Abstract:
A process for recovering carbon dioxide from a pressurized hydrocarbon containing feed stream includes the following steps. A high pressure hydrocarbon containing feed stream that comprises at least methane and carbon dioxide is introduced into a first membrane separation unit at a temperature that is above the liquefaction temperature of carbon dioxide, the first membrane separation unit containing one or more membranes that are selective for carbon dioxide over the other components in the hydrocarbon containing feed stream, each membrane having a permeate side and a residue side and allowing for the passing of carbon dioxide to the permeate side to form a first membrane stream on the permeate side of the membrane and the substantial retention of the remaining components in the hydrocarbon containing feed stream to form a second membrane stream on the residue side of the membrane. The second membrane stream is withdrawn for further use. The first membrane stream is compressed. The compressed first membrane stream is cooled using a multi-stream heat exchanger in order to form a compressed, cooled two phase first membrane stream. The compressed, cooled, two phase first membrane stream is separated and purified in a carbon dioxide separation unit to produce a carbon dioxide rich liquid stream and a carbon dioxide lean vapor stream. The carbon dioxide rich liquid stream is recycled to the heat exchanger where the carbon dioxide rich stream is used to provide cooling of the first membrane stream thereby producing a warmer carbon dioxide rich liquid stream. The warmer carbon dioxide rich stream is recovered from the heat exchanger as a high purity carbon dioxide product.
Abstract:
A gas mixture comprising carbon dioxide, at least one gas having a lower boiling point than carbon dioxide, and at least one gaseous impurity having a higher boiling point than carbon dioxide (the impurity typically being hydrogen sulphide) is purified by a rectification process. The gas mixture (typically with a carbon dioxide partial pressure of 20 atmospheres) is precooled to the dewpoint of the carbon dioxide or below and is then rectified to form a liquid fraction relatively rich in the impurity or impurities and a product gaseous fraction relatively lean in or free from the gaseous impurity or impurities. The liquid fraction may be subjected to a second rectification to yield pure carbon dioxide.
Abstract:
The invention provides a process for the separation of a contaminant or mixture of contaminants from a CH 4 - comprising gaseous feed stream, comprising the subsequent steps of: a) passing a CH 4 -comprising gaseous feed stream comprising the contaminant or the mixture of contaminants into and through a cold porous body having a temperature below the sublimation temperature of the contaminant or the mixture of contaminants and contacting the CH 4 - comprising gaseous feed stream at elevated pressure with the surface of the cold porous body to obtain a porous body comprising solid contaminant or mixture of contaminants and a contaminant-depleted product gas; and b) reducing the pressure to obtain fluid contaminant or mixture of contaminants and a cold porous body. c) removing the fluid contaminant or mixture of contaminants, wherein the contaminant is selected from CO 2 , hydrogen sulphide, mercaptans, siloxanes and carbonyl sulphide, or a mixture thereof.
Abstract:
The invention provides a method of removing solid carbon dioxide from cryogenic equipment, comprising the steps of: (a) introducing a stream including ethane to said cryogenic equipment to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and carbon dioxide from the cryogenic equipment. In particular, the method can be used in a liquefied natural gas (LNG) plant wherein cryogenic equipment contains LNG, and the method comprises the steps of: (a') removing the LNG from the said cryogenic equipment; (a) introducing a stream including ethane to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. The result is an effective cleaning method for fouled LNG equipment.
Abstract:
Methods and apparatus for desalination of salt water (and purification of polluted water) are disclosed. Saline (or otherwise polluted) water is pumped to a desalination installation and down to the base of a desalination fractionation column, where it is mixed with hydrate-forming gas or liquid to form either positively buoyant (also assisted buoyancy) or negatively buoyant hydrate. The hydrate rises or sinks or is carried into a lower pressure area and dissociates (melts) into the gas and pure water. In preferred embodiments, residual salt water which is heated by heat given off during formation of the hydrate is removed from the system to create a bias towards overall cooling as the hydrate dissociates endothermically at shallower depths, and input water is passed through regions of dissociation in heat-exchanging relationship therewith so as to be cooled sufficiently for hydrate to form at pressure-depth. The fresh water produced by the system is cold enough that it can be used to provide refrigeration, air conditioning, or other cooling; heat removed from the system with the heated residual water can be used for heating or other applications. In other embodiments, desalination or other purification is carried out in "artificially" or mechanically pressurized vessels, which embodiments may be comparatively mobile. Such pressurized systems can be used to capture carbon dioxide from industrial waste gases and to provide liquid carbon dioxide.
Abstract:
Dans un procédé de compression d'un fluide riche en CO 2 contenant de l'eau dans lequel le fluide riche en CO 2 est comprimé dans un compresseur (5), en amont de l'étape de compression, un agent anti-gel est injecté dans le fluide riche en CO 2 contenant de l'eau afin de baisser la température de solidification de l'eau, le fluide riche en CO 2 contenant l'agent anti-gel est refroidi, de l'eau est extraite du fl u ide refroid i et le flu ide refroid i est comprimé dans le compresseur.
Abstract:
A method of separating light component(s), such as helium, from carbon dioxide. A pressurized feed stream (10) is at least partially condensed. The resulting containing light component(s) and carbon dioxide stream (14) is degassed to produce a first vapor stream (22) enriched in the light component(s) and a first liquid stream (20) having entrained light component(s). The first liquid stream (20) is expanded (26) to create another two-phase stream (28) that is degasified to produce a second vapor stream, (36) enriched in the light component(s), and a second liquid stream (38) enriched in carbon dioxide. The second liquid stream (38) is repressurized and vaporized. In case of a supercritical feed (90), the pressurized feed stream (90) is expanded (94) after having been cooled. Thereafter, the feed (98) is degassed to produce the light component enriched vapor stream (102) and a liquid stream enriched in the carbon dioxide (104). The resultant vapor streams, enriched in the light component(s) may be further processed to isolate the light components.
Abstract:
Es wird eine Anlageneinheit zur Desorption von Kohlendioxid und anderen Verunreinigungen aus unter erhöhtem Druck stehendem Methanol beschrieben, wobei die Anlageneinheit mindestens einen oder mehrere, hintereinander angeordnete Entspannungsbehälter, mindestens einen Wärmeaustauscher und mindestens einen Flüssig/Gasabscheider aufweist. Diese Anlageneinheit enthält a) eine Leitung (1), durch die das den Entspannungsbehälter C verlassende, stark abgekühlte Methanol von unten in den Wärmetaustauscher E eingeleitet wird; und b) eine Leitung (2), durch die das erwärmte Methanol oben aus dem Wärmeaustauscher E herausgeführt wird und ihn mit einem Flüssig/Gas-Abscheider verbindet, in dem das restliche, noch im Methanol enthaltene Kohlendioxid weitestgehend desorbiert und abgetrennt wird. Durch diese Anlageneinheit wird die bei der Desorption von Kohlendioxid entstehende Verdunstungskälte in einem Wärmeaustauscher gewonnen und steht dann als wichtige Kälteenergiequelle für für die Absorption zur Verfügung.
Abstract:
Separation of carbon dioxide and hydrogen sulfide in a distillation column 14 is improved by adding a component to increase the relative volatility of carbon dioxide to hydrogen sulfide. Increasing the relative volatility facilitates the separation. The additional component comprises for example a C3-C6 alkane, SO2 or SO3.
Abstract:
A method of separating light component(s), such as helium, from carbon dioxide. A pressurized feed stream (10) is at least partially condensed. The resulting containing light component(s) and carbon dioxide stream (14) is degassed to produce a first vapor stream (22) enriched in the light component(s) and a first liquid stream (20) having entrained light component(s). The first liquid stream (20) is expanded (26) to create another two-phase stream (28) that is degasified to produce a second vapor stream, (36) enriched in the light component(s), and a second liquid stream (38) enriched in carbon dioxide. The second liquid stream (38) is repressurized and vaporized. In case of a supercritical feed (90), the pressurized feed stream (90) is expanded (94) after having been cooled. Thereafter, the feed (98) is degassed to produce the light component enriched vapor stream (102) and a liquid stream enriched in the carbon dioxide (104). The resultant vapor streams, enriched in the light component(s) may be further processed to isolate the light components.