A system for hydrogenation C.sub.3 and C.sub.4 acetylenes contained within a hydrocarbon stream generated in a stream cracker unit where a debutanizer is placed upstream of a depropanizer for more economical processing of the hydrocarbon stream to produce lighter hydrocarbons, where the system requires only one stripper tower downstream of hydrogenation to remove residual hydrogen.

Methods for cracking a hydrocarbon feed stream include contacting a hydrocarbon feed stream with a catalyst system in a catalytic cracking unit having a flowing gas stream to obtain a cracking product containing light olefins. The catalyst system includes at least a base catalyst. The base catalyst includes a pentasil zeolite. The pentasil zeolite includes from 0.01% to 5% by mass lithium atoms, as calculated on an oxide basis, based on the total mass of the pentasil zeolite. The flowing gas stream comprises hydrogen and, optionally, at least one additional carrier gas.

This method comprises passing a residual stream into a flash drum to form a gaseous overhead flow and liquid bottom flow, and feeding the bottom flow into a distillation column, It comprises cooling the overhead flow in a heat exchanger to form a cooled overhead flow. It comprises the extraction of a gaseous overhead stream at the head of the distillation column, and the formation of at least one effluent stream from the overhead stream and/or from the top stream. The separation of the cooled overhead flow comprises passing the cooled overhead flow into an absorber, and injecting a methane-rich stream into the absorber to place the cooled overhead flow in contact with the methane-rich stream.

A transfer line between the outlet of a steam cracker and the inlet for the quench system has metallic or ceramic inserts having a pore size from about 0.001 to about 0.5 microns inside the line forming a gas tight barrier with the inner surface of the line and having a vent for the resulting gas tight pocket are used to separate H.sub.2, CH.sub.4, CO and CO.sub.2 from cracked gases reducing the load on the down-stream separation train of the steam cracker.

The present subject matter relates generally to methods for selectively saturating the unsaturated C.sub.2-C.sub.4. More specifically, the present subject matter relates to methods for saturating butadiene and butenes from a hydrocarbon stream before it is combined with a fresh feed and enters a reaction zone. Removing the unsaturates from the hydrocarbon stream before the hydrocarbon stream enters the reaction zone prevents the reactor internals from coking.

This invention provides a fluidized catalytic cracking apparatus and process for converting a hydrocarbon feedstock containing higher concentrations of Conradson Carbon Residue (CCR), metal impurities, etc into lighter products by employing two riser reactors in which the feed impurities are removed using an adsorbent in a first riser reactor and cracking a portion of first riser reactor liquid product in a second riser reactor to lighter products using the active catalyst thus eliminating the catalyst deactivation due to metal, impurities and FCC catalyst activity dilution effect to achieve a better conversion and higher catalyst longevity.

The invention relates to mixtures comprising molecular hydrogen, hydrocarbons, and nitrogen oxides; to processes for removing at least a portion of the nitrogen oxides therefrom; to equipment useful in such processes; and to the use of such hydrocarbons for, e.g., chemical manufacturing.

A method of recovery of rich gas where the rich gas is a hydrocarbon gas comprising less than 50 mole % methane is disclosed. The method comprises the steps of gathering the low pressure gas, compressing the gathered gas, cooling the compressed gas in a condenser so that a portion of the compressed gas condenses to form a liquefied gas and liquefied gas vapour in the condenser, and discharging the liquefied gas and liquefied gas vapour from the condenser, in which the cooling of the compressed gas is performed using at least one heat exchanger (40).

In an FCC apparatus and process structured packing should be located at the very top of the stripping section in an upper region. The lower region below the structural packing may be equipped with fluidization equipment such as stripping media distributors and one or more gratings. This arrangement enables stripping of entrained hydrocarbons off the incoming catalyst immediately upon entry into the stripping section allowing the entrained hydrocarbon to exit the stripping section with minimized residence time to minimize post-riser cracking. Revamp of stripping sections with tall stripping sections should conducted in this way to improve performance and reduce down-time for equipment installation.

A process for separating a component mixture comprising essentially hydrocarbons having two or two or more carbon atoms, methane and hydrogen using a distillation apparatus (10) is proposed. Fluid (a, c, e, g, i) from the component mixture is cooled stepwise to a first pressure level, with separation of first condensates (b, d, f, h, j) out of the fluid (a, c, e, g, i) in each case. Fluid (k) from the component mixture that remains in gaseous form thereafter is expanded to a second pressure level in an expander, giving a second condensate (l). Fluid from the first condensates (b, d, f, h, j) is expanded from the first pressure level to the second pressure level and fed together with the fluid from the second condensates into the distillation apparatus (10) which is being operated at the second pressure level. The present invention likewise provides a corresponding separation apparatus.