Abstract: A method for preparing a homogeneous blend of asphalt and ground tire rubber. An asphalt base material is heated to a temperature sufficient to permit the stirring of the asphalt base material within a mixing vessel. A particulate crumb rubber component having a designated average particle size is added to the asphalt base material. The crumb rubber material can be partially devulcanized or partially depolymerized and may be accompanied by the incorporation of another rubber component, such as a ground styrene butadiene rubber. Zinc oxide is added to the asphalt base material. The mixture incorporating the zinc oxide is stirred for a period sufficient to provide for substantial solubilization of the crumb rubber within the asphalt base material to provide a blend which has a higher homogeneity than a corresponding blend of the same asphalt and particulate rubber components which is heated and stirred under the identical conditions, but without the addition of the zinc oxide.

Abstract: Methods and systems for diesel formation are described herein. The diesel hydrotreating systems generally include a hydrodesulfurization unit having a catalyst system disposed therein and adapted to contact an input stream with the catalyst system therein to form diesel. The catalyst system generally includes a plurality of catalysts including a first catalyst including a hydrodesulfurization catalyst having a first pore diameter and a second catalyst having a second pore diameter, wherein the second pore diameter is larger than the first pore diameter.

Abstract: Hydrocarbon streams are heated uniformly and directly using one or more flameless oxidation burners. Flameless oxidation burners may control the temperature within a range of about 50° C. to reduce the tendency to coking due to localized “hot spots”. The hydrocarbon streams, which may be monomer streams, may pass cross-current (perpendicular) to burners having a longitudinal design or configuration, or may pass parallel to such burners.

Abstract: A process for the production of ethylbenzene by the ethylation of benzene in the critical phase over a molecular sieve aromatic alkylation catalyst. An aromatic feedstock having a benzene content of at least 90 wt. % is supplied into a reaction zone into contact with a zeolite beta alkylation catalyst having a silica/alumina ratio within the range of 20-500, specifically 50-150. The alkylation catalyst is a zeolite beta specifically a lanthanum-modified zeolite beta. Ethylene is supplied to the reaction zone to provide a benzene/ethylene mole ratio of 1-15. The reaction zone is operated under conditions in which benzene is in the supercritical phase to produce an alkylation product containing ethylbenzene as a primary product with heavier alkylated by-products of no more than 60 wt. % of the ethylbenzene. The alkylation product is recovered from the reaction zone and supplied to a separation and recovery zone to separate ethylbenzene from a polyalkylated component including diethylbenzene.

Abstract: A process for the regeneration of a deactivated zeolite beta catalyst such as rare earth promoted zeolite beta catalyst deactivated in the course of an aromatic alkylation reaction. A zeolite beta conversion catalyst deactivated with the deposition of coke is heated to a temperature in excess of 300° C. in an oxygen-free environment. An oxidative regeneration gas is supplied to the catalyst bed with oxidation of a portion of a relatively porous coke component to produce an exotherm moving through the catalyst bed. At least one of the temperature and oxygen content of the gas is progressively increased to oxidize a porous component of the coke. Regeneration gas is supplied having at least one of an increased oxygen content or increased temperature to oxidize a less porous refractory component of the coke. The regeneration process is completed by passing an inert gas through the catalyst bed at a reduced temperature.

Abstract: Methods of forming ethylbenzene are described herein. In one embodiment, the method includes contacting dilute ethylene with benzene in the presence of an alkylation catalyst to form ethylbenzene, wherein such contact occurs in a liquid phase reaction zone and recovering ethylbenzene from the reaction zone.

Abstract: The present invention provides a method for preparing an asphalt and thermoplastic elastomer composition. The process comprises heating an asphalt cut in a stirred tank to a temperature sufficient to allow the stirring of the asphalt in the tank. A thermoplastic elastomer or rubber is added to the asphalt while continuing to stir the asphalt. The mixture is stirred at a speed and for a period of time sufficient to increase the distribution of the elastomer into the asphalt. The stirring speed is reduced and the temperature is increased to add crosslinking agents to the tank. Stirring is continued for a period of time sufficient to improve the distribution of the crosslinking agent dispersion in the asphalt. Crosslinking agents include compositions of mercaptobenzothiazole, zinc oxide and elemental sulfur; compositions of mercaptobenzothiazole, zinc oxide, and mixed polythiomorpholine; and compositions of zinc 2-mercaptobenzothiazole and dithiodimorpholine.

Abstract: A process for the dehydrogenation of a C2 or C3 alkyl aromatic compound to a corresponding vinyl aromatic compound in a tubular reactor incorporating a spiral flow path. Preferred embodiments of the invention provide processes for the production of styrene or divinylbenzene by the catalytic dehydrogenation of ethylbenzene or diethylbenzene, respectively. A feedstock containing a C2 or C3 alkyl aromatic and steam is supplied into the inlet of a tubular reactor containing a dehydrogenation catalyst and comprising a hydrogen permeable outer wall. The alkyl aromatic compound is dehydrogenated to a corresponding vinyl aromatic compound with the attendant production of hydrogen. The feedstock and products of the dehydrogenation reactor are flowed along a longitudinal spiral flow path providing for an outward radial flow of hydrogen to provide a pressure gradient through the hydrogen permeable outer wall of the reactor with the flow of hydrogen therethrough. Hydrogen is removed from the outer wall of the reactor.

Abstract: A process and system for the vapor phase alkylation of an aromatic substrate in a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds spaced from one another to provide mixing zones between adjacent catalyst beds. A feedstock containing an aromatic substrate and a C2–C4 alkylating agent is supplied to an inlet side of the reaction zone. The reaction zone is operated at conditions in which the aromatic substrate is in the gas phase and causing vapor phase alkylation of the aromatic substrate as the aromatic substrate and the alkylating agent flow through the reaction zone and pass from one catalyst bed to the next. A quench fluid comprising one or both of the aromatic substrate and the alkylating agent is supplied into the interior of the mixing zone through a plurality of flow paths in which one portion of the flow paths is directed upwardly within the mixing zone and another portion downwardly within the mixing zone.

Abstract: A process for the regeneration of a deactivated zeolite beta catalyst such as rare earth promoted zeolite beta catalyst deactivated in the course of an aromatic alkylation reaction. A zeolite beta conversion catalyst deactivated with the deposition of coke is heated to a temperature in excess of 300° C. in an oxygen-free environment. An oxidative regeneration gas is supplied to the catalyst bed with oxidation of a portion of a relatively porous coke component to produce an exotherm moving through the catalyst bed. At least one of the temperature and oxygen content of the gas is progressively increased to oxidize a porous component of the coke. Regeneration gas is supplied having at least one of an increased oxygen content or increased temperature to oxidize a less porous refractory component of the coke. The regeneration process is completed by passing an inert gas through the catalyst bed at a reduced temperature.

Abstract: It has been discovered that a synthetic flux oil can contain and deliver asphaltites, such as gilsonite, more easily and readily to an asphalt to improve its properties. The synthetic flux oil includes the asphaltite and a carrier oil. Depending on the nature of the carrier oil, the synthetic flux oil may or may not need to be heated during mixing and incorporation into the asphalt.

Abstract: It has been discovered that certain nitrogen-containing thiols other than mercaptobenzothiazole (MBT) perform equivalently as accelerators in preparing asphalt polymer compositions. Typically, the crosslinker in these compositions is sulfur. Nitrogen-containing thiols containing at least one functional group —N?(SH)— have been found to be useful alternate accelerators along with activators such as zinc oxides. Particular nitrogen-containing thiols include, but are not necessarily limited to, 2-mercaptobenzoxazole (MBO), 2-mercapto-5-methyl-1,3,4-thiadiazole (MMTD), and combinations thereof.

Abstract: Disclosed is a method for extending the life of dehydrogenation catalysts used to prepare vinyl aromatic hydrocarbons. The catalysts, which typically include both iron oxide and potassium containing catalysis promoter, are exposed to additional potassium delivered using a potassium carboxylate. The potassium carboxylates are desirably free of halogens and other catalysts poisons or groups that could result in the undesirable properties in vinyl aromatic hydrocarbons produced therewith. The present invention is particularly useful with the production of styrene and methyl styrene.

Abstract: A process for the production of ethylbenzene by the ethylation of benzene in the critical phase over a molecular sieve aromatic alkylation catalyst comprising cerium-promoted zeolite beta. An aromatic feedstock having a benzene content of at least 90 wt. % is supplied into a reaction zone and into contact with the cerium-promoted zeolite beta having a silica/alumina mole ratio within the range of 50-150 and a cerium-aluminum ratio of 0.5-1.5. Ethylene is supplied to the alkylation reaction zone in an amount to provide a benzene/ethylene mole ratio of 1-15. The reaction zone is operated at temperature and pressure conditions in which benzene is in the super critical phase to cause ethylation of the benzene in the presence of the cerium zeolite beta alkylation catalyst. An alkylation product is produced containing ethylbenzene as a primary product with the attendant production of heavier alkylated by-products of no more than 60 wt. % of the ethylbenzene.

Abstract: The present invention provides a dispersing agent that facilitates the delivery of a cross-linking agent to polymer modified asphalt. The present invention further includes a composition comprising a liquid hydrocarbon, the dispersant and cross-linking agent, and methods of preparing the composition and of preparing cross-linked polymer modified asphalt composition.

Abstract: A process for the transalkylation of polyalkylated aromatic compounds over a high porosity zeolite-Y molecular sieve having a surface area of no more than 500 m2/g. A feedstock comprising a polyalkylated aromatic component, including polyalkylbenzenes in which the predominant alkyl substituents contain from 2 to 4 carbon atoms, is supplied to a transalkylation reaction zone containing the high porosity zeolite-Y catalyst. Benzene is also supplied to the transalkylation zone, and the reaction zone is operated under temperature and pressure conditions to maintain the polyalkylated aromatic component in the liquid phase and which are effective to cause disproportionation of the polyalkylated aromatic component to arrive a disproportionation product having a reduced polyalkylbenzene content and an enhanced monoalkylbenzene content.

Abstract: The alkylation of benzene-containing feedstock over a zeolite beta alkylation catalyst which is formulated with a silica binder and has an average regeneration coefficient of at least 95% for at least three regenerations. The alkylation reaction is carried out in the liquid phase or supercritical region with a C2-C4 alkylating agent, specifically ethylene. The catalyst exhibits a regeneration coefficient of at least 95% after ethylation of the benzene with ethylene at a benzene/ethylene mole ratio of less than 10. The ethylation of benzene occurs at an initial designated primary activity. The operation of the reaction zone is continued until the activity of the catalyst for the ethylation of benzene decreases by a value of at least 0.1% and not more 1% from the initial designated primary activity.

Abstract: A method is provided for conversion of heavy alkylaromatic compounds, particularly those in the C8-C12 range, into more valuable aromatics of benzene, toluene and xylene utilizing a toluene disproportionation unit containing a nickel, palladium or platinum-modified mordenite catalyst. The method allows large amounts of these heavy alkylaromatic compounds to be processed without adversely affecting catalyst activity or catalyst life. This is accomplished by introducing the heavy alkylaromatic compounds into the reactor at constant reaction severity conditions and maintaining those conditions during conversion.

Abstract: The present invention provides a dispersing agent that facilitates the delivery of a cross-linking agent to polymer modified asphalt. The present invention further includes a composition comprising a liquid hydrocarbon, the dispersant and cross-linking agent, and methods of preparing the composition and of preparing cross-linked polymer modified asphalt composition.