combusting in the regenerator. Bubble breakage in a dense bed avoids generation of a flame that can generate hot spots in the regenerator which can damage equipment and catalyst. The fuel gas can be obtained from paraffin dehydrogenation products, so it can sustain operation of the unit even in remote locations. Heavier streams can be mixed with lighter streams to obtain a fuel gas composition with a desirable induction time to avoid such hot spots. Mixing of a depropanizer bottom stream and/or deethanizer overhead stream with lighter gas streams such as cold box light gas or PSA tail gas can provide the desired fuel gas composition.

In chemical processes for cracking hydrocarbons, reactors are subject to coking During the decoke process carburization of the metal substrate can occur, negatively impacting reactor life. Decokes are also costly due to down-time where costs are incurred without production of commercial products. Reducing the frequency of decokes provides an opportunity to reduce the financial impacts of downtimes. A start-up procedure is described herein that limits initial coke deposition, leading to a reduced tendency for carburization of the metal substrate, improving reactor life, and more importantly, extending reactor run length.

A process for selectively making hydrocracked n-paraffins from hydrocarbon compositions comprising heavy n-paraffins is disclosed. The process generally comprises the use of a hydrocracking catalyst comprising an unsulfided low acidity noble metal containing zeolite. The invention is useful for making lighter n-paraffin products for various applications, generally including upgrading hydrocarbon feedstocks to produce fuels, solvents, lubricants, chemicals and other hydrocarbonaceous compositions, and more particularly, as feedstocks for ethylene and linear alkyl benzene production and as jet and diesel fuel blend components.