A method and apparatus for reducing heat bumps following regeneration of adsorbers in an air separation unit is provided. Certain embodiments of the current invention utilize the two waste streams available at very different temperatures from the two main exchangers (low-pressure and high-pressure core exchangers) for regeneration of the front-end purification adsorbers in the air separation unit (ASU) to reduce its energy consumption without compromising the stability of process. Certain embodiments help to eliminate/minimize high air temperature disturbance (heat bump) for the process downstream of the front-end purification unit during the transition from offline to online.

An air separation apparatus and process, which produces gaseous oxygen and/or nitrogen products at an elevated pressure through internal compression of respective liquid products, are disclosed. Split-core main heat exchangers are employed to warm up product streams generated in an air rectification unit against 1) a main feed air stream in the low-pressure heat exchanger and 2) at least one boosted pressure air stream in the high-pressure exchanger. Because the boosted pressure air stream is at a higher pressure and temperature than the main feed air stream, after separate heat exchange in the split main heat exchangers, the subsidiary waste nitrogen stream exiting the high-pressure heat exchanger is also warmer than the subsidiary waste nitrogen stream exiting the low-pressure heat exchanger. The warmer waste nitrogen stream is fed into the air purification unit for regeneration purposes and the cooler waste nitrogen stream is introduced into the nitrogen water tower to perform cooling duty. The two subsidiary waste nitrogen streams are also connected on the warm side of the main heat exchangers to allow flexible distribution of the flow.

A carbon dioxide capture system includes a first heat exchanger that exchanges heat between an exhaust stream and a lean carbon dioxide effluent stream. The carbon dioxide capture system also includes a second heat exchanger in flow communication with the first heat exchanger. The second heat exchanger is configured to cool the exhaust stream such that a condensate is formed, and the second heat exchanger is configured to channel a condensate stream for injection into the lean carbon dioxide effluent stream. A first turboexpander including a first compressor is driven by a first turbine. The first compressor is coupled in flow communication with the first heat exchanger. The first turbine is coupled in flow communication with the first heat exchanger and configured to expand the lean carbon dioxide effluent stream. The carbon dioxide capture system further includes a carbon dioxide membrane unit coupled in flow communication with the first compressor.

The present invention relates to a cryogenic air separation process that provides high pressure oxygen for an oxy-fired combustion of a fuel (e.g., a carbonaceous fuel). The air separation process can be directly integrated into a closed cycle power production process utilizing a working fluid, such as CO.sub.2. Beneficially, the air separation process can eliminate the need for inter-cooling between air compression stages and rather provide for recycling the adiabatic heat of compression into a process step in further methods wherein an additional heat supply is beneficial.

A method for reducing heat bumps following regeneration of adsorbers in an air separation unit is provided. The air separation unit can include a front end purification unit, a main air compressor, a main heat exchanger, a distillation column system, a regeneration gas heater, and a regeneration gas cooler, wherein the front end purification unit comprises a first adsorber and a second adsorber. The method can include the steps of: regenerating the first adsorber while the second adsorber operates in an adsorption cycle, wherein the step of regenerating the first adsorber further includes the steps of heating the first adsorber and then cooling the first adsorber, wherein during the step of cooling the first adsorber, a regeneration gas sourced from the distillation column system and cooled in the main heat exchanger is further cooled in a regeneration gas cooler prior to being used to cool the first adsorber.

The method and the device arc used for the cryogenic decomposition of air in a distillation column system for separating nitrogen and oxygen, said system having a first high-pressure column (23), a low-pressure column (25, 26), and three condenser-evaporators, namely a high-pressure column head condenser (27), a low-pressure column bottom evaporator (28), and an auxiliary condenser (29; 228).

Processes for purifying and liquefying natural gas in conjunction and integration with cryogenic processing natural gas to recover natural gas liquids (NGL) is disclosed. In the process, the natural gas stream to be purified and liquefied is taken from top outlet stream of demethanizer in the cryogenic NGL recovery plant, first purified and then cooled under moderate pressure to condense it as a liquefied natural gas (LNG) product stream. Some of the cooling required for the demethanizer reflux stream is provided by natural gas liquefaction section before supplied to top of the column to serve as reflux. The top outlet stream from the demethanizer preferentially contains up to 3 mole percent of CO.sub.2 and the majority of methane and small portion of any hydrocarbon heavier than methane, a split portion of this stream is taken and routed to cryogenic CO.sub.2 removal section, in which a molecular sieve that forms a physical adsorption column is used to extract pure CO.sub.2 as a product stream, then purified stream is routed to the liquefaction section where only two stages of coil-wound exchangers with a Semi-C3-MR cycle are used to liquefy natural gas. This present invention process is suited for LNG production in small-scale. This zeolite-based small-scale LNG process can be integrated with the design of any new natural gas facility and the technology can also be retrofitted to existing natural gas liquid (NGL) recovery plants, allowing for co-production of LNG and CO.sub.2 with high purity.

A chiller can be configured as a chiller for a gasification system or other type of system or plant. In some embodiments, the chiller can be configured to utilize a single heat source, such as low grade waste heat in the form of hot water, and/or low pressure steam to drive one or more absorption-based chillers to cool inlet air to one or more adsorbers of a pre-purification unit (PPU). In the event of the detection of an undesired impurity spike (e.g. carbon dioxide spike, etc.) an additional amount of heat source can be withdrawn from the gasification system to increase the level of cooling the absorption chiller can provide to improve the removal of impurities. An automated control loop can be utilized in some embodiments. The control loop can be configured to check for an impurity concentration and adjust operations accordingly.

A device and a method for separating a vapor component from a gas is disclosed. A vessel comprising a top portion and a bottom portion is provided. The top portion comprises a gas outlet, a fluid inlet, and a direct-contact heat exchanger. The bottom portion comprises an indirect-contact heat exchanger, a gas inlet manifold, and a fluid outlet manifold. The indirect-contact heat exchanger is aligned vertically and comprises parallel exchange surfaces. Plenums between the exchange surfaces comprise alternating, adjacent ascending gas channels and descending fluid channels. The gas inlet manifold comprises one or more inlets adjacent to a top portion of each of the ascending gas channels. The fluid outlet manifold comprises one or more outlets adjacent to a bottom portion of each of the descending fluid channels.

The invention relates to a method and device for generating two purified partial air streams under different pressures. A total air stream (1) is compressed to a first total air pressure. The compressed total air stream (5) is cooled with cooling water under the first total air pressure by way of heat exchange (4, 6). The heat exchange with cooling water for cooling the total air stream (5) is carried out as a direct heat exchange in a first direct contact cooler (6), at least in part. The cooled total air stream (9) is divided into a first partial air stream (10) and a second partial air stream (11). The first partial air stream (10) is purified in a first purification device (18) under the first total air pressure, generating the first purified partial air stream (19). The second partial air stream (11) is re-compressed to a higher pressure (12), which is higher than the first total air pressure. The re-compressed second partial air stream (14) is cooled with cooling water in a second direct contact cooler (15) by way of direct heat exchange (13, 15). The cooled second partial air stream (17) is purified under the higher pressure in a second purification device (30), thus generating the second purified partial air stream (31).