A method and device to produce oxygen by the low-temperature separation of air at variable energy consumption. A distillation column system comprises a high-pressure column, a low-pressure column and a main condenser, a secondary condenser and a supplementary condenser. Gaseous nitrogen from the high-pressure column is liquefied in the main condenser in indirect heat exchange with an intermediate liquid from the low-pressure column. A first liquid oxygen stream from the bottom of the low-pressure column is evaporated in the secondary condenser in indirect heat exchange with feed air to obtain a gaseous oxygen product. The supplementary condenser serves as a bottom heating device for the low-pressure column and is heated by means of a first nitrogen stream from the distillation column system, which nitrogen stream was compressed previously in a cold compressor.

A cryogenic method for capturing carbon dioxide in the gaseous emissions produced from the fossil-energy combustion of solid, liquid, or gaseous fossil fuels in a power generation installation employing an OxyFuel mode of combustion. The method includes: producing essentially pure carbon dioxide under elevated pressure and at near ambient temperatures in a Carbon-Dioxide Capture Component from the carbon-dioxide content of at least a part of the gaseous emissions produced from fossil-energy fueled combustion in the Oxyfuel mode of combustion; separating atmospheric air in an Air Separation Component into a stream of liquid nitrogen and a stream of high-purity oxygen; supplying low temperature, compressed purified air to a cryogenic air separation unit (cold box) within the Air Separation Component; collecting low temperature thermal energy from coolers employed within the Carbon-Dioxide Capture Component and the Air Separation Component; and converting the collected thermal energy to electricity within a Thermal-Energy Conversion Component.

A method and plant for the cryogenic separation of air, the plant having an air compressor, a heat exchanger and a distillation column system having a low-pressure column at a first pressure and a high-pressure column at a second pressure. Feed air is compressed in the air compressor to a third pressure at least 2 bar above the second pressure A first fraction of compressed feed air is cooled in the heat exchanger and expanded in a first expansion turbine. A second fraction is cooled in the heat exchanger and expanded in a second expansion turbine A third fraction is compressed to a fourth pressure, cooled in the heat exchanger and then expanded. The third fraction is compressed to the fourth pressure in sequence in a recompressor, a hot first turbine booster and a second turbine booster. A dense fluid expander is used to expand the third fraction.

A compressed air stream is cooled in an exchanger to form a compressed cooled air stream. The stream is then cryogenically compressed in a first compressor to form a first pressurized gas stream. The first pressurized gas stream is further cooled in the exchanger, cryogenically compressed in a second compressor, and then it is cooled and partially liquefied. The cooled and partially liquefied product is then fed to a system of distillation columns. A liquid product is removed from the system of distillation columns. This product is then pressurized, vaporized and warmed in the exchanger to yield pressurized gaseous product.

The invention relates to a method and device for obtaining compressed oxygen and compressed nitrogen by the low-temperature separation of air in a distillation column system for nitrogen-oxygen separation, said distillation column system having at least one high-pressure column (8) and one low-pressure column (460), wherein the low-pressure column (460) is in a heat-exchanging connection with the high-pressure column (8) by means of a main condenser (461) designed as a condenser-evaporator. Feed air is compressed in an air compressor (2). The compressed feed air (6, 734, 802, 840) is cooled down in a main heat exchanger (20) and at least partially introduced into the high-pressure column (8). An oxygen-enriched liquid (462, 465) is removed from the high-pressure column (8) and fed to the low-pressure column (460) at a first intermediate position (464, 467, 906). A nitrogen-enriched liquid (468, 470) is removed from the high-pressure column (8) and/or the main condenser (461) and fed to the head of the low-pressure column (460). A liquid oxygen flow (11, 12) is removed from the distillation column system for nitrogen-oxygen separation, brought to an elevated pressure in the liquid state (13), introduced into the main heat exchanger (20) at said elevated pressure, evaporated or pseudo-evaporated and heated to approximately ambient temperature in the main heat exchanger (20), and finally obtained as a gaseous compressed oxygen product (14). A high-pressure process flow (34, 734) is brought into indirect heat exchange with the oxygen flow in the main heat exchanger (20) and then depressurized (36, 38; 736, 738), wherein the depressurized high-pressure flow (37, 737) is introduced at least partially in the liquid state into the distillation column system for nitrogen-oxygen separation. A gaseous circuit nitrogen flow (18, 19) is drawn from the high-pressure column and at least partially (21) compressed in a circuit compressor (22). A first sub-flow (45, 46; 244, 242, 230; 845, 846) of the circuit nitrogen flow is removed from the circuit compressor (22, 322), cooled down in the main heat exchanger (20), at least partially condensed in the bottom evaporator (9, 209) of the high-pressure column (8) in indirect heat exchange with the bottom liquid of the high-pressure column (8), and conducted back into the distillation column system for nitrogen-oxygen separation. A second sub-flow of the circuit nitrogen flow is branched

A piping module is described which comprises at least two fluid connections or ports for connection to at least one main heat exchanger of an air fractionation plant, whereby the main heat exchanger becomes linked to at least two fluid lines in a warm part of the air fractionation plant. The piping module comprises at least two ports on the main compressor side, couplable to at least two fluid lines in the warm part of the air fractionation plant, and at least two ports on the main heat exchanger side, couplable to at least two fluid ports of the at least one main heat exchanger, and at least two fluid lines connecting the ports on the main compressor side to the ports on the main heat exchanger side. A corresponding air fractionation plant and a method for erecting such an air fractionation plant (100) are likewise described.

A method for obtaining one or more air products by means of an air separation unit comprising a first booster, a second booster, a first decompression machine, and a rectification column system which has a high-pressure column operated at a first pressure level and a low-pressure column operated at a second pressure level below the first pressure level. All of the air supplied to the rectification column system is first compressed to a third pressure level, which lies at least 3 bar above the first pressure level, as a feed air quantity. A first fraction of the feed air quantity is supplied to a first booster at the third pressure level and at a temperature level of −140 to −70 ° C. and is compressed to a fourth pressure level using the first booster.

A method and the apparatus for the cryogenic separation of air in an air separation plant which has a main air compressor, a main heat exchanger and a distillation column system with a high-pressure column and a low-pressure column. All of the feed air is compressed in the main air compressor to a first air pressure which is at least 3 bar higher than the operating pressure of the high-pressure column. A first part of the compressed total air flow, as first air flow at the first air pressure, is cooled and liquefied or pseudo-liquefied in the main heat exchanger, then expanded and introduced into the distillation column system. A second part of the compressed total air flow, as second air flow, is post-compressed in an air post-compressor to a second air pressure and at least part is further compressed in a first turbine-driven post-compressor to a third air pressure.

Enhancements to a dual column, nitrogen producing cryogenic air separation unit with waste expansion are provided. Such enhancements include an improved air separation cycle that uses: (i) three condenser-reboilers; (ii) a reverse reflux stream from the condenser-reboiler associated with the lower pressure column to the higher pressure column; and (iii) a recycle stream of a portion of the vapor from one or more of the condenser-reboilers that is recycled back to the incoming feed stream and or the compressed purified air streams to yield improvements in the performance of such dual column, nitrogen producing cryogenic air separation units in terms of overall nitrogen recovery as well as power consumption compared to conventional dual column, nitrogen producing cryogenic air separation units employing waste expansion.

The present disclosure relates to systems and methods that provide power generation using predominantly CO.sub.2 as a working fluid. In particular, the present disclosure provides for the use of a portion of the heat of compression from a CO.sub.2 compressor as the additive heating necessary to increase the overall efficiency of a power production system and method.