Abstract: The xylene isomerization process unit and the transalkylation process units are combined in the present invention. A fractionation column can be shared by the two units, reducing the capital cost of the complex. In some embodiments, a split shell fractionation column and a split separator can be used.

Abstract: The present invention features a center feed system in combination with a coking vessel of a delayed coking system, or any other similar system. The center feed system features an inlet sleeve which slidably engages a retractable nozzle, with inlet and outlet, in fluid connection with a feed source of residual byproduct, allowing residual byproduct to flow from the feed source into the interior of the vessel, thus effectuating or inducing even thermal distribution throughout the vessel. The retractable nozzle is structured to extend through an opening in the coking vessel while introducing the residual byproduct into the coking vessel and retract out of the coking vessel and cover the opening for at least a portion of a coking cycle.

Abstract: A process and apparatus for producing solid petroleum coke. The solid petroleum coke product is formed in a coking drum which has a rotatable coke breaking structure installed therein. Quench water or other quench fluid is delivered into the coking drum to quench the coke product and the coke breaking structure is rotated to break up the coke product such that the coke will empty out of the lower end of the coking drum.

Abstract: A process and apparatus for cracking a hydrocarbon feed in a steam cracking furnace by withdrawing a resid-rich stream from a resid knockout vessel and recycling the resid-rich stream through a convection heating section of the furnace.

Abstract: A control system for performing a global-decoke of a tube furnace comprising a plurality of passes.

Abstract: A technique of preparing oil from waste plastics, especially the one to which a mechanism of an extrusion molding machine is applied, is provided wherein an effective control of a decomposition process is conducted in order to effectively prevent the generation of carbon and to efficiently obtain recovered products having a desired composition. For this purpose, reactors 1a, 1b, and 1c having built in carrying means 3a, 3b, and 3c, respectively are used as connected in stages, in which reactors waste plastics are heated and decomposed into oil as carried. One or a series of reactors are used as a unit to form a melting zone and a decomposing zone in the carrying direction.

Abstract: A reaction tube system of a steam reformer, more generally referred to as tubular cracking furnace, for the indirect heating of cracking feedstock, such as the catalytic cracking of hydrocarbons, includes a plurality of reaction tubes and headers, the reaction tubes penetrating through the bottom of the steam reformer and being extended to the associated header by low-alloy tube sections attached to the tubes by circumferential welds. The reaction tubes are surrounded in the area of the weld(s) by a coaxial protective tube having one open end and defining a free annular space around the reaction tube. The protective tube prevents deterioration by corrosion of the weld(s) joining the tube sections of high-alloy steel with low-alloy extension sections with unalloyed steel extension section.

Abstract: Hydrocarbons are preheated, particularly for a hydrodesulfurization process by first heating the hydrocarbon stream to produce a vapor and a liquid stream, thereafter superheating at least some of the vapor phase and mixing the superheated vapor phase with the liquid phase to generate the hydrocarbon feedstream at the desired temperature. By this procedure only the evaporated hydrocarbons are subjected to a high temperature, but not the heavier hydrocarbons.

Abstract: An improved, multiple-well screen structure is provided which is especially adapted for use in a large scale reactor employed in oil shale processing operations. The screen includes a plurality of adjacent, juxtaposed concavities each presenting perforate sidewalls and a lower outlet opening. Preferably, the screen is circular in plan configuration and includes three sector-shaped (in plan) concavities respectively formed from cone sections. The sections are interconnected along arcuate, reinforced juncture lines to present a structurally sound material supporting, gas-pervious screen which can be easily and completely emptied using only gravity-induced material flow.

Abstract: Petroleum coke slumping in a petroleum coking drum is reduced by the use of a petroleum coking drum comprising a) a generally cylindrical vessel having a principal diameter portion, an upper reduced diameter portion at an upper end of the vessel, an upper reducing diameter portion extending from a lower end of the upper reduced diameter portion to an upper end of the principal diameter portion, a lower reduced diameter portion at a lower end of the vessel and a lower reducing diameter portion extending from an upper end of the lower reduced diameter portion to a lower end of the principal diameter portion; b) a top head removably positionable to close the upper reduced diameter portion; c) a bottom head removably positionable to close the lower reduced diameter portion; and d) a plurality of restraining bars positioned around an inner circumference of the lower reduced diameter portion.