摘要:
The invention relates to a method for producing at least one gas lean in CO 2 and one or more primary fluids rich in CO 2 from a fluid to be processed that contains CO 2 and at least one compound more volatile than CO 2 , implementing: a) a first cooling of the fluid to be processed by heat exchange without state modification; b) a second cooling of a at least a portion of the fluid to be processed cooled during step a) in order to obtain at least one solid mainly containing CO 2 and at least one gas lean in CO 2 ; and c) a step including the liquefaction and/or sublimation of at least a portion of said solid in order to obtain said one or more CO 2 -rich primary fluids; wherein the method is characterised in that step b) is carried out in at least one expansion turbine, the solid being formed inside said turbine.
摘要:
The method of the invention recovers CO2 from an inlet cold feed stream containing a low concentration thereof, and includes the following steps. An inlet feed stream is passed through a heat exchanger, against a compressed flow of the inlet feed stream, to cool the compressed flow. The compressed flow is further cooled and compressed to a high pressure, fed to a distillation column and there converted into a vent gas including CO2 and a high purity bottom liquid CO2. A first portion of the bottom liquid CO2 is expanded to achieve a first cooled liquid CO2 refrigerant flow, which is then vaporized against the vent gas to recover condensed CO2 therefrom. The condensed CO2 is then reintroduced into the distillation column. A second portion of the bottom liquid CO2 is expanded to achieve a second cooled liquid CO2 refrigerant flow, which is then used to subcool the CO2 product output.
摘要:
The present invention relates to a process for removing essentially all carbon dioxide and acid gases, e.g., sulfur dioxide, from the flue gas of a fossil fuel combustion power plant in which the fossil fuel (3) is completely combusted with oxygen (1) in a boiler/furnace (5). The flue gas (7) from the boiler/furnace (5) is cooled (23), compressed (33) and dried (35) to produce a compressed, water-free, flue gas (41). This compressed, water-free, flue gas (41) is cooled (43) and introduced to a first distillation column (51), thereby producing an overhead (53) rich in light components, i.e., oxygen, nitrogen, and argon, and essentially free of acid gases and a bottoms vapor (75) containing the bulk of the carbon dioxide and essentially all of the acid gases. The overhead (53) is cooled (55) to condense the condensibles and phase separated (57). A portion (59) of the liquid portion is returned to the top of the first distillation column (51) as reflux; the vapor is expanded (68) and warmed (43) to recover refrigeration. The bottoms vapor stream (75) is then introduced to a second distillation column (77) for distillation into an essentially pure carbon dioxide overhead (81) and an essentially pure acid gas liquid bottoms (91).
摘要:
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.
摘要:
Impurities that are less volatile than carbon dioxide, e.g. hydrogen sulfide, are removed from crude carbon dioxide by processes involving distillation of said crude carbon dioxide in a distillation column system operating at super-atmospheric pressure(s) to produce carbon dioxide-enriched overhead vapor and bottoms liquid enriched with said impurities. Where such processes involve a single heat pump cycle, significant savings in power consumption are realized when the distillation column system is re-boiled by at least partially vaporizing liquid in or taken from an intermediate location in the column system.
摘要:
In a process for separating "heavy" impurities such as hydrogen sulfide from crude carbon dioxide comprising significant quantities of "light" impurities such as non-condensable gases, involving at least one heat pump cycle using as working fluid a fluid from the "heavy" impurity separation, the "light" impurities are removed from carbon dioxide-enriched gas generated in the "heavy" impurity separation. The carbon dioxide-enriched gas, or a compressed carbon dioxide-enriched gas produced therefrom, is at least partially condensed by indirect heat exchange against intermediate liquid also generated in the "heavy" impurity separation. Total and specific energy consumption is reduced compared to conventional processes in which "light" impurities are removed from carbon dioxide product gas.
摘要:
The present disclosure relates to a method of operating a boiler system (27) comprising an oxy-fuel boiler (7) in which an oxygen stream (6) and a fuel stream (2) are combusted to generate a flue gas stream (8), an air separation unit (4) producing the oxygen stream (6) for the oxy-fuel boiler (7), and a gas processing unit (25) for cleaning and compressing at least a portion of the flue gas stream (6) generated in the oxy-fuel boiler (7) producing a pressurized carbon dioxide stream (18), the method comprising: operating the boiler system (27), at least for a period of time, in a recirculation mode, during which a carbon dioxide stream (20) from a CO 2 compression unit (17) within the gas processing unit (25) is evaporated in the air separation unit (4) and forwarded as a stream (24) to the gas processing unit (25). The present disclosure further relates to a boiler system for an oxy-fuel process as well as to a power plant comprising such a system. The present disclosure also relates to the use of a carbon dioxide containing stream as a refrigerant.
摘要:
The present disclosure relates to a method of operating a boiler system (1) comprising an oxyfuel boiler (4) in which an oxygen stream and a fuel stream are combusted to generate a stream of flue gas, an oxygen gas source (26) producing the stream of oxygen for the boiler, and a gas processing unit (45) for cleaning and compressing at least a portion of the stream of flue gas generated in the boiler for producing a stream of pressurized fluid comprising carbon dioxide, the method comprising: operating the boiler system (1), at least for a period of time, in an evaporation mode, in which a stream of oxygen from the oxygen gas source (26) in liquid form is evaporated prior to being introduced in the boiler (4) by transferring heat energy to the stream of liquid oxygen from a first stream of carbon dioxide of the gas processing unit (45). The present disclosure further relates to a boiler system for an oxy-fuel process as well as to a power plant comprising such a system.