Abstract:
An air distillation unit comprises an air distillation column (10) suitable for producing a nominal flow of gaseous nitrogen, the top of said column being connected to a liquid nitrogen source (8), and operates by carrying out the following steps: a flow of compressed, cooled and purified air is sent to an exchanger (11) and then to the column, a flow of gaseous nitrogen is withdrawn from the column, the level of liquid at the bottom of the column is controlled; and injection liquid (20), sent from the source to the column, is no longer sent if the required production reduces to at most the nominal production. Application to the separation of air by cryogenic distillation.
Abstract:
The invention relates to an air separating device by means of cryogenic distillation for producing nitrogen, comprising an exchange line (3), a simple distillation column (7) containing plates and/or structured packings, a supply line for delivery of compressed purified air (1) to the exchange line, a supply line for delivery of the compressed purified and cooled air from the exchange line to the distillation column, a line for withdrawal of a liquid (11) enriched in oxygen from the distillation column for delivery to the exchange line, said exchange line having two sections, a rectifying section (3B) and a heat exchange section (3A), the rectifying section being connected to the column and the line for the enriched liquid and the heat exchange section is connected to the air supply line and the rectifying section.
Abstract:
An air distillation unit comprises an air distillation column (10) suitable for producing a nominal flow of gaseous nitrogen, the top of said column being connected to a liquid nitrogen source (8), and operates by carrying out the following steps: a flow of compressed, cooled and purified air is sent to an exchanger (11) and then to the column, a flow of gaseous nitrogen is withdrawn from the column, the level of liquid at the bottom of the column is controlled; and injection liquid (20), sent from the source to the column, is no longer sent if the required production reduces to at most the nominal production. Application to the separation of air by cryogenic distillation.
Abstract:
In a process for delivering pressurized gas from an apparatus for separating air by cryogenic distillation, a stream of oxygen-rich liquid or gas having a nominal flow rate is withdrawn from a low-pressure column, an oxygen-rich liquid purge stream is withdrawn as bottoms from the low-pressure column and the oxygen-rich liquid purge stream is sent to a storage tank, in the event of a reduction in the production by the column system or an increase in the demand by a customer, a back-up stream is withdrawn from the storage tank and vaporized in a back-up reboiler and only if the liquid level in the storage tank exceeds a given threshold, a liquid stream is withdrawn from the storage tank constituting at most 2% of the nominal production output of the oxygen-rich stream and is sent to the back-up reboiler.
Abstract:
The invention relates to a method for treating a gas stream comprising combustion fumes containing CO2 in an initial proportion, water vapor, one or more volatile acid compounds, and one or more additional impurities selected from among oxygen, nitrogen and argon, comprising the steps of: i) compressing the gas stream to a final pressure of 1 bar to 74 bar absolute; ii) cooling the gas stream to a temperature of around −10° C. to around −130° C. and eliminating at least one additional impurity; and iii) recovering a CO2-enriched gas stream containing a final proportion of CO2 greater than the initial proportion of CO2 in the stream to be treated. In addition, the method comprises, prior to step i), a step of pre-drying the stream for removing therefrom at least a portion of the water vapor which it contains.
Abstract:
The invention relates to a method for compressing and cooling air upstream from a facility for cryogenic separation of air, with no means for exchange by indirect heat, in which humid air is compressed in a compressor, the air compressed in the compressor is cooled in a first exchanger having indirect heat exchange, water is recovered from the air upstream and/or downstream from cooling in the first exchanger, the air cooled in the first exchanger is sent to a purification unit in order to produce air purified of carbon dioxide and/or water, the purified air is sent to the cryogenic separation facility, and at least one gas is recovered from the cryogenic separation facility.