"rapacious demand" is correct and usable in written English.
A possible example could be: "The rapacious demand for natural resources is causing irreversible damage to the environment."
Judges have passed draconian sentences for minor cases of corruption and abuse of power, frightening much of a business class that almost universally submitted during Mr Mubarak's long reign to rapacious demands for bribes.
Countries like New Zealand and Australia struggled to sell out their Test grounds; empty seats were seen in Ireland at the new Lansdowne Road ground, too, thanks to the rapacious demands made over ticket prices by the out-of-touch IRFU.
In order to satisfy the increasingly rapacious demands of landlords, the entertainment to be obtained in Soho will come at an increasingly high price and will be of an increasingly predictable nature.
They feel that the strongly-held religious conviction in the rite of circumcision – whatever the science finally concludes – definitely sends a powerful message to a lactating mother still recovering from childbirth that she cannot protect her baby boy from the most rapacious demands of patriarchal ritual.
They have troubles of their own, and rapacious shareholders demanding blood as they grapple with an uncertain future.
Her Siren — astonishingly confident in her facial and physical allure — was bold, demanding, rapacious, at once icy and hot.
Lonesome George obliged me with a weary crank of his long neck, a testudine testament, it seemed, to the rapacious, ecologically awful demands of man.
It managed, despite years of gut-wrenching exposure of a deep-dyed drugs culture, to remind us of the essential courage of the men who embrace its rapacious physical and psychological demands.
