Absorbent regeneration with flashed lean solution and heat integration

A method for regeneration of a rich absorbent having absorbed CO2, to give a regenerated, or lean absorbent, and CO2, the method comprising the steps of

• a) introducing a stream of rich absorbent into a regeneration column in which the absorbent flows downwards and countercurrent with steam generated by heating lean absorbent in a reboiler at the base of the regeneration column,
• b) withdrawing released CO2 and steam from the top of the column and separation of the withdrawn CO2 and steam to give a stream of CO2 that is removed, and condensed water that is recycled into the regeneration column,
• c) withdrawing lean, or regenerated, absorbent from the base of the column,
• d) flashing the withdrawn lean absorbent to produce a gaseous phase that is compressed and reintroduced into the regeneration column, and a liquid lean absorbent phase,
• e) heating the rich absorbent by a first heat exchanging against the flashed lean absorbent,
• f) heating of the rich absorbent after being heat exchanged against the lean absorbent by heat exchanging against a heat medium having an inlet temperature lower than 130° C., and
• g) introducing the heated rich absorbent into the regeneration column.

A regenerator for a liquid absorbent for CO2 comprising a regeneration column, a rich absorbent line for introduction of rich absorbent into the regeneration column, withdrawal means for withdrawing lean adsorbent from the bottom of the regeneration column, a reboiler for heating of a portion of the withdrawn absorbent before reintroduction into the regeneration column for production of steam that is reintroduced into the column, a lean absorbent line for recycling of a portion of the absorbent withdrawn by withdrawal means to an absorber, a heat exchanger for heating rich absorbent against the withdrawn lean absorbent and a heat exchanger to additionally heat the heated rich absorbent against a low temperature heat source before the rich gas enters the regenerator, a gas withdrawal line for withdrawal of CO2 and vapor from the top of the regeneration column, and separation means for separating the gas withdrawn from the top of the regeneration column in a CO2 stream that is exported from the regenerator, and water that is recycled to the regeneration column, wherein that it further comprises flashing means, a steam withdrawal line connecting said flashing means with a compressor for compression of a withdrawn gaseous phase, a line for injecting the compressed gaseous phase into the regeneration column, and a lean absorbent line connecting the flashing means with the heat exchanger.