Air separation power generation integration

An apparatus for separating air and generating electrical power comprising:

• a main air compressor to compress air and thereby to produce a compressed air stream;
• an air separation unit in flow communication with the main air compressor;
• the air separation unit configured to selectively operate in a design operational condition and a turn-down operational condition such that during the design operational condition the air within the compressed air stream is separated through cryogenic rectification to produce one or more products and during the turn-down operational condition, the one or more products are not being produced or being produced at a lesser rate than during design operational conditions;
• means for producing a combustion air stream from at least part of the compressed air stream;
• a combustor in flow communication with combustion air stream producing means such that during the turn-down operation condition, a fuel stream is combusted in the combustor through combustion supported by the combustion air stream and a heated and pressurized combustion stream is produced from the combustion;
• a turbine in flow communication with the combustor to expand the heated and pressurized combustion stream to produce an exhaust stream;
• an electrical generator connected to the turbine to generate the electrical power;
• the main air compressor having sufficient capacity to allow the combustion air stream to be available during the turn-down operational condition to support combustion of the fuel stream for generation of the electrical power;
• wherein a recuperator is positioned between the turbine and the main air compressor such that an exhaust stream produced by turbine indirectly transfers heat to the combustion air stream prior to introduction of the combustion air stream into the combustor;
• a means for adding moisture to the combustion air stream is positioned between the recuperator and the main air compressor such that the combustion air stream contains moisture prior to the exhaust stream indirectly transferring heat to the combustion air stream;
• wherein the means for adding moisture comprises:
• a condenser for condensing a steam stream in a condenser to produce a condensed stream;
• a pump connected to the condenser to pump the condensed stream and thereby to produce a first pressurized water stream;
• a saturator configured to counter-currently contacting a heated water stream with the combustion air stream to produce the combustion air stream with moisture and a bottoms liquid;
• and
• a recirculation flow path connected to the pump, the condenser and the saturator and configured to combine the first pressurized water stream with a second pressurized water stream to produce a combined water stream, to heat the combined water stream in the condenser through indirect heat exchange with the steam stream to produce the heated water stream and having a recirculation pump positioned to recirculate at least part of the bottoms liquid to form the second pressurized water stream.