The present disclosure provides a distillation tower for separating a feed stream. The distillation tower includes a controlled freeze zone section having a controlled freeze zone upper section and a controlled freeze zone lower section below the controlled freeze zone upper section. The controlled freeze zone section includes: (a) a spray assembly in the controlled freeze zone upper section; (b) a melt tray assembly in the controlled freeze zone lower section; (c) a feed stream distribution mechanism between the spray assembly and the melt tray assembly. The feed stream distribution mechanism is constructed and arranged to uniformly distribute the feed stream in the controlled freeze zone section.

A process for removing a foulant from a gas stream is disclosed. The gas stream, containing a foulant, is cooled across a first heat exchanger and a second heat exchanger, producing a solid foulant entrained in cryogenic liquid as a foulant slurry, and a foulant-depleted gas stream. The foulant-depleted gas stream is passed through a cryogenic turbine and a first separation vessel, producing a light gas stream and further solid foulant. The solid foulants are recovered by a combination of pressurization, melting, and distillation to produce a liquid foulant product. Heat is recovered from the various streams in the various heat exchangers and the melter.

An apparatus is disclosed for maintaining constant fluid pressure and equalized fluid flow among a plurality of downcomer lines through which liquid from a tower is directed. A substantially annular fluid distribution belt is disposed at the circumference of the tower. The fluid distribution belt collects liquid from the tower. At least two outlets direct liquid from the fluid distribution belt out of the tower and into a corresponding number of downcomer lines disposed external to the tower.

Embodiments described herein provide methods and systems for separating a mixed ethane and CO.sub.2. A method described includes generating a liquid stream including ethane and CO.sub.2. The liquid stream is flashed to form an ethane vapor stream and solid CO.sub.2. The solid CO.sub.2 is accumulated in an accumulation vessel and the gas is removed from the top of the accumulation vessel.

A method and device are disclosed herein for distributing a gas into a vessel. The method comprises providing a gas distribution apparatus, wherein an exposed surface of the apparatus comprises a material that inhibits adsorption of the gas and deposition of the gas' solid form. The material chosen is chemically repulsive to the gas and the gas' solid form. In this manner, desublimation of the gas and deposition of the gas' solid form onto the exposed surface is prevented. The device disclosed herein is the gas distribution apparatus referenced above.

The disclosure includes techniques associated with a collector tray assembly for a cryogenic distillation tower disposed below a slurry mix zone and above a lower distillation zone, wherein the collector tray assembly comprises a deck at a lower end of the slurry mix zone, and wherein the deck comprises at least one vapor riser configured to pass the vapor from the lower distillation zone into the slurry mix zone, wherein the vapor riser comprises a substantially vertical heat transfer section configured to pass the vapor substantially upwards through the slurry mix zone, and a vapor outlet section comprising at least one vapor outlet, wherein the vapor outlet section is below the heat transfer section.

Embodiments described herein provide methods and systems for separating a mixed ethane and CO.sub.2. A method described includes generating a liquid stream including ethane and CO.sub.2. The liquid stream is flashed to form an ethane vapor stream and solid CO.sub.2. The solid CO.sub.2 is accumulated in an accumulation vessel and the gas is removed from the top of the accumulation vessel.

In a method for cooling a flow containing at least 35% carbon dioxide and at least 0.2 ?g/Nm.sup.3 of mercury, the mercury being in liquid and/or gas form, the flow is cooled in a first brazed aluminum plate-fin heat exchanger from a first temperature to a second temperature higher than ?38.6? C. to form a cold flow at the second temperature, and the flow cooled to the second temperature is cooled in a second heat exchanger, which is a tube and shell heat exchanger, to a third temperature lower than ?38.6? C.

The present disclosure provides a method for separating a feed stream in a distillation tower which includes separating a feed stream in a stripper section into an enriched contaminant bottom liquid stream and a freezing zone vapor stream; contacting the freezing zone vapor stream in the controlled freeze zone section with a freezing zone liquid stream at a temperature and pressure at which a solid and a hydrocarbon-enriched vapor stream form; directly applying heat to a controlled freeze zone wall of the controlled freeze zone section with a heating mechanism coupled to at least one of a controlled freeze zone internal surface of the controlled freeze zone wall and a controlled freeze zone external surface of the controlled freeze zone wall; and at least one of destabilizing and preventing adhesion of the solid to the controlled freeze zone wall with the heating mechanism.

The present disclosure provides a method for preventing accumulation of solids in a distillation tower. The method includes introducing a feed stream into a controlled freeze zone section of a distillation tower; forming solids in the controlled freeze zone section from the feed stream; discontinuously injecting a first freeze-inhibitor solution into the controlled freeze zone section toward a location in the controlled freeze zone section that accumulates the solids; and destabilizing accumulation of the solids from the location with the first freeze-inhibitor solution.